Palomar Magnum

It's used to indicate an im balance in one of the final output stages, in the real world that resistor would carry half the total output of the amp but that not being the case it just shows you that one of the final output stages has a problem so you'll need to search further for the problem that caused the 100 ohm to heat up.

It's usually a transistor that has failed or has become leaky and by leaky I mean voltage spuing from collector to base.

So you made need to lift the transistor tabs and check them out.

I was also informed that it may be a issue with the bias making one stage produce more power that the other.

Happy_Hamer said:

DAMN! I was just hoping the guy who had it before me just over drove it and I could replace the resistor and be done

Is it a 100 ohm? I cant tell the color of the band in the burnt area,

But in this one from the cbworldinformer It looks like brown,

BROWN - BLACK - BROWN - GOLD?

Click to expand...

Yes brown/black/brown is a 100 and that is typical for the output combiner stage in amps.

If the previous owner had it open before you got it he might have had a twitle with the trimmers there at the bias on either side of the input transformers and if that the case that would have changed the bias voltage to the base of the transistors and it may be too high or too low on one of them causing an imbalance, this is all just speculation and without checking the bias voltages on each stage one would never know.

Where's bob when you need him? It would not hurt anything to change the resistor and try it at normal drive levels and then you could feel of it to see if it's heating up rapidly(do not grab it while amp is in tx mode) you will recieve a nasty little rf burn.

If it does not heat up, by this I mean too warm to hold for 5 seconds immediately after being in tx it's probable that your overdrive scenario is correct.

So replace the resistor and transmitt for 10 seconds at normal drive and see what happens, worst thing is it will brown again and then you'll know that something is definately unkosher and if you feel it's beyond your capabilities you can ship it to me and I will play with it for several months or until you forgot where it's at.

If you need some resistors just say the word and I'll pop you some 2 watters in the post.

Unsolder one end and check for 100 ohms. If it appears good I would still change your 100 ohm carbon resistor to a 100 ohm metal oxide which appears to be an update by looking at the pictures.