Matt, Yes it sounds like you have blown the right channel of the speaker audio amp. The headphone amp is a different chip.
I don't know how to confirm that is what failed other than to devise a connection means for a 'scope at the input and output of each channel. 73, Don W3FPR On 8/27/2010 2:48 PM, Matt Zilmer wrote: > Hi Don, > > I was wiring up a switch box for dual-sourcing hifi speakers, and > looks like I had a short on the Sub (right) side circuit. This may > have damaged the speaker amp, U1 on the DSP board (sh 3 of 9 from > 6/2010 schematics). > > Symptoms: > > If only the main RX is operating, output is roughly equal from both > speakers. BTW, the Sub AF is set to Balance. > > If the sub RX is also enabled in diversity with balance set full CW, I > hear nothing. If the control is set full CCW, I hear the main RX. > > If I use the headphone jack with sub RX enabled, I get the two signals > as expected. > > -- > > This seems to point to U1, the speaker amp on the DSP since the > headphone output is OK for both channels. > > Is there some way to confirm U1 is bad? I will be running a sig gen > into the main and aux antenna inputs to drive the two channels > separately and try to isolate the problem. > > Any ideas are welcome. Meanwhile, is the LM4950TS stereo amp > available as a component from Elecraft, and is it user-repairable? > > Many Thanks! > matt W6NIA > K3 #24, K2 #2810 > ______________________________________________________________ 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

