[Amps] AL1200 weak receive

Mark Bitterlich markbitterlich at embarqmail.com
Fri Jul 29 17:49:23 EDT 2022


You could also go to "operate" and verify that the voltage is the same on both sides of the relay.  If it is NOT the same, you've got a path to ground that is partially pulling the relay in. Yes, just a WAG, but if you feel the relay contacts and spring are both good, this is all it can be. Famous last words. Markwa3jpy
-------- Original message --------From: Mark Bitterlich <markbitterlich at embarqmail.com> Date: 7/29/22  5:45 PM  (GMT-05:00) To: "Ed Swiderski, KU4BP" <ku4bp at triad.rr.com>, amps at contesting.com Cc: markbitterlich at embarqmail.com Subject: RE: [Amps] AL1200 weak receive 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 at triad.rr.com> Date: 7/29/22  12:33 PM  (GMT-05:00) To: amps at 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 KU4BP_______________________________________________Amps mailing listAmps at contesting.comhttp://lists.contesting.com/mailman/listinfo/amps


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