Thanks, Don I'm getting more or less the same as you except for the RF out on U5 pin 4. I'm seeing the BFO of about 400mV pp with no AF, and then going up to 800mV pp when I whistle into the Mic.
Doh! I thought I had the carrier balance right, but obviously not. Switching on the SSBA=BAL shows a bif signal on U5 pin 4. I've adjusted that down to almost zero on the 'scope, but I'm still not getting much RF out. 73, Gareth, M5KVK On 29 September 2014 16:38, Don Wilhelm <w3...@embarqmail.com> wrote: > Gareth, > > During transmit you should have about 1.4 volts DC on pin 1 or the > balanced modulator U5. > I just measured the U5 pin 1 audio using a 'scope with a 10X probe and > found the peak to peak voltage ranged from 200 to 400 millivolts. If you > have a good microphone, you should see a similar amplitude signal. The RF > output at U5 pin 4 should have a similar amplitude. > The BFO injection at U5 pin 6 should be greater than 200 millivolts peak > to peak and on the one I just measured there was a 1 volt BFO signal there. > > 73, > Don W3FPR > > On 9/29/2014 4:52 AM, Gareth - M5KVK wrote: > >> I have K2 serial no 03885. I've recently finished building the KSB2 SSB >> adapter, but I'm having problems getting it to work. >> >> The problem is very low output power when I speak into the mic. I'm using >> an Icom MK36 mic and I've set the P1 header as per the KSB2 manual; >> including the resistor to get Mic bias. >> >> The options as set SSBA = 2, SSBC = 2-1 and I've done the carrier balance. >> >> >> >> I've checked all the DC voltages and they are OK. I used a scope on U5 >> (NE602) and there is an enormous disparity between the voltages on pin 6 >> (hi) and on pin 1 (very low). The waveform on U3 pin 7 (the compressed AF >> out) is greater than that on pin 4, (the AF input), but not by much. >> >> I want to eliminate the Mic as the source of the problem (It works >> perfectly with the IC-756 Pro II) by using an AF sig gen, but I'm not sure >> how much AF drive should cause 100% output power. >> >> Gareth - M5KVK >> >> > ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
