Quantar repeater : PA low

[jaaredmond]

I'm getting a PA low beep on my vhf quantar. When I went to check it out, it displays the PA low when keyed. The service manual says if the unit isn't recieving enough DC voltage that this will happen. I checked that batteries and the charger was showing around 28.5 volts. Which is above the required dcv.

I also changed the battery setting to "NONE" so the unit doesn't think there is a battey, and still get the same PA low LED and the 2 beeps.

Is there a way to do a reset? Or can anyone shed some light on what may be going on? This is a fairly new repeater that has only been in service a few months.


Thanks,


James

 

[zz0468]

Go into the service mode with CPS, and try to recalibrate the PA. I've seen Quantars develop a low power condition, and that sometimes corrects it. More often than not, though, the PA has failed and needs to be replaced.

If that fails to correct the problem, try reading the codeplug, and re-writing it back to the radio. Sometimes a failure in the EPIC board will manifest itself as an RF problem, and reading and writing the codeplug will unmask a firmware problem.

Either a PA fail or an EPIC board fail is an expensive proposition.

 

[WayneH]

This is a fairly new repeater that has only been in service a few months.

Any reason you could have developed a coax issue (e.g., water)? Hi VSWR will cause the PA to drop down also.

 

[jaaredmond]

Thanks. I re-wrote the original codeplug several times trying to correct the problem. I will try just re-writing the current cp tomorrow and calibrating the PA and see what happens.

Thanks again,

James

 

[jaaredmond]

Not likely, but possible. I waterproofed the crap out of it. Will re-check the vswr though. Thanks!

James

 

[ramal121]

Any reason you could have developed a coax issue (e.g., water)? Hi VSWR will cause the PA to drop down also.

That should give a high viz-war alarm also and the OP mentioned none. You can try all the resets you want but me thinks the PA is fried. Time for a soldering iron or a FRU.

 

[zz0468]

Thanks. I re-wrote the original codeplug several times trying to correct the problem. I will try just re-writing the current cp tomorrow and calibrating the PA and see what happens.

Sometimes just reading the codeplug, then immediately writing it back to the radio will either clear a problem, or you'll get an error message as the EPIC board arfs. At that point, it's a dead radio, but the problem has been identified.

If the radio just takes the codeplug, and successfully writes it, then it's not likely to be an EPIC board, and it's a hard failure of the PA - which is not field repairable, btw.

Don'tcha just LOVE Quantars! :roll:

 

[ramal121]

Don'tcha just LOVE Quantars! :roll:

I do! Just as much as MTRs...

And I don't care what Motorola says, I'll poke around a dead PA anyday before I wait to have them send me a spare.

 

[zz0468]

Have you had any luck actually repairing them?

 

[jaaredmond]

Hey guys,

The station was in the same status when I went to the site today, PA low.... I disconnected the batts, then powered off the station, and then finally unplugged the AC power from wall. I then plugged up the AC power, connected the batts, and powered on station.

I had read somewhere about the order in which the quantars needed to be powered up to recognize the dc power correctly. Luck must have been on myside for once, and the unit powers up and transmits properly!

Thanks for everyone's advise!

Take care,

James

 

[fineshot1]

Quantar innards do not like power hits.

You'd best keep it on a heavy duty ups or run it on heavy duty batteries with an
inverter/charger system to keep the batteries up to snuff if at all possible.