Quantar 800MHz 100W Station P/A Fail

[Jaedwards3206]

I have a Quantar Base station 800MHz 100W. I have stripped it down from all of its filters to where it is just the cabinet with the 100W PA, 24V PS, the Exciter, and the Receiver. I attached a dummy load to the TX end and it gets really hot when I key up the station. But, at the same time, the system says that there is a PA Fail. When I check the messages it gives me an DRIVER_OVERDRIVE ALARM. Does anyone know what the cause of this is? Could it possibly be because my dummy load is too small? I have part number: TLN3391A for my load. I don't know what the specs of this load are and if there is one that can carry more of a load. Any suggestions on any of my problems?

[MSS-Dave]

Do a PA calibration. You will need an accurate wattmeter.

[Jaedwards3206]

I have a few PAs that are new and in working condition, and they all say the same thing on the status message

[MSS-Dave]

Ok..

Do a PA calibration. You will need an accurate wattmeter. The load you have is a reject load from a circulator. I really doubt it is rated at 100 watts, hence the really hot statement. Probably 45-50 watts is more like it. So, you will need a bigger load that is good at 800.

You cannot assume that every PA for a 800 Q-Tar will slide right in and work. You MUST (IMHO from working on 900 Quantars in the past) do the calibration whenever replacing/repairing the PA. I even did it whenever the PA came out of the chassis and went back in.

If you have removed filters, you have changed the loading on the output of the transmitter from where it was calibrated before, so you will have to do it again as well.

[dag]

The exciter controls the power output and generates the errors. If after doing a proper TX power output alignment you are still getting the same messages, you should try another exciter.

You need a 150-200w watt meter and 200w or higher dummy load. Follow the alignment procedure to the letter.