[Hammarlund] Hammarlund HX-500 problems

[Charles Ochs]

I think you are going down the wrong path here. The tip-off was "blows 6 amp fuse after a minute".
This obviously indicates that something in the transmitter (somewhere) is drawing excessive current. This is a very dangerous situation, and you should NOT run the thing for long until you have located the problem. 
Get an ammeter in line with the AC input so that you can constantly monitor line current. A 10 amp meter will do fine.
Pull ALL of the rectifier tubes, and turn the beast on. A variac would be very helpful here, as you could then back off the voltage if you see something "bad" happening. It is very possible that you have a bad power transformer, probably a few shorted turns in the primary, and this test will determine if this is so. If you can run the set with the rectifier tubes removed indefinitely without drawing excessive current, than the transformer is probably OK. Count your blessings, and move on. Replaced a lot of electrolytics, you say? Did you use NEW ones? Are any in backwards? Did you test them before installation? I have known even brand new caps to be shorted. Rare, but it happens. Start here. Then, get back to us!
Chuck N1LNH