Galaxy-X4 popped a pill

[Cable Guy]

All finished. I didn't have a 10 ohm carbon resistor so I used a metal oxide. Is that okay?

 

[Xracerx13]

I wouldn't lay those brown mylar caps over. Wouln't want a leg touching the transistor flange screw.

 

[lonestarbandit]

Looks good though I agree on not encouraging potential shorts. In fairness though, mine had flyover resistors nearish to flange. Obviously not a TS though.

 

[Cable Guy]

Thanks. I was putting it back like it was but if that isn't meant to be like that I will change it.

 

[lonestarbandit]

I'd say honestly whatever works for you.
If thats how you found it then that's how ya found it. If it smokes, it you'll rebuild it. It could run forever like that and never have an issue.

 

[Xracerx13]

The only thing that bothers my eyes is the little jumper from the center of the board behind the input transformer that goes to the 3rd transistor flange. Whats up with that?

 

[lonestarbandit]

The only thing that bothers my eyes is the little jumper from the center of the board behind the input transformer that goes to the 3rd transistor flange. Whats up with that?

Good eye I missed that. Only thing it could be is a ground? IDK I've not seen that before but I haven't been in TS amps.

 

[Xracerx13]

Its not a TS (Texas star), its a glorified Palomar 400.

 

[lonestarbandit]

Its not a TS (Texas star), its a glorified Palomar 400.

Quite right Sir. I've been following a TS repair on another page and my mind totally conflated the two leading to my two idiotic statements. It is quite clear from the photos it is not a TS.

 

[nomadradio]

The strap across the emitter leads of the transistors reduces the resistance of the transistors' ground circuit. Any voltage drop between the transistor and ground reduces drive power to the transistor. The strap provides a tiny boost to peak power output, but nowhere near enough to matter in a practical way.

73

 

[Cable Guy]

The only thing that bothers my eyes is the little jumper from the center of the board behind the input transformer that goes to the 3rd transistor flange. Whats up with that?

It looks to be a ground. The chassis is grounded to board ground plane via so239 ground, side rails and that ground strap to pill 3 flange. My inexperience doesn't see an issue unless Maybe ground loops.

 

[Cable Guy]

The strap across the emitter leads of the transistors reduces the resistance of the transistors' ground circuit. Any voltage drop between the transistor and ground reduces drive power to the transistor. The strap provides a tiny boost to peak power output, but nowhere near enough to matter in a practical way.

73

That's kinda where I was going with it, figured it would be a negligible thing unless it also acted as a RF shield of some sort

 

[Cable Guy]

What numbers should I be seeing out of this amp with a 3 watt dk and 18 pep? I know it should be driven from about 1 watt dk but the radio I'm testing with isn't variable and I don't want to pop the hood on it. I'm currently seeing 40-110 dk from low to high but only ~300 pep on high. Friend said it was about 450 watts before but he could've been overdriving it, entertaining a reading from a happy meter, or both. I want it to be right before I give it back to him and not pop the $200 investment in this old box.

I reinstalled it for more accurate numbers (as accurate as the meter(mfj-870))
Dk 3 watts is low 30, med 65, hi 100.
Peak 18 watts is low 130, med 260, hi 325.
Into dummy load.

Sorry, posted this in the wrong thread so moving here.

 

[144inBama]

The numbers are pretty good for 4x1446s. You could get a little more if you beat the guts out of her and stressed everything, shortening the life by half....I wouldn't push her much more than what you have if it were mine.