I meant to mention, WRT your worrying aout reading near ground at the filter
terminals....impedance matching is critical to good filter performance, and
they often have matching transformers at the input and/or output for that
One end of that transformer will be tied to ground, and they will read very
low DC resistance to ground as a consequence.
Phil C. Sr.
----- Original Message -----
From: "Phil Chambley, Sr." <email@example.com>
To: "Discussion of Ten-Tec Equipment" <firstname.lastname@example.org>
Sent: Saturday, February 18, 2012 3:20 PM
Subject: Re: [TenTec] Some progress made! --Omni D low to
>I haven't been in on this entire thread, but it seems to me he has a
> sideband/mode switching issue. Here's why:
> His rcv is OK....Question: Listening on LSB? What about other modes?
> Question #2: No output. In what mode? Tune? CW? Different oscillator
> frequency than the receive test?
> I think he may have a problem with one of the crystals in the sideband
> generator board, or possibly a trimmer or switching diode on that same
> board, or on the Control board or Mode switch associated with
> Needs to run tests on other modes to check that out.
> Phil C. Sr.
> Phil C. Sr.
> ----- Original Message -----
> From: "Mike Bryce" <email@example.com>
> To: "Discussion of Ten-Tec Equipment" <firstname.lastname@example.org>
> Sent: Saturday, February 18, 2012 2:24 PM
> Subject: Re: [TenTec] Some progress made! --Omni D low to no
>> You see why that was such a head scratcher for me. Rick may have seen a
>> filter go bad, but since TT uses the filter for rec and TX, and the rec
>> worked just fine. There's something else (no kidding!) wrong.
>> If the filter was open, then you'd need to be in the shadow of the W1AW
>> tower to be able to hear much, if anything.
>> When you subed in the 1.8 filter, that now points to something else
>> a bad filter.
>> Does the output on the TX mixer show short when you pull the board from
>> the rig? It shouldn't
>> however plug in the board and the output of the TX mixer goes to the
>> bandpass filter. Here, the output of the TX mixer goes the bandpass
>> On bands 7 mhz and up, the input of the bandpass board will show dc
>> continuity. ( the output of the TX mixer goes into the input of the
>> bandpass board)
>> start looking for shorted cables, loose cable, the simple over looked
>> things. Use that scope and unplug the TX mixer and see if the signal out
>> of the filter pops up, or stays the same.
>> Keep the group informed
>> mike, wb8vge
>> On Feb 18, 2012, at 2:02 PM, Scott Sheppard wrote:
>>> So the next stage of the problem would seem to be finding out why teh
>>> crystal is baving linke it is...here is the situation:
>>> 1. Normal filter left in place
>>> -great receive, no problem...
>>> -virtually no output at all (as has been beat to death already)
>>> 2. Filter removed and jumpered with a .01 capacitor
>>> -wide open receive as expected, lots of signals
>>> -full power TX at all the stages...100 watts out
>>> 3. 1.8 khz filter fitted
>>> -receive ok albeit narrower
>>> -virtually no TX power at all (as per situation #1)
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