Anyone retrofit an older base Amp case with solid state?

[Don_Q]

This is my other project. Just got it, voltage needs work. This is what the seller quoted "It does work but high voltage is off by 200 volts. It does have a ding in the front around the chassis and maybe one on rear top. It works and all tubes light up fine."

 

[Tallman]

The amp choice really depends on which radio you will run as your primary.
I strongly suggest using Mega Watt power supplies. Especially the 50 amp version.
You can parallel 2, 3, 4, or more together easily and maintain good regulation and they are tough as nails. I have two of the 36 amp supplies and I have admittedly ABUSED them and they still work fine. I also have one of the 50 amp units and these are all used on my ham radio station and amp repair station.(It is closed)

 

[Don_Q]

Very cool, I will most likely look into these and see if I can shoehorn it into the case or have them outside the case. Obviously I dont want the case cluttered to keep it as cool as possible, might do a fan like my other amp (pictured above).

 

[Onelasttime]

Just install different tube socket for an available tube. If want solid state you pretty much will have to gut the old tube amp so why bother might as well just build what you want and toss it in a project box. I would not waste my time with old bipolar designs like the 2879 unless you have a lot of them on hand. Let be clear for a base station amp. I would go LDMOS and either go with 110 or 220V. Then you are not having to step up or step down power from mains. You would then just be regulating and cleaning up the power mostly to make sure you did not draw more current than your wall socket can supply and to clean up the dirty electricity most of us int he USA have supplied to our homes. If you choose wisely you can find LDMOS that can work from 50V to about 500V depending on what you choose. The latest stuff designed for RF has crazy insane SWR rating both loaded and unloaded. They have really high multiplication factor or gain so long as the voltage is not low. So you can realistically get 1200-5000 watts with an input drive of 100watts. The really good stuff is high voltage and high amperage so the only limiting factor at home is the wiring inside your walls and going to the power poll and the breaker ratings. Most home circuits in America vary between 16 and 45 amps of current rating in all the places I have lived with 25-30amps being the norm. I am not an Electrician so my observations really only apply to me. If you are already set up for 220V I would consider going that way as well. I have 220 in my garage so it would not be hard to brin 220 into the rest of my home. If I had large enough tube amps I would consider 220V as well.

I have some LDMOS transistors sitting around but I have about 8 bipolar PCB boards I need to build before I play around with my LDMOS.

You could prob. use most of those parts inside that amp to build a single tube unit with a Russian GI-7BT tube. Might need a different diode board like one from a Heath Kit SSB-220 or the like.

 

[Tallman]

 

[loosecannon]

you are not going to be able to use the transformer and other power supply components from that tube amp to power transistors.

the tubes need high voltages, and the transistors will need low voltages.

the other guys are giving you good advice about the switching power supplies, i just didn't see anyone else actually telling you 'no' to the idea you had about using the tube power supply for a transistor amp.
LC

 

[Tallman]

you are not going to be able to use the transformer and other power supply components from that tube amp to power transistors.

the tubes need high voltages, and the transistors will need low voltages.

the other guys are giving you good advice about the switching power supplies, i just didn't see anyone else actually telling you 'no' to the idea you had about using the tube power supply for a transistor amp.

It can be done. Just need to pull the High Voltage power supply for the tube amp and put a low voltage power supply like a Megawatt 12 volt.

 

[n8fgb]

This is my other project. Just got it, voltage needs work. This is what the seller quoted "It does work but high voltage is off by 200 volts. It does have a ding in the front around the chassis and maybe one on rear top. It works and all tubes light up fine."

This amp loves the GI7B tube. Everything is available, if you search.
Rich

 

[Robb]

With tubes getting harder to find I was wondering if anyone has retrofitted solid state into an older base station style amplifier (lets say a Palomar 300)? Did you use the existing power supply transformer? With the size of that case I think it would have plenty of real estate for putting in 6 pills. The reason I ask is that I like the look of the older (vintage?) amps, but want the reliability of the newer solid state hardware.

I agree with loosecannon. Fix it as a tube amp. I don't see any real reason why one would go to the trouble to gut an old tube box just to put a transistor amp in. Seems silly to me. But hey; its your toy.

 

[Don_Q]

I agree with loosecannon. Fix it as a tube amp. I don't see any real reason why one would go to the trouble to gut an old tube box just to put a transistor amp in. Seems silly to me. But hey; its your toy.

Thanks, I am looking at options at this moment. thanks again

 

[SuicideRide]

I have 35+ tube amplifiers & the Bearfoot is 1 of my FAVORITES!

Tubes are still cheap & available on feebay (& there's only 3 of them!)
It doesn't weigh a ton
fan noise is negligible
it's lowest output setting works really nice as a driver
very clean output signal

Pay to fix it (or fix it yourself) & you won't be disappointed!

SR