CDM1550 PL Audio Behavior Question

[dapaq2]

Hello Group,

I have a Motorola CDM1550LS that I have a couple of channels with PL for the decode/receive side. When I am manually monitoring those channels, the squelch stays closed audio muted when no PL is present. However, when I have system scan enabled and am scanning those channels when they are in the scan list, the squelch opens up and I can hear everything from any radio transmitting without a PL. Does anyone know how I can get the squelch to remain closed while scanning and receiving transmissions that have no PL present? I am assuming that I just need to make a minor adjustment in the programming, but unsure where or what I am overlooking...

Thanks,
Doug

 

[krazybob]

Are you monitoring through the built-in speaker, a speaker plugged into the external Jack, or from the accessory port on the back of the radio? The reason I ask this is because I had a Vertext do this. When monitoring from the line-out it would not pass PL. By that I mean anything and everything came through with no protection. Because it's a commercial radio it should also have a setting for off hook scan. Unless you ground the metal circle on the back of the microphone during skin there won't be any PL. The FCC requires that when used on shared channels you monitor before transmitting in the way they enforce this is with the requirement that the plb disabled when you remove the microphone from the microphone holder. If you are not using a microphone you can take an RJ45 connector and looking at the schematic determine what the ground pin setting is and create a dummy microphone connection that is always grounded.

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[KG4INW]

Go to your Scan List, on the General tab, make sure PL Scan Type is set to "Priority and Non-Priority Channel".

 

[dapaq2]

KG4INW thank you for that information! That was the cause of the problem, all good now.

Doug

 

[SteveC0625]

Are you monitoring through the built-in speaker, a speaker plugged into the external Jack, or from the accessory port on the back of the radio? The reason I ask this is because I had a Vertext do this. When monitoring from the line-out it would not pass PL. By that I mean anything and everything came through with no protection. Because it's a commercial radio it should also have a setting for off hook scan. Unless you ground the metal circle on the back of the microphone during skin there won't be any PL. The FCC requires that when used on shared channels you monitor before transmitting in the way they enforce this is with the requirement that the plb disabled when you remove the microphone from the microphone holder. If you are not using a microphone you can take an RJ45 connector and looking at the schematic determine what the ground pin setting is and create a dummy microphone connection that is always grounded.

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There's a setting in Waris CPS for that. A jumper is NOT needed. Older products like the earlier Radius and Maxtracs did require the jumper.

The correct solution is in post #3.

 

[KG4INW]

KG4INW thank you for that information! That was the cause of the problem, all good now.

Doug

Excellent! I've had to adjust many CDMs that were exhibiting that behavior because they were set to scan PL on priority channels only (I believe that might be default?).

 

[krazybob]

It never hurts to learn something new. Although I did write that it should have a setting for off-hook scanning

 

[krazybob]

I guess what threw me is the terminology used by the Motorola. Priority and non-priority instead of busy channel lock out? Even Vertex evades a straight answer by referring to it as off-hook scanning.

As I said I don't mind learning something new. In radio there's always something new to learn and that's what makes it so fascinating.

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