MCS2000 Model 1 - No Status Lights

[ScanRite]

I have an MCS2000 Model 1, which was previously used in some sort of telemetry system. Got it off eBay, extremely clean radio.

I currently have it programmed for an 800mhz trunk system and it's working great (receive only). My only issue is, the status lights don't do anything. They light up (Red/Orange/Green) when the radio powers up, but nothing after that.

Not a biggie, but wondering why they aren't working. Radio setting? CPS programming thing? Just curious.

Thanks,

 

[Skypilot007]

I have several of these used in the same application as yours and they do the same thing. I also have had model II and III radios and they do the same thing. The only time the orange receive light comes on is when the radio receives a signal on a conventional channel.

My XTL radios do the same thing, no orange receive light on trunking channels, only on conventional. The red light works on all of them when transmitting. I forget what the green light is for.

 

[ScanRite]

Odd... Thanks much for the info. I'll program a conventional freq in and see if it works.

Thanks again!

 

[RKG]

What you report is typical and, while it may seem "odd," it has to do with how the radio works vis-a-vis conventional versus trunked.

A conventional radio uses a "squelch" function which is triggered by inverting the noise from a channel. High noise means no signal; low noise equals good RF signal. The radio converts noise to a voltage, inverts the voltage and uses that both to trigger the audio gate and the Rx light.

Trunked radios handle audio gating as a function of trunking data. The line that controls the Rx light is simply not part of the "circuit."

As for Tx, what happens when you press the key is complex. First, the radio keys up on the control channel and sends a data stream known as the ISW. It then unkeys and looks for a response from the controller on the outbound side of the control channel, known as the OSW. Assuming a channel grant, the radio then switches to the assigned voice channel frequency and transmits a data stream (the "low level handshake"), and then listens on the outbound side of the voice channel for an acknowledgement. If that is received, the radio emits the "talk permit tone" and keys up on the inbound side of the voice channel frequency with mike audio gated to the transmit encoder.

TMI? Perhaps, but I sensed you might be interested.

 

[ScanRite]

TMI? Perhaps, but I sensed you might be interested.

Not TMI. I knew how it all worked, just surprised they couldn't feed that circuit in a different fashion.