PC based Digital/Analog Repeater Controllers

PC based Digital/Analog
Repeater Controllers
Don Russell W9DRR
Linux Asterisk PBX – app_rpt
•  The AllStar Link network consists of a
number of individuals and groups who wish
to provide efficient large-area
communications to the Amateur Radio public
in their respective local areas. This is done
by providing a repeater system controlled by
a Linux based computer system running the
open-source Asterisk PBX telephone switch
platform along with the app_rpt module.
connected to a high speed Internet
A PBX can be a repeater!
•  The computer system running Linux/Asterisk PBX
coupled with the app_rpt module makes a powerful
repeater, link, or remote base controller capable of
controlling many (like up to hundreds, theoretically)
repeaters and/or remote bases per computer system.
•  provides linking of these repeater and remote base
"nodes", with "nodes" on other systems of similar
construction anywhere in the world, over the
•  It also, of course, provides for an Autopatch (public
switched telephone network access over the radio)
on each node (Asterisk is a phone switch after all!
Multi Connectivity
•  The core function of a PBX is to
•  App_rpt can talk to Echolink, D-star, IRLP,
PSTN, and more are possible.
•  More than just RF in/out of box.
•  Via PSTN, RF, Internet, Iphone/Android,
PC client (IAXrpt)
•  Reverse and Forward Autopatch and
IAXrpt Client
•  Runs on Mac, Windows,
•  Can control/monitor
•  Full duplex w/ control
•  Dispatch for police/fire/
•  Did I say it’s FREE!
Hardware Requirements
•  Linux PC, old hardware is fine
•  P4 2.4 + 512M ram couple nodes easy.
•  Can run on low end hardware without
doing DSP like the beagleboard below.
Radio Interface
•  Basically same as PSK31 but full duplex.
•  Started out as a modified CM108 USB
soundcard. Took volume/mute button and
led control for PTT and PL/COR detect lines.
•  Pots for line/mic level conversion
•  Caps for dc block
•  Really simple, DMK engineering pre-made
(Extra GPIO, and Op amp, DB25 connector)
Linking example
•  All audio is ULAW 64kbps fuller bandwidth than GSM 13.2
can do others which are in-between and sound fantastic.
Can’t tell local vs Japan with ULAW. G726.a is really close.
•  *32000 links to node 2000 main hub
*12000 unlinks
•  *33393633 links to echolink (3) *NIRA*
•  *13339633 unlinks
I know seems a little complex.. Macros!
•  *55 calls macro 5 which is *3393633*32000*32182*3393830…
unlimited macros
•  *91 kills all links
•  DSP does DTMF, PL/DPL, de-emphasis, pre-emphasis, RSSI,
squelch, kerchunk, telemetry.
•  GPIO for PTT, COR/PL, external IO like fans
•  Change PL on the fly or go COR for net
•  DTMF commands or via internet, phone, ipod, even website.
•  Change courtesy tones for events like WX/ares.
•  Change repeater profiles or messages like announce hamfest
only for weekend.
•  Can gather weather and playback on request.
•  Full text to speech by cepstral voices (~$30 per voice)
•  Download and playback Arnews line, arrl news, rain report…
•  2-tone paging, MDC1200 Paging. DTMF paging.
Autopatch Example
•  Call 1800-repeater
hear prompt to enter 1 for admin 2 for non-admin.
•  1 prompts for password (many levels admin)
2 prompts for name.
•  If 1, then you have live audio coming in
*98 ptt on repeater (full duplex) # to clear ptt
all dtmf like via RF and more
•  If 2, plays back message that “insert audio” is calling and
press *740 to connect caller to repeater. If no answer can go
to voicemail, which can be emailed to a user, or just play a
message and hang up
•  Can make outgoing calls from repeater.
•  *618005551212 talk *0 to clear (timeout options or bypass)
Remote Base or Link
*80 146520# sets base freq to 146.52Mhz
*80 14320A# sets base to 14.320 USB
Vox operation. Can control via half duplex
*811 go to memory 1
Fully user definable can control +- 1hz 10hz 10khz…
etc *98 ptt control…etc for rxonly
•  Link in/out of remote, access remote via PBX or
other app_rpt system anywhere , even via IAXrpt.
•  Imagine sitting in airport with laptop and getting on
HF voice from home. Can do, easy and free
software. Remember quality. Really good quality
D-star Digital Radios/Repeater
D-Star FAQ
What does "D-STAR" stand for?
The D-STAR stands for Digital Smart Technologies for Amateur Radio. It is an open
standard digital communication protocol established by JARL. Not proprietary, just 1
manufacturer for some hardware.
What can I do with the D-STAR radio?
4.8kbps digital voice (DV) mode V/UHF and 128kbps data * (DD) 1.2 Ghz
Can I send data with a voice transmission?
Yes, you can. In DV mode operation only, you can simultaneously send up to 950bps of
data, such as call sign, short data message or GPS position with a voice transmission.
Can I make a call with foreign countries?
Yes, you can. The Internet gateway allows you to relay your call to a remote D-STAR
repeater over the Internet. The D-STAR repeater call sign and IP address must be
registered to the gateway server. Some restrictions may apply based on specific country
Can I use the D-STAR repeater without connecting to the Internet?
Yes, you can use a D-STAR repeaters a local repeater. You can also communicate with
other D-STAR radios directly.
Can I receive a call only when the call is intended for me?
Yes, you can. the call sign squelch function opens the squelch only when you call sign is
•  D-RATS is a multi-platform integrated tool for
communication using D-STAR. With only a pair of
radios (or an entire repeater stack) a variety of
data transmission methods are supported,
•  Instant-message chat
•  Automatic beacon messages
•  File transfers with error detection
•  Structured forms NTS/ ICS-213
•  GPS position reports
•  And much more!
Non Icom D-star Repeater
Software open source by Jonathan G4KLX and Scott KI4LKF.
The technique of using a soundcard to emulate a GMSK hardware modem
to strip out the call signs and routing info. Separate out AMBE codec data.
Fully regenerate the GMSK data for retransmission via RF or over the
It uses the raw discriminator audio, and goes direct to the fm varactor
(9600 baud port). Old Motorola or GE.
Most any 9600 baud packet radio and software.
Yes you can do a d-star radio if you have a codec chip. Dvdongle, Icom
208H, pc software, and a cable, and your on RF with D-star.
Serial port optoisolated for PTT control.
Embedded Intel Atom Motherboard no fans, solid state HD runs on 12V.
Need internet for routing, can work standalone without
Did I say software is free? Stable, and development is continuing.
Oh, It is dual mode capable. Analog and Digital off same RF deck.
Homebrew D-star Repeater
•  RF access point via USB
•  DV Access Point Dongle
Internet Labs (AA4RC)
•  The new DV Access Point Dongle allows
licensed Amateur Radio operators to access
the D-Star international network using a Dstar HT and Internet connection.
•  USB Connected to PC (Mac, Windows)
•  The DVAP can be pre-ordered from HRO.
The DV Dongle connects to your PC or Apple Mac via a USB port and
provides encoding and decoding of compressed audio using the DVSI
AMBE2000 full duplex vocoder DSP chip. AMBE technology is used in
all D-Star radios to provide efficient voice transmissions. It is also
used in some HF digital protocols by vendors like AOR. The DVTool
application used with the DV Dongle may be installed and run on
Microsoft Windows XP/Vista, Mac OS X Leopard, or many flavors of
Gateway and linking
•  Icom proprietary network for linking. Works but
was slow. Costly and old software. Re-engineered
to use custom IRC (internet relay chat) to allow
interconnection from K5TIT trust server also to
Japan, and Europe trust servers.
•  Dextra replaces Dplus and has it’s own gateway
and doesn’t need trust at all, ie what is being
called freestar. For experimenters, multi
interconnect IE analog and digital, echolink,
allstar. Phone. Interconnect to commercial, etc…
In conclusion
•  Asterisk app_rpt makes a full function controller for
analog, remote base, and link systems. Stable enough
for commercial use.
•  D-star is growing, now has stable homebrew
•  Wow, is it like it was back in the 70’s again. Hacking
up motorola radios for ham use again!
•  Questions??
Links for Software/Hardware
Link for ordering the cheap usb soundcard:
App_rpt premade interface by DMK Engineering:
Links for allstar network and app_rpt info:
Link for dvap and dvdongle info:
D-Star hardware from randl.com:
DVDONGLE ($199.95)
DVAP ($239.95)
IC80AD ($429.95) Cheapest D-star HT
Download PDF