Request for advice on troubleshooting...
I use my Omni-D daily (CW/SSB nets). Last week after a lightning storm the ALC
LED does not light up at all (mere coincidence? the Omni was turned off but
antenna still connected...). I can increase the drive until the power supply
kicks off-- no LED. The rest of the rig functions perfectly.
At the suggestion of a friend, I pulled out the board containing the ALC
circuit and checked the 4 1N4002 diodes (lifted one leg, used DVM with diode
checker) and the diodes are good. I also checked the ALC voltage coming off of
this board and it matches the specs in my service manual (12.7 volts with no
drive) and the voltage drops as drive in increased. The difference between
this ALC voltage and the +13.8V bias should cause the LED to light up, yes?
Should I suspect the LED or something else?
If the LED is the place to look, how do I get to it on the Omni-D? I fear the
answer is "remove the front panel"... my service manual (actually for Omni-A
and Omni-D) shows a special tool being used on the main tuning knob. I don't
have such a tool. Is it essential to the process and what can be substituted
in its place?
Thanks in advance,
Barrett / KE4R
Fayetteville, GA
KE4R@arrl.net
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