[Johnson] Ranger adventures live on

[Bill Cromwell]

Hi,

I haven't posted about my Ranger for a while. I have been using it on
160 and 80 meters. The VFO hasn't sounded good enough to use on 40 and
higher frequencies. I started work on it again today. I examined the
drift problem more closely. I used my digital, general coverage Ten Tec
receiver to evaluate drift. The Ten Tec tunes in 50 Hz steps but
displays in 100 Hz increments. Normal hearing response makes 50 Hz
differences at zero beat pretty much indistinguishable. So I have that
and the fact that the Ten Tec is tuning in those digital steps while the
Ranger tunes (and drifts) continuously variable. I decided that my
readings could be no better than +/- 75 Hz and recorded all of my
readings at the 100 Hz steps. That could be 25 Hz of 175 Hz. Even
listening above zero beat and below zero beat then splitting the
difference leaves some ambiguity. Especially if the the VFO is drifting
as much as this one on 40 meters.

First a warmup. Even though it's digital the Ten Tec had been on 48
hours. I let the Ranger warmup a half hour. I pulled the buffer and
doubler tubes as I have some suspicions about those on 40 meters. So it
was just the VFO with no load. Forty meters started drifting upward
immediately. After a half hour it was 2200 Hz high and still drifting
upward. The rate did slow down after about ten minutes key down. It was
1200 Hz high at that point. And 300 Hz at 2.5 minutes. Without plotting
the drift, the drift was about the same as the night before. Clearly
that is completely unacceptable for on air use. It would be outside most
ham receiver passbands at 2.5 minutes AND on top of the next QSO. I
turned the VFO off and let it cool back down. It did not come all the
way back to the start point after ten minutes.

Next I checked to see that the 160 meter VFO (160 and 80) worked as well
as I thought. I set it up on 80 meters and locked it on. At 12 minutes
it was 100 Hz high (+/- 75 Hz) and stayed there for more than a half
hour. I believe the error was on the small side and was less than 100 Hz
of drift with the key locked down. I almost did not notice that it had
drifted at all. Also keying on 80 and 160 sounds very good. It's lousy
on 40.

I have looked at the circuits and I see there are only a very few parts
in the VFO that are in use on only 40 meters. I will order a complete
set of those parts and take the Ranger apart far enough to work on and
and test the VFO. I will not do that until *AFTER* I have a transmitter
online to fill the gap it will leave (maybe the DX-100). Meanwhile, I
have removed the VFO switch dog so I can use the 160 VFO on 40 meters
(all bands really) and that seems to be working but with somewhat lower
power - as expected. VFO calibration is changed for 40 meters as well -
also expected. The 40 meter signal sounds very good and the drift is not
noticeable in operation. That gives me 160 through 40 on the Ranger and
it may also work on 20 but I don't go there very much. Does anybody have
hard information regarding a reason to NOT do that. I am not using the
Johnson VFO to determine my operating frequency as I have much better
means in the receivers. Some of the radios I have or have used already
operate the 40 meter band from a 160 or 80 meter oscillator. None of
them operate 20 meters (or higher) from anything less than a 40 meter
oscillator but I suppose that would work with even less power out. To be
clear about the question..the bandswitch and everything from the buffer
on is operating with it's bandswitch on 40 meters - NOT on 80 or 160.

73,

Bill  KU8H