#187805

I've got a 25 watt GM300 UHF model that was given to me with blown finals. I used it as a repeater receiver for a while but it was just about deaf. My research shows that possibly the antenna switching relay pins went bad when the finals blew. I was able to source a working 25 watt brick. I installed the brick and ran through PA replacement option in the service menu and got that all situated. However, now the radio doesn't want to receive anything. I hooked it up to an antenna and tried to key the repeater down the street while listening on another working radio and it also appears the GM300 is not generating the proper PL tone as the repeater wouldn't key up. I checked programming and that is not the issue.?

I injected a full quieting signal into the radio and the squelch didn't even break, I adjusted the squelch pot on the RX board and forced the squelch open and I didn't hear the injected tone at all. Checked the jumper wires coming from the PA deck going into the RX board and they are all fully inserted and locked into place. Is this radio just bad or did me swapping the PA deck cause the RX VCO not to lock. I didn't do an RF board replacement, just a PA deck replacement.

I've got two 40 watt UHF GM300s that also have blown finals I could try the new brick on, but with them being 40 watt, is this 25 watt brick even going to work on them?

#187806

You probably have a defective 2nd mixer crystal. That's a common problem.?

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From: computerwhiz02@...

Sent: September 21, 2021 12:54 AM

To: [email protected]

Reply to: [email protected]

Subject: [repeater-builder] Replaced GM300 PA Deck and Now Radio Is Deaf

I've got a 25 watt GM300 UHF model that was given to me with blown finals. I used it as a repeater receiver for a while but it was just about deaf. My research shows that possibly the antenna switching relay pins went bad when the finals blew. I was able to source a working 25 watt brick. I installed the brick and ran through PA replacement option in the service menu and got that all situated. However, now the radio doesn't want to receive anything. I hooked it up to an antenna and tried to key the repeater down the street while listening on another working radio and it also appears the GM300 is not generating the proper PL tone as the repeater wouldn't key up. I checked programming and that is not the issue.?

I injected a full quieting signal into the radio and the squelch didn't even break, I adjusted the squelch pot on the RX board and forced the squelch open and I didn't hear the injected tone at all. Checked the jumper wires coming from the PA deck going into the RX board and they are all fully inserted and locked into place. Is this radio just bad or did me swapping the PA deck cause the RX VCO not to lock. I didn't do an RF board replacement, just a PA deck replacement.

I've got two 40 watt UHF GM300s that also have blown finals I could try the new brick on, but with them being 40 watt, is this 25 watt brick even going to work on them?

peter oesterle

#187807

开云体育

just rip the PA? out and run the? RX antenna into the? small??? coax input in the RX board.

You can power up the radio? by applying?? + 12Vdc? to? the correct pin on the jack that the? PA? wire harness plugs into.

If you are just using it as an RX,? No need for that? dead? PA assembly.

73?? pete ve3hoh/w3

Show quoted text

From: [email protected] <[email protected]> on behalf of Jared Smudde <computerwhiz02@...>
Sent: Tuesday, September 21, 2021 4:54 AM
To: [email protected] <[email protected]>
Subject: [repeater-builder] Replaced GM300 PA Deck and Now Radio Is Deaf

?

I've got a 25 watt GM300 UHF model that was given to me with blown finals. I used it as a repeater receiver for a while but it was just about deaf. My research shows that possibly the antenna switching relay pins went bad when the finals blew. I was able to source a working 25 watt brick. I installed the brick and ran through PA replacement option in the service menu and got that all situated. However, now the radio doesn't want to receive anything. I hooked it up to an antenna and tried to key the repeater down the street while listening on another working radio and it also appears the GM300 is not generating the proper PL tone as the repeater wouldn't key up. I checked programming and that is not the issue.?

I injected a full quieting signal into the radio and the squelch didn't even break, I adjusted the squelch pot on the RX board and forced the squelch open and I didn't hear the injected tone at all. Checked the jumper wires coming from the PA deck going into the RX board and they are all fully inserted and locked into place. Is this radio just bad or did me swapping the PA deck cause the RX VCO not to lock. I didn't do an RF board replacement, just a PA deck replacement.

I've got two 40 watt UHF GM300s that also have blown finals I could try the new brick on, but with them being 40 watt, is this 25 watt brick even going to work on them?

#187809

开云体育

Have you checked the 2nd oscillator xtal?? They were notorious for failures...

On 9/21/2021 5:34 AM, peter oesterle wrote:

Show quoted text

just rip the PA? out and run the? RX antenna into the? small??? coax input in the RX board.

You can power up the radio? by applying?? + 12Vdc? to? the correct pin on the jack that the? PA? wire harness plugs into.

If you are just using it as an RX,? No need for that? dead? PA assembly.

73?? pete ve3hoh/w3

From: [email protected] <[email protected]> on behalf of Jared Smudde <computerwhiz02@...>
Sent: Tuesday, September 21, 2021 4:54 AM
To: [email protected] <[email protected]>
Subject: [repeater-builder] Replaced GM300 PA Deck and Now Radio Is Deaf
?

I've got a 25 watt GM300 UHF model that was given to me with blown finals. I used it as a repeater receiver for a while but it was just about deaf. My research shows that possibly the antenna switching relay pins went bad when the finals blew. I was able to source a working 25 watt brick. I installed the brick and ran through PA replacement option in the service menu and got that all situated. However, now the radio doesn't want to receive anything. I hooked it up to an antenna and tried to key the repeater down the street while listening on another working radio and it also appears the GM300 is not generating the proper PL tone as the repeater wouldn't key up. I checked programming and that is not the issue.?

I injected a full quieting signal into the radio and the squelch didn't even break, I adjusted the squelch pot on the RX board and forced the squelch open and I didn't hear the injected tone at all. Checked the jumper wires coming from the PA deck going into the RX board and they are all fully inserted and locked into place. Is this radio just bad or did me swapping the PA deck cause the RX VCO not to lock. I didn't do an RF board replacement, just a PA deck replacement.

I've got two 40 watt UHF GM300s that also have blown finals I could try the new brick on, but with them being 40 watt, is this 25 watt brick even going to work on them?