[Lowfer] The transverter's working, but I can't drive the amp !!
Andy - KU4XR
ku4xr at yahoo.com
Sun Mar 28 00:18:33 EDT 2010
Home alone today, so I finally built another Class " D " amp to go
with the transverter. Only problem is; I can't get any measurable
output thru the amp from the transverter. First thought was I made
some mistake in wiring the new PA. That all checked fine, why not
try my known good PA from the " XR " QRSS beacon ?? I did; and
still nothing. The transverter is generating a signal of some level,
but it's not enough to drive the complimentary pair amp. I have
switched out the LM318 in the output stage and get the same results,
If the chips were fried, I wouldn't think that any signal would make
it thru the transverter, so I don't believe that's the problem.
The only way I can get any signal strength at all, is to tap the
output of the SA612 mixer. I've done all the usual voltage checks,
continuity checks, look for shorted circuits, everything is clean.
So my suspicion is that the LM318 OP amp just dosen't have enough
output to drive the usual amp we use here on LF for 1 Watt.
I am assuming that the transverter output is a sine wave, so that
might account for the low output level. Do I need another amp stage??
If so; Any comments, and suggestions will be appreciated.
I have to work all day Sunday, so I won't be able to check emails
until I get home, so if I don't respond to something direct, you'll
know why.
73, and good night to all :::
Andy - KU4XR - EM75xr - Friendsville, TN. USA
LOWfer Beacon " XR " @ 185.29875 KHz ( QRSS-60 )
Coordinates: N: 35º 43' 54" - W: 84º 3' 16"
http://www.myspace.com/beaconxr
http://webpages.charter.net/ku4xr/
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