[Collins] re zener diode mod to kwm-2 pto

[Al Schapira]

Posted for the 2nd time:

Its known as the "Vietnam Fix". It is documented here:
 http://www.collinsradio.org/Signal/newsletters/SIGNAL_24_4Qtr01.pdf
with a followup note in here
 http://www.collinsradio.org/Signal/newsletters/SIGNAL_25_1Qtr02.pdf
and also described here 
 http://www.angelfire.com/de/vk3kcm/drift.html

        --Al, W2ADS

On Fri, 2011-01-28 at 10:02 -0700, Fern wrote:
> 
>     Since I haven't been able to find any information re the zener diode mod 
> to correct a shift in frequency between transmit and receive on a collins 
> kwm-2, last night I contacted Dennis Brothers about that and here's what he 
> told me.
>    The fix for that will appear in a late manual of January 1978 Rev 1. 
> Apparently, there never were any service bulletins to show that fix so it's 
> a case of having this late manual. Along with that Collins had a fix for the 
> xtal oscillator circuit V13 which should also be shown in the same manual.
>   Since I don't have that late a manual, I would appreciate if anyone could 
> scan those two portions of the schematic especially the one to do with the 
> zener in the pto circuit so that I can properly repair this kwm-2 that I 
> working on now. Or I would be interested in purchasing a complete manual 
> issued Jan 1978 Rev 1 please. The shift between transmit and recieve is 
> enough that I'm told that I'm off frequency which is quite anoying.
>    73 from Fern   VE7GZ
> 
> ______________________________________________________________
> Collins mailing list
> Home: http://mailman.qth.net/mailman/listinfo/collins
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Collins at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html