[TMC] SBE-2 tbls
LARRY D GODEK
telegrapher at q.com
Tue May 31 16:33:32 EDT 2011
My SBE-2 will not do anything other than turn on with the power switch. The big item is that i don't have any carrier insert. I've done some measureing underneath with a freq counter. I do have 17 kc and 270 kc at points where it should be. However when i measure the 17 kc at it's first TP i only see about .5 volts and i'm thinking it should be a bit more, maybe almost 1v? Anyway as i profress onward thru the circuit the different frequencies apparently are to low a level to hold the counter steady. I don't have an O scope so i'm relying on counter indications and VTVM readings. I did replace a couple 3 tubes that were below par but i don't think that is the major trouble. I'm hoping it isn't one of the diode matrix plugins but for now i guess i'm looking for someone who might have or know what the different voltages should be at the inputs to the various amp sections of the 12AT and 12AU7 tubes up to and including the MF. Somewhere below that point is where things aren't happening properly.
When i measure the xtal frequency at pin 2 of V115 i do see the correct xtal frequency showing that the 2-4 mc HF section is working.
this is a nice clean unit and i'd like to get it running. I heard a ham in San Francisco using an SBE-3 today and it sounded pretty good. Mine should do as well.
Larry
W0OGH
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