Eveready Model 32

Radio Description

Manufacturer: Eveready (National Carbon Co.)
Model: 32
Approximate Date Of Manufacture: 1929
Type: 8 tube TRF BC band radio
Tube lineup: 80, 71A (x2), 27 (x5)
Status: working, restored
Where purchased: newspaper ad, given away, July 2005

General

This is an Eveready model 32 made in 1929. It is in a wooden high-boy cabinet with mahogany veneer. The front panel is made of pressed repwood with the Eveready name imprinted on it. The tuning is via a large wooden knob with a movie dial surrounded by a brass escutcheon. Two gain controls are provided; these knobs are bakelite.

The radio was made by Canada National Carbon Co. (the parent company of Eveready) in Toronto, Ontario, Canada. According to the book "Radios of Canada", Eveready produced about 10 models of radios in Canada from 1929-1930. The same model of radio, with a different cabinet, is pictured in that book. The same model was sold in the US. Apparently Eveready only produced radios for a short time in the 1920s and 30s. On page 38 of Radio Manufacturers of the 1920's volume 2, a picture of a Model 32 console is shown. It was advertised in Radio Retailing of June 1929 at a list price of $175 (without tubes).

Electrical

This is a tuned radio frequency (RF) design, with 3 RF amp stages, a detector, an AF amp and a push-pull AF output stage driving a field coil speaker. The power supply uses an 80 rectifier. Tuning is via a 3-gang capacitor.

The power supply has a pin that is inserted to select for 105, 115, or 125 volt input. A full-wave rectifier produces the B+ using the field coil for filtering. There are taps on the transformer for the 2.5 and 5 volt tube filaments.

There is a phono input, as well as binding posts for ground and short and long antennas. A long piece of wire inside the radio was apparently used as the antenna.

Somewhat unusual is the fact that it is constructed from two separate chassis which are linked together. One contains the power supply and audio output, the other has the RF amp, detector, and 1st AF amp stages. Possibly this was to allow sharing the chassis with other models.

One of the 27 tubes was missing as was the 2.5V pilot lamp. The state of the other parts is still being investigated.

Restoration

The cabinet was water damaged by the previous owner who had overwatered a plant that was sitting on the radio. The veneer is cracked and lifted up. I plan to completely replace the top veneer. There are some other relatively minor scratches on the cabinet that can be touched up.

Electrical restoration is just starting and will be updated as it progresses.

All tubes tested good. These old tubes do take a long time to warm up in comparison to more modern tubes. Speaker voice and field coils have continuity. I found a plot lamp that should work.

26-Jul-2005 update

Cleaned inside of chassis. Replaced wiring for power switch. Inside I found the missing pilot lamp. Also found a loose resistor but it doesn't seem to belong anywhere.

27-Jul-2005 update

Did a careful power up smoke test, first without tubes, then with 80 tube, then with all tubes. All power supply voltages and current appear nominal. No sound from speaker. Determined speaker is okay. Found a bad (open) 1K power resistor in power supply. Jumpering a new one across it made some hum come out of the speaker. Looks like speaker and power amp is okay now. Still missing a tube so I don't expect it to work yet. Will try injecting some RF into the RF amp stages and see if I get a signal.

28-Jul-2005 update

Replaced the bad 1K resistor. I confirmed I can feed RF from a signal generator into the grid of the 2nd RF amp tube and receive the signal. Now I need to examine the tuner portion more carefully for bad parts and align the stages. I need to get that missing tube...I ordered a couple from tubedepot.com.

31-Jul-2005 update

Replaced a previously replaced wax cap and an original cap, both 0.5uF. Replaced 1uF and 2uF caps. Found a bad resistor related to the volume control -- replaced it. All other resistors were a little high in value but within limits. One of the original resistors has another in parallel with it, probably a previous repair for an out of spec resistor.

Now if I connect a short wire to the grid of the second tube I can tune in several stations and get good audio, and the volume control works. I am still missing the first RF tube. Found good coverage of how to align and neutralize TRF receives in my copy of Modern Radio Servicing by Ghirardi. I found it funny that a book published in 1936 said that TRF receivers were obsolete but that many were still being used and servicemen needed to know how to service them. I guess now it is really obsolete.

1-Aug-2005 update

Wired an in-line fuse holder into the AC circuit and installed a 1 amp fuse. If the electrolytic caps ever fail by shorting they should blow a fuse before the power transformer or a choke is destroyed.

I put the chassis back together on the supporting board that in mounts on. Made some measurements of voltages during normal operation.

I noted that the tuning caps have slotted vanes which facilitate more accurate alignment over several frequencies, if needed, so that the receiver tracking can be carefully adjusted. I also confirmed that the adjustable trimmer caps inside the radio are for neutralization and match the scheme used in the Neutradyne circuit, as described in the Ghirardi book. If I turn the gain way up it appears I can get some oscillation, so neutralizing should be done.

9-Aug-2005 update

I received the two 27 tubes that I ordered. I tested them both and installed the better of the two in the radio. Strangely, neither one shows visible glow from the filament but they do test as good.

I did some final alignment and installed the speaker and chassis back in the cabinet and took some more pictures.

The top veneer was glued down. The water stains were mostly removed and some of the cabinet was refinished with varnish and some scratches touched up with stain.