Any info on 606 Amp???

[WB4SNU]

A friend gave me a amp that he used on a CB rig. I can't find any info on this one. It has a metal plate on the back stating it can't be used on the CB bands.
I am going to assume it is a 10 meter amp. It has one tube inside ( can't remember which one without opening it back up). He used it on SSB but there isn't anything there to use it on CW.

I'll try to give a little info
The cover is green, white front with a off,stdby,operate,ssb knob and at tune knob. Small meter on the right front top. In and out on the back along with a fuse holder. Inside it looks like it was factory made with nice brackets and a couple of printed circuit boards along with the tube. It surely doesn't look home brew.

Anyone seen one of these and if so, what do I have. If I could post a pic. I haven't figured that out yet.

Thanks
Richard

[KA5N]

If it was a factory made amateur radio amplifier it would have a manufacturers name on it
and probably a serial number.  It sounds like a "disguised" CB amplifier.  Since it has a tube
instead of "Pills" (transistors) it might do for ham use depending on the circuit etc.
The plaque on the back saying it is not to be used for CB is just to confuse the quilty.
A picture and the tube type might help with identifying it.

Allen KA5N

[WB4SNU]

Thanks Allen for the info.
There's nothing on it to tell me a mfg. or maker. I was a little wrong on the metal plate on the back. It is a printed statement but definitely not a home brew printing. If it was homebrew, someone went to a lot of trouble to make it look professionally stamped.
 
I haven't found a way to attach a pic here yet.

The tube is a 6LQ6. That's the only tube in it.

It's quality looking inside. Nice transformer and circuit boards.
The next time I see my friend, I'll ask him where he got it.

I understand from asking about it to other friends that there was a couple of very small companies making CB amps fairly close to my town. It could be one of theirs.

If I can find any info, it might be a good amp for qro from qrp rigs since CB was 5 watts ( I  think).

[KB4QAA]

Have you checked the 'CB Tricks' website?

[K7MH]

Many CB amps didn't have any manufacturer info on them. Many were made in fly by night sorts of shops, basements and garages. Usually they were poorly designed without any biasing etc. They all had warnings about use on CB but that is what the target market was. There are very few ham amplifiers that you cannot find info about on the internet.
The 6LQ6 is a sweep tube with 30 watts of plate dissipation and is not a good choice for a linear amplifier. They were however extremely cheap to purchase back then so if you wanted to keep costs down to maximize profits they were a good choice on only that dimension.
Good for a few parts but that is about it.

[WB4SNU]

Thanks fellows for the input.
I think what I have is a good start on a homebrew amp. I am going to go back into my handbooks/internet and use what is there, as far as chassis and parts, for a small amp to build. The case is in very good shape and this will make a good winter time project.

Yesterday, I was given a Hallicrafters HT-32B to restore and so I have a good supply of restorations/homebrew to do this winter. It is in such good shape, it won't be a hard project. Just heavy to handle.

I am mostly QRP/CW now and the amp project could make a good start on a QRO amp when conditions are'nt that good.

Thanks
Richard

[W8JI]

A friend gave me a amp that he used on a CB rig. I can't find any info on this one. It has a metal plate on the back stating it can't be used on the CB bands.

Some people think that makes a CB amp legal to sell or build. Usually it means it is a CB amp.

The tube is a 6LQ6. That's the only tube in it.

It's quality looking inside. Nice transformer and circuit boards.
The next time I see my friend, I'll ask him where he got it.

Virtually none of the sweep tube amps, or any other CB amps, are acceptable for Ham use.  Usually they are class C, or have intentionally loose bias supplies that move in and out of class C, so they "swing" when "modulated" and so they are not critical for driver power.

If you use a very loose bias supply, it acts like ALC. Drive it hard and bias moves up, and reduces gain. Drive it light and bias stays low and gain goes up.  The only problem is, that trashes up the signal.

Encourage your friend to keep CB amplifiers off the Ham bands. Almost all CB amps have terrible odd order IM product levels. No good comes from using them.

73 Tom

[WB4SNU]

Encourage your friend to keep CB amplifiers off the Ham bands. Almost all CB amps have terrible odd order IM product levels. No good comes from using them.



Hey Tom
He is not a ham but when he gave it to me, I thought maybe it would be a ham amp converted to CB. No such luck on this one.

I'll keep it for chassis and other parts for my homebrew projects. I might use the parts that I can for a homebrew transmitter. Nice looking cabinet it came with and a few other parts that is in it.
I was hoping I could find a schmatic for it but no luck on that.

Thanks
Richard

[W9GB]

He is not a ham but when he gave it to me, I thought maybe it would be a ham amp converted to CB. No such luck on this one.
I'll keep it for chassis and other parts for my homebrew projects. I might use the parts that I can for a homebrew transmitter. Nice looking cabinet it came with and a few other parts that is in it.
I was hoping I could find a schmatic for it but no luck on that.

R -

NOPE.
VERY EASY for a Novice to ID .... No Multi-band switching, poor construction, assembly, RF keying (because CB radios could not remote key amplifiers!!).

It has a metal plate on the back stating it can't be used on the CB bands.

That was another Quick CON game ... there were less than TEN amateur radio HF amplifier mfg. in that period.  They are recognizable brand names with long histories.

There are tens of thousands of these illegal CB amps made in late 1960s / early 1970s.
Deaths, estate sales, hard economic times have produced thousands on Craigslist, eBay, flea markets -- but no $$ -- NOBODY wants them, especially on 10 meters.

The 6LQ6 vacuum tube was made for TVs as a Sweep tube, very cheap before solid-state TVs in 1970s.
Sweep tube mfg. in USA, an Western Europe closed in 1981.  
You surely remember that time period of rapid technology obsolescence.

Diagrams and circuits were adopted (some poorly) from 1950s and 1960s Amateur Radio literature.  
Parts salvage?  Throw out the capaciors and resistors.  You are left with a chassis already punched and maybe a good AC transformer of unknown ratings.
Metal scrap prices have risen faster.

[WB4SNU]

 
 
Parts salvage?  Throw out the capaciors and resistors.  You are left with a chassis already punched and maybe a good AC transformer of unknown ratings.
Metal scrap prices have risen faster.
[/quote]

That will be the plan. It will be good for metal parts, maybe the final cap., and the transformer.
I'll start looking tomorrow for a good small amp schematic or article for 40meters. That is about all I operate on anymore.

Catch you later and thanks for all the info.

Richard