Batboard

Looking to see if it's possible to take a xtl radio receiving in UHF digital encryption mode and rebroadcast it in analog UHF using the pin out of the radio

BFD319 wrote:Looking to see if it's possible to take a xtl radio receiving in UHF digital encryption mode and rebroadcast it in analog UHF using the pin out of the radio

Anything is possible. You will need a simple audio interface to control the audio level and some sort of timer control to be able to control the tail timer of the second radio. The second radio needs to have the TOT (time out timer) set to shut down the transmitter if something goes wrong and your link gets hung up. Depending on what the second frequency is and how much activity is on the channel, you should consider some way of preventing the transmitter from keying up if there is current activity on it. There is a busy channel lock out feature that probably could be used for this solution.

If your second transmitter is an XTL or a CDM, there are audio gain settings that you should know about when using the accessory connector pins. On the XTL there is also a software selection setting that if not set right will not provide any TX audio from the accessory connector. It is only 2 selections, so if one doesn't work, try the other. The Motorola software jerks can't seem to make up their mind with this setting. It has been flip flopping with almost each new version of the software that has come out. So just try one and if there is no audio, try the other one.

The next issue is of course the legality of the second frequency your transmitting on. If it is a public safety pair of frequencies on both radios, you can probably get away with it. If these are business frequencies, your probably not in good standings with the FCC in doing it.

Jim

You can use a VRS750 to do the same thing... big question is, why? Make sure you aren't compromising OPSEC by rebroadcasting crypto traffic in the clear.

We had an agency that was hell bent on console patching an encrypted channel together with a clear channel to extend coverage.

Once we pointed out to them that the entire concept of encryption became pretty much moot in doing so, they decided to switch from a patch to a multi-select. Not much better, but at least half the traffic is actually encrypted.

Never understood why someone would want to do this.