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Unmute rules

Posted: Thu Jun 01, 2006 5:37 am
by Pj
After reading the help files for years, and some experimenting, what do people find the best?

Standard, Or, And, or any of the combinations? With standard I find more squelch crashes on simplex channels, with Or Unmute those tend to stop but sensitivity seems to be a tad less.

In my area I have a good mix of simplex, repeater both with and without PL (imagine my joy).

Most of the radios I am using are ASTRO if that helps

Posted: Thu Jun 01, 2006 5:42 am
by RKG
Most of my experience deals with public safety systems (PD or Fire). By definition, you will always have a good talkout signal, and by definition, you do not want any co-channel stuff coming through (and all the questions that raises). So I automatically unmute AND and mute OR. According to Motorola , this reduces sensitivity: I have never seen anything that establishes this empircally (vs. theoretically) or quantifies it, but for the PD and FD applications, the point isn't important.

Posted: Thu Jun 01, 2006 7:05 am
by kj7xe
I did some tests recently on some XTS2500s and 5000s in regards to this and found that the radios programmed for 'UnMute/Or Mute' seemed to always have quicker squelch crashes than on 'Standard' or 'UnMute/Std Mute'. However, this is only in situations where you're on a channel programmed for PL RX and the transmitting unit at the other end has no reverse burst. If the other end is using reverse burst, they all pretty much mute right away at the same time as they should.

I have yet to notice any 'sensitivity' issues as a result of changing around the unmuting - the squelch setting is more critical with this one, especially for units receiving on the fringe.

Posted: Thu Jun 01, 2006 4:29 pm
by Will
kj7xe wrote: I have yet to notice any 'sensitivity' issues as a result of changing around the unmuting - the squelch setting is more critical with this one, especially for units receiving on the fringe.
I have only noticed a slight delay in the opening of the 'squelch' in the AND unmute which requires both a valid RUS (receiver un-squelch on carrier) and a valid PL or DPL detect. No loss of accual sensitivity.

But in the Normal setting the radio will unmute with a vaild PL even tho the signal to noise ratio is below the squelch setting(s). Sort of PL only squelch if you will.

I use the OR Mute to reduce 'squelch tails' from the others who do not have reverse burst or turn off code. This setting will MUTE on loss of RUS OR PL DETECT. Great on repeaters that have 'tone on the tail' and no RB.