I fixed the R18 problem. But I'm still having distortion problems. One weird thing is that when I turn all three nobs counterclockwise I never get any voltage reading. I only get readings when I boost the gain and modulation(and supply an audio signal). At this point it may be time to break out the $30 to send it back and have Phil look at it.
I fixed the R18 problem. But I'm still having distortion problems. One weird thing is that when I turn all three nobs counterclockwise I never get any voltage reading. I only get readings when I boost the gain and modulation(and supply an audio signal). At this point it may be time to break out the $30 to send it back and have Phil look at it.
Hi again,
Two more things to check:
Use a magnifying glass and check for solder bridges and cold solder joints. If possible, get someone to check it also. It is easy to miss something with only two eyes.
Use your voltmeter to check the voltages, especially around the RF output and bias circuit (Q1,2,3,4,5). The voltages you measure should be close to those marked on the schematic (within a few tenths of a volt). If they are not, then check that the right parts are installed. From what you describe I think the problem is with the final bias. I have been "reading" the color code for 50 years and I still had two resistors switched when I built mine. Orange, red, brown, and violet look a lot alike on these resistors. Check with an ohmmeter (power off, meter diode mode off). Even in the circuit, the resistances measured should be close to or smaller than the nominal values.
If you are not comfortable with this, then maybe you can send it to Phil.
Neil
Thanks, I will check that stuff when I get back. I was starting to get afraid that I destroyed one of the chips while soldering them to the board. I accidently destroyed the sockets. But the more I think about it, I like your theory.
I got alot of good ideas. Problem is, most of em suck.
George Carlin (WINO)