Amplifiers
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Double Click Photo's for a larger image!

 

Here is  a nice lk-550 amp made by the amp supply company.  It runs 3 of the 3-500 tubes and works great, qsk and a vacuum relay standard!
 

 



 

Commander HF-2500e

I was lucky enough to find this amp from an individual. Ok step one was to install the transformer, it weighs in at 85 lbs or so.

to get this bad boy in there you have to let the front cover come down

boy what beautiful craftsmanship! the high voltage supply and capacitors, rectifiers are all underneath this deck. the fan pressurizes the deck. Nice way to get everything a little air.

boy looks at those torroids!

no whimpy bandswitch here

no qsk . well we can fix that in the next picture

The old relay was operated on 12v. I ordered the 12v coils for these kilovac relays. 12 bucks each . not too bad at all. now no more clickady clack.

there is not much space wasted. this is with the back panel layed back while installing the new relays

Here is a shot of the blower and control circuit power board with the back panel down

Well there it all is ready to go what a nice machine, well done commander!

 



 

Henry 2k-2

 I did a few mods to the old henry. this shows the tuned input I built for

160 meters. It is installed in the 80 meter position.
 


 

Alpha 76pa amp I came across and is as clean as I have seen. No dust even on the plate caps or the fan blade. Sure is pretty to look at inside, must be a later model as the capacitor equalizing resistors are of the newer style. The capacitors look new in the power supply also.  I hate to even use it!

 


 

ALPHA 76PA Tube Conversion

Here is one of my alpha 76pa amps. ready for conversion to 3cpx800a7 tubes. This is with the 3 3cx400a7 tubes

This shows the tube box with the middle socket removed and one of the 800 tubes in place for effect. There are many ways to cover the hole

Here you can see i built my own parasitic supressors and replaced the disc coupling capacitors with a single doorknob cap. Also i had already installed the vacuum relays nice and quiet!

I opted for the peter dahl transformer they offer for this conversion. Although not needed to do the conversion, it makes it a plug and play conversion you also you end up with 2800v of plate voltage, which the "cpx" version tubes really enjoy! Tuning is smooth and power is great.

 


 


Alpha 76pa to 6 meters conversion!

Here is the alpha with the tank circuit removed.

Here is the finished tank circuit, the plate choke was retained as well as the input circuit which was well suited for this freq. The old plate capacitor is now the in the C2 position. I also installed vacuum relays. Power out is just under a kilowatt with good tubes.

The finished amp is on the right with no more bandswitch, also I have a chrome plug inserted for now. On the left is the 3 hole hf amp.


 

This is an AEA Amp LA-50 made for 6 meters, it uses a single 3-500 tube

Older model al-1200 it has the Grey front panel and the serial# is 150. works like a champ

This is my highly modified LK-500za made by amp supply. I have spent many hours inside this dude, now it is one of my favorite ones to use. It uses 2 of the 3-500 tubes. still has the old eimacs in it


 

Henry 2 meter amplifier, uses a single 3cx800a7 tube


 



 

My homemade Amplifiers. 160 meter through 10 meter amp it uses a 4-1000 tube and runs 5000 volts on the plate.



 


 

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