VXR-7000 Random TX noise

Joined
Sep 1, 2009
Messages
26
#1
The repeater is sending out randomly timed bursts of TX noise that sounds like a squelch tail. The repeater is NOT receiving a signal when this occurs and the busy light does NOT come on. The TX light does com on during the burst.

This repeater has been in service for years and this is a recent problem.

Help is appreciated.

Thanks!
N
 
Joined
Dec 22, 2013
Messages
2,739
#2
1 what is the CTCSS tone?

2 try disconnecting the receiver from the duplexer for a while to see if this stops.

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Joined
Dec 22, 2013
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#4
Thank you. D131
And I will try to disconnect duplexer... Why would this help? What's causing it?
1) Assuming you are in North America where power line is 60 Hz, electrical discharge or NTSC TV Video can trip CTCSS tones harmonically related to 60 Hz.

2) If disconnecting the receiver from the duplexer cures it, then it is a signal on air. If not, perhaps a fault in the repeater like a microprocessor reset or other.
 
Joined
Sep 1, 2009
Messages
26
#5
Thank you for the quick reply I do not believe the radio is receiving any signal because the busy light does not come on when it sends out the rogue squelch sound. Additionally, I put another radio nearby programmed to receive on the same frequency and it does not receive any signal when those bursts appear.

Anything you can suggest that I can do to repair if it's a micro processor reset or other issue?
 
Joined
Dec 22, 2013
Messages
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#6
Thank you for the quick reply I do not believe the radio is receiving any signal because the busy light does not come on when it sends out the rogue squelch sound. Additionally, I put another radio nearby programmed to receive on the same frequency and it does not receive any signal when those bursts appear.

Anything you can suggest that I can do to repair if it's a micro processor reset or other issue?
I don't think you can assume that the busy light reacts fast enough to respond to a fast noise burst.

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Joined
Mar 30, 2005
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#7
What RFI-EMI-Guy says, and:

IS the repeater's receiver squelch set properly. Is AND squelch enabled?

Did the OP disconnect the RECEIVE side from the duplexer?
IS the duplexer properly aligned?
 
Joined
Sep 1, 2009
Messages
26
#8
What RFI-EMI-Guy says, and:

IS the repeater's receiver squelch set properly. Is AND squelch enabled?

Did the OP disconnect the RECEIVE side from the duplexer?
IS the duplexer properly aligned?
Yes, I believe squelch is set properly and I turned the knob all the way up and all still works except that it still sends out the bursts.

I will try the disconnect idea from the duplexer....I did try it with a low quality antenna in the building and listened with a different radio on the repeater RX frequency in the same location, and did not receive a signal.

The duplexer has worked for years, the unit has not been moved.
 
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