[Elecraft] RE: K3: TX audio setup

[Joe Subich, W4TV]

> Now I can PTT and it remains silent... until I say 'test', 
> then the jet takes off again. As if someone taps a large 
> sheet of metal. 

Open the Foster plug and clip the wire attached to Pin 8 (center). 

Elecraft connect pin 7 (mic ground) and pin 8 (PTT ground) in 
parallel and use a single RF choke to ground.  This causes a 
"pin 1" common mode RFI problem because PTT and microphone 
circuits are "mixed."  

If the PTT ground wire is cut in the microHAM cable, PTT ground 
will use the shield of the cable which is connected directly to 
the chassis (shell of the Foster).  Separating the PTT and mic 
grounds will work around (bypass) the common choke.  
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Franki ON5ZO
> Sent: Saturday, October 18, 2008 12:40 PM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] RE: K3: TX audio setup
> 
> 
> OK Barry N1EU, I just set these parameters to your values:
> 
> mic: 30
> cmp: 20
> TX EQ .20 +5
> TX EQ .40 +2
> TXG-VCE = 2.0dB
> 
> Now if I push the PTT I get the sound of a 747 taking off and 
> full scale 
> deflection on the power meter... without even talking!
> 
> Per ON4WIX's advice I then tried:
> 
> CONFIG:TXG VCE: +2.5 dB
> Mic gain: 15
> Comp: 16
> TX EQ: as flat as a pancake
> 
> Now I can PTT and it remains silent... until I say 'test', 
> then the jet 
> takes off again. As if someone taps a large sheet of metal. 
> My last on air 
> report talked about 'metallic audio', which is about how it 
> sounded with my 
> original parameters too.
> 
> So not quite there yet...
> 
> - ON5ZO 
> 
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft    
> 
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com