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Good day all,

I have a TR7 that has a few small quirks.? Before I go tearing into it,? just wonder if anyone else in this group has experienced this:

When switched to CW mode, no key attached, the rig emits a continuous side tone.? There is no RF out, just the continuous tone.? Any suggestions as to where to look first?

73
Gordon
VE9GC

I am not an expert on the TR-7 but other Drake transmitters have shorting switches in the key connector so that they are key down with no key attached. This is to allow tuning up without a key. Does it do the same thing with a key attached or even just a plug stuck in?

--
Richard Knoppow
1oldlens1@...
WB6KBL

Sorry, I forgot to state that in my original post.? Makes no difference if there is a key attached or not.? Just a steady tone as soon as placed in CW position and no RF out until the key is depressed.? Then full carrier and the tone mutes a little when keying.

Yeah, it shouldn't do that. Under some conditions a TR7 can pop into TX if the VOX is enabled and you rotate the band switch to CW. Ensure than VOX is off and set all of the VOX controls (both SSB and CW) full CCW. See if that helps. Report back and we can proceed from there.

73

-Jim
NU0C


On Sun, 08 Mar 2020 08:53:46 -0700
"Gordon Cotton" <VE9GC@...> wrote:

Sorry, I forgot to state that in my original post.? Makes no difference if there is a key attached or not.? Just a steady tone as soon as placed in CW position and no RF out until the key is depressed.? Then full carrier and the tone mutes a little when keying.

Good day Jim,

Thanks for the suggestion(s).??

So PTT / VOX switch in PTT position or VOX setting no change.

All controls full CCW? tone initiated immediately on selecting CW.? Meter reads about half scale even with carrier control fully CCW.

With CW VOX delay fully Clockwise, switching to CW from SSB or RTTY position, the tone doesn't start for about 3-4 seconds.

Thinking something in the VOX circuit, though no issues on SSB.

Gordon
VE9GC

Gordon,

Does the radio transmit and receive normally in SSB? Most of the T/R magic happens on the TX Exciter board. CW keying pulls the VOX circuit here, which in turn pulls the T/R relay and toggles the switching transistors on this board that supply the +10T and +10R voltages. The CW key also activates the CW oscillator on the 2nd IF/Audio board when the key is down.

The first suspect with strange 7-line problems is oxidized Molex connectors that interconnect the various boards. Often just re-seating the boards will clear the problem, but full cleaning may be required.

73

-Jim
NU0C


On Sun, 08 Mar 2020 11:42:56 -0700
"Gordon Cotton" <VE9GC@...> wrote:

Good day Jim,

Thanks for the suggestion(s).

So PTT / VOX switch in PTT position or VOX setting no change.

All controls full CCW? tone initiated immediately on selecting CW.? Meter reads about half scale even with carrier control fully CCW.

With CW VOX delay fully Clockwise, switching to CW from SSB or RTTY position, the tone doesn't start for about 3-4 seconds.

Thinking something in the VOX circuit, though no issues on SSB.

Gordon
VE9GC