Thanks Mike. I built this along with the XV432 a LONG time ago :-) The 432 unit had loads of issues. My rover partner, a EE grad from 1964 who designed military radios and antennas for a living was not impressed with either of these transverters, especially the XV432. For a hobby, he checks the math in QEX articles. One time he told me that the author mis-applied Maxwell’s equation and he ran his own set of differential equations to prove the point.
On to the my results: > On Sep 17, 2020, at 9:44 PM, M Cresap <[email protected]> wrote: > > Take off the top cover of the transverter, check the voltage between TP2 and > ground (should be between 200 to 275 millivolts). That measures part of the > source voltage of Q3, the first receiver amplifier. 65mV > > Find R16 (a 120 ohm resistor) and measure the voltage to ground on each side > of the resistor. One side should be 12 volts, the other should be about 5 > volts. That measures the series dropping resistor for U1, the second receiver > amplifier. R16 will normally be very warm to the touch. 13.8 and 4.9V > > If those measurements are correct, the problem is most likely elsewhere. > > You can check the condition of the local oscillator by measuring the voltage > between TP1 and ground. It should be between 1.0 and 1.5 volts. 0.92V Additionally, TP1 is 0.76V, not the minimum 1V. The output pin of U1 is 0V, not 3.0-6.0V. > > > > > On Thursday, September 17, 2020, 8:58:35 PM EDT, k2qo <[email protected]> > wrote: > > > During the recent September VHF contest I could only hear the absolute > strongest local stations on the XV222/K3 in my rover. It worked FB in June. > My XV432 worked just OK as usual. Stations told me I was the loudest signal > on the 222 band so the TX side is fine. > > I put it on the bench and connected my Elecraft N-Gen. When turned on I > could barely detect an increase in noise. Tried the same on my XV432 and it > went from S0/1 to a solid S9. > > I'm guessing that I somehow blew up U1 (an ERA6) and/or Q3 (an ATF 34143). I > don't have a good scope, RF generator, or RF voltmeter but kinda think > replacing both will fix my XV. A bad relay is an option too. > > Thoughts? I'd like to fix it to have for a spare as I plan on moving > non-BigE transverters for 222 and 432. > > 73, > Mark K2QO > NF2RS/R for the September VHF > > > > -- > Sent from: http://elecraft.365791.n2.nabble.com/ > <http://elecraft.365791.n2.nabble.com/> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > <http://mailman.qth.net/mailman/listinfo/elecraft> > Help: http://mailman.qth.net/mmfaq.htm <http://mailman.qth.net/mmfaq.htm> > Post: mailto:[email protected] <mailto:[email protected]> > > This list hosted by: http://www.qsl.net <http://www.qsl.net/> > Please help support this email list: http://www.qsl.net/donate.html > <http://www.qsl.net/donate.html> > Message delivered to [email protected] <mailto:[email protected]> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
