Re: [Drakelist] R4C Hum and audio transistor

[Bert Almemo]

Hi Max,
 
I replaced the original audio amp in the R4C with a Velleman audio kit board
with an TDA2003. The Velleman kit # K4001. I believe I paid around $ 15.00.
Works great. 
 
If you're interested I can send you pics.
 
73 Bert, VE3NR
 
 

  _  

From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net]
On Behalf Of Max Cotton
Sent: Wednesday, October 31, 2012 3:12 PM
To: drakelist@zerobeat.net
Subject: Re: [Drakelist] R4C Hum and audio transistor


I must admit this receiver will probably benefit from the Sherwood audio
board, however comparing both my R4C's one is perfect with no hum and very
good audio whilst this one is shushy and has bad hum, maybe the main caps
need replacing but when I couple another cap accross them no change so I am
a little reluctant to ditch them quite yet. swapping the tubes between each
made no difference either. It does do an odd thing though, gradually as it
warms up the audio and signal gets worse until it is distorted and with a
lot of white noise. When switched on, the hum is really bad immediately and
does not go away. both receivers are 26000 serials within about 700 from
each other.
Ideas? 
73 Max
M0GHQ
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Re: [Drakelist] Vox not holding on TR4CwRIT running CW.

[Bert Almemo]

Hi Michael,
 
Have you adjusted the VOX delay time and VOX Sensitivity? As far as SSB goes
maybe you have to turn up the MIC gain? Just a couple of thoughts. Good
luck!
 
73 Bert, VE3NR
 
 
  _  

From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net]
On Behalf Of Michael A. Kelly
Sent: Saturday, October 20, 2012 12:27 PM
To: drakelist@zerobeat.net
Subject: [Drakelist] Vox not holding on TR4CwRIT running CW.


Hello everyone - 


I have a TR4CwRIT that will not hold once it switches from receive to
transmit, running CW. It sounds like I am running QSK full break when
sending ... after turning up the sidetone to make sure it was loud enough



I have substituted (one at a time) the:


1.  V-2 The sidetone oscillator 12AV6


2,  Then the 9Mhz Xtal Oscillator V-16 (6GX6) 


3. Then the VoxAmp/Relay V-19 (6FQ7) also tried using the earlier used 6EV7


4. Finally the V-17 Anti-Vox 6AQ5A


Each time nothing changed, I put the original back, trying to eliminate
extra variables  and while some guys may want to try and get a TR4CwRIT
to run QSK ... with the relay cycling so rapidly (between dits) I don't care
for it at all, not to mention the workout for the relay.


Anyone have a suggestion?  

PS One other clue is when I try to operate using the microphone, I am
getting a normal vox relay change over that does not fall out and cycle back
to receive, but I get no drive when whistling in the microphone ... so it
keys up to transmit mode seemingly perfectly normal, but regardless of my
drive setting I get no deflection on the meter to indicate output.  BUT I do
get normal output when using a key in CW mode ... just does it in QSK
fashion.


Thanks everyone ... I am stumped.


Michael NZ4D
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