Just to close off the issue (if anyone else has this problem and wonders
what happened ...)
It turned out to be a shorted overdrive protection LED (D10, D11).
Apparently it was overdriven at some point and the LED sacrificed itself.
Replaced the LED and everything is working well again. The L16 slug is
approximately a couple turns from the top of the can, which is where the
instructions say it should be.
73
joe n6kk
----- Original Message -----
From: "Joe Barger" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, September 04, 2007 10:20 PM
Subject: [Elecraft] XV144 L16 Adjustment
Hi All,
I'm having trouble getting 20W out of an XV144. I get around 7W out with
5W drive (with the jumpers set for 5W drive), and more drive doesn't
produce more output. The drive attenuation resistors show a little
"burned" color, but a check with an ohm meter says they are OK. The
voltages in the troubleshooting chart look fine. Receiving seems to be OK
as well. It's part of a club station, so it's possible it's been
overdriven at one point or another. I replaced the MAR-3 (in case it was
damaged), but no difference. While adjusting the 28MHz IF strip I noticed
that L16 peaks when the slug is removed from the top of the can. The
instructions say this is normal for L17, but is it also normal for L16?
The voltage at TP5 was still going up quickly when the slug came out, so
it seems the inductance needs to be even lower to reach resonance.
When I first build the unit it tuned right up and worked fine.
Unfortunately I didn't make any notes on where L16 was then.
Any sage advice before I drag a 'scope out of a lab to the shack to
continue troubleshooting?
Thanks
joe n6kk
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