Silver Bullet Portable 80-10 Meters Vertical Base SS Coil
For when you need an emergency antenna, a stealth antenna or a portable antenna for
camping or Field Day
Measurements were taken with a Mini VNA Pro. Antenna was ground mounted with no
radials. Lower SWR can be achieved using ground radials system. 17, 15, 12 meter band can
also be tuned when using one aluminum section. 10 meters use the short tube only.
Blue trace = SWR, Red trace (where plotted) = input impedance
20 Meter Trace
40 Meter Trace
30 Meter Trace
80 Meter Trace
Just add your own ground mount (a 4 foot ground rod works well), coax and you have yourself
a portable antenna you can erect in minutes. Perfect for those in antenna restricted
The Silver Bullet Vertical antenna can be mounted either using a pair of 2” U clamps, the
supplied zinc coated thumb screws or simply drilling out the mounting holes and mount
directly to your 1 inch diameter or smaller mount.
Using common U Bolts the coil can be
mounted on a standard TV antenna mast pipe.
Attached the braid (ground) side of the coax to
the U bolt and the center conductor to the coil
Using the supplied zinc coated thumb screws
the coil can be mounted on a 1 inch diameter
or smaller pipe or ground rod. Tightening up
on the thumb screws will make contact with
your mount and using the supplied ¼ 20 nut
on one of the thumb screws to mount the
braided (ground) end of the coax. Perfect for
the apartment balcony installation.
To connect coax cable to the base vertical you
need to make a pig tail connection for both the
center conductor as well as the ground braided
conductor. The center conductor connects to
the tuning coupler via the #8 screw mounted
thru the base of the coil. Loosen the wing nut
and attached the center conductor between
the fender washers then tighten the wing nut
(hand tight). The ground, braided side can go
either on the one of the supplied thumb
screws mount, or directly to your ground radial
system. It’s a good idea to waterproof your
connections the best you can.
The following are the recommended steps for tuning our antenna coil to specific
bands. On the 80, 60, 40 and 30 meter bands very little right/left rotation of the
collar is necessary. Tuning the 20, 17, 15 or 12 meter bands some collar rotating is
needed to fine tune the frequency. One click can be heard when the collar is
moved up or down one turn of wire.
All but small aluminum sections used:
60 clicks from the top 3.700
55 clicks from the top 3.980
29 clicks from the top 5.400
20 clicks from the top 7.250
10 clicks from the top 10.100
02 clicks from the top 14.250
With 1 aluminum section used:
very top of the coil
04 clicks from the top 18.100
With Small section
4 clicks from top (this will vary) 28.450
This was with my setup that uses ¾ inch pipe 3 feet in the ground with 2 feet above
ground with antenna on top. This setup uses three 35 to 40 foot ground radial on
top of the ground. All of the above SWR readings were below 1.5 SWR.
You’re tuning may vary from the above due to installation and ground. Radials,
other antennas type of soil ect, but this is a good starting point.
Add the small aluminum section if you want to tune CW part of the 80 meter band.
Power Ratings: 300 Watts SSB, 150 Watts CW and 80 Watts Digital.
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