President Dwight D

Having fun digging out some of the barn finds and such from the junk pile in my attic. I picked up a President Dwight D CB base station sometime in the early 80's, don't remember when exactly. Got in a deal with some other radios and it had a few problems, mostly screwdriver related. Tossed it on the 'to do' pile, and never did it. It's been in the attic of our home since we bought it and moved in back in '93. Repaired the squelch circuit, cleaned all the controls, aligned the receiver, cranked up the audio a bit and tuned the transmitter. Clock is bad, and from what I hear, that's not uncommon. Wired one of my Turner +2 desk mics to it, and it plays good. After a lot of scrubbing and cleaning, I found a there was a pretty nice looking rig in there. It's just a 40 channel AM rig, but still a nice CB radio from 'back in the day'!

 

JPS ANC-4 finally repaired!

My XYL, Debbie AC4QD, bought this for me as a gift back around the early 90's...don't remember when, exactly. It came from Bill K4BWC (now SK) at Omega Electronics, and was a huge help at our apartment ham shack. We were plagued by all sorts of locally generated noises and interference, and this thing did the trick!

We bought our home in Youngsville in '93, moved , and set up the ham shack at our new location. All was well until a big lightning strike in '97 that destroyed nearly every piece of gear we had, including the little JPS ANC-4. I repaired most everything, but this one got tossed on the shelf in the workshop, unrepaired. Time moved along. Our new location was much better and very few noises bothered us. Every now and then I'd think about it when spurs from the wide screen TV or laptop would bug me.

Recently, I decided to pull it down off the shelf and revisit repairs to it. The damage looked worse than it really was... a melted & destroyed relay, a flamed out pair of 100 ohm resistors, some minor curcuit board damage, and a pair of blown 2N7000 FETs in the rf sensing circuit. All parts were less than $5 from Mouser Electronics.

I ordered up the parts, made repairs, and it's back in it's rightful place in Studio A, fighting away spurs from the TV and looking good. I had forgotten what a neat accessory this is. JPS has long since gone out of business, and TimeWave picked this unit up and produced it for a number of years. The TimeWave circuit is basically the same, with only a couple of improvements over the original JPS design. The parts layout on the PC board are the same, even the cabinet is the same. I see these on the ham radio swap forums for $75-$125, and it seems that all parts are still available for repairs.

If you live in a location with locally generated noises and interference that hamper your HF/6 meter  operations, this is a good solution. It uses a built in telescopic whip antenna for noise reception, and has a port on the back for an external antenna if your noise is coming from a source that's not physically in or near  the shack. It samples the primary antenna and the noise antenna, and uses a phase cancellation method to eliminate the unwanted signal. I can even hear signals that were previously below the interfering signals.

When you see these at the swap meets or online, remember that it's a great accessory for your shack, and works quite well at removing those aggravating spurs and extraneous signals that most all of us deal with from time to time. I'm happy that mine is finally back up and running, though it took me 17 years to 'get around to it'  :-)

73
Dave WB4IUY
www.WB4IUY.net

Wawasee 8417 One Tube Mobile Amp

This was a mobile amp that was somewhat common back around the late 1970's. It used a single 8417 tube (similar to a 6L6, but much higher output), and a pair of chopper transistors with a toroidal transformer to generate the high voltage. This is a grid driven amp, using a variable transformer input / 50 ohm swamping resistor to maintain a 50 ohm input, and a link coupled output. They work pretty good with a QRP rig on 10m, and would provide about 100w output on SSB, 50w on CW, and about 35 watts carrier on AM. The DC-DC converter in amps like this is noisy, but you could stuff it under the seat or in the trunk and it all was well. 

This one originally had TO-3 style PNP germanium switchers. They had failed (not uncommon on this model) and damaged some wiring when that happened. I drilled the heat sink for a pair of much heavier TO-36 devices, capable of handling much higher current values and better heat dissipation. The flex cable from the center pole of the relay is what switched heavy current for the power supply, and had also failed. I replaced it with a heavy piece of copper braid, as well as a few capacitors were replaced. 

Kris Boomer Upgrades

This is an old Kris monoband amp from back around the late 70's. They were simple grounded grid amps using a pair of 6JU6 sweep tubes. This amp was a dog when I got it...power supply problems, rf sensing problems in the keying circuit, tubes shot, and other issues. I set out to get it running and back on the air. 

Before I would repair the other issues, I had to locate a set of tubes. The 6JU6's are almost unobtainium these days, in new condition. I had been looking at a Russian glass tube that is still available as new, and decided this was a good time to test my idea. The Russian tubes are larger, but have the same tube socket (and are fairly inexpensive!)...I rewired the sockets, repaired all of the other issues, and set it up on 10 meters. With a Radio Shack HTX-10 this little amp now does about 150 watts out on SSB, & about 100 watts out on FM. 

Below are a few pics, including some to show the difference in the physical size of the tubes...

There was a considerable difference in the physical size of the tubes. They were pretty close to the top cover, but with some work around the parasitic suppressors and plate caps, I was able to fit it all inside.

Craig 4201 23 Channel CB Base Station

This is a Craig 4201 23 Channel CB Base Station that a friend found on eBay, and purchased it for another friend as a gift. He brought it to me for a quick checkup before delivering it, but when we opened the box, it was broken and bent. Considering it was a fine specimen from around 1977, I decided to see if I could straighten and repair it. The main PCB was cracked, the channel selector had been smacked around, the bottom was bent, the faceplate was cracked, side panel banged in, and more. 

I couldn't help myself...so first I got it working electrically. I found 2 of the synthesizer crystals to be bad... so I found a couple online, got and installed them, and padded back on frequency. The PCB crack was repaired, and a full alignment and tx tuneup was in order. Once it was running, I started repairing the cosmetic issues. In the end, it turned out pretty darn good and another piece of radio history from the '70's lives again :-) Here's a few pics...

Here's a little video of the completed radio, receiving signals off the air... It sounds good, and was taken to it's final home. The person he gifted this to is now a ham radio operator, but this was the same exact model of the first CB radio he ever had.