Squelch on DMR

[Watchman1]

Is the squelch gate on DMR adjustable or can it be disabled ? When receiving a DMR transmission the squelch interrupts the transmission and cuts it short. It mentions squelch gate in the manual but has no details. When this happens the S icon appears on the display... Appreciate any help.

 

[Watchman1]

The scanner is a TRX 1

 

[troymail]

Not exactly sure what you are saying/asking ("squelch interrupts the transmission and cuts it short") but I can say that for best results, you'll want the squelch knob set at about 10 o'clock position.....

 

[Watchman1]

Regardless of where the squelch control is set ...the S icon flashes on DMR transmissions and cuts off part of it. The manual of the TRX 1 mentions the "S" icon and the squelch gate on DMR but thats all i can find out about it.

 

[troymail]

Regardless of where the squelch control is set ...the S icon flashes on DMR transmissions and cuts off part of it. The manual of the TRX 1 mentions the "S" icon and the squelch gate on DMR but thats all i can find out about it.

I suspect the "squelch gate" is really more or less and internal radio processing thing and the only control users have is the squelch knob itself.

The "S" will be shown when the radio is seeing some amount of power on the frequency (fully counter-clockwise would most likely be noise unless you are hearing voice. You could see "S" when a signal is present but it isn't voice (control, data, etc.) or the quality is poor.

I'm still unclear on what you mean by "cuts off part of it". What method are you using to monitor that/any DMR frequency? What frequency/system are you trying to monitor? Or is it during search? Can you capture a recording or two and post them?

 

[Ubbe]

If the S shows it means the squelch is still open and haven't cut the signal short. If it is an inverted S symbol then it still decodes the digital signal but doesn't do it succesfully or there are no conversation on that frequency.

Have you tried entering that frequency manually with Fn+0 and set SQ to 0 fully open?
Are you on the exact frequency?
Do you have all frequencies programmed for that system?
Could it be a system using RAS that are problematic to decode during scan and only work in search and manual tune?

/Ubbe

 

[Watchman1]

So far I have tried everything .....the squelch gate only operates on DMR and even if the scan is paused on an active frequency such as THP. There doesn appear to be any adjustment on it. When receiving a call the "S" still appears and interrupts the call making it difficult to hear all of it. Can't believe this radio is the only one doing this. Its the only thing I dislike about this scanner.

 

[BrianG61UK]

That S on the top left should be present when anything is being received.
What happens to the signal bars when reception cuts off?

 

[troymail]

What is THP? I'm now trying to determine exactly what you are trying to monitor. Looking at the RRDB listings for Wayne County, I see some (potentially) incomplete DMR frequency listings (no slot, color code, TGID, etc.)... they may or may not be needed... On the other hand, I'm not even sure this is what you are trying to monitor.

Does the radio exhibit this things regardless of location? If you are seeing "S" regardless of squelch setting (particularly fully clockwise), that might indicate some type of interference unless you are sitting right next to the transmitter.

You had also previously reported potential use of encryption. Perhaps that is factor here... can't say for sure.

You really need to provide more information, make a video and/or at least post some recordings so we can have a better overall understand what is happening...

 

[troymail]

Thought about it a bit more --

I am only assuming what frequencies you are having trouble with given your location and what is in the RRDB...

None of the conventional DMR frequencies listed have a "slot" assigned. This could well be just fine and correct. However, if I'm not mistaken, if no slot is specified in the programming, the TRX will try to receive activity on either slot - potentially without a break/scanning in between - that is, you could hear something that is coming over slot 1 of frequency 453.2375 and when that transmission stops, if something is active on slot 2 of that same frequency, you'll start hearing that as if it is part of the slot 1 conversation.

Note that if the radio receives an unencrypted voice call on slot 1 of a given frequency and an encrypted voice call is active on slot 2 of the same frequency, you could potentially hear voice that seems to transition to garbled noise and potential back to clear voice again.

Again, assuming these are the frequencies you are having problems with, you may want to create entries for both slot 1 and slot 2 for each frequency (double the number of entries) just to see if that helps.

These are the only DMR frequencies I see listed for your county - if you are hearing DMR on some other frequencies (you mentioned THP but they aren't listed as DMR), please advise.

I could be totally missing the target on your issue but I can only speculate based on the information available.