Hi Garey,
I was able to replicate the raspy warble that I've come to know in my PTO
signal only TOO well here, by slightly turning the mode switch away from what I
consider to be its "normal" detente. By turning it ever so slightly
counter-clockwise, that induced shift would "hold"---by turning the switch
clockwise, it would hold only for the duration of the VOX hold setting...
Interesting, huh...?
Maybe that's what's plaguing poor Steve there with his PTO, i.e. the PTO itself
may well be good, but its environment isn't...
Just a thought...
In any event, I've just loaded the Drake Twins into the car, & will fire 'em up
at the cottage shortly. I'm gonna monitor my signal directly from the R-4, too,
rather than use the keying monitor.
Stay tuned...! (pun intended, Hi).
~73~! de Eddy VE3CUI - VE3XZ
*************************************************************************************************************************
On 2011-08-26, at 1:08 PM, Garey Barrell wrote:
> Eddy -
>
> The Carrier Oscillator is shifted in frequency by about 900 Hz in the CW
> position. This is accomplished by putting a capacitor (C177) in series with
> the ground end of the CO crystal. The MODE switch shorts this capacitor to
> ground in SSB and TUNE position. So certainly a poor switch contact could
> easily shift the frequency anywhere from 0 to 900 Hz or so depending upon
> just how well it shorts that cap.
>
> 73, Garey - K4OAH
> Glen Allen, VA
>
> Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
> and TR-4/C Service Supplement CDs
> <www.k4oah.com>
>
>
> Eddy Swynar wrote:
>> Hi Again All,
>>
>> Well, to-day I could have SWORN that some demon had taken possession of the
>> PTO in my T-4X transmitter,& that it was sent to this earth with the
>> express purpose of taunting me...!
>>
>> I mentioned before that last week I re-soldered a visibly bad connection of
>> the 33-pfd. temperature compensating capacitor to the board of my PTO, and
>> that---so far!---it appeared to be the proverbial "silver bullet" in fixing
>> the "warbling". Well, this morning---at the very moment that I was seriously
>> considering taking the "4-Line" on a road trip to the cottage to test the
>> PTO "in the field"---the frequency suddenly jumped a coupla KHz, and was
>> raspy-sounding...!
>>
>> Oh no, here we go again! ("Why do the gods taunt me so...?!").
>>
>> Turns out---I think!---that I was monitoring the T-4X with the function
>> switch in the "Tune" position. By wiggling that switch ever-so-slightly, I
>> could make the frequency jump a prescribed amount of KHz----exactly the
>> amount that I get when switching the mode switch to Phone.
>>
>> I wonder if a dirty mode switch may have contributed to my initial confusion
>> in this whole matter...?
>>
>> The testing continues...
>>
>> ~73~ de Eddy VE3CUI - VE3XZ
>>
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