Can anyone shed any light on these ancient valve devices?

[bigal_scorpio]

Hi to all,

I have just inherited this pair of instruments from someones loft. They didn't know where they came from originally and had no idea they were even in there.

Both the cabinets look home made and they are certainly oldish. What do you think they are guys?

Al

 

[ronsimpson]

It looks like one box plugs into the other.
I think you have a home made HAM transmitter.

 

[JimB]

The box with the tuning dials is a shortwave receiver.
It looks like a TRF type with regeneration (reaction) to increase sensitivity and selectivity.
It is a bit difficult to guess the frquency range, but looking at the plug in coil in the back, I would say 7 to 10Mhz.

The box with the meters looks like the power supply for the receiver.

At a guess I would say that it was built in the 1950s or early 1960s.

It is certainly not a transmitter.

JimB

 

[KeepItSimpleStupid]

There are two unidentifiable connectors (what they might do) on the back. The banana's and the other one. There is a "phone" connector on the front which really does suggest a receiver, however, the power side looks big.

An antenna and a test point are possibilities. I agree, I doubt it's a transmitter.

How about a home made "grid dip meter"? https://en.wikipedia.org/wiki/Grid_dip_oscillator

 

[ronsimpson]

Grid dip meters I have used are really small.
This thing, probably not a transmitter, has a huge power supply. I guessed transmitter mostly by the size of the supply. I have sever home made receivers from the 60s/70s. My best is AM, SSB, 5 band, very complicated...and has a much much smaller transformer. I had transmitters with that size of supply.

 

[KeepItSimpleStupid]

I agree with you there, the size of the supply is what you might have for a transmitter. I maintained a 1000 W tube xmitter for a while and it was huge and heavy and in two pieces.

This is home made and it could have been nearly free so he/she used it.

 

[rumpfy]

photo #1 is the front view;#2 is the back view.
Looks like a simple radio receiver. #2 shows two wartime radio valves probably pentodes. The code numbers are british military types but i dont have details. The coil is wound on an 'Eddystone' coil former. Eddystone radio produced a wide range of special components for the Amateur radio boys. You buy the bits and make what you want. The small Variable tuning capacitor shown in#2 is an Eddystone variable capacitor. This capacitor is behind the large tuning dial. Note that the shaft has an insulated coupling so the capacitor is probably floating above ground. There is another small variable capacitor just above the coil. This is another Eddystone radio product.
Dont know what happened to Eddystone but I suppose they just faded away.
The valve on the rhs of photo #2 looks like a 6L6, which would be used as a power amp for the headphones.
Photos 3 and 4 look like a power supply. The 8 pin plug/socket reminds me of a Belling/Lee type, but the notation says "HV" and 6.3 v"
The 6.3 V is the supply for the valve heaters. The small valve near the camera in #4 looks like a gas filled voltage reference valve and this suggests the power supply was or had, an adjustable voltage setting using a series pass valve.
The whole thing shows is how life used to be before the japanese radio industry took off and we all just built what we wanted. All this gear reeks of immediate post war army disposals stuff.
It is conceivable that the radio set includes a small transmitter but I very much doubt it. If you were able to find a heap of old "Wireless World" books, you might even find the design given there. I would start looking about 1948.

 

[ericgibbs]

hi Al,
The VR65 is an ex WW2 RF pentode, I used to buy a lot of ex Govt gear in the 1950's
http://www.r-type.org/exhib/aaa0090.htm

The large glass valve could be a 6V6 audio output.

I would agree with JimB, short wave TRF regen RX, the other unit is the PSU.

If its not been powered up since goodness knows when, watch out for exploding electrolytic's.

Eric

 

[alec_t]

I would agree with JimB, short wave TRF regen RX, the other unit is the PSU.

That's my opinion too. The power supply looks way more than needed for an Rx, but in those days the big trannies were probably available cheaply on the war-surplus market and the philosophy was to err on the generous side.

 

[4pyros]

Dont power it up without some repairs. The big cap in a can is probly all dried up and the shunt resister across the voltage meter has one leg broken off.

 

[KeepItSimpleStupid]

Give **broken link removed** a read: Capacitor Reforming

 

[4pyros]

Give **broken link removed** a read: Capacitor Reforming

Thats neat, never hard of that before. Thanks KISS

 

[KeepItSimpleStupid]

Other techniques exist that basically involve monitoring and using a Variac to bring up equipment that's been idle for a long time.

See: https://www.nmr.mgh.harvard.edu/~reese/electrolytics/

The caps I exploded was intentional like when I was a kid: metal can electrolytics connected directly across the AC line and exploding small radial electrolytics with an AC toy train transformer. The latter makes a miniature firecracker.