RT97 Repeater issue - locking on transmit

[WRHX768]

I have a Retevis RT97 repeater set up at my house. It's been on the air for just over a year and has worked flawlessly, until last week. When I key it up now, it locks into transmit and doesn't stop until I shut it down.

Feed line is LMR-400, which I know is a no no for repeaters, but it's what I had and it was working fine up until now. Is it possible that the LMR could be causing this behavior?

The repeater does work normally if I switch to a spare magmount antenna that I have laying around.

Anyone experienced anything like this before?

[OffRoaderX]

When  you switch to the mag mount, is that using the same coax?

 

[WRHX768]

13 minutes ago, OffRoaderX said:

When  you switch to the mag mount, is that using the same coax?

 

No, different coax. I did just increase the squelch of the RT97 and I'm not getting the lock up at the moment on the original coax.

[WRHX768]

Also, a bit of a brain fart. It's not LMR-400 coax, but MPD-400 Super Flex

[JLeikhim]

You have one of the following:

Bad feedline, antenna or connector causing wideband noise when transmitting.
Loose connector in one of the above.
A noise source nearby like a computer or monitor that is so close to the antenna that it reradiates the TX signal plus wideband noise.
Loose mounting hardware on the antenna or mast.
Nearby interference like an AM station or FM station mixing with TX and reradiating the RX frequency.

This should be considered last and not at all if it works on a different antenna. Duplexer out of tune.

Think about what might have changed...

Sent from my SM-T350 using Tapatalk

[JLeikhim]

No, different coax. I did just increase the squelch of the RT97 and I'm not getting the lock up at the moment on the original coax.

Has the temperature changed where the repeater is located?

Sent from my SM-T350 using Tapatalk

[WRHX768]

On 5/25/2023 at 6:47 PM, JLeikhim said:

You have one of the following:

Bad feedline, antenna or connector causing wideband noise when transmitting.
Loose connector in one of the above.
A noise source nearby like a computer or monitor that is so close to the antenna that it reradiates the TX signal plus wideband noise.
Loose mounting hardware on the antenna or mast.
Nearby interference like an AM station or FM station mixing with TX and reradiating the RX frequency.

This should be considered last and not at all if it works on a different antenna. Duplexer out of tune.

Think about what might have changed...

Sent from my SM-T350 using Tapatalk
 

Thanks. I checked the connections and tightened and re-wrapped them. Everything seems to be working now. The problem started after an all day rain, so I'm assuming some moisture was the culprit.

[WA8GXF]

I had a similar issue with my rt97. I fought it for a couple of months, I am using lmr 400 cable. Increasing the squelch has solved the issue. Been working fine for 2 months now with no issues.

[WRHX768]

On 6/5/2023 at 2:31 PM, WA8GXF said:

I had a similar issue with my rt97. I fought it for a couple of months, I am using lmr 400 cable. Increasing the squelch has solved the issue. Been working fine for 2 months now with no issues.

Good to know. Thanks