Anyone heard of this amp and do I want it.

[lonestarbandit]

Chriscom thunderbird modulator

Looks like an older palomar style build with a meter? I'm not sure what it is.
4 pills but they're strapped Motorola so probably 4x mrf 455.

Are they decent? I see a 10ohm looks like smoke went out along with fact the smoked 10 ohm is with a oddball transistor to the other 3 so its probably not worth it, someone has tried to fix, but it's "interesting" by virtue of being different. Never heard of or seen this amp before.

 

[AudioShockwav]

The three 455's with green dots are matched for gain ( I think it's green I am on my phone) the oddball is not and even the MRF logo on that one transistor looks suspect.
If you were getting it, plan on replacing all four just to be good.

73
Jeff

( the twisted input/output wires looking like a BDW "gimmick" capacitor gives a clue who built it.)

 

[lonestarbandit]

The three 455's with green dots are matched for gain ( I think it's green I am on my phone) the oddball a not and even the MRF logo on that one transistor looks suspect.
If you were getting it, plan on replacing all four just to be good.

73
Jeff

( the twisted input/output wires looking like a BDW "gimmick" capacitor gives a clue who built it.)

It's worse than that. I think the last mrf 455 is NOT green but maybe brown? I didn't notice at first. Anyway the price has run away already people must be bidding expecting a working amp.
It intrigued me by being strange, but I'm betting I don't need that aggravation.

So Billy..... Billy and the G-G-G-Gray's (sung to Benny and the Jets) eh?

 

[AudioShockwav]

Unless you have a stash of 455 transistors I would pass......

73
Jeff

 

[lonestarbandit]

Unless you have a stash of 455 transistors I would pass......

73
Jeff
View attachment 65812

I do not Jeff. Yes, I saw that price list and about choked on my coffee. I think I shall heed that avoid advice.

 

[nomadradio]

Like the man said, it's a Gray, with a different name on the front. Has Billy's bonehead neutralizing trick, with the wire from each coax socket twisted around each other. Technical name for this is a "gimmick" capacitor. I call it the ghost of Billy.

It won't be a working amplifier until some mods have been done to it, even if the transistors are all still okay.

Won't catch me betting on that possibility.

73

 

[357]

I'd pass on it. if you want a ok 4 pill get a boomer 600

 

[lonestarbandit]

Like the man said, it's a Gray, with a different name on the front. Has Billy's bonehead neutralizing trick, with the wire from each coax socket twisted around each other. Technical name for this is a "gimmick" capacitor. I call it the ghost of Billy.

It won't be a working amplifier until some mods have been done to it, even if the transistors are all still okay.

Won't catch me betting on that possibility.

73

I'd pass on it. if you want a ok 4 pill get a boomer 600

Oh I've got amps. I just like dabbling with interesting or interesting different looking stuff. I've had my share of boomers, palomars, TNT, messenger and skippers, phantoms, firebirds, Kris etc but that one would be aggravating after talking it out lol. Glad everyone changed my mind for me.

 

[9C1Driver]

I'd pass on it. if you want a ok 4 pill get a boomer 600

The Boomer, Gray, and Palomar 600 were class C 1x4 amps with the 1446 final. They were prone to oscillation and ran hot. If you talk SSB you will want a different amplifier for sure.

 

[lonestarbandit]

The Boomer, Gray, and Palomar 600 were class C 1x4 amps with the 1446 final. They were prone to oscillation and ran hot. If you talk SSB you will want a different amplifier for sure.

Yep had a boomer 600. Got rid of it fairly quickly. Have a class B biased base amp and a AB palomar magnum clone aka Skipper/Cobra blue face and a few others. Do just fine on SSB quite a few compliments actually though I put that down to the Turner Plus 3 on the President Lincoln II +. Garbage in equals garbage out right? This one would have been just for giggles. I miss my PDX 400.

 

[357]

OK I thought they were biased ab1. maybe those big resistors are for something else?

 

[AudioShockwav]

It has the parts for bias, they just grounded it out.
There is a wire with a ferrite bead on it that grounds out the base of the transistor and puts the four finals in class c.
When you bias a amp the gain actually goes up, good thing bad thing.
Good because more output for less drive and it cleans up the signal, and bad because if you don't do it correctly it can make the amp unstable.
This builder chose to ground the bias out to avoid stability problems because it is a CB amp...
There are a ton of these and the 4 transistor amps that have the bias disabled.

73
Jeff