Wednesday night, Sept. 16, 2020
I have been working some on cleaning my main shack this week and making progress. I found some goodies that I’ve already sold on eBay, so I need to keep digging out more. I have not one, but TWO Heil Classic microphones that I bought when Heil was discontinuing that model. I got a good price on them, but never put used either one. I later found a used one on eBay and I have it on a boom here in Studio B in the library. I’m going to put both of them on eBay, they’re new in the box and should bring a decent price.
But the last couple of days I’ve been digging deeper in the attic, and finding some good gear, including two National transceivers I bought back in — believe it or not — 2004.
One rig is a National NCX-200 HF transceiver. It included a Heathkit HP-23 for a power supply. The voltages match with the exception of the bias. The Heathkit rigs have a positive bias voltage; the National has a -80 vdc bias.
I connected everything an hit the power … the dial lights lit very briefly and then one of the 3 amp fused blew. I replaced the fuse twice, thinking at first that the power cord was shorted at the plug, but no go. I think the problem is the power supply, either the caps or the rectifiers. I looked at the chassis and it looks like a bunch of resisters were installed to create the proper bias. I considered buying a rebuild kit to replace the caps and diodes, but I’ll still have to leave the jury rigged voltage divider thingie to provide the bias.
The NCX-200 is very very mint — no major blemishes or scratches; there’s a molding on the lower part of the front panel that is supposed to have the model number there; mine is missing the lettering, though it looks like it was polished.
NATIONAL NCX-500. This rig and the matching supply were boxed together in one big-ass, heavy-duty box. Each component was boxed separately, which did a good job of protecting each from damage. When I finally got thru the packing, both the power supply and rig were in fantastic shape for staying in my attic since early 2004!
I couldn’t help but connect the radio up to see what would happen. The dial lights came on and the radio warmed up to signals on the 75-meter band. It took a while for the rig to warm up and settle down, but once it was warmed up it played quite well. I did a preliminary test of the transmitter and it was a solid 100 watts. I need to check the bias and make sure that its set correctly before I try any extended transmit testing. The manual is very specific about how to tune up the rig, so I need to review the setup before I try the rig out on CW.
The rig looks fantastic! The only problem I could find was a tight spot in the tuning. The knob acts like it is slipping a little, but the dial mechanism is gear-driven, so I’m thinking the mechanism may be binding a little, and the knob is turning on the shaft. I need to take a jeweler’s screwdriver in the shack and check the set screw.
I’m not sure I’m interested in keeping both rigs or either rig. I wouldn’t mind running the NCX-500 for a while, just to run a different classic rig. If I find the proper supply, I’m thinking that the NCX-200 is probably OK, and the fuse problem is in the power supply. The power supply for the NCX-500 is a heavy beast; I’m thinking I would probably sell them separately when I do list them.
The ironic thing is that I had marked the box with the NCX-500 and supply as a “Hallicrafters SR-150”! When I tried to move the box, I knew it had to be a rig and power supply in the same box, though I had the wrong rig in mind!
Speaking of Hallicrafters, I did run across a PS-150 supply that goes with the SR-150 and SR-160 transceivers. I have a SR-160 in the basement I’ve never opened up either, so maybe its time to check that one out — after I get these National rigs out of here.
POWER SUPPLY REVAMP. One of my recent discoveries in my shack was a new-in-the-box rebuild kit for a Swan 117XC supply. Its the complete kit, including board, caps and all the parts. I’m going to put that kit to good use; actually, I could use a second one since I have two of those Swan supplies.
The most recent one I have used with the Swan 350 doesn’t have any hum, snaps or crackles. The original Swan supply I have that’s in the shack — and I used 1990 with my Swan 250 — had some crackling and hum. But both supplies could probably use a rebuild.
I’m thinking of buying a rebuild kit for the HP-23; the only thing I have to keep in mind is that I will need to retain the -80 volt bias for the NCX-200. Actually, before I do that, I’m thinking of checking to see if I still have a National power supply that’ll work with the 200. I’m tempted to rebuild the HP-23 back stock to work with one of my Heathkit rigs.
The NCX-200 and the NCX-500 are basically the same rig; the difference is in the finals. The NCX-500 supply features 1,100 vdc high voltage, while the NCX-200’s supply tops out at about 800 volts. I’m tempted to hook up the supply to the NCX-200 just to check out the rig; it might be ok since the high voltage only serves the finals.
73 es CUL … de KY4Z …. SK … SK …. (dit dit) …