[Elecraft] NG0R - K2+K60XV+XV144/222/432 - Setup Issue #2

[John Hoaglun]

Hi Don and the list,

After replacing R6 on the KAT2 board I went back thru the transverters
to see where I am at after the change.

XV144 - ~1mW of drive = 12w power (into a Bird 43 slug + dummy load)
Target is 25w
XV222 - ~.42mW of drive (virtually no power out) Target is 10w
XV432 - ~.50mW of drive (virtually no power out) Target is 10w

I decided to go back to the XV432 since that is what we have been
talking about recently.  After peaking the filters again and I am seeing
about 1.9V at TP6. What kind of number should I see?

I will pick this up again in the morning when I my mind is fresh.

73

-- 
John Hoaglun
NG0R - EN25
http://www.hoaglun.com



On Sat, 2010-08-21 at 16:42 -0500, John Hoaglun wrote:

> Hi Don & the list,
> 
> I am making some slow progress on the 432 transverter setup.
> 
> Initially TP6 was almost nill so I hooked up the Oscope and worked my
> way from the IF-In to the Mixer. The 28MHz band pass looked suspect,
> specifically C52/C54 as the drop at each capacitor was pretty sharp
> even for a BP filter. I replaced them with fresh 150pF caps that I had
> on hand. That improved the situation but my levels were still low
> measured at TP5, TP6, and the output with an RF meter, and analyzer.
> 
> I tried tuning up the filters with using the analyzer & rf meter. That
> once again slightly improved things but not enough to quantify.
> 
> I reset the PA bias back to the 20mV and then went to TP6 again. I was
> able to very slowly move from almost 0 to 2V by working my way thru
> the filters and then going back thru it again several times
> 
> TP3/TP4 20mV 
> PA voltage 2.35V & 13.7V
> TP5 0V
> T6 2.05V
> U6 Output pin 4.97V
> 
> My 60MHz Oscope is not fast enough to make a good measurements at U6
> IN/OUT and U7 IN/OUT but it does not appear that I am seeing enough
> gain at U6. I suspect that U6 is not driving U7 hard enough for U7 do
> any work. 
> 
> Any suggestions how to test this?
> 
> What else should I be looking at & testing?
> 
> Thanks, JH
> 
> -- 
> John Hoaglun
> NG0R - EN25
> http://www.hoaglun.com
> 
>