For those that want a BIG amp

[Wiskey Delta-40]

All I can say is... I would hate to get that power bill at end of month




Linear Amplifier 3-500Z Power Triode (9 Tube Mono Band) | eBay

 

[AudioShockwav]

9 tube 3-500Z amp....mono band, hummm wonder what band that is built for?
Give you 3 guesses.


73
Jeff

 

[wavrider]

Cooling fans only on the top of chassis, no air flow around the tube sockets.

Three guesses?
11 meter
CB
Charlie Brown

Looks to have a Peter Dahl transformer so it does have some heavy Iron.

 

[vo1ks]

It would likely have been easier to build around a single 3CX3000A7 than try to lash nine tubes together in parallel that way. I have the tube, socket, filament transformer, etc. Just don't have the time or interest to glue the rest of it together.

 

[Captain Kilowatt]

It would likely have been easier to build around a single 3CX3000A7 than try to lash nine tubes together in parallel that way. I have the tube, socket, filament transformer, etc. Just don't have the time or interest to glue the rest of it together.

REALLY? : Hmmmmmmmmmmmmmmmm......................................that would be a lot better than a pair of 3-500Z's. If I had that I would say the hell with the nice glow of the tubes and worry about the nice coronal glow of the antennas instead.

 

[Robb]

9 tubes being driven by two ??? tubes???
New to this stuff . . . sooo, what tubes are they?

A parasitic choke too . . . how thoughtful . . . lol . . .

 

[WA8ZYT]

Room would have to be air conditioned, to take the heat, even in the winter.

If the price were lower, might be worth it for the spare parts.

I wonder if it even works?

 

[Captain Kilowatt]

Nine being driven by two?? Where are the other two??

Oh wait...............those things on the left of the picture mounted horizontally are not tubes. They are vacuum variable capacitors for the tune and load controls. The tubes are 3-500Z's.

9 tubes being driven by two ??? tubes???
New to this stuff . . . sooo, what tubes are they?

A parasitic choke too . . . how thoughtful . . . lol . . .

 

[wavrider]

Looking at the tubes I see no markings at all. Tubes were probaly driven so hard they got so hot the markings are gone.

I still have the original tubes for the SB220 in the shack, lettering is still bright RED and full power out.

Those 3-5's are a rugged tube but when over driven they can become soft real fast.

Notice lack of meters on the RF deck? No metering circuit so who knows what the Grid current is. Looks like maybe an Plate current meter on the PS deck.

Not even worth parts both the filament TR and Plate TR, variable caps and sockets can be purchased a lot less expensive than asking price. Tubes most likely shot and who knows how much solder has been melted in the filaments due to excessive heatand no proper cooling on the socket.

 

[RatsoW8]

Someone must have reported it because it's gone from eBay!

 

[BJ radionut]

CK: I don't think the ding-aling that built that was concerned with Grid or Plate current
What an honest waste of good tubes!
Notice if you will the plates in 3 or 4 tubes in the upper part of the picture...notice the distortion in the alignment of the fins...Looks to me compared to the others they show excessive heat....showing me there was not a balanced load...
If I had to guess you would find multiple filament chokes under the chassis and none the same construction...just a guess though
But look at her swang...
All the Best
BJ

 

[vo1ks]

One of the tubes was on the table in the garage when you dragged away the other parts. How could you miss a 3CX3000A7?

REALLY? : Hmmmmmmmmmmmmmmmm......................................that would be a lot better than a pair of 3-500Z's. If I had that I would say the hell with the nice glow of the tubes and worry about the nice coronal glow of the antennas instead.

 

[555]

It would likely have been easier to build around a single 3CX3000A7 than try to lash nine tubes together in parallel that way. I have the tube, socket, filament transformer, etc. Just don't have the time or interest to glue the rest of it together.

for some the 3000 would be a better choice
and for other some people have to go to the radio station at the first of every year and pick up the old tubes and replace with new tubes
even the pulls are at 85 to 90 %
since the tubes have to be "recycled" not just thrown in the trash
then thats where some of us have a good supply of tubes

and by the way this is just a 9 tuber
you should see the 12 and 15 tuber that was sent to Colorado

 

[vo1ks]

I've seen a Loran-C transmitter built in a similar manner. There was a string of 4-1000A tubes placed in parallel just like that. They were drivers for the final tubes. I think output power was on the order of about 50kW peak at 100kHz. It connected to a 1800 foot tower as the active radiator. A few years later the tower collapsed. I saw pics of what landed. Tower legs bent like pretzels...

 

[Captain Kilowatt]

CK: I don't think the ding-aling that built that was concerned with Grid or Plate current
What an honest waste of good tubes!
Notice if you will the plates in 3 or 4 tubes in the upper part of the picture...notice the distortion in the alignment of the fins...Looks to me compared to the others they show excessive heat....showing me there was not a balanced load...
If I had to guess you would find multiple filament chokes under the chassis and none the same construction...just a guess though
But look at her swang...
All the Best
BJ

It wasn't me that mentioned the lack of grid or plate monitoring but I agree with you 100%.

One of the tubes was on the table in the garage when you dragged away the other parts. How could you miss a 3CX3000A7?

OK Warren, now you are just killing me. ONE of the tubes he says...........jeeeeeesh.

So it was in plain sight hey? How did I miss that? Is it still there? What time do you leave the house tomorrow? How long will you be gone? Do you set the alarm every time you leave? What`s the code?

Oh wait................I work tomorrow. In fact I begin another four day rotation starting tomorrow. You're safe.