Which would indicate that the relay in the radio has its contacts welded
together (or its transistor or FET shorted).
73, Jim W7RY
On 7/29/2022 4:45 PM, Mark Bitterlich via Amps wrote:
Try unplugging the PTT line from the amp and see if the problem goes away. Sounds like when
you are going to "operate" on the front panel, there is a path to ground from the relay
coil. Either inside the amp, or the PTT cable going to the radio. To confirm you could unsolder one
side of the relay coil, etc. Markwa3jpy
-------- Original message --------From: "Ed Swiderski, KU4BP" <ku4bp@triad.rr.com> Date: 7/29/22
12:33 PM (GMT-05:00) To: amps@contesting.com Subject: [Amps] AL1200 weak receive I have a confusing problem with
my AL1200. During operation when the stdby/oper is on, the received signal is very weak. Switching back to standby
and the signal level is fine. Checked the relay and it was operating correctly. Engaging with 12v applied to it.
With no power to the amp and a rx signal going through, manually engaging the relay weakens the signal. Releasing
it and it's back to normal. Cleaned the contacts using the method described by W8JI on his site. Still no go.
Stumped on where to look next to track this down. A tests on another radio produced the same results.With no power
to the amp, I connected my RigExpert analyzer to the "RF in" and a dummy load to "RF out".
Doing a sweep, the SWR reads around 1:1. Engaging the relay by hand shoots the SWR very high. Goes back down when
released.That's the best symptoms I can give. Any suggestions would be an immense help.Thank you,Ed
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Thanks and 73, Jim W7RY
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