CIRCUIT DESCRIPTION. Kenwood TS-2000 X

The TS-2000 X is an all-mode multi-band transceiver that incorporates an IF/AF DSP for satellite communication. It also features an independent FM/AM sub-receiver for the VHF and UHF bands. The main band side has an independent front end for each of the HF, 50MHz, 144MHz, 430MHz and 1.2GHz bands. The sub-band receiver is not used during satellite operation, but it can receive signals while the main band receiver is sending a signal. In addition to the standard features of a transceiver, the TS-2000 X also includes features such as a noise blanker, a digital IF filter, and a digital AGC. It also has a speaker separation function that allows you to output the audio to two separate speakers or headphones. The TS-2000 X is a powerful and versatile transceiver that is suitable for a wide variety of applications, including satellite communication, HF and VHF/UHF operation, and contesting.

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2

TS-2000/X

Overview of the Operation

The TS-2000/X basically consists of an all-mode-receiver incorporating an IF/AF DSP for satellite communication with an independent FM/AM sub-receiver for the VHF and UHF bands.

■ Overview of the operation of the all-mode trans-

ceiver unit (main band side) with an IF/AF DSP for satellite communication

The receiver unit has an independent front end for each of the HF, 50MHz, 144MHz, 430MHz and 1.2GHz bands

(some products do not support the 1.2GHz band). The circuits following the 10.695MHz IF stage are common to all the bands. (Thus, it cannot receive two SSB signals at the same time.)

The IF frequency of the transmitter unit is shifted from the IF frequency of the receiver unit by 100kHz to enable satellite operation (full duplex operation). The final section is independent of the HF, 50MHz, 144MHz, 430MHz and

1.2GHz bands. Consequently, you can select a combination of bands permitting satellite communication from the HF,

50MHz, 144MHz, 430MHz and 1.2GHz bands.

The transmitter unit and receiver unit on the main band side operate simultaneously during satellite transmission.

The receiver unit on the sub-band side does not work. (The sub-band receiver is not used during satellite operation.)

Two 16-bit DSP ICs are used; one performs IF processing

(main band side) and the other carries out AF processing

(main and sub bands). Although the DSP IC is a 16-bit unit, it carries out “double-precision operations” for critical parts of

IF processing to perform 32-bit equivalent processing. In addition, the DSP IC uses a 100-MHz high-speed internal clock. The conversion from an analog signal to a digital signal (A/D conversion) is performed with 24 bits at high precision.

The DSP circuit for IF operates in any mode other than

FM mode for both transmission and reception. FM modulation, detection and squelch processing are conventional analog processes. (The processing prior to modulation and after demodulation in FM is performed by the DSP.)

In the mode in which the IF DSP circuit operates, it carries out modulation and demodulation, digital IF filtering, digital AGC, and CW waveform processing during transmission, as in the TS-870. All these functions are operated in all the bands on the main band side, including satellite operation.

The AF unit is processed by the DSP in all modes. The operating range of the DSP circuit depends on the mode, but it performs beat cancellation, noise reduction, AF DSP filtering, etc.

CIRCUIT DESCRIPTION

■ Overview of the operation of the independent

FM/AM sub-receiver unit (sub-band side) for the

VHF and UHF bands

The local oscillator system and IF/AF signal system of the sub-receiver unit are independent of the main band side.

Therefore, the sub-band receiver can receive signals while the main band receiver is sending a signal. (Except when reception is impossible due to harmonics of the transmit frequency and when the main band and sub-band are on the same frequency band.)

The sub-band receive signal is branched from the RF unit on the main band side. It is, therefore, not necessary to install a dedicated antenna for sub-band reception.

Transmission can be performed with the sub receive frequency by shifting the “PTT band” to the sub-band side. It is made possible by internally using the transmission function on the main band side.

AF processing is also carried out by the DSP on the subband side and the noise reduction function works.

The sub-band reception function, including display, can be turned off.

Frequency Configuration (Fig. 1)

This transceiver utilizes double conversion in FM mode and triple conversion in non-FM modes during transmission.

It utilizes triple conversion in FM mode and quadruple conversion in non-FM modes during reception. The fourth

12kHz IF signal is converted from analog to digital and connected to the DSP.

When the carrier point frequency of the signal input from the antenna is f

, the relationship between these signals when demodulating this signal is expressed by the following equations:

HF MAIN f

= f

LO1

– f

LO2

– f

LO3

+ f

LO4

– 12kHz

VHF MAIN f

= f

LO1

– f

LO2

– f

LO3

+ f

LO4

– 12kHz

UHF MAIN f

= f

LO1

+ f

LO2

+ f

LO3

– f

LO4

+ 12kHz

1.2G MAIN f

= f

LO1

x 2 + f

LO2

+ f

LO3

– f

LO4

+ 12kHz

Reference Signal Generation Circuit

The 15.6MHz reference frequency fstd for PLL frequency control is generated by the TCXO (X400). The signal passes through a buffer amplifier (Q420) and is used as the reference signal for the second local oscillator (HFLO2) for HF band reception and the first local oscillator (SLO1) subband reception.

The reference signal is doubled by Q412, and the resulting 31.2MHz signal is used as the reference signal for DDSs

(IC406, IC407, IC408, IC601, IC602, IC603).

The 31.2MHz signal is supplied to the TX-RX2 unit (X57-

606 A/11) as LO2 for VHF and UHF bands.

TS-2000/X

CIRCUIT DESCRIPTION

HF/

50MHz

TX MIX

68.985MHz

TX MIX

75.825MHz

10.595MHz

TX MIX

LO1HF

75.955~

129.085MHz

VHF UHF

RX MIX

69.085MHz

RX MIX

75.925MHz

LO2

58.390~

65.230MHz

TX MIX 41.795MHz

TX MIX

LO1TX

183.795~418.205MHz (K)

185.795~398.205MHz (E)

RX MIX 41.895MHz

RX MIX

TCAR

10.583MHz

10.695MHz

RX MIX 455kHz

DET

LO3

11.150MHz

RCAR

467kHz

DSP

MIC input

AF output

1.2G

LO1RX

183.895~

LO31

418.105MHz (K)

31.2MHz

185.895~398.105MHz (E)

SUB

RX MIX 58.525MHz

Mixer

IF detector

SLO1

322.95~

465.04MHz (K)

371.475~409.050MHz (E)

TX MIX

135.395MHz

TX MIX

SLO2

58.070MHz

RX MIX

135.495MHz

RX MIX

1.2GLO1

1104~

1165MHz

1.2GLO2

124.8MHz

Fig. 1 Frequency configuration

HF/50MHz LO1

When the HF and or 50MHz band is operating in the main band, the HF REF VCO (Q427) generates 31.17 to 32.834

MHz. (See Table 1, frequency configuration.)

The output signal from the DDS (IC408) is input to pin 8 of the PLL IC (IC409) for HF REF, divided into 1/16 in IC409 to produce comparison frequency fø 2 of 487 to 513kHz.

The output signal from the VCO (Q427) goes to pin 6 of

PLL IC (IC409), is divided into 1/64 in IC409, and compared with the signal with comparison frequency fø 2 by a phase comparator. The frequency is locked and the HF REF signal is output.

The output signal from the PLL IC (IC409) for HF REF is fed to pin 8 of the PLL IC (IC414) for HF LO1 as a reference frequency, and divided to produce comparison frequency fø 1 of 975 to 1358kHz.

The HF LO1 VCO (Q459, Q460, Q464) generates 75.955

to 129.185MHz. The output from this VCO goes to pin 6 of

IC414, is divided into 1/N 1 in IC414, compared with the signal with comparison frequency fø 1 by a phase comparator.

The frequency is locked and the HF LO1 output frequency is generated.

The DDS (IC408) sweeps output frequency (7.792 to

8.209MHz) in 10Hz steps by equation f

DDS STEP

(Hz) =

(10*R 1)/(N 1*4) and in 1Hz steps by equation f

DDS STEP

(Hz) = (1*R 1)/(N 1*4), the HF LO1 covers the frequencies of 75.955 to 129.085MHz in 10Hz or 1Hz steps.

One of three VCOs (Q459, Q460, Q464) is selected by the signal (HF VCO1,HF VCO2,HF VCO3) from the serial-parallel IC (IC404).

The output from the VCOs (Q459, Q460, Q464) passes through a buffer amplifier (Q462), is amplified by Q476, and passes through a low-pass filter. The impedance is converted by an attenuator and the signal is output as HFLO1.

The cut-off frequency of the low-pass filter in the output section is changed by turning Q474 ON/OFF with a VCO select signal (HF VCO1).

3

4

TS-2000/X

CIRCUIT DESCRIPTION

HF LO2

When the HF and or 50MHz band is operating, the

HF LO2 VCO (Q409) generates 65.230 to 58.390MHz. (See

Table 1, frequency configuration.)

The 15.6MHz reference signal fstd is input to pin 8 of the

PLL IC (IC401) for HF LO2, divided into 1/226 and 1/319 in

IC401 to produce comparison frequency fø of 69.027 to

48.903kHz.

The output signal from the VCO (Q409) goes to pin 6 of

IC401, its frequency is divided into 1/945 and 1/1194 in

IC401, compared with comparison frequency fø by a phase

Display frequency f

(MHz)

Start

0.030000

Stop

1.999999

2.000000

6.000000

9.000000

13.000000

5.999999

8.999999

12.999999

16.999999

17.000000

18.000000

22.000000

24.000000

25.000000

26.000000

30.000000

33.000000

17.999999

21.999999

23.999999

24.999999

25.999999

29.999999

32.999999

36.999999

37.000000

41.000000

45.000000

49.000000

52.000000

56.000000

40.999999

44.999999

48.999999

51.999999

55.999999

60.000000

comparator, and locked. The division ratio data comes from the control unit.

The output signal from the VCO (Q409) passes through a buffer amplifier (Q415), is amplified by Q421, and passes through a low-pass filter. The impedance is converted by an attenuator and the signal is output as HF LO2.

When the HF and or 50MHz band is not operating, Q403 is turned OFF with the LO2SEL signal and HF LO2 VCO

(Q409) stops operation.

LO1 OUT

(MHz)

LO1

= f

+ IF

IC414 :

LMX2306TMX

100

115

119

115

113

115

127

HF REF

(MHz)

HF REF

+ IF)

*R1

IC409 : DDS output (MHz)

LMX2306TMX IC408 : AD9835BRU

16 f

DDS

HF REF

*R2

LO2 OUT

(MHz)

65.230088

58.389969

65.230088

58.389969

65.230088

58.389969

65.230088

58.389969

IC401 :

LMX2306TMX

945

226

1194

945

1194

945

319

226

319

226

1194

945

1194

319

226

319

75.925088

69.084968

75.925088

69.084968

75.925088

69.084968

75.925088

69.084968

75.825088

68.984968

75.825088

68.984968

75.825088

68.984968

75.825088

68.984968

Table 1 Main HF and 50MHz band frequency configuration

TS-2000/X

CIRCUIT DESCRIPTION

144MHz LO1

When the VHF band is operating in the main band, the

VHF REF VCO (Q441) generates 36.057 to 37.288MHz (K),

36.450 to 36.842MHz (E). (See Table 2, Frequency Configuration.)

The output signal from the DDS (IC406) is input to pin 8 of the PLL IC (IC411) for VHF REF and divided into 1/16 in

IC411 to produce comparison frequency fø 2 of 563 to

583kHz (K), 569 to 576kHz (E).

The output signal from the VCO (Q441) goes to pin 6 of

IC411 and its frequency is divided into 1/64 in IC411, compared with the signal with comparison frequency fø 2 by a phase comparator, and is locked.

The VHF REF PLL output signal is fed to pin 8 of IC410 as a reference frequency, and divided into 1/30 in IC410 to produce comparison frequency fø 1 of 1202 to 1243kHz (K),

1215 to 1228kHz (E).

The VHF LO1 VCO (Q433) generates 183.895 to 193.895

MHz (K), 185.795 to 187.895MHz (E) in receive mode and

183.795 to 193.795MHz (K), 185.795 to 187.795MHz (E).

The VCO (Q433) output signal goes to pin 6 of IC410, and its frequency is divided into 1/N1 in IC410 and compared with comparison frequency fø 1 by a phase comparator. The frequency is locked and LO1 is generated.

The DDS (IC406) sweeps output frequency (9.014 to

9.321MHz (K), 9.112 to 9.210MHz (E)) in 10Hz steps by equation f

DDS STEP

(Hz) = (10*R1)/(N1*4) and in 1Hz steps by equation f

DDS STEP

(Hz) =(1*R1)/(N1*4), the LO1 covers the frequencies of 183.895 to 193.895 MHz (K), 185.895 to

1 8 7 . 8 9 5 M H z ( E ) i n r e c e i v e m o d e a n d 1 8 3 . 7 9 5 t o

193.795MHz (K), 185.795 to 187.795MHz (E) in transmit mode in 10Hz or 1Hz steps.

The PLL output signal is changed by the switching circuit of Q469 (receive) and Q470 (transmit) so that the output amplifier and low-pass filter correspond to VHF band transmission and reception.

In receive mode, the signal is amplified by the broadband amplifier (IC415), and passes through a low-pass filter.

The impedance is converted by an attenuator and the signal is output to the RF unit (X57-606) as the first local oscillator

RXLO1.

In transmit mode, the signal is amplified by the broadband amplifier (IC416), and passes through a low-pass filter.

The impedance is converted by an attenuator and the signal is output to the RF unit (X57-606) as the first local oscillator

TXLO1.

When the VHF is not operating, Q436 is turned OFF with a signal from the serial-parallel IC (IC404) and VHF LO1 VCO

(Q433) stops operation.

Display frequency f

(MHz)

LO1 OUT

(MHz)

Start Stop

142.000000 (K) 146.999999 (K) LO1

144.000000 (E) 146.000000 (E) = f

+ IF

147.000000 (K) 151.999999 (K)

IC410 :

LMX2306TMX

153

156

VHF REF

(MHz)

VHF REF

+ IF)

*R1

IC411 : DDS output (MHz)

LMX2306TMX IC406 : AD9835BRU

16 f

DDS

VHF REF

*R2

IF = RX : 41.895

TX : 41.795

Table 2 Main VHF band frequency configuration

430MHz LO1

When the UHF band is operating in the main band, the

UHF REF VCO (Q431) generates 378.105 to 418.105MHz

(K), 388.105 to 398.105MHz (E) in receive mode and

378.205 and 418.205MHz (K), 388.205 to 398.205MHz (E).

(See Table 3, Frequency Configuration.)

The output signal (8.328 to 8.475MHz (K), 8.344 to

8.469MHz (E)) from the DDS (IC407) passes through a ceramic filter (CF400), is input to pin 8 of the PLL IC (IC412) for

UHF and divided into 1/16 in IC412 to produce comparison frequency fø of 520 to 530 kHz.

The output signal from the VCO (Q431) goes to pin 6 of

IC412 and its frequency is divided into 1/N in IC412, compared with comparison frequency fø by a phase comparator, and is locked.

The DDS (IC407) sweeps output frequency (8.328 to

8.475MHz (K), 8.344 to 8.469MHz (E)) in 10Hz steps by equation f

DDS STEP

(Hz) = 10*R/N and in 1Hz steps by equation f

DDS STEP

(Hz) = 1*R/N, the LO1 covers the frequencies of 378.105 to 418.105MHz (K), 388.105 to 398.105MHz (E) in receive mode and 378.205 to 418.205MHz (K), 388.205 to

398.205MHz (E) in transmit mode in 10Hz or 1Hz steps.

The PLL output signal is changed by the switching circuit of Q471 (receive) and Q472 (transmit) so that the output amplifier and low-pass filter correspond to UHF band transmission and reception.

In receive mode, the signal is amplified by the broadband amplifier (IC415), and passes through a low-pass filter.

The impedance is converted by an attenuator and the signal is output to the RF unit (X57-606) as the local oscillator signal RXLO1.

In transmit mode, the signal is amplified by the broadband amplifier (IC416), and passes through a low-pass filter.

The impedance is converted by an attenuator and the signal is output to the RF unit (X57-606) as the local oscillator signal TXLO1.

When the UHF is not operating, Q434 is turned OFF with a signal from the serial-parallel IC (IC404) and UHF VCO

(Q431) stops operation.

5

TS-2000/X

CIRCUIT DESCRIPTION

Display frequency f

(MHz)

Start

420.000000 (K)

Stop

425.999999 (K)

425.000000 (K)

430.000000 (E)

431.499999 (K)

431.500000 (K,E) 435.499999 (K,E)

435.500000 (K,E) 439.499999 (K,E)

439.500000 (K,E) 443.499999 (K)

440.000000 (E)

443.500000 (K) 447.999999 (K)

LO1 OUT

(MHz)

LO1

= f

– IF

IC412ÅF DDS output (MHz)

LMX2306TMX IC407 : AD9835BRU

726

736 f

DDS

– IF

747

754

762

770

448.000000 (K) 449.999999 (K) 778

IF = RX : 41.895

TX : 41.795

Table 3 Main UHF band frequency configuration

6

SUB LO1

When the sub band receiver is operating, the sub VCO

(Q406, Q407) generates 322.95 to 465.040MHz. (See Table

4, frequency configuration.)

The 15.6MHz reference signal fstd is input to pin 8 of the

PLL IC (IC402) for the sub VCO, divided into 1/R in IC402 to produce comparison frequency fø of 5 and 6.25kHz. The division ratio data comes from the control unit.

The output signal from the VCO (Q406, Q407) goes to pin

6 of IC402, its frequency is divided into 1/N in IC402, compared with comparison frequency fø by a phase comparator, and locked.

The output signal from the VCO (Q406, Q407) passes through a buffer amplifier (Q413, Q414), is amplified by the broad-band amplifier (IC405), and passes through a low-pass filter. The impedance is converted by an attenuator and the signal is output as SLO1.

When the sub band receiver is not operating, Q411 and

Q411 are turned OFF with the BSW1 and BSW2 signals and sub VCO (Q406, Q407) stops operation.

Display frequency f

(MHz)

Start Stop

118.00000 (K) 118.94500 (K) SLO1

118.95000 (K) 134.99500 (K) = (f

+ 58.525) *2

135.00000 (K) 154.49500 (K)

144.00000 (E) 146.00000 (E)

154.50000 (K) 173.99500 (K)

220.00000 (K) 235.99500 (K) SLO1

236.00000 (K) 252.49500 (K) = (f

– 58.525) *2

252.50000 (K) 271.54500 (K)

271.55000 (K) 289.99375 (K)

290.00000 (K) 296.42000 (K) SLO1

296.42500 (K) 328.99500 (K) = f

SLO1 OUT

(MHz)

+ 58.525

329.00000 (K) 367.52000 (K)

367.52500 (K) 399.99500 (K)

400.00000 (K) 413.47000 (K) SLO1

413.47500 (K) 445.99500 (K) = f

– 58.525

IC404 :

BU4094BCFV

13pin : Q6 12pin : Q7 11pin : Q8 R

(BSW2) (BSW1) (B LU SW)

IC402 : LMX2316TMX

Step : 5,10,15,20,30 (kHz) Step : 6.25,12.5,25,50,100 (kHz)

Formula

R N

Formula

3120

N =

2 x (f

+ 58.525) 2496

0.005

N =

2 x (f

+ 58.525)

0.00625

N =

2 x (f

– 58.525)

0.005

N = f

+ 58.525

0.005

N = f

– 58.525

0.005

N =

2 x (f

– 58.525)

0.00625

N =

0.00625

N = f f

+ 58.525

– 58.525

0.00625

430.00000 (E) 440.00000 (E)

446.00000 (K) 484.57000 (K)

484.57500 (K) 511.99500 (K)

Table 4 Sub band frequency configuration

TS-2000/X

CIRCUIT DESCRIPTION

1.2GHz Unit Local Oscillator

The 12LO31 signal (31.2MHz) is quadrupled to 124.8MHz

in Q14 and 15. This signal is sent to the mixers of the transmitter section (Q1 and Q2) and the mixers of the receiver section (Q7 and Q8)

In the DDS (C4) , 8.323~8.488MHz are output using

12LO31 as the reference signal. This signal passes through a filter (CF1 and CF2) and is input to the mixers for reference

PLL signals (Q313 and 314).

In Q313 and Q314, the DDS output is mixed with

12LO31 (31.2MHz) and an approximately 39.6MHz signal is obtained. This signal passes through a filter and an amplifier

(Q312) and becomes the reference signal of the PLL IC

(IC5).

The VCO (Q301) oscillates at 552.253~582.303MHz.

This signal is amplified in Q302 and goes to the PLL IC (IC5) and Q19.

The PLL IC (IC5) divides the reference signal (approximately 39.6MHz) to 1/72. The signal from Q302 is divided to

1/N (N=1006~1058).

The two signals are compared in the phase comparator within the IC and the VCO (Q301) oscillation frequency is locked.

The signal input into Q19 is doubled. This signal passes through a filter and an amplifier (Q20) and goes to the sending mixer (D1) and the receiving mixer (Q10).

X57-606

TX-RX 3 (X57-607)

Q7,8

Q15 L42,43 Q14

LO31

31.2MHz

Q65

12LO31

D11

D10

Q10

31.2MHz

Q20

1104~

1165MHz

L52

Q19 IC5

PLL

Q312

L340~

342

Q302

Q1,2

124.8MHz

39.6

Q301

MHz

552.253~

582.303MHz

Q313,314

39.523~

39.688MHz

8.4

MHz

Q310,311

CF1,2 Q16

31.2MHz

IC14

DDS

8.323~

Q13

8.488MHz

Fig. 2 1.2GHz unit local oscillator

Display frequency

Start f

1240.000000 (K)

1246.000000 (K)

1250.000000 (K)

(MHz)

Stop

1243.999999 (K)

1249.999999 (K)

1253.999999 (K)

Q301 oscillation f frequency LMX2316TMX IC4 : AD9851BRS f

VCO

(MHz) R N

VCO

1244.000000 (K) 1245.999999 (K) = (f

– IF)/2

C5 :

1006

1008

1015 f

DDS output (MHz)

DDS

– IF)*R

1011 2*N

– 31.2

1254.000000 (K) 1255.999999 (K)

1256.000000 (K) 1258.999999 (K)

1259.000000 (K)

1260.000000 (E)

1262.999999

1017

1020

1023

1263.000000

1267.000000

1271.000000

1275.000000

1278.000000

1281.000000

1285.000000

1289.000000

1292.500000

1295.000000

1298.000000

1266.999999

1270.999999

1274.999999

1277.999999

1280.999999

1284.999999

1288.999999

1292.499999

1294.999999

1297.999999

1299.999999

1027

1030

1034

1037

1040

1043

1047

1050

1053

1056

1058

Table 5 1.2GHz band frequency configuration

IF=RX : 135.495

TX : 135.395

Local

Signals

The RXLO3 (11.15MHz) and RCAR (467kHz) for reception and TCAR (10.583MHz) for transmission are output from

DDSs (RXL03 : IC603, RCAR : IC601, TCAR : IC602).

The frequencies of local oscillator output signals (LO1,

LO2, RCAR, TCAR) for each band are shifted by offset (IF filter setting), RIT, XIT, IF SHIFT as listed in Tables 5 to 11.

7

TS-2000/X

CIRCUIT DESCRIPTION

8

HF TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

HF TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

–1.5k

+(D RIT)

LSB

–

+(SSB H)

+(D 10.695)

FSK

–(1.5k–Fcenter)

+(D XIT)

–

+(FSK H)

–

–1.5k

–

+(D XIT)

–

+(D XIT)

–

DDS IC408 : AD9835BRU

USB

TX RX

+1.5k

+(D RIT)

–

–(SSB H)

+1.5k

–

+(D XIT)

–

+0.7k

+(D RIT)

–

–(CW H)

– –(D 10.695)

FSK-R

+(1.5k–Fcenter)

+(D RIT)

–

–(FSK H)

–

+(D XIT)

–

+(D RIT)

–

+0.7k

–

+(D XIT)

–

+(D XIT)

–

Table 6 HF band LO1 frequency shift data

–0.7k

+(D RIT)

CW-R

–0.7k

–

+(CW H)

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

144MHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

144MHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

–1.5k

+(D RIT)

LSB

–

+(SSB H)

+(D 10.695)

FSK

–(1.5k–Fcenter)

+(D XIT)

–

+(FSK H)

–

–1.5k

–

+(D XIT)

–

+(D XIT)

–

DDS IC406 : AD9835BRU

USB

TX RX

+1.5k

+(D RIT)

–

–(SSB H)

+1.5k

–

+(D XIT)

–

+0.7k

+(D RIT)

–

–(CW H)

– –(D 10.695)

FSK-R

+(1.5k–Fcenter)

+(D RIT)

–

–(FSK H)

–

+(D XIT)

–

+(D RIT)

–

+0.7k

–

+(D XIT)

–

+(D XIT)

–

Table 7 144MHz band LO1 frequency shift data

–0.7k

+(D RIT)

CW-R

–0.7k

–

+(CW H)

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

430MHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

430MHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

–1.5k

+(D RIT)

–

LSB

+(SSB H)

+(D 10.695)

FSK

–(1.5k–Fcenter)

+(D XIT)

–

+(FSK H)

–

–1.5k

–

+(D XIT)

–

+(D XIT)

–

+1.5k

DDS IC407 : AD9835BRU

USB

+1.5k

+0.7k

+(D RIT)

–

–(SSB H)

–(D 10.695)

FSK-R

–

+(D XIT)

–

+(D RIT)

–

–(CW H)

–

+0.7k

–

+(D XIT)

–

+(1.5k–Fcenter)

+(D RIT)

–

–(FSK H)

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

Table 8 430MHz band LO1 frequency shift data

–0.7k

+(D RIT)

–

CW-R

+(CW H)

–

–0.7k

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

TS-2000/X

CIRCUIT DESCRIPTION

1.2GHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

1.2GHz TX/RX LO1

Filter offset

RIT

XIT

SLOPE H

10.695MHz Filter Adj.

–1.5k

+(D RIT)

–

LSB

+(SSB H)

+(D 10.695)

FSK

–(1.5k–Fcenter)

+(D XIT)

–

+(FSK H)

–

–1.5k

–

+(D XIT)

–

+(D XIT)

–

+1.5k

DDS IC4 : AD9851BRS

USB

+1.5k

+0.7k

+(D RIT)

–

–(SSB H)

–(D 10.695)

FSK-R

–

+(D XIT)

–

+(D RIT)

–

–(CW H)

–

+(D XIT)

–

+(1.5k–Fcenter)

+(D RIT)

–

–(FSK H)

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

Table 9 1.2GHz band LO1 frequency shift data

–0.7k

+(D RIT)

–

CW-R

+(CW H)

–

–0.7k

–

+(D XIT)

–

+(D RIT)

–

+(D XIT)

–

RX LO3

LSB USB

BASE

SLOPE H

SLOPE L

+(SSB H)

+(SSB L)

–(SSB H)

–(SSB L)

10.695MHz Filter Adj.

+(D 10.695) –(D 10.695)

455kHz Filter Adj.

144 SLOPE H

+(D 455)

+(SSB H)

–(D 455)

–(SSB H)

MHz SLOPE L +(SSB L) –(SSB L)

10.695MHz Filter Adj.

+(D 10.695) –(D 10.695)

455kHz Filter Adj.

430 SLOPE H

+(D 455)

–(SSB H)

–(D 455)

+(SSB H)

MHz SLOPE L –(SSB L) +(SSB L)

10.695MHz Filter Adj.

–(D 10.695) +(D 10.695)

1.2

GHz

455kHz Filter Adj.

SLOPE H

SLOPE L

–(D 455)

–(SSB H)

–(SSB L)

+(D 455)

+(SSB H)

+(SSB L)

10.695MHz Filter Adj.

–(D 10.695) +(D 10.695)

455kHz Filter Adj.

–(D 455) +(D 455)

DDS IC603 : AD9835BRU

CW-R FSK

–(CW H)

–(CW L)

–

–(CW H)

–(CW L)

–

+(CW H)

+(CW L)

–

+(CW H)

+(CW L)

–

11.150 (MHz)

+(CW H)

+(CW L)

–

+(CW H)

+(CW L)

–

–(CW H)

–(CW L)

–

–(CW H)

–(CW L)

–

+(FSK H)

+(FSK L)

–

+(FSK H)

+(FSK L)

–

–(FSK H)

–(FSK L)

–

–(FSK H)

–(FSK L)

–

Table 10 RX LO3 frequency shift data

FSK-R

+(FSK H)

+(FSK L)

–

+(FSK H)

+(FSK L)

–

–(FSK H)

–(FSK L)

–

–(FSK H)

–(FSK L)

–

AM FM

–

9

TS-2000/X

CIRCUIT DESCRIPTION

RCAR

BASE

Filter offset

CW pitch

FSK tone H

FSK tone L

SLOPE L

455kHz Filter Adj.

144 Filter offset

MHz CW pitch

FSK tone H

FSK tone L

SLOPE L

455kHz Filter Adj.

430 Filter offset

MHz CW pitch

FSK tone H

FSK tone L

SLOPE L

1.2

455kHz Filter Adj.

Filter offset

GHz CW pitch

FSK tone H

FSK tone L

SLOPE L

455kHz Filter Adj.

LSB

+1.5k

–

+(SSB L)

+(D 455)

+1.5k

–

+(SSB L)

+(D 455)

–1.5k

–

–(SSB L)

–(D 455)

–1.5k

–

–(SSB L)

–(D 455)

USB

+(SSB L)

+(D 455)

+1.5k

–

+(SSB L)

+(D 455)

–

–(SSB L)

–(D 455)

+1.5k

–

–1.5k

–

–(SSB L)

–(D 455)

–1.5k

–

DDS IC601 : AD9835BRU

CW-R FSK FSK-R

–0.7k

467 (kHz)

+0.7k

–(PITCH) +(PITCH)

+(1.5k–Fcenter)

–

–(1.5k–Fcenter)

–

–(CW L) +(CW L)

– –

+2.125k

+1.275k

+(FSK L)

–

–2.125k–FSK SHIFT

–1.275k–FSK SHIFT

–(FSK L)

–

–0.7k

+0.7k

–(PITCH) +(PITCH)

–

–(CW L) +(CW L)

– –

+0.7k

–0.7k

+(PITCH) –(PITCH)

+(1.5k–Fcenter) –(1.5k–Fcenter)

–

+2.125k

+1.275k

+(FSK L)

–

–2.125k–FSK SHIFT

–1.275k–FSK SHIFT

–(FSK L)

–

–(1.5k–Fcenter) +(1.5k–Fcenter)

– –

–

+(CW L) –(CW L)

– –

+0.7k

–0.7k

+(PITCH) –(PITCH)

–

+(CW L) –(CW L)

– –

–2.125k

–1.275k

–(FSK L)

–

+2.125k+FSK SHIFT

+1.275k+FSK SHIFT

+(FSK L)

–

–(1.5k–Fcenter) +(1.5k–Fcenter)

– –

–2.125k

–1.275k

+2.125k+FSK SHIFT

+1.275k+FSK SHIFT

–(FSK L)

–

+(FSK L)

–

Table 11 RCAR frequency shift data

–

TCAR

144MHz

430MHz

1.2GHz

BASE

Filter offset

LSB

–1.5k

+1.5k

USB

+1.5k

–1.5k

DDS IC602 : AD9835BRU

CW-R FSK

+0.7k

–0.7k

10.583 (MHz)

–0.7k

+0.7k

Table 12 TCAR frequency shift data

10

Description of variables in Tables 6 to 12

(D RIT) RIT frequency variable amount (–9.99~+9.99kHz)

(D XIT)

(SSB H)

XIT frequency variable amount (–9.99~+9.99kHz)

SSB slope high cut frequency variable amount = 2.8k – Fhi

(SSB L)

(CW H)

(CW L)

(FSK H)

SSB slope low cut frequency variable amount = Flow – 300

CW slope high cut frequency variable amount = 2.7k – (FSK SHIFT + Fwidth / 2)

CW slope low cut frequency variable amount = FSK SHIFT – Fwidth / 2 – 100

FSK slope high cut frequency variable amount = 2.8k – (Fcenter + Fwidth / 2)

(FSK L)

(D 10.695)

(D 455)

(PITCH)

FSK slope low cut frequency variable amount = Fcenter – Fwidth / 2

RX 10.695MHz filter adjustment frequency variable amount

RX 455kHz filter adjustment frequency variable amount

CW pitch frequency (400~1000Hz, Initial value 800Hz)

(FSK SHIFT) FSK shift width frequency (170Hz, 200Hz, 425Hz, 850Hz, Initial value 170Hz)

(Fcenter) FSK RX center frequency = (2125Hz or 1275Hz) + (FSK SHIFT / 2)

FSK-R

AM FM

TS-2000/X

CIRCUIT DESCRIPTION

HF Receiver System and Main IF System

Three antenna terminals used for the HF and 50MHz band reception are ANT1, ANT2 and HF RX ANT.

After the incoming signal from ANT1 and ANT2 passes through the transmission/reception changeover relay in the filter unit (X51-315), and is sent to the HFRX terminal of the

TX-RX unit (X57-605). There is an HF RX ANT terminal there, and one of the antennas can be selected from the menu for reception .

The HF RX ANT terminal is used to connect a dedicated

HF-band low-band receiving antenna, such as a Beverage antenna, and operates at frequencies up to 30MHz. (If an antenna, such as a solid wire antenna, is connected to this terminal, unwanted radio signals in the shack may be picked up. It is recommended that a 50 (coaxial cable be used for routing in the shack.)

The signal passes through an RF ATT, an image filter and a limiter for surge absorption and enters the RF BPF for both transmission and reception. The division of the RF BPF is in the range shown in the block diagram. For 6.9~7.5MHz,

13.9~14.5MHz and 49~54MHz, a dedicated BPF (adjustable type) is used and particularly effective for eliminating unwanted signals in the low band. Other BPFs (non-adjustable type) are designed as circuits with independent armature bands, except that the 24MHz and 28MHz bands are shared. Signals pass through these BPFs at the time of transmission, so they are useful for producing radio signals with little radiation.

Although the conventional RF ATT had an attenuation level of 20dB, the attenuation level of the current RF ATT is

12dB. It can, however, be changed to approximately 20dB by removing the jumper (CN2) near the ATT within the unit.

The pre-amplifier (Q12, Q705) have been changed to a power MOS FET from the combination of the conventional cascade amplifier and MOS FET amplifier. This element is a

FET that is used in a younger stage for transmission and has

ANT1 ANT2 HF RX ANT

X51-315

FILTER

TX-RX1

ATT

–12dB

X57-605

30kHz~1.705MHz

LPF

D7 D8 D10

D11

HPF

1.705MHz~

60MHz

RF BPF

1.705~2.5MHz

BPF

D12 D13

D33 D34

BPF

49.0~54.0MHz

10.695

MHz

2nd Mixer

Q19,Q20

Q18

XF1

69.085MHz

1st Mixer

Q7~Q10

PRE AMP

Q12

30kHz~21.5MHz

Q13

D39 D38

Q705

21.5MHz~60MHz

D42

XF2

75.925MHz

D41

TX-RX 1 (X57-605 A/9)

D705

LO1HF

75.955~

129.085MHz

D36

D704

D35

Fig. 3

excellent large input characteristics. The actual circuit contains two amplifiers using this FET. Large input characteristics with a low gain are given priority on the low band (Q12) with respect to 21.5MHz, and sensitivity is given priority on the high band (Q705). circuit on the low band side bordering

21.5 MHz favoring a gain with moderately large input characteristics and that on the hybrid side (Q705) favoring .

When the pre-amplifier is off, the signal from the RF BPF enters the receiving first mixer (Q7~Q10) in the next stage as it is.

The receiving first mixer circuit uses a double balance type mixer with four joint type FETs. The signal is converted to the first IF frequency by the first local oscillator signal.

The TS-2000S has adopted a method that changes the first

IF frequency according to the receive frequency. For this reason, it has two sets of roofing filters (MCF) that determine the selectivity of the first IF. Table 1 shows the relationship between the receive frequency and the first IF frequency. The central frequencies for the reception and transmission of the first IF frequency are different from each other by 100kHz because the transmission and reception is performed simultaneously during satellite communication.

RX/TX frequency (MHz) RX 1st IF (MHz)

0.03~ 9.0

75.925

9.0 ~17.0

17.0 ~24.0

69.085

75.925

24.0 ~26.0

26.0 ~30.0

30.0 ~37.0

37.0 ~49.0

49.0 ~60.0

69.085

75.925

69.085

75.925

69.085

TX 1st IF (MHz)

75.825

68.985

75.825

68.985

75.825

68.985

75.825

68.985

Table 13 RX frequency and 1st IF frequency

11

TS-2000/X

CIRCUIT DESCRIPTION

The signal is then amplified by the first IF amplifier (Q18) and is converted to the second IF frequency of 10.695MHz

in the second receive mixers (Q19, 20). The tuning frequency of each stage, the second local oscillator frequency and others are changed according to the receive frequency to respond to the changeover of the previously stated first IF frequency.

A circuit for changing over the IF signal from the units of the VHF, UHF and 1.2GHz bands and IF signal from the HF band is provided on the output side of the second receive mixer. That is, the circuits following this stage are commonly used circuits, regardless of the receive frequency on the main side.

In addition, there is a semi-fixed volume (VR4) on the output side of the first receive mixer. The volume is used to eliminate the gain differential generated due to the changeover of the first IF frequency.

The signal for the noise blanker is extracted from this point by passing through Q22. The noise blanker circuit is based on the same principle of operation as the conventional one, but can change the threshold level by changing the emitter potential of the noise detection stage (Q29).

The 10.695MHz signal is amplified by Q26 which also serves as a noise blanker gate circuit and passes through a

10.695MHz IF filter. It has three bandwidths, 2.7kHz, 6kHz and through, and when it is combined with the 455kHz filter group, the same continuous band change function (analog IF throughput: operation in modes other than FM) as in conventional analog devices is implemented. The band in this analog stage does not affect the operation of the digital IF filter in the IF DSP and is automatically set to the optimum band for removing unwanted signals outside the band.

Then, the signal is converted to the third IF frequency of

455kHz in the third receive mixer (Q700, 701). The 455kHz filter has three bandwidths: 2.7kHz, 9kHz and 15kHz. In FM mode (main band side) the 15kHz filter is selected for WIDE and the 9kHz filter is selected for NARROW, and signals passing through the filter are sent to the FM IC (ICI), amplified and detected. IC1 processes squelch, S meter, etc.

As a characteristic operation in this stage, a tuning error detection voltage for the ALT function operating in the

1.2GHz band FM mode is generated. It utilizes the DC voltage that is overlapped with the ICI detection output.

In a mode other than FM, the receive signal is amplified by the next third IF amplifier (Q38) and operational amplifier

(IC18) and converted to the final 12kHz IF frequency by the fourth receive mixer (IC3). The converted IF signal in FM

(audio signal) and non-FM mode (IF signal) is selected by the multiplexer (IC7) and the signal is sent to the DSP of the control unit for processing. The signals processed in the control unit become audio signals in all modes and return to the TX-RX1 unit (X57-605). These audio signals are power amplified to the level that drives the speaker with the AM amplifier (IC9).

A speaker separation function is available as an accessory circuit. The bands can be changed as shown in Table

14.

2nd Mixer

Q19,20

D46

Q25

10.695MHz

D60,64 D52,56

Q18

LO2

10.695

MHz

65.230MHz

58.390MHz

Noise blanker

Q22 Q26 Q28

Q29~Q31

X57-606

RIF

X57-607

12RIF

ALT

FM IC

DET

IC1

D68

D69

D71

CF1

CF2

Q38

IC2

IC18

CF3

CF4

455kHz

4th Mixer

IC3

12kHz

Q709 Q42

Q41

RCAR

467kHz

D49,55

D50,53

D67

D70

XF5

XF6

D57,61

D58,62

3rd Mixer

Q700,701

LO3

Q32

11.15MHz

DSP

X53-391

AF PA AMP

IC9

TX-RX 1 (X57-605 A/9)

Fig. 4

12

TS-2000/X

CIRCUIT DESCRIPTION

■ Speaker output changeover

When external speakers 1 and 2 and headphones are connected, you can change over the sub/main band outputs.

The headphone connection is preferred over the all the speaker output and you can select from three patterns for headphone left-right changeover.

When SP1 only has been connected, the built-in speaker will change over to SP1.

When SP1 and SP2 are connected, you can select the

SP1 and SP2 output method from three patterns, the same as for the headphones.

Connection Conditions (● : connected)

Headphone

●

SP1

●

SP2

●

→

Left-right output patterns

Selected Pattern

Pattern 0

Pattern 1

In case of headphones

Left side

Main-sub full mox

Main : Full sound

Right side

Main-sub full mix

Main : 1/4 sound

Pattern 2

Sub : 1/4 sound

Main

Sub : Full sound

Sub

This is a reverse function and left-right changeover is possible.

Headphone

Pattern 0~2

Output condition by connection of left table

Built-in speaker

Stop

Pattern 0~2 (Left)

Stop

Main-sub full mix

SP1

Stop

Pattern 0~2 (Left) Pattern 0~2 (Right)

Main-sub full mix

In case of SP1 & SP2

SP1 or Built-in SP2

Main-sub full mix main : Full sound

Main-sub full mix

Main : 1/4 sound

Sub : 1/4 sound main

Sub : Full sound

Sub

SP2

Stop

Pattern 0~2 (Right)

Table 14

Main VHF/UHF Band Front-End and

Sub Receiver System

The VHF and UHF band receiver circuit is configured with two systems, a main band (FM/ AM/ SSB/ CW/ FSK) and a sub-band (FM/AM), each of which has a VHF and a UHF band path.

In the main band, the first IF is 41.895MHz and the second IF is 10.695MHz and the signal lower hetero to the second IF is sent to the TX-RX1 unit (X57-605) and linked to the second IF, which is shared by the other bands. The subband is a double conversion where the first IF is 58.525MHz

and the second IF is 455kHz. It is configured so that detected AF signals are sent to the control unit (X53-391).

■ VHF/ UHF band front end

The circuit operation of the sub-receiver unit differs depending on whether it is for K destination or others. The circuit operation for each of the destinations is described below.

• K destination

The incoming signal from the VHF band antenna terminal passes through the TX/RX changeover relay (K2) in the filter unit (X51-315) and goes to the TX-RX2 unit (X57-606). Then, it passes through the 12dB ATT circuit and is divided to the

136~155MHz path and the 118~136MHz, 155~174MHz and 220~300MHz path by the L distribution circuit. The

136~155MHz signal passes through a 2-pole BPF (bandpass filter) and enters the pre-amplifier (Q15). The amplified receive signal is again distributed to the paths for the main and sub receiver units by the L distribution circuit.

The signal distributed to the main receiver unit passes through the 2-pole variable tuning BPF, is amplified by the second amplifier (Q24) and goes to the mixer (IC4) for the main band common to the VHF and UHF bands through the variable tuning BPF. The 2-pole x 2-stage BPF for the main band VHF controls the tuning frequency by output from the

D/A of the TX-RX1 unit (X57-605).

13

TS-2000/X

CIRCUIT DESCRIPTION

14

The 118~174MHz signal distributed to the sub-receiver unit passes through a variable tuning filter and is amplified by the second amplifier (Q24). Then, it passes through the

2-pole variable tuning BPF, and the 220~300 MHz signal is amplified by Q23 and is then input into the mixer (IC5) for the sub-band common to the VHF and UHF bands. The 1pole and 2-pole BPFs for the sub-band VHF also controls the tuning frequency by the output from the D/A of the TX-RX1 unit (X57-605).

The incoming signal from the UHF band antenna terminal enters the UHF section of the final unit (X45-360), passes through the HPF and LPF and goes to the TX-RX2 unit (X57-

605). Then, it passes through the 12dB ATT circuit and goes to the pre-amplifier (Q14). The amplified receive signal is distributed to the paths of the main and sub-receiver sections by the L distribution circuit.

The signal distributed to the main receiver section passes through the 3-pole variable tuning BPF and is amplified by the second amplifier (Q21). Then, it passes through the 3-pole variable tuning BPF and is input into the mixer

(IC4) for the main band.

This 3-pole x 2 stage BPF for the UHF also controls the tuning frequency by the output from the D/A of the TX-RX1 unit (X57-605).

Filter

X51-315

VHF

The 438~450MHz signal distributed to the sub-receiver section passes through the SAW filter (L29), is amplified by the second amplifier (Q25), and passes through another

SAW filter (L50). The 300~438MHz and 450~512MHz signals are amplified by Q19 and goes to the mixer (IC5) for the sub-band.

• E, E2 destinations

Then, the signal passes through the 12dB ATT circuit and the 2-pole BPF (band-pass filter) and enters the pre-amplifier

(Q15). The amplified receive signal is distributed to the paths of the main and sub receiver sections by the L distribution circuit.

The signal distributed to the sub-receiver section passes through a variable tuning filter and is amplified by the second amplifier (Q22). Then, it passes through the 2-pole tuning BPF, and goes to the mixer (IC5) for the sub-band common to the VHF and UHF bands. The 1-pole + 2-pole BPFs for the sub-band VHF also control the tuning frequency by the output from the D/A of the TX-RX1 unit (X57-605).

The signal distributed to the sub-receiver section passes through the SAW filter (L29), is amplified in the second amplifier (Q25), passes through another SAW filter (L50) and goes to the mixer (IC5) for the sub-band.

Final

X45-360

UHF

ATT

–12dB

D10

Q15

D22 D24

L23,24

LO1RX

183.895~

418.105MHz

Q24

L47,55

Q30

D48

IC4

XF1

41.895MHz

ATT

–12dB

Q14 D23 Q21 D49

L108~111,137 L116~119,133

Q42,43

Q38

Q44

LO31

31.200MHz

Q61

RIF

TX-RX 2 (X57-606 A/11)

X57-605

Fig. 5 Main band receiver section

Filter

X51-315

VHF

ATT

–12dB

D24

D10 Q15 D22 D95 D101

L28

Q22

L44,52

D46

D96

Q23 D82

Final

X45-360

UHF

D97

D90

L29

Q25

L50

D91

ATT

–12dB

D9 Q14 D20 D92 D81 Q19 D93 D94

D23

TX-RX 2 (X57-606 A/11)

Fig. 6 Sub band receiver section

IC5

TS-2000/X

CIRCUIT DESCRIPTION

■ Main receiver IF section

The signal input to IC4 is mixed with the signal produced by amplifying the first local oscillator RXLO1 from the PLL section by Q30 and lower hetero to the first IF of

41.895MHz. Then, it passes through the MCF (XF1) and

AGC amplifier (Q38) and goes to the second mixer (Q42 and

43). The signal input to the second mixer is mixed with the signal produced by amplifying the second local oscillator

21.2MHz from the PLL section by Q44 and lower hetero to the second IF of 19.695MHz. The signal then passes through a temperature compensating resistor and the IF amplifier (Q61) and is sent to the TX-RX1 unit (X57-605).

■ Sub receiver IF section

The signal input to IC5 is lower hetero to the first IF of

58.525MHz. In the VHF band, the local oscillator SLO1 from the PLL section is divided into two by the divider (IC6) and passes through amplifier (Q23). In the UHF band, the IF signal passes through amplifier (Q33) and is input to IC5. The

IF signal passes through the MCF (XF2), passes through the post amplifier (AGC amplifier in the AM mode) Q37 and goes to the FM IC (IC7). The local oscillator is supplied to

IC7 by the 58.07MHz crystal oscillator (X1) and is lower hetero to the second IF of 455kHz by a mixer in the IC.

The circuit operation when the signal passes through a ceramic filter after lower hetero is different for K destination and E destination. The circuit operation for each of the destinations is explained below.

• K destination

In FM mode, the signal passes through a ceramic filter

(CF1), is quadrature-detected, and the resulting signal is output.

• E, E2 destinations

The signal passes through a ceramic filter (CF1) in FM

WIDE mode and it passes through a ceramic filter (CF2) in

FM NARROW mode. The signal is then quadrature-detected and the resulting signal is output.

In AM mode, a 455kHz signal passes through the AGC amplifier (Q51) and amplifier (Q48 and Q45) and is detected by D58. The detection signal retrieved for the AGC is rectified, passes through the DC amplifier (Q39) for AGC control and goes to the Q37 gate terminal (G2).

The FM/AM detection signal is switched by the multiplexer (IC8). Then, it is amplified by the operational amplifier

(IC9) and output to the control unit (X53-391).

■ Squelch voltage and S-meter voltage of the sub

receiver section

The S meter voltage is introduced to the A/D through a

LPF for RSSI output of the FM IC (IC7).

The squelch voltage is supplied to the A/D by passing the detection output of the FM IC through a filter amplifier in the

FM IC, amplifying it with the noise amplifier (Q63), and rectifying it with D83.

LO1RX

VHF

Q30

IC4

UHF

TX-RX 2 (X57-6060 A/11)

XF1

41.895MHz

Q38

Q44

LO31

31.2MHz

Q42,43 Q61

RIF

10.695

MHz

D46 Q22

D49

HF 1.2GHz

X57-605

Fig. 7

455kHz

CF2 (E type only)

CF1

S-meter

Q63

D83

IC5 Q37

XF2

58.525MHz

FM IC

IC7

Q51 Q48 Q45

D58

58.07

MHz

AGC

Q39

176.5~

231.5MHz

D53 Q32

IC6

1/2

D56

VHF

SLO1

IC6

322.95~

465.04MHz

UHF

348.5~

458.5MHz

Q33

IC9

DSP

X53-391

TX-RX 2 (X57-606 A/11)

Fig. 8

15

TS-2000/X

CIRCUIT DESCRIPTION

Ref No.

Parts No.

Nominal center frequency

Pass bandwidth

XF1

L71-0566-05

41.895MHz

3dB :

7.5kHz

Ripple

Insertion loss

1.0dB or less

3.0dB or less

Guaranteed attenuation Fo+(500~1000)kHz

Fo–(200~1000)kHz

Cener

Terminating impedance

Spurious

70dB or more

–

960

Ω

//1.0pF

CC=7.0pF

1.0MHz

40dB or more

CF2 : Only E destination

XF2

L71-0565-05

58.525MHz

3dB :

7.5kHz

1.0dB or less

3.5dB or less

1MHz

80dB or more

–

350

Ω

//4.0pF

CC=15.5pF

1.0MHz

40dB or more

XF3

L71-0582-05

41.795MHz

3dB :

15kHz

1.0dB or less

1.5dB or less

Fo–(500~1000)kHz

50dB or more

–

960

Ω

//1.0pF

–

CF1

L72-0984-05

CF2

L72-0986-05

455kHz 455kHz

6dB :

7.5kHz or more 6dB :

4.5kHz or more

50dB :

15kHz or less 50dB :

10kHz or less

2.0dB or less 2.0dB or less

6.0dB or less

100kHz

35dB or more

6.0dB or less

100kHz

35dB or more

455kHz

1.0kHz

1.5k

Ω

Table 15 Filters rating (TX-RX 2 unit : X57-606)

–

455kHz

1.0kHz

2.0k

Ω

–

1.2GHz Unit Receiver Section

The incoming signal from the antenna (12ANT) passes through a filter, is amplified in the receiver RF amplifier (Q11 and 12) and input to the first mixer (Q10).

The signal is converted to the first IF (135.495MHz) in

Q10, passes through the MCF (XF1) and the AGC amplifier

(Q9) and enters the second mixer (Q7 and Q8).

The signal is converted to the second IF (10.695MHz) in

Q7 and Q8, amplified in the receiver IF amplifier (Q303) and sent to the TX-RX1 unit (X57-605).

12ANT

TX/RX SW

Q12

L33

Q11

L30

1240~

1300MHz

1st Mixer

CN12

CN11

D11

Q10 XF1 Q9

2nd Mixer

Q7,8 Q303

12RIF

X57-605

D47

135.495

MHz

AGC

1104~

1165MHz

10.695

MHz

Q15

124.800

MHz

TX-RX 3 (X57-607)

Fig. 9

16

TS-2000/X

CIRCUIT DESCRIPTION

Transmit

System IF Section

■ Transmission IF

The details of the processing by the DSP depend on the mode.

• Modes other than FM

Transmission bandwidth change, speech processor and microphone gain control are performed in the AF stage. A

12kHz IF signal is produced after PSN modulation and output modulation control.

• FM mode

The baseband processing in the AF stage is carried out by the DSP and a VCXO (voltage controlled X’tal Oscillator) is used as a modulator.

The transmit signal output from the control unit (X53-391) is switched by an analog SW (IC8) and is input to the balanced mixer (IC6). The 12kHz IF signal and local oscillator signal enters the IC6 and become a 10.595MHz signal. The local oscillator signal is generated by the DDS (IC602).

The 10.595MHz IF component is amplified by the IF amplifier (Q54) and passes through the 6kHz bandwidth crystal filter, then becomes a 10.595MHz IF signal by eliminating local oscillator signals. The diode switch (D90) changes between FM modulator output and non-FM 10.595MHz IF signals.

The temperature compensation of the transmitter circuit is done by the thermistor near the IF amplifier (Q54) and the thermistor on the input side of the IF amplifier (Q711). They reduce the gain at low temperatures and raise it at high temperatures.

D84

Q711

TH5

D90

Q58

XF9

10.595MHz

Q59

10.595MHz

TH8

IC6

O/I 2

SSB,CW,

AM,FSK 2

O/I 1

IC8

O/I 3

X53-391

TX signal

Q54

TH7

Q604

TX-RX 1 (X57-605 A/9)

IC602

DDS

10.595MHz

Fig. 10

The output signal from the IF amplifier (Q711) passes through D84, Q40, D82, D48, D80 and D81 and becomes the IF transmit signal for each band. D84 is a voltage controlled attenuator circuit. This circuit changes the attenuation level according to the control voltage (TGC), in the same way as the TGC (TX gain control) used in the TS-870 and TS-

570 and is set to the adjusted attenuation level for each band. Q49 is an IF amplifier circuit with an ALC circuit. The gain is controlled by the voltage generated by the ALC circuit.

D82 is a voltage controlled attenuator circuit as D84. The attenuation level is minimum at full power and as the power decreases, the control voltage rises and the attenuation level increases. When the power is reduced, the gain will become relatively excessive if the IF gain is not lowered. It is set to an attenuation level adjusted by the PGC (Power

Gain Control) accordance to the power of each band.

Q48 is an IF output buffer. It changes to the transmitter section of each band with a diode switch (D80, D81) to supply a 10.595MHz IF signal.

During transmission in the 144MHz and 420MHz bands, the signal is output to the TX-RX2 unit (X57-605), and during transmission in the 1.2GHz band, it is output to the TX-RX3 unit (X57-605).

In the 1.8~54MHz band, the frequency is converted to the final target transmit frequency in the TX-RX1 unit (X57-

605).

The local oscillator frequency changes according to the band in second transmit mixer of Q46 and 47 to generate different IF frequencies. (TX third IF: 68.985MHz or 75.825

MHz)

D703 and D715 are used to change the tuning frequency of the local oscillator signal and D79, D78, D77 and D76 are used change the frequency of the IF filter (L102).

The variable tuning filter containing these variable capacitance diodes performs the coarse adjustment of the coil

(L100, L99, L98, L96, L102) in the band (18.085MHz) where the IF is 75.825MHz. Then, it changes the tuning frequency control voltage from the D/A in the band (14.100MHz) where the IF is 68.985MHz and tunes it to the necessary frequency by readjusting the coil.

HFLO1

75.955~

129.085MHz

HFLO2

58.390MHz

65.230MHz

TX-RX2

X57-606

TIF

TX-RX3

X57-607

12TIF

D40

L96,98~100

68.985MHz

75.825MHz

BPF

Q44,45

1.8~54MHz

D45

Q46,47

L102

D76~79

D80

D703,715

HBPF HBPF

D81

Q48

D82

Q49

D84

Q711

10.595

MHz

TX-RX 1 (X57-605 A/9)

Fig. 11

17

TS-2000/X

CIRCUIT DESCRIPTION

The third IF signal is input to the third transmit mixer

(Q44, 45).

A GaAs FET is used to obtain the satisfactory intermodulation characteristics. VR3 adjusts the second gate voltage to maximize the gain. VR2 adjusts the balance of the source current of two FETs and prevents the generation of spurious components by minimizing IF output leakage. It also adjusts the leakage of the IF signal (68.985MHz) to the minimum during 50MHz band transmission.

The signal with the target frequency passes through the

BPF shared by the receiver section to eliminate spurious components. The transmitter circuit is separated from the receiver circuit to implement satellite communication, but only this BPF is shared to prevent generation of spurious components.

Finally, the signal is amplified to a sufficient level (approximately 0dBm) by the broadband amplifier and supplied to the final section. Q43 is a power MOS FET and provides an output of approximately 20dBm when the ALC is inactive.

HFTX

Q43

RF HPF

1.705~2.5MHz

BPF

2.5~4.1MHz

BPF

4.1~6.9MHz

BPF

6.9~7.5MHz

BPF

7.5~10.5MHz

BPF

10.5~13.9MHz

BPF

13.9~14.5MHz

BPF

14.5~21.5MHz

BPF

21.5~30.0MHz

BPF

30~49, 54~60MHz

BPF

49~54MHz

BPF

D26

L95

Q44

Q45

L96

L97

TX-RX 1 (X57-605 A/9)

L98~100

HBPF

■ ALC

The progressive and reflected wave signals detected by the final section in each band enters the TX-RX1 unit (X57-

605) and is synthesized by a diode. It is synthesized simply because no signal is transmitted in multiple bands at the same time.

When the progressive signal voltage is input, it is divided by a resistor, and enters the differential amplifier composed of Q73 and Q74. When the voltage increases, the emitter voltage rises, the base current of Q74 decreases, and the collector voltage of Q74 also rises. When the voltage exceeds the base emitter voltage plus the emitter voltage (approximately 2.4V) of Q76, the base current of Q76 begins to flow and the voltage of the collector to which the ALC time constant CR is connected decreases. This collector voltage is buffered by Q78, the voltage is shifted by D108, and matched with the keying control voltage by Q79 and D111 to produce the ALC voltage. When the ALC voltage (2.7V

when inactive) decreases, the second gate voltage of the IF amplifier (Q49) decreases and the gain lowers.

During AM transmission, Q75 turns on approximately

20ms after transmission, and the ALC voltage is controlled by the average power. The voltage output from the DAC

(IC14) is applied to the base voltage of Q74, which is the reference voltage of the ALC. This DAC (IC14) is controlled by the adjustment value (POC) from the main microcomputer. In addition, the input voltage of the DAC fluctuates according to the power supply voltage and the output drops when the voltage is reduced.

■ SWR protection

The reflected wave detection signal is divided by the

DAC (IC14) and input to the base of Q77. When this voltage increase, the collector current of Q77 increases and output power is limited.

■ Meter voltage

The progressive wave voltage is calculated as the power meter voltage, the reflected wave voltage is calculated as the progressive wave voltage and its value is input as the

SWR meter voltage, and the ALC voltage is input as the ALC meter voltage. These voltages are input into the A/D converter of the main microcomputer.

Fig. 12

■ Packet signal

The control unit contains a TNC and a changeover switch circuit that enables data signals to input from the ACC2 connector. (See the block diagram)

The 1200bps signal is processed by the DSP in the same way as for audio signals, but the 9600bps signal is input directly to the FM modulator without passing through the

DSP.

18

TS-2000/X

CIRCUIT DESCRIPTION

Q76

Q78

Q79

R439, ALC meter

Q49

Q711

Q48

D82 D84

10.595MHz

Q73 Q74

IC14

D85

L119

IC17 (Q6),

R509

Q75

REMOTE

(6 pin)

HF ALC

D123

VSF

X45-360

(A/2)

D119

D121

43VSF

X45-360

(B/2)

X57-607

12VSF

TX-RX 1 (X57-605 A/9)

Q77

50ALC

14ALC

43ALC

12ALC

EXT. CONT

Fig. 13

IC13

(AOUT)

14S

D109

D110

D113

D124

X45-360

(A/2)

VSR

D120

X45-360

(B/2)

43VSR

D122

X57-607

12VSR

VHF/UHF Band Transmitter Circuit (RF~IF)

The TIF (10.595MHz) signal input from the TX-RX1 unit

(X57-605) first enters the mixers (Q46 and 47). The

31.2MHz signal from the PLL passes through the RF amplifier (Q50), enters the mixer as a local oscillator to output the

41.795MHz IF through both the signals. It passes through the 41.795MHz MCF (XF3) and enters the wideband diode mixer (D54) in the next stage, and upper hetero to a VHF/

UHF band output signal. The local oscillator TXLO1 of the mixer is on a common line for both VHF and UHF band local oscillators, and the local oscillator signal is amplified by the

VHF and UHF band broadband amplifier (Q34) and supplied to the mixer.

The signal converted to the VHF/UHF band is divided into a VHF band path and a UHF band path after it is output from the mixer.

X45-360

(A/2)

VHF

IC3

X45-360

(B/2)

UHF

D19

Q26 Q17

The VHF band signal passes through a filter and a trap and is amplified in the 2-stage RF amplifiers (Q20, Q18), and the resulting signal goes to the wideband amplifier (IC3) common to the VHF and UHF bands.

The UHF band signal is amplified by the RF amplifier

(Q17), passes through a 3-pole variable tuning BPF and is amplified by the amplifier (Q26). Then, it passes through a

2-pole variable tuning BPF and enters IC3. The total 5-pole variable tuning BPF controls the tuning frequency according to the control signal output from the D/A converter of the

TX-RX1 unit (X57-605).

The signal amplified by IC3 is again divided into VHF band and UHF band paths by a diode switch and output to the final unit (VHF band: X45-360 A/2, UHF band: X45-360 B/2).

D21

L48,158

VHF

UHF

Q18 Q20

FILTER

L128,129 L121~124,140

D52

Q34

D54 XF3 Q46,47

X57-605

TIF

10.595

MHz

41.795

MHz

Q50

TXLO1

418.205MHz

LO31

31.2MHz

TBPF

DAC

IC5

TX-RX 2 (X57-606 A/11)

Fig. 14

19

TS-2000/X

CIRCUIT DESCRIPTION

Transmitter Final Amplifier

The final unit (X45-360 A/2) is composed of an HF and

VHF band final amplifier, an antenna turner matching circuit, and a power supply circuit.

The LPF section and antenna tuner detection circuit are located in the filter unit (X51-315).

The 1.8~144MHz band is amplified by the final unit, but it operates in the broadband up to the drive amplifier. The final unit amplifies signals using independent amplifiers in the 8~50MHz and 144MHz bands. The amplifiers are switched with a diode switch (D1).

■ Q1 : First stage amplifier

This amplifier uses a FET. It has frequency characteristics so that the gain increases in the 144MHz band.

■ Q2 : Pre-drive amplifier

This amplifier uses a bi-polar transistor. It has unique frequency characteristics.

■ Q3 and 4 : Drive amplifier

This is a push-pull type amplifier. It amplifies a signal with a broadband up to the 144MHz band, then the signal is branched to the HF and 144MHz bands through a relay.

■ Q6 and 7 : HF final amplifier

This amplifier uses a bipolar transistor with push-pull. It amplifies a signal up to the 54MHz band, using an output transformer with a coaxial cable. It outputs the signal to the

LPF section through an effective and light matching circuit in the 50MHz band.

■ Q101 and 102: 144MHz final amplifier

A 144MHz band signal passes through the HPF and enters the branch circuit with two amplifiers.

It functions as a parallel amplifier that branches the signal with the same phase, amplifies it with the Q101 and 102 amplifiers and re-synthesizes it. As a result a 100W output is produced.

Since the output matching section is an LPF type, it attenuates harmonics as well. After the output has been synthesized, it detects the power of the progressive wave and reflected wave with a directional coupler according to the strip line, and outputs it to the LPF section.

■ LPF section

In the 1.8~50MHz band, the signal passes through the

LPF as shown in Table 3.

It has an independent LPF circuit and an antenna changeover circuit for the 144MHz band.

The signal output from the LPF passes through the detection circuits, the transmission/reception changeover relay (K1), the antenna tuner changeover relay (K3) and the antenna changeover relay (K4) and is output to ANT1 or

ANT2.

Select signal

14M

21M

28M

50M

Frequency

1.8~ 2.0

2.0~ 4.1

4.1~ 7.5

7.5~14.5

14.5~21.5

21.5~30.0

49.0~54.0

X51-315

144ANT

LPF

LPF section

DET

Q101,102

HPF

144MHz

VSF VSR

Q3,4 Q2 Q1

Q6,7

Final (X45-360 A/2)

Fig. 15

X57-605

HFTX

X57-606

14TX

20

TS-2000/X

CIRCUIT DESCRIPTION

■ Progressive wave and reflected wave output circuits

The signal is detected by L7, D3 and D4. A voltage output corresponding to the progressive wave and reflected wave is produced by synthesizing the magnetically combined component by L7 with the corrected electrostatically combined component by TC1 and C9 and detecting the resulting signal.

It is adjusted by TC1 so that the reflected wave voltage under a 50

Ω

load is minimized. VR1 adjusts the frequency characteristics in the 50MHz band.

These outputs are synthesized with detected output of the 144MHz band and are fed to the TX-RX1 unit (X57-605).

■ Antenna turner detection circuit

The passing current is converted to voltage by L9, and the voltage is stepped down and detected by L10. One of these components is buffered by Q1 and Q2 and rectified by

Q3 and Q4, are input to the phase comparator (IC2) . The IC determines the IC2 Q output “H” or “L” according to the phase difference with a D-flip-flop. The other component is detected by diodes (D10 and D11) and the amplitude difference is compared with the comparator (IC1).

The capacitor capacitance on the input side is changed according to the phase difference detection output, and the capacitor capacitance on the output side is changed according to the amplitude difference detection output.

■ UHF final unit (X45-360 B/2)

The 430MHz band transmit signal output from the TX-

RX2 unit (X57-606) is amplified to 50W by four amplifiers

(Q901, 902, 903 and 905). The final unit consists of single amplifiers Q901, 902, 903 and 905. The input and output of the final stage is composed of micro-strip lines. The progressive wave and reflected wave detection circuit is also made of micro-strip lines and used for power control and reflected wave protection.

ANT1 ANT2 HF RX ANT

ATT

–12dB

X57-605

Q output

IC2

D10

IN–

IN+

IC1

D11

L10

Filter (X51-315)

430ANT

DET

VSR

VSF

X57-606

(43RX)

Q905 Q903 Q902 Q901

X57-606

Final (X45-360 B/2)

Fig. 17

1.2GHz Unit Transmitter Section

The 10.595MHz transmit signal from 12TIF is amplified in the sending IF amplifier (Q304). This signal is input into the sending mixer (Q1 and Q2).

The 135.395MHz signal converted in Q1 and 2 passes through the MCF (XF2) and IF amplifier (Q3), is input into the diode mixer (D1) and converted to 1240~1300MHz. This signal is amplified to approximately 0dB in the sending RF amplifier (IC1 and Q5), then input to IC2.

It is amplified to approximately 1W in the drive power module (IC2) and to approximately 10W in the final power module (IC3), then sent to the antenna terminal (12ANT).

12ANT

D5 IC3

IC2 Q5

L12

IC1

L10

1240~

1300MHz

1240~

1300MHz

D10

D1 Q3

XF2

135.395

MHz

Q1,2

Q304

12TIF

X57-605

10.695

MHz

Q48

Q15

1104~

1165MHz

124.800

MHz

TX-RX 3 (X57-607)

Fig. 18

LPF

1.8MHz

3.5MHz

7MHz

10MHz : E

14MHz : E, 10&14MHz : K

21MHz

X45-360

(A/2)

Q6,7

28MHz

50MHz

VSR

VSF

X57-605

Fig. 16

21

TS-2000/X

CIRCUIT DESCRIPTION

Digital Control Circuit

■ Outline

The TS-2000/X control circuit has a multi-chip configuration centered around a main microcomputer (IC8), and contains a latch circuit for input/ output, a TNC and a DSP. Refer to the digital control block diagram.

■ Main microcomputer peripherals

Four serial communication devices utilizing a UART function (panel microcomputer, TNC, mobile head and PC serial port) are connected to the main microcomputer. An

EEPROM (IC7) for backup and a DTMF decoder (IC12) for

DTMF signal detection are also connected to the microcomputer.

The input/output circuit and DSP are connected through an address bus and a data bus. The bus to the DSP is connected through 5V

↔

3V voltage conversion ICs (IC9, IC10, and IC11)

The microcomputer operates with an internal core voltage of 3.3V, an external I/O voltage of 5V and an internal frequency of 22.1184MHz (11.0592MHz x 2).

■ TNC

The TNC is the same as the one used in the TH-D7. The

TNC uses a lithium battery to back up various settings.

When a 9600bps communication speed is used, the TNC analog signal is connected directly to the transmitter/receiver circuit without passing through the DSP.

■ Input/output latch circuit

A latch IC is used in stead of several input/output ports.

Since the latch IC has a latch function only, the latch circuit contains an input latch logic circuit (IC13, IC14, IC15) and an output latch logic circuit (IC16, IC17, IC18) to generate the s i g n a l s r e q u i r e d f o r t h e l a t c h I C u s i n g t h e m a i n microcomputer’s address bus information. This configuration is also used for the latch IC of the DSP section.

■ Other peripheral circuits

The main microcomputer is connected with other peripheral circuits, such as a reset circuit that generates a reset signal, a reduced voltage detection circuit that detects reduced voltage and generates a reduced voltage signal, and an over-voltage detection circuit that detects over-voltage and generates an over-voltage signal.

Panel microcomputer

2 Chip TNC

(by TASCO)

Mobile head

PC (RS-232C)

22

Reset circuit

Over voltage detection circuit

Main microcomputer

Data bus (5V)

IC8

Address bus (5V)

EEPROM

ATMEL

AT25128N

IC7

DTMF decoder

LC73881

IC12

Conversion from 5V to 3V

IC10,IC11

Conversion between 5V and 3V

IC9

AGC Output port

Control (X53-391)

Address bus (3V)

Logic circuit for output latch

IC16~IC18

Logic circuit for input latch

IC13~IC15

Latch IC for output

TC74VHC573FT

IC21~IC25

Latch IC for input

TC74VHC573FT

IC19,IC20

RIF

SDET

CODEC IC

AK4524

IC518

TIF

DSP2 (IF DSP)

TMS320VC5402PGE

IC515

DSP2 address bus (3V)

DSP2 data bus (3V)

Output port Input port

Logic circuit for output latch

IC507

FLASH ROM

IC504

Latch IC for output

TC74VHC573FT

IC505,IC506

Data bus (3V)

DSP1 (AF DSP)

TMS320VC5402PGE

IC516

DSP1 address bus (3V)

CODEC IC

AK4518

IC522

CODEC IC

AK4518

IC523

MANO

SANO

MIC/DRU

VS-3

DSP1 data bus (3V)

Logic circuit for input latch

IC509~IC511,IC513

FLASH ROM

Latch IC for input

TC74VHC573FT

IC512,IC514

Input port

IC508

Fig. 19 Digital control block diagram

TS-2000/X

■ Firmware

The main microcomputer firmware includes adjustment firmware and user firmware. When repairs or adjustments are made in service, the user firmware must be rewritten to make adjustment firmware. It must be restored to the original user firmware after repairs or adjustments. The adjustment firmware provides a warning display and a warning sound when the power goes on.

DSP Circuit

■ Outline

The TS-2000/X DSP circuit is composed of two DSPs

(IC515 and IC516) and CODEC ICs (IC518, IC522 and

IC523), an input latch circuit, flash ROM (IC504 and IC508).

It is connected with the main microcomputer (IC8) by an address bus and a data bus through the voltage conversion

ICs (IC9, ID10 and IC11). The SSB, CW, AM and FSK detection, modulation and AGC operation are done by the DSP, and digital processing (digital filtering, noise reduction, etc.) is performed in all modes.

■ DSP

The DSP operates with an internal core voltage of 1.8V, an external I/O voltage of 3.3V and an internal frequency of

99.5328MHz (11.0592MHz x 9).

The two DSPs perform the respective IF processing and

AF processing. The IF processing is done by DSP2 (IC515) and a 24 bit CODEC IC (IC518) is connected to it. DSP2 performs detection, modulation, AGC processing and IF digital filtering. It is designed so it does not exceed the processing time, even if the main band transmission and reception and sub-band reception are done simultaneously. An output latch circuit is connected to DSP2 to convert the analog AGC voltage signal from digital to analog before output.

The conversion is done by the ladder resistance method.

The AF processing is done by DSP1 (IC516) and a 16 bit

CODEC IC (IC522, IC523) is connected to it. DSP1 performs the speech processing (signaling generation, detection, noise reduction, speech filtering, and various volume processing). The input latch circuit is connected to DSP1 and various signals from the main microcomputer and the microphone selection signal are input into it.

CIRCUIT DESCRIPTION

■ Flash ROM

The respective programs and data are stored in the Flash

ROM (IC508 and IC504) connected to DSP1 and DSP2.

■ CODEC IC

A 24 bit CODEC IC (IC518) is used as the IF signal system. DSP2 carries out 32 bit digital processing for detection and modulation. The operation of this IC is controlled by the main microcomputer.

Two 16 bit CODEC ICs (IC522 and IC523) are used as the

AF signal system. These IC outputs directly enter the AF amplifier, are amplified and then output from the speaker.

The IC input consists of the MIC input and the optional speech synthesis unit (VS-3).

The various timing signals required by both CODEC ICs are generated and supplied by a 12.288MHz quartz crystal and a peripheral circuit.

■ Communication between DSPs

DSP1 and DSP2 are connected via serial communication and perform such interchanges as audio signals for transmission processed in DSP1, received speech signals detected in DSP2 and information from the DSP1 input latch circuit. If this interchange does not go well when the power starts up, a “DSP COMM” error will be displayed on the

LCD and the fact that the DSPS is not operating will be notified to the main microcomputer. Likewise, when the content of the flash ROM is abnormal, a “DSP COMM” error is displayed.

23 Key features

Satellite communication
Independent FM/AM sub-receiver
Noise blanker
Digital IF filter
Digital AGC
Speaker separation function
IF/AF DSP
Triple conversion
Quadruple conversion

Frequently asked questions

The main band receiver is used for all modes of operation, including satellite communication, while the sub-band receiver is only used for FM and AM reception. The sub-band receiver is independent of the main band receiver, so you can receive signals in the sub-band while the main band receiver is transmitting.

The IF/AF DSP is a digital signal processor that is used for a variety of functions, including IF filtering, AGC, and audio processing. It is used in all modes of operation except for FM.

The speaker separation function allows you to output the audio to two separate speakers or headphones. This is useful for situations where you want to listen to the audio in a different location than where the transceiver is located.