On Tue, March 17, 2015 05:16, Peter Lambert wrote: Thanks Peter. Good clues and I will have a look. Schematics printed and heading to work where we maintain an electronics lab that is an anti-static wonderland.
I wonder, though, if there isn't some external forensics to try first. I mean if the I or Q are not proper at the points you mention, there should be some evidence in the operation right? Although I do note proper I an Q levels when the VFO is close to the test frequency and within the demodulating bandwidth. Elecraft has been sent a note along with o-scope plots of the IQ out connector, but I will perform a visual inspection of the spots you mention. John > Hello again John, > > > Looking at the schematic, any difference you see should be so slight that > you'd not make comment on it. If it were me I'd take a look at the > inductors LD-LG (on page 4 of the schematic) to see if there is the > possibility of one of them being shorted. I haven't had look at these > but it's common to twist the terminating wires together - a likely spot > for a short. > > I'd stick the CRO on the output of each of the 4 inductors (where the > circuit shows "RX_I" and "RX_Q" and the opposite side of C1K and C1L) all > the levels here should be pretty much identical. > > Of course you can only expect this over the range of +- 96kHz or so. > > > 73's Peter VK4JD > > ______________________________________________________________ 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]
