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 On Sat, 2010-08-21 at 09:07 -0400, Don Wilhelm wrote: > John, > > On the XV432, can you vary the DC voltage measured at TP6 when you > adjust the Input Attenuator? TP6 is a built-in RF probe which measures > the RF voltage at the output of U6. If you can see that voltage change > when adjusting the input attenuator, you can use it for peaking the > bandpass filters. > On the XV222, there is no TP6, but you can use an external RF Probe to > do the same thing. > If there is no output from U6, try the input. The first step to your > troubleshooting is to determine what works, and secondly to discover > where in the chain of events the failure occurs. > > 73, > Don W3FPR > > John Hoaglun wrote: > > Hi Don & group > > > > I tried using a low pass filter between the K60XV and the 432 > > transverter and went thru the tune-up from scratch with similar results. > > I removed the LP filter. > > > > I measured the K60XV out at -3dBM or about 50mW which what I say last > > night as well. I put it on my counter & analyzer and notice that it > > there is something at 18MHz that is about +8-10 dB louder than the 28MHz > > IF. --Interesting note. > > > > I then tried your second suggestion: I reconfigured the transverter for > > a high power IF input, JP3/JP4 2-3, and JP5/JP6 1-2, and the associated > > menu settings. Using port A on the radio I tried rerunning the > > transverter setup and got similar results. > > > > Common theme: TP5 has almost no reading on it while adjusting R22. > > Adjusting the inductors does not cause a significant change in TP5. (I > > can see it on the analyzer with a directional coupler on the output but > > it is a TINY signal.) > > > > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
