Looking for "Gray 600" Info

[Hoss903]

Good afternoon fellow radio enthusiast. Got another question to ask because yet again Google has failed me. Haha

My buddy has a "gray 600" and we opened it up today and saw it has 5x2sc2290 inside of it. ( I know this is useless w/o pictures. I will get some tommorrow) he was told it was a 1 driving 4 linear, but everything I can find on the net is showing a 2290 driving 2879's. So this doesn't seem to make sense to me. Is it possible that it is just a strait "5 pill"? Oh and they are toshiba transistors!! Any thoughts on this guys?

 

[Hoss903]

Here is an external. All I have for now.

 

[AudioShockwav]

It is a knock-off cb style amp using the gray name.
1 2290 driving 4 2290 transistors.
Low drive, couple of watts input and i doubt it has any bias for SSB.
Transistor amps are built in push/pull pairs, 2, 4, 6, 8, and so on 5 is 1 driving 4....not really needed, but they do it anyway.
73
Jeff

 

[Hoss903]

It is a knock-off cb style amp using the gray name.
1 2290 driving 4 2290 transistors.
Low drive, couple of watts input and i doubt it has any bias for SSB.
Transistor amps are built in push/pull pairs, 2, 4, 6, 8, and so on 5 is 1 driving 4....not really needed, but they do it anyway.
73
Jeff

Oh ok. Thanks again Jeff. I wish we didn't have to deal with the "knock off" stuff. It makes it real hard for the newbies to find info. Lol. But if the demand is there its gonna happen. I will post an internal pic tommorrow that way it might be able to help the next person in my situation.

 

[9C1Driver]

H & Y used to sell three versions of that amp, Boomer 600, Palomar 600, and Gray 600. They were all 1x4's and had either all 1446 finals or 2290's.

 

[ExitThirteen]

They can be reworked with biasing so they can sound good, but I highly recommend bypassing the single "driver" transistor, and making it a "straight 4 pill". It will run much better that way.

~Cheers~

 

[Hoss903]

They can be reworked with biasing so they can sound good, but I highly recommend bypassing the single "driver" transistor, and making it a "straight 4 pill". It will run much better that way.

~Cheers~

Awesome! I'll let by buddy know. Appreciate the info

 

[Hoss903]

Here are the internal pictures.

 

[psycho]

I have always been amused at how these amps get named........1 2290 x 4 2290 is a 400 watt peak amp. The assembly looks real nice.

 

[psycho]

H & Y used to sell three versions of that amp, Boomer 600, Palomar 600, and Gray 600. They were all 1x4's and had either all 1446 finals or 2290's.

That amp looks nothing like a crappy Boomer or Palomar.

 

[AudioShockwav]

Exit has very good advice, lose the single 2290, add some bias and keep the drive at a reasonable level.
This would then be a decent 250/300 watt amp after that.



It is the way all of these type amps have been rated that is deceiving.
For real use, 4 2290`s realistically should be called a 250, and 4 2879`s a 350.
For sure these amps will make more power, but none were built anything close to being able to run modes like AM at 100% duty cycle, some struggle to do SSB for any length of time without getting too hot.
And no bias just sucks...really.
Big numbers equal more money in the wallet of the builder, and "feel good" in the buyers mind.
Even older tube amps were rated at the total input power, not output in RF and suddenly they were 100% efficient and guys would claim they would make 8 or 900 watts output.
Feel good is some powerful stuff,it can get you to empty your wallet out for extra seat-of-the-pants horsepower

73
Jeff

 

[Hoss903]

What would be the purpose of getting rid of the single 2290? I do not doubt what you guys say but I would like to know why. I understand the push/pull and running the transistors in pairs but what was the "intended" purpose or reason of having the extra 2290.

And thanks again for all of the replies guys.

 

[9C1Driver]

That amp looks nothing like a crappy Boomer or Palomar.

Maybe they made others I don't know. I have an old paper flyer from H & Y that shows a Palomar 600, Boomer 600, and Gray 600 for sale. All three amps looked the same except for the nameplate. They were all 1x4's with 1446 finals.

 

[AudioShockwav]

Most of the boomer knockoffs h&y sold had vertical transformers in them.
This one don't look like a Vern built, it is class c from the ground-up.....

The single 2290 is a "driver"
Unless you have a weak radio, it is not necessary to put a driver in front of 4x2290's or 4 x1446's, both transistors have enough gain.
(I have never been a fan of amps with a driver built in, so take my advice with a grain of salt.)
More heat, more current, more possible problems and not enough difference to make it worth it.


73
Jeff

 

[grimace]

looks like a old Real Deal amp to me