The AM Forum

OK, so I finally put the Viking II that I got at the W0ZUS auction on the workbench tonight. It was filthy and had no power cord, so I was expecting the worst. First, I noticed that all the cabinet screws were present, every last one of them. That was good I thought, usually about half (or more) are missing. There was only one extra hole on the back of the chassis which had a shielded clump of wires coming out of it. Got it out of the cabinet to find that it was a factory wired unit, serial# 11507 (did they really make that many of these?) The shielded wires were in parallel with the high voltage switch probably to throw a relay for receiver mute or something similar. That was easy to restore. Installing a new power cord also no problem. Everything else appeared to be original, and looked great. The filth was just dust, dirt, tobacco residue, and some straw(??) It cleaned up very nice. Applied power with no tubes in the sockets, no blown fuses or fireworks. Reinstalled tubes one by one, everything still OK. Measured voltages - right on. Put a crystal in the socket, meter readings also right on. Attached dummy load, loaded up to 300mA on 40 meters just like new. Guess I'm living right.

I have an idea for the audio. Rather than do one of the usual mods, I think I'm gonna build an external modulator with 809's and a Triad M12AL mod transformer. Will just leave the stock audio section on the chassis, but disconnected. Has anybody ever done something similar?

Ron W8ACR

Great find Ron!  Based on your thread title, I assumed the story was going to include an "I got across the final B plus  on top of the plate choke while troubleshooting, but lived to tell the tale"!  Glad that it didn't.

10,118 built reportedly across all versions.
My CDC version serial is obliberated but various date codes indicates it was one of only 48 produced in 1961, the final year.

Carl

Is there any other mechanical device known to man that has screws more difficult than those ten machine screws that hold the Viking II cabinet together?  ............. Or mebbe I just don't have the right tool :P

Still easier than the kw match box

The eighty bazillion screws that hold the (3) shields on a HT-20.  There's one per inch or so, and closer at the corners.  Not that they're difficult to get to, most of them, just a giant PITA.

A  bit more spread out. but the same with the shielded RF deck for the Viking Kilowatt. The back of the RF deck for the KW-1 has 2 removable plates not counting the alignment door. Must be 30 or more of those little self-tapping things involved, which will wear out and strip if removed and installed too many times. At least as many on the Viking KW. Haven't had a Matchbox apart for a few years, but it's no walk in the park either.

The HRO-500 is up there in the PITA factor since getting at many requires being a contortionist, wobble extensions and some other disassembly to reach. At least its only 42 pounds. Replacing them is about 3X more fun requiring additional speciality tools or procedures.

Ron, if the screws are like the HT-20 screws forget about using a flat head driver.   If the screw heads are the kind that have 6 (or is it 8 ) sides and a flat head slot that is.  On the HT-20 the heads stick up no more than 1 mm--some may be so tight they are sunk into the surrounding sheet metal a bit.  

You have to use a socket nut driver.  The driver won't work as-is for the end of it is rounded too much and won't grab the screw head.  You have to get a file and file it down so the end surface of the driver is flat.  Put it down over the screw and push down and turn slowly by hand and the screw should loosen.  The nice thing is that if the screws are in weird places you can use extenders to get to them.  It's not a bad idea to file down the ends of all nut drivers (in my opinion).

At least with the Matchbox the screws (annoyingly flat head slots) are easy to get to if one needs to be backed out.

Rob

Nope, these are flat head round machine screws. They usually aren't stuck, it is simply impossible to get a flat tip screwdriver tip onto the top of the screw due to the impossible angle and the proximity of large immovable objects on the chassis such as transformers. Very poor mechanical design. >:(

Ron

PS: after much wailing and gnashing of teeth, all ten screws are happily ensconced in their assigned position :)