1920's Radio set restoration help - UK Vintage Radio Repair and Restoration Discussion Forum

Astonman · 9th Mar 2023, 12:39 pm

I am restoring a table top radio set from the 1920's era.
It had 2 Valves when I purchased it but on tracing the circuit and examining the internal wood base the components are screwed to, it looks like a valve base has been removed leaving the connections to it dangling. It is the audio output triode so it is easy to fit a replacement. I have a few valves but the valve socket I don't have. I have a chassis mounted 4 pin base but the surface mounted type (which are sprung on this set) I don't have. Does anybody here know where I can buy one from?
The tuning coil is quite interesting being a permeable tuned arrangement with a rotating coil inside the main two coils. There is a 10 position selector switch, which could act like a wave change switch that short out turns on the tuning coil, presumably to tune higher frequencies. I don't know if it was a short wave receiver.
It might be a home brew radio as there are no brand name labels. It will be interesting to fire it up to see what I receive.......if anything.
I have an Amplion Convette psu to power it with a meter to adjust the filament voltage. There is a flying lead inside the cabinet which must be for the grid bias battery.
I have attatched some photo's to see if anyone recognises the set.

PJL · 9th Mar 2023, 1:00 pm

The coil arrangement is termed a variometer and was used in many 1920's crystal and valve sets.

It will be a homebrew probably built to a published circuit, the coil looks to be a commercial unit and may have a label on it somewhere. SW in the 1920's is what we call
MW now.

Mr 1936 · 9th Mar 2023, 2:14 pm

Hi

It might be an idea to check out the Amplion Convette with a resistor load on its filament output, just to make sure the voltage is OK before trusting it with the valves.

greenstar · 9th Mar 2023, 3:09 pm

If you have any difficulty finding a valve socket, pm me, and I will send one for cost of postage. The vulnerable component on these are the interstage transformers, a quick check will tell you if the windings are intact. If o/c, it is often the case that the break is inside the case, in the connection. imo, these homebrew sets are under appreciated. Even a roughly made one, which your's is not, is evidence of somebody's interest in an era home construction was a thing, as such sets were expensive.

DrStrangelove · 9th Mar 2023, 8:27 pm

I have a 1920s component catalogue "somewhere".

The prices of the components shown were eyewatering when you consider the average wage at the time.

Astonman · 11th Mar 2023, 12:37 pm

Yes, I have just bought a copy of the excellent Radio! Radio! book by Jonathan Hill. It lists a lot of the sets available and their prices for each era of Radio. Very expensive to buy a valve set and run it! No wonder crystal sets were popular. There is also a picture of a 1930's Ultra Tiger mains set that I remember my parents being given by my Grandad. It still gave good service in the 60's. He gave me a crystal set with a coil that had a brass scraper to tune it and of course a cats whisker. I managed to pick a few of the stronger MW stations on it with a length of wire tied to a tree and an earth connected to the cold water pipe. I wish I had it now!

9th Mar 2023, 12:39 pm	#1
Astonman Diode Join Date: Feb 2023 Location: Grantham, Lincolnshire, UK. Posts: 3	1920's Radio set restoration help I am restoring a table top radio set from the 1920's era. It had 2 Valves when I purchased it but on tracing the circuit and examining the internal wood base the components are screwed to, it looks like a valve base has been removed leaving the connections to it dangling. It is the audio output triode so it is easy to fit a replacement. I have a few valves but the valve socket I don't have. I have a chassis mounted 4 pin base but the surface mounted type (which are sprung on this set) I don't have. Does anybody here know where I can buy one from? The tuning coil is quite interesting being a permeable tuned arrangement with a rotating coil inside the main two coils. There is a 10 position selector switch, which could act like a wave change switch that short out turns on the tuning coil, presumably to tune higher frequencies. I don't know if it was a short wave receiver. It might be a home brew radio as there are no brand name labels. It will be interesting to fire it up to see what I receive.......if anything. I have an Amplion Convette psu to power it with a meter to adjust the filament voltage. There is a flying lead inside the cabinet which must be for the grid bias battery. I have attatched some photo's to see if anyone recognises the set. Attached Thumbnails

9th Mar 2023, 1:00 pm	#2
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: 1920's Radio set restoration help The coil arrangement is termed a variometer and was used in many 1920's crystal and valve sets. It will be a homebrew probably built to a published circuit, the coil looks to be a commercial unit and may have a label on it somewhere. SW in the 1920's is what we call MW now.

9th Mar 2023, 2:14 pm	#3
Mr 1936 Heptode Join Date: Mar 2017 Location: Romsey, Hampshire, UK. Posts: 524	Re: 1920's Radio set restoration help Hi It might be an idea to check out the Amplion Convette with a resistor load on its filament output, just to make sure the voltage is OK before trusting it with the valves.

9th Mar 2023, 3:09 pm	#4
greenstar Octode Join Date: Jul 2011 Location: Leicester, Leics. UK. Posts: 1,685	Re: 1920's Radio set restoration help If you have any difficulty finding a valve socket, pm me, and I will send one for cost of postage. The vulnerable component on these are the interstage transformers, a quick check will tell you if the windings are intact. If o/c, it is often the case that the break is inside the case, in the connection. imo, these homebrew sets are under appreciated. Even a roughly made one, which your's is not, is evidence of somebody's interest in an era home construction was a thing, as such sets were expensive.

9th Mar 2023, 8:27 pm	#5
DrStrangelove Banned Join Date: Jan 2023 Location: Neath, Port Talbot, Wales, UK. Posts: 286	Re: 1920's Radio set restoration help I have a 1920s component catalogue "somewhere". The prices of the components shown were eyewatering when you consider the average wage at the time.

11th Mar 2023, 12:37 pm	#6
Astonman Diode Join Date: Feb 2023 Location: Grantham, Lincolnshire, UK. Posts: 3	Re: 1920's Radio set restoration help Yes, I have just bought a copy of the excellent Radio! Radio! book by Jonathan Hill. It lists a lot of the sets available and their prices for each era of Radio. Very expensive to buy a valve set and run it! No wonder crystal sets were popular. There is also a picture of a 1930's Ultra Tiger mains set that I remember my parents being given by my Grandad. It still gave good service in the 60's. He gave me a crystal set with a coil that had a brass scraper to tune it and of course a cats whisker. I managed to pick a few of the stronger MW stations on it with a length of wire tied to a tree and an earth connected to the cold water pipe. I wish I had it now!