[Johnson] Ranger 1 Turbo Modulator Instability-Solved?

[Kenneth Goodwin]

First I would like to thank all of those that gave me some great insight
into the Ranger 1.  I believe it turned out to be a start up transient in
the D-104's T-UG8 amplifier that the Ranger audio input circuitry doesn't
like, causing a modulator plate current spike when the push-to-talk is
depressed.  The push-to-talk circuit in the D-104 has two functions, it
grounds the PTT line of the Ranger and it applies power to the T-UG8 mic
amp.  When I applied 9VDC continuously to the mic amp, the PTT transient in
the Ranger's modulators was no longer present when the D-104's PTT was
depressed.  I had earlier interfaced this D-104/T-UG8 to an FT-1000D and
didn't observe any modulator transients (ALC) so I surmise that it is odd
combination of the D-104's T-UG8 audio amp and the modifications to the
Ranger's PTT that are the root cause.  I had replaced the D-104 crystal mic
element with an FET electret mic element (W2ENY) which requires a DC voltage
which is easy to pull from the T-UG8. The audio definitely improved with the
modern mic element.  An on/off switch for the T-UG8 would solve the start-up
transient problem since the battery draw is minimal while in use. I will
interface my Yaesu MD-1 mic in the Hi-Z mode to see if this mic will
interface with the Ranger without any problems.   Ken K5RG