Batboard

How do I tell the difference between the quantar fireball onan power supplies and the replacement ones that don't burn down repeater shacks ? Has anyone ever figured out why the power supplies go BOOM & spit fire?

Thanks!

The ONAN supplies have a larger vent in the front of them that is rectangular. The non-ONAN supplies have a square vent in the front of them with a fan behind it. The ONAN supplies are much heaver in weight than the non-ONAN supplies. I also believe the ONAN supplies had a silver housing whilst the non-ONAN supplies were gold, but that may not always be the case.

This Quantar has an ONAN power supply:



This is a non-ONAN power supply:




They explode because of a capacitor failure, likely due to inrush current but I don't have specifics on that.

It's important to know that there are two versions of all the AC supplies, AC high and AC low. Depends on the power output of the RF power amplifier. AC low for ~35W stations, AC high for ~110W stations.

Could a 625 Watt (High power capable) newer design Non ONAN Supply CPN1047 be used in a lower power 25 Watt Quantar (VHF) without issue?

Yes.