Hi Jerry,
The use of the Ten Tec counterpoise tuner is pretty simple. You need a
counterpoise wire at least 10 feet long but longer lengths make it
easier to tune on the low HF bands. You have s short connection to the
rig or if a tuner is used with your antenna to the chassis of the tuner
if common with the coax connection to the rig.
You tune for maximum indicated current on the meter. The knob switches
in various fixed ceramic capacitors, and the variable inductor forms the
other tuning element to have a series tuned circuit. Thus, the metering
is showing the current flow to the counterpoise wire. This "output"
wire should be insulated and taped on the end which can be a high
voltage point. The character of a series tuned circuit is to have
maximum current at resonance, thus when you get a peak in the meter from
varying the adjustments of the caps and the variable toroid inductor,
you will have the optimum setting at the peak current. The unit removes
RF in the shack symptoms from the chassis of your rig and tuner. If an
RF voltage has appeared on your chassis, the 1251 functions to provide a
low impedance path to drain this RF voltage and dissipate it in the
tuned counterpoise wire.
The counterpoise replaces having an external earth ground wire on the
transceiver, so if you have a long run of wire to an earth rod, you
would replace that. The electrical ground of the outlet for your
transceiver power supply should give you the proper safety ground in
that case, if the outlets are modern wiring with 3 conductors.
If you cannot find a peak using the 1251 and any length of insulated
wire, you may have other problems due to your antenna / feed line, and
should address issues such as the feed line being an odd multiple of a
quarter wave length that can increase problems of RF voltage in a
shack. Make sure first your feed line and antenna have good
connections, and the antenna is not touching anything conductive. Make
sure the antenna insulators are in good condition.
This was a great kit from Ten Tec, and easy and fun to build and use.
It is pretty easy to trace out the circuit knowing that everything is in
series. The meter samples some RF from one side of the tuned circuit
and uses a diode detector to convert it to a current for the meter.
-Stuart Rohre
K5KVH
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