Think I tried subbng V8 before but will try again.
I'm afraid I'm going to have to look at everything in that signal path. The
fact that I'm getting, after warm up, the same symptoms with two different
PTO's strongly suggests to me that there's an intermittent component, as you
suggest. Man, I wish I still had all my old parts cabinets!
BTW, Garey, the B-Line CD is going to be vital to me: I took the bottom off
the R-4B and it's a mess in there. Lots and lots of mods including use of
the INJ jack for somthing to do with audio. More on that in a separate
email.
Steve Wedge, W1ES/4
"I can't complain, but sometimes I still do."
- Joe Walsh
If the above message appears, it came from Steve's Son of Laptop!
----- Original Message -----
From: "Garey Barrell" <[email protected]>
To: "Steve Wedge" <[email protected]>
Cc: <[email protected]>
Sent: Sunday, August 21, 2011 6:42 PM
Subject: Re: [Drakelist] You just know I'm not going to have any hair
left...
I've been 'PTO-ing'.... There are no fewer than 17 variations in 4
series PTOs.!! And that does NOT take into account semiconductor changes.
MANY are merely changes in the decoupling of the DC power input, but there
are a lot of other changes as well. Looks like we were a little too
optimistic thinking that you could just 'mix and match' PTOs from
different radios..........
I think your R-4A is an early one, and the first change is from the
Common-Base buffer stage to the Common-Emitter buffer in the 'late' R-4A'.
There are a couple of differences in the T-4XB units, but shouldn't be
significant.
I assume you have tried subbing V8??????? Swap with V2? The PTO drives
a 470 ohm resistor in the cathode of that stage, noisy tube? Noisy
resistor?
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>
Steve Wedge wrote:
That's the thing: it's a different PTO that was working properly before I
transplanted it.
Looks like I've got to try replacing the components on the filter board.
Something is pulling the frequency...
Steve Wedge, W1ES/4
"I can't complain, but sometimes I still do."
- Joe Walsh
If the above message appears, it came from Steve's Son of Laptop!
----- Original Message -----
*From:* Eddy Swynar <mailto:[email protected]>
*To:* Steve Wedge <mailto:[email protected]>
*Cc:* [email protected] <mailto:[email protected]>
*Sent:* Sunday, August 21, 2011 5:16 PM
*Subject:* Re: [Drakelist] You just know I'm not going to have any
hair left...
*/Hi Steve,/*
Well, I'm almost hesitant to say this, but ever since I re-soldered
that connection of the
33-pfd. temperature compensating tubular capacitor in the PTO of my
/T-4X/transmitter, I have
not---*/FINGERS/**/CROSSED!/*---experienced anymore warbling of my
signal...
...In fact, I just checked it again a couple of hours ago. Still
sounds A-OK.
Now, that is /NOT/to say that the situation is 100% cured---I know
better than to publicly
proclaim anything like that, having been "burned" so many times in
the past! Hi Hi.
Best get that ailing PTO into a mailing container & ship it */POSTE
HASTE/*to Garey
first-thing Monday morning, for his evaluation of the doggone thing
(and to think that I once
thought that only my old /Heathkit SB-102 /was the proverbial
".../rig from hell"!)/. *: >)*
*/~73~ de Eddy VE3CUI - VE3XZ/*
*/
/*
********************************************************************************************************************
On 2011-08-21, at 4:57 PM, Steve Wedge wrote:
Turned the R-4A on, with the replacement PTO from the T-4XB, and I
am back to square one. :-(
The frequency is jumping all over, occasionally chirps, then
un-chirps.
Any suggestions aside from selling it cheap?
Steve Wedge, W1ES/4
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