I found a Heathkit "EF-1," disassembled it, cleaned off all the rust and re-created the "kit experience." This will be a small power supply used for hands-on experiments. I will be using it with my rebuilt Eico Model 232 VTVM.
Spring clips provided courtesy of K8AXW.
I really wanted to do this Heathkit tube radio course but that price is ridiculous! So, instead of buying the "extremely rare unbuilt Heathkit" shown above, I "replicated" the Heath course by obtaining a beat-up, already built EK-2B radio and disassembling it -- in effect, turning it back into a kit! I also obtained used copies of the manuals. The total cost was around one-tenth of the above auction price, including the nominal cost of replacing some decayed 50-year-old components with NOS/new versions.
The EK-2B superhet receiver, the culmination of Heathkit's "Basic Radio Course." This one was assembled some time in the 1950s/1960s by an unknown builder. I will be disassembling this into its component parts, and then re-doing the entire 200-page radio course from used copies of the manuals that I found on Amazon.com.
The top of the chassis. Nothing missing. I actually plugged in the set and connected it to a long-wire antenna and ground. It works just fine! Too bad I will be taking it apart!
Underneath the chassis. The original builder did a good job. These vintage components are in very good shape. I should be able to re-use almost all of them, apart from some of the capacitors.
It looks like I'm going to be winding this coil myself. It was not included in the assembled EK2-B that I have because it is part of earlier experiments from EK2-A -- the coil was removed from the chassis, as specified in the Heathkit manual, and discarded long ago.
Calling all Old Timers! If you did the Heathkit Basic Radio course in the late 1950s or early 1960s, you installed this coil (#40-303) as part of the experiments in Part 1 and for the early experiments in Part 2. You then *removed* this coil and never used it again. I hope you still have it somewhere! If so, I would like to purchase it from you or at least borrow it so I can determine its properties. It is used in numerous early experiments in the radio course, including a crystal radio, a regenerative receiver, and a TRF receiver. Click on the "zoom" button at the top of the screen to get a clear view.
After full renovation.
You can still see leftover of battery acid after sanding.
Replaced capacitors, rewired, etc.
This thing is fun!
Nice outside, a big mess "under the hood."
With Electronic Switch, poor man's "dual trace" scope.
Morse key down! Top trace shows it.
RF signal generator, after cleaning the copper-plated chassis.
RF signal generator, prior to renovation. Great build quality, but some rough edges.
After replacing most of the capacitors, fixing some "cold joints," replacing the original connectors with modern BNCs, cleaning the switches with DeOxit, etc.
Powering up. All voltages checked out fine except two. One of them was fixed by cleaning a rotary switch, the other one was a loose solder joint from the original wiring. My "new" VTVM was an invaluable troubleshooting tool.
Glowing in the dark. Some of the copper plating came off the back plate when I cleaned it.
It works!!! It's very stable and, after calibration, quite accurate. This is a fantastic dial: 10.5" x 7" and ultra-smooth action, plus an additional vernier in the center. I stripped the paint off the bezel and resprayed with Rustoleum black gloss. The original handle was disintegrating so I replaced it with a new leather one. I also replaced the glass face, which was broken. The connectors were upgraded to modern BNCs with new coaxial leads.
My Morris Coilmaster, a universal coil winder from the 1950s
The Coilmaster came with the original instruction sheet
I actually managed to find a copy of Summerville's booklet (from a kind ham in Canada)
Here's the booklet
BC-453 "Command" receiver awaiting rebuild
I built the blank coil forms from a kit provided by WB5OFD. The Air Dux coil stock was purchased for $5 (+$7 shipping) on eBay. These 7 coils will be used for "A Low Cost Transmitter" -- a project from the 1963 edition of ARRL's "Understanding Amateur Radio." The 5 output tank coils are on the right. The two blank forms on the left will eventually be used for the two oscillator coils.
Here are several views of the 80m output coil for "A Low-Cost Transmitter." The 14AWG wire was quite stiff, and it was a challenge maneuvering it into tight spaces inside the form, and soldering the wires without damaging the form with heat from the iron. Where necessary I was able to separate the form from its base (because they were in kit form) and could partially wire up the base before gluing it to the form with polycarbonate cement.
My first ham log! No digital technology here....
These NOS parts were purchased on the Web from specialty providers. Most of them are destined for various receiver projects, including a ham bands converter for my BC-453 "Command" receiver.
This came with some of the original resistors!
This crystal case came from a former military CW op....
....and included a great collection of vintage 40m and 80m FT-243 crystals.
Bought this on eBay: "IF Transformer Kit" by Harnett Corp. It contains components to build 33 IF transformers or other shielded coils from scratch!
Tube parameters for the 12BA6 tube in my "Novice Q5er" ham converter for the BC-453.
The front panel of my WWII vintage BC-453 receiver, which I bought for $17 on eBay. Not completely cleaned up, but I don't think I'll clean any more (I like the "working set" look). I'm curious about WWII surplus gear: was it simply "overstocked," brand-new stuff left over after the war, or on the other hand was it actually used aboard fighting aircraft and removed from those planes when they were scrapped?
Finally restoring my BC-453. It will be used as a tunable IF in my "Novice Q5er" converter based on the original W6TNS design from the mid-1950s. Here's the raw chassis before cleaning. This six-tube set is smaller than you might think: the front panel is 4.75" wide and the chassis is 10.75" deep. A triumph of 1940s miniaturization.
Here are the 6 tubes, coming to the end of their 50-year retirement as they will soon be powered up again! A philosophical question: is this truthfully a "homebrew" project? I'll be building the ham converter from scratch, but it will be feeding an only minimally modified BC-453. I don't really care, mainly because coaxing a 60-year-old military receiver back (hopefully) to life is a lot of fun.
Underneath the chassis of my BC-453 WWII receiver. Aargh. I'm planning to replace most of the capacitors (those metal cylinders) wth modern equivalents. This is a really tight design, bravo Uncle Sam.
Sometime in the 1950s/60s, another ham modified this set for amateur use. S/he soldered a power supply cable to the connector at middle right. The four metal/rubber prongs toward the edges of the chassis are the mounting studs/shock absorbers for the Dynamotor, a motorized power supply used aboard military aircraft.
Sometimes, the best cleaner is a human fingernail.
Q-tips are sacrificed in the cleaning operation....
The original Western Electric serial number plate.
Just behind the front panel of this WWII BC453, another ham made the classic "Novice Q5er" modification to this vintage set.
Sometime in the 1950s/60s, a ham from a previous generation wrote in pencil: "Filament 24 Volts. B+ 150-250 V.Top B+. Middle 24V." I will be re-wiring the filaments in parallel for a 12V supply.
In the 1950s/60s, a ham modified this WWII receiver BC453 set and installed this BFO "on/off" switch.
Side view after completing most of the cleaning on my BC453 receiver of WWII vintage. This set tunes 190-550 KHz. I'll be using it with a ham bands converter to make a crystal-controlled double-conversion set (the BC-453's IF is 85 KHz as you can see from the photo).
Another side view of my WWII vintage BC453 receiver after cleaning.
After cleaning, I got curious. So I unplugged the coils and removed the tuner cover.
The tuning assembly is a thing of beauty.
Overall view after completing cleaning of the chassis top.
Figuring out a coil's inductance experimentally with the Eico 710 grid-dip meter. These instructions are in the 50-year-old manual for the 710.
Figuring out a coil's "Q" experimentally with the Eico 710 grid-dip meter. These instructions are in the 50-year-old manual for the 710.
The classic formulae for resonant tuned circuits. These come from the 1963 ARRL Radio Amateur's Handbook.
Note the coupling capacitor C6, connecting the plate of V1 to the grid of V2. It looks like I should leave it out!
Another hobby: plastic models. This one is only half built.
I've decided to standardize on the National "HRS" series knobs for all of my homebrew gear. These knobs are still available as "new old stock" but are very pricey. So I've been scrounging to find cheap/free "distressed" National knobs, and those I find often need restoration. I'm going to ask the folks on the "Boat Anchor" forum for advice. I like the black knobs but the gray ones are much more widely available, so I'll be repainting them black with modelers' acrylic paint. Many of the knobs I've scrounged have tarnished skirts (no double entendre intended) so I'm trying to figure out how to fix them.
Ameco Morse code course (I ended up ditching this and using the Koch method with G4FON software). At right, an Ameco K4 key (very nice) and Ameco code practice oscillator (also very nice).
Spotted this photo on eBay.
I obtained this James Millen capacitor for about $15 from a former ham family. It was brand new and still inside its original box.
Another view of the James Millen tuning capacitor.
From ARRL "How to Become a Radio Amateur" 1956 edition.