Batboard

I've been experimenting with the carrier squelch and PL (CTCSS) settings on my VISAR.

I have always assumed that the carrier squelch (CSQ) setting set the minimum threshold at which the squelch will open. A channel with PL encode/decode usually required a slightly stronger signal to open the squelch.

I have not yet adjusted the carrier squelch on my VISAR down to the absolute minimum although its already set reasonably low.

However , I did some tests using a PL encoded test carrier. Interestingly, I found that the "PL decode" channel opened when the "carrier squelch" channel still remained closed. In fact the PL channel opened on a signal that was completely unreadable!!

My conclusion is that the PL squelch "minimum threshold" is NOT dependant on the level of carrier squelch setting. Is this correct?

Thanks

Here your are going into the gating options of the Visar. If you hit F2 in the channel options screen you'll see the std/std or you will see and/or somewhere on the left. (I'm too lazy to go to my dos comp and give you exacts at this point) Those settings make a big difference in how the radio squelches and unsquelches. I'm not seeing where you have an actual issue just an interesting question. Also since it's a VHF visar if you haven't already taken the values down this far it's not uncommon (in fact there is an OLD OLD OLD SRN out there) to set your squelch values to 20 across the board. As another note you can only set the gating to and/or if you have Rx options set to a PL or DPL.

Thanks Karfield.

Its beginning to make sense!! I set the squelch gating options to "std/std" as it said that this gave the max sensitivity. I guess the "and/or" setting probably uses the carrier squelch threshold together with PL - so PL decode can be set to only open on stronger signals (as set by the carrier squelch level).

g8tzl2004 wrote: Its beginning to make sense!! I set the squelch gating options to "std/std" as it said that this gave the max sensitivity. I guess the "and/or" setting probably uses the carrier squelch threshold together with PL - so PL decode can be set to only open on stronger signals (as set by the carrier squelch level).

A very important setting in any Jedi. The and/or setting uses the carrier squelch AND valid PL code detect to unmute as you found. The OR part, loss of either PL OR carrier squelch will mute the receiver. This is also useful for receiving the systems that do not transmit reverse burst or DPL turnoff code.

The STD setting will override the squelch as you have found. The receiver will "hear" the PL way into the noise and force the receiver to unmute. The receiver will not mute until the PL goes away, causing lots of "squelch crashes".