I am offering these homebrew 4-1000A amplifiers, with the below listed extra items, for TRADE only. I have never had either of them powered up. There are some nice quality high power RF parts inside these if you'd rather use them for parts. For trade material I am particularly interested in other boatanchor gear ( NO HEATHKITS! ) or ESPECIALLY 1920s - vintage battery sets. Don't hesitate to make me a trade offer, I am very interested in getting this stuff out of my garage. I've decided I won't be able to use this stuff at my current QTH.
The catch is, they are so heavy that it will be necessary to pick them up at my QTH in Westminster, CO ( near Denver ). I would like to get rid of the stuff all at once, so bring a truck.
Again, I'm really only interested in trades for this stuff. Contact me at [email protected] or [email protected] if you are interested.
The first amplifier deck looks mostly complete, however you would have to add the HV supply ( I have it but it is not built into the amplifiers, see below ) and an exhaust blower. Filament transformer is built in. The plumbing is there for the chimney exhaust, just need to add a blower. I have a squirrel cage blower I'll throw in to the deal. The amp has a 4-1000A tube with SK-500 socket and chimney. The OT from whom I received the set told me that the 4-1000A was still good, and the amplifier worked when he put it away in storage. I have no way to test this, but I certainly trust him. I believe it covers 80, 40, and 20 meters. I was told it was designed as class AB1.
Here is the bottom side of the first amp. Here you can see the plumbing for the 4-1000A cooling.
Closeup of socket:
Here is the back end of the first amp:
Here are the "guts" of the second amp. Some nice bread-slicer caps in there. I beleive that some of this amplifier was cannabilized a little for parts to make the first amplifier. Who knows? It is still mostly there.
Front/side/bottom?:
Closeup of socket and input circuit. Looks like multi-band tuned input.
Here is the side of the second amp. There is a blower fan and a MASSIVE filament transformer visible on the right. This deck is HEAVY! Input circuitry is seen on the left.
This apparently was part of the power supply. It is a Thordarson choke, 10 Henry at 450 mA, with a rectifier (diode/cap) network built onto a perfboard sitting above it. Very heavy.
Below is also apparently part of the power supply.
Some big old variacs mounted on a panel. He told me that they were used to adjust the primary of the filament transformers for the 4-1000As. They are: Variac Type 100R, 230 V 60 hz at 9 AMPS. The other is a Powerstat with the same specs. Super-heavy.
A spare 4-1000A and two extra chimneys.
Very large HV plate transformer. Probably 100 lbs! Has 2 primaries- 0-117-141 each; secondary rated at 5760 VDC @ 320 ma or 4800 VDC @475 ma. Scary stuff....
More high-voltage power supply.
