Batboard

I'm using Astron 28v power supplies to power 4 100w UHF MTR2000s. The Astron was more cost effective to get battery back up at remote sites. However, I don't have an on-air alarm to alert that the repeaters are on battery. Any thoughts on an internal circuit from the Astron to an input on the MTR (?) for an alarm???

I'll have to check. We used the Argus PS from Motorola on a system we just installed, but doesn't the MTR have a point that say it lost AC ?

JAS

The MTR2000 will send an internal AC fail alarm if the built-in power supply loses AC and it switches to battery power.

However, it sounds like this application is running the MTRs off of an external DC power supply full time, so that wouldn't do any good here.

There is an AC fail sense pin on the system connector that you can use to signal the MTR2000 when using an external supply but, if memory serves, you need the optional I/O board installed to make use of it.

The AC FAIL line is what you need, high indicates AC failure.

Pin 8 of the power supply connector P8 eight pin Molex plug.

This is a logic level. Pulls up to 5V in the radio's Station Control Module at PB0 on the uP. Normally held low in the power supply by a open colector transistor, sinks 1ma.