3
Using the Optional Z-Match Tuner
The addition of an antenna tuning device adds a
high degree of utility to the TR-45L transceiver
when used in the field, especially with simple
wire antenna systems. Because this tuner does
add additional cost to the TR-45L, it is offered as
an option at the time the order is placed. The
tuner controls are located on the upper rear
panel of the radio and consist of two toggle switches and two variable capacitors. The first
switch selects either a conventional standard 50-ohm BNC output or places the tuner in-line
between the transmitter and antenna connector while the second switch selects balanced or
unbalanced outputs.
The simplest portable operation solution would involve a length of wire supported at one end
with a high support (tree) and the other end connected to one of the TR-45L binding post
connectors, with a similar length counterpoise wire stretched out on the ground and connected
to the other binding post. Similar setups were tried with different wire lengths and gave good
results. The tune-up procedure is as follows:
With the antenna wire and counterpoise connected, flip the tuner toggle switch to the IN
position. Adjust both the tune and load capacitors for maximum band noise on receive. Turn
down the RF power pot so that the meter indicates power at about half-scale on the meter with
the RF Power toggle switch set to read forward power with the key down. The High VSWR
indicator might be on but will go out as the reflected power is reduced. Next, switch the RF
Power toggle switch to show reflected power on the meter.
Now reach over the top of the radio to the tuning controls and adjust both the tune and load
capacitors for minimum reflected power as shown on the meter. Note that there is
considerable interaction between the two capacitors. Slowly adjust the caps with short bursts
of key-down times of about 5 to maybe 10 seconds or so each with a short rest time between
tuning attempts. Admittedly, there is an art to doing this quickly. Sometimes it takes a while to
find a deep null in the reflected power which indicates a good match.
How to use the Keyer Record and Playback Functions
The record and playback functions are initiated with the “
Play/Record
” switch. There are two
message memories provided. Each can store 25 words using the “PARIS” standard, or 125 ASCII
characters if stored with no word spacing. This should be plenty for POTA or SOTA activations.
Before starting the recording, set the keyer speed control to a comfortable setting; a little slower
than normal might be better. Don’t adjust the speed control while in record mode. To record a
