Armstrong Radio - UK Vintage Radio Repair and Restoration Discussion Forum

Hermit6345 · 14th Dec 2009, 1:35 am

Anyone know anything about Armstrong radios? I acquired one today and from what little I have read it will have been made by the Armstrong Radio and TV Company in about 1940. Can't find a great deal on the web.

I have not had a chance to look at it in detail but I did notice that the mains transformer is a very robust unit as is the O/P tranny, which is a large Gardiners unit. Unfortunately the radio has no back or speaker(s) but seems to be crammed with octal valves. Wooden case. Tuning scale is a large circular affair with an aeroplane pointer. Magic eye above dial. Long/Med/Short. Two speaker apertures above. I will post a picture when I get a chance.

I guess that I will be looking for a schematic when I have identified the model number.

The only Armstrong stuff I have seen is the much later Hi Fi tuner amps from the 50s/60s.

TIA

Ian.

percival007 · 14th Dec 2009, 1:48 am

I take it you have already tried here :-

http://www.audiomisc.co.uk/Armstrong/armstrong.html

Any chance of a picture?

Regards,

James.

Hermit6345 · 14th Dec 2009, 10:59 am

Hi James,

Thanks for the link. I had read a history of the company elsewhere and your website,which I had not discovered, adds a bit more to the story. I had come across the page which was linked with the one you sent me. It mentions the early valve sets c1940, so was wondering if my set was either an AW73 or 93. I will take a photo of the receiver and post it here. The picture in the website you suggested is not my radio but I can see that it's similar in the number of valves! It looks as if my radio will be an interesting radio to restore.

Ian.

Hermit6345 · 14th Dec 2009, 12:11 pm

Herewith the photos of the Armstrong. I have a suspicion that the cabinet may not be original as part of the tuning scale is obscured by the edges of the square aperture. I had originally thought that the dial pointer was an aeroplane type but it's not as can be seen from the photo. The 2 off 6v6, one a GT version and the other a G version can be seen next to the transformer.

Ian

Mr Moose · 14th Dec 2009, 8:51 pm

Hello,
Armstrong did make radios and tuners without cabinets which you fitted into your own cabinet, and they seem to be of quite high quality. I think in your case, someone may have fitted a tuner-amplifier into an old radio cabinet.
Yours, Richard

mickjjo · 14th Dec 2009, 9:58 pm

Going by the dial markings, the Light and Third programmes both appear so the chassis should date to post September 1946. There are several Armstrong ads in 1947-48 Wireless Worlds with pictures of circular dial chassis but the layout is different

.

Regards, Mick.

Nickthedentist · 14th Dec 2009, 9:59 pm

I would say it's the same well-known hifi company as James mentions above.

If you look here, you can see that the typeface used for the brand name is the same: http://www.audiomisc.co.uk/Armstrong/general/Pub1.html

Moreover, the control layout of the chassis pictured towards the bottom of the page looks very similar indeed. Maybe an e-mail to the webmaster (Jim Lesurf) might be worthwhile?

Nick.

Hermit6345 · 14th Dec 2009, 10:34 pm

Thanks to Richard, Mick and Nick. Yes, I read the history of the Company and they started off making TVs and radios. In fact I read that they were called Armstrong Radio and TV Ltd. They then morphed into making the familiar Armstrong tuner amps which were advertised in old mags.

Mick, well spotted! I wonder if any of those sets advertised had a model number? I guess that there is a slight chance that though the layout is different, the circuitry might be similar to mine. Mine looks to be a little more straightforward than some I have read about. Looks like a standard superhet with an RF stage and push-pull output. None of their fancy circuitry using octal triodes driving the 6V6s. I don't have any mags going back that far but I am sure someone on here has.

Richard, I think that you are right. I am convinced that the box which this thing is in now is not something that it was purchased in! What company would provide a radio in a cabinet which obscured part of the short wave tuning scale as it does in the one I have.

Nick, yes, it's the same company and a friend noticed that the layout of the knobs on the radio shown is similar to mine. The knobs on mine, or what remains of them, are not all the same pattern either. Perhaps knobs weren't supplied.
Brilliant idea regarding the website owner. I also thought about the Radio and TV museum as well. I also read somewhere that all of the old paperwork was lost/destroyed at Armstrongs so perhaps no-one has a schematic now.

So thanks to everyone helping me to reach the goal of a model number and a schematic!

Ian.

mickjjo · 14th Dec 2009, 11:00 pm

Hi Ian, I've attached an Armstrong ad from October 1947 with various model numbers listed, after late 1949-50 they started using miniature valves so I would think your chassis dates from 1947-8.

Regards, Mick.

SeanStevens · 15th Dec 2009, 10:33 am

Unless I cannot count, I think you have an 8 valve model.

So it must be either:

EXP83 - 10 Watts - AC Mains

or

INI-83 - 8 Watts - AC & DC Mains

So, if you can tell if it will take DC (or not), you know which model you have.

Hercule Poirot
AKA Sean

Hermit6345 · 15th Dec 2009, 11:02 am

Quote:

Originally Posted by SeanStevens

Unless I cannot count, I think you have an 8 valve model.

I think you may have forgotten the magic eye indicator Sean. I guess that is one of the valve count, making 9 in total.

Mick, thanks for the cutting. That is very revealing. Mine will definitely be from that era, that's obvious. I think that the 8 valve unit is going to be a straightforward superhet with an RF amp, Mixer/Osc, IF amp, 2nd Detector/AGC/1st AF Amp, Phase splitter, 2 X Output valves and rectifier. No magic eye fitted. I will take a further look at it today if I get time and see what's what in mine.

Ian

Nickthedentist · 15th Dec 2009, 12:52 pm

Sometimes though, magic eyes and rectifiers were not taken into account when counting valves.

Either way, an intesting set though. It would look a lot more pleasing if the escutcheon weren't so wide.

I wonder whether the cabinet was purchased empty as surplus, post-war. I don't know what the normal lifespan of a radio was back then, but it would seem odd to have used a relatively new set merely as a cabinet donor.

Nick.

Hermit6345 · 15th Dec 2009, 4:16 pm

Hi Nick, well now having removed the radio from it's cabinet, I can clearly see that the cabinet was not intended for this radio. A piece of the plastic trim fell off and underneath were the holes for whatever chassis had been in there originally. In addition, the speaker baffle, which was missing has been used as the base to the cabinet. There is a large hole in it suitable for an 8 inch speaker.

Additionally, now I have it out of the cabinet, another valve has been exposed. It's a little metal 6K7 hidden in between two IF transformers.

So now the valve cmplement is:
CV281 (X61M), 6K7, 6K7, CV1100 (KTW62), 6Q7, 6J5, 6V6, 6V6 and GZ32 rectifier. The magic eye is a 6U5G. If they are counting the magic eye as a valve then that makes a total of 10 valves. I guess it could be the RF103 as a pair of 6V6 are capable of 10 watts output and the O/P tranny is rated at ten watts. Maybe it's been cracked and it is the RF103.

Thanks all for the help so far.

Ian.

Nickthedentist · 15th Dec 2009, 5:16 pm

A tabletop set with 10W output and 8" speaker could sound rather good.

Hermit6345 · 15th Dec 2009, 6:32 pm

I agree with that Nick. It should sound wonderful. It's got all manner of tone controls fitted .

Any way with the set off, I removed the rectifier valve and fed in 200 volts to the HT line from my variable PSU and the current taken was negligable. A quick and dirty test for leaking decouplers. Replaced rectifier, gradually brought up the mains from a Variac and it wasn't long before I was greeted with horrible crackling. Measured the grid volts on each of the 6V6s and each time it cracked up went the grid voltage. Turfed out the caps fitted by a previous owner replaced them with my stock 0.1 at 630 volt. Replaced a couple of electrolytics because they were. Did the same test again and this time I was greeted with smooth noise. Tuned around with my wire aerial connected and found many stations on both LW and MW but nothing on SW. Fitted new magic eye as old one shot but I have no AGC by the looks of things as the eye doesn't move when I tune through a station. Need to look at that but at least I can see the wood for the trees now. Still hopeful that someone can come up with a schematic but at least I have something going without it.

Ian.

cmjones01 · 16th Dec 2009, 9:26 am

Quote:

Originally Posted by mickjjo

Hi Ian, I've attached an Armstrong ad from October 1947...

It's interesting that the advert says 'Overseas Buyers are cordially invited...'. Presumably such luxury radiogram chassis were export only in those austere post-war years. Perhaps this might help to explain why it's in an odd cabinet? Maybe it was a grey re-import, or something?

Chris

Hermit6345 · 16th Dec 2009, 3:47 pm

Chris, you may well be right as it wasn''t a cheap set by any means. Especially as you had to provide your own cabinet or other housing.

However, I can confirm that it is an RF103 because written in tiny letters at the bottom of the tuning scale it says "RF103/2CP" So thanks to all especially Mick who submitted the cutting that helped so much. It's working well, AGC problem sorted (Leaky mica cap) and it's beginning to look very nice. Got to find some knobs now.

Ian

14th Dec 2009, 1:35 am	#1
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Armstrong Radio Anyone know anything about Armstrong radios? I acquired one today and from what little I have read it will have been made by the Armstrong Radio and TV Company in about 1940. Can't find a great deal on the web. I have not had a chance to look at it in detail but I did notice that the mains transformer is a very robust unit as is the O/P tranny, which is a large Gardiners unit. Unfortunately the radio has no back or speaker(s) but seems to be crammed with octal valves. Wooden case. Tuning scale is a large circular affair with an aeroplane pointer. Magic eye above dial. Long/Med/Short. Two speaker apertures above. I will post a picture when I get a chance. I guess that I will be looking for a schematic when I have identified the model number. The only Armstrong stuff I have seen is the much later Hi Fi tuner amps from the 50s/60s. TIA Ian.

14th Dec 2009, 1:48 am	#2
percival007 Heptode Join Date: May 2005 Location: Oxfordshire, UK. Posts: 852	Re: Armstrong Radio I take it you have already tried here :- http://www.audiomisc.co.uk/Armstrong/armstrong.html Any chance of a picture? Regards, James.

14th Dec 2009, 10:59 am	#3
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio Hi James, Thanks for the link. I had read a history of the company elsewhere and your website,which I had not discovered, adds a bit more to the story. I had come across the page which was linked with the one you sent me. It mentions the early valve sets c1940, so was wondering if my set was either an AW73 or 93. I will take a photo of the receiver and post it here. The picture in the website you suggested is not my radio but I can see that it's similar in the number of valves! It looks as if my radio will be an interesting radio to restore. Ian.

14th Dec 2009, 12:11 pm	#4
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio Herewith the photos of the Armstrong. I have a suspicion that the cabinet may not be original as part of the tuning scale is obscured by the edges of the square aperture. I had originally thought that the dial pointer was an aeroplane type but it's not as can be seen from the photo. The 2 off 6v6, one a GT version and the other a G version can be seen next to the transformer. Ian Attached Thumbnails

14th Dec 2009, 8:51 pm	#5
Mr Moose Octode Join Date: Jul 2008 Location: Gloucestershire, UK. Posts: 1,043	Re: Armstrong Radio Hello, Armstrong did make radios and tuners without cabinets which you fitted into your own cabinet, and they seem to be of quite high quality. I think in your case, someone may have fitted a tuner-amplifier into an old radio cabinet. Yours, Richard

14th Dec 2009, 9:58 pm	#6
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Armstrong Radio Going by the dial markings, the Light and Third programmes both appear so the chassis should date to post September 1946. There are several Armstrong ads in 1947-48 Wireless Worlds with pictures of circular dial chassis but the layout is different . Regards, Mick.

14th Dec 2009, 9:59 pm	#7
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Armstrong Radio I would say it's the same well-known hifi company as James mentions above. If you look here, you can see that the typeface used for the brand name is the same: http://www.audiomisc.co.uk/Armstrong/general/Pub1.html Moreover, the control layout of the chassis pictured towards the bottom of the page looks very similar indeed. Maybe an e-mail to the webmaster (Jim Lesurf) might be worthwhile? Nick.

14th Dec 2009, 10:34 pm	#8
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio Thanks to Richard, Mick and Nick. Yes, I read the history of the Company and they started off making TVs and radios. In fact I read that they were called Armstrong Radio and TV Ltd. They then morphed into making the familiar Armstrong tuner amps which were advertised in old mags. Mick, well spotted! I wonder if any of those sets advertised had a model number? I guess that there is a slight chance that though the layout is different, the circuitry might be similar to mine. Mine looks to be a little more straightforward than some I have read about. Looks like a standard superhet with an RF stage and push-pull output. None of their fancy circuitry using octal triodes driving the 6V6s. I don't have any mags going back that far but I am sure someone on here has. Richard, I think that you are right. I am convinced that the box which this thing is in now is not something that it was purchased in! What company would provide a radio in a cabinet which obscured part of the short wave tuning scale as it does in the one I have. Nick, yes, it's the same company and a friend noticed that the layout of the knobs on the radio shown is similar to mine. The knobs on mine, or what remains of them, are not all the same pattern either. Perhaps knobs weren't supplied. Brilliant idea regarding the website owner. I also thought about the Radio and TV museum as well. I also read somewhere that all of the old paperwork was lost/destroyed at Armstrongs so perhaps no-one has a schematic now. So thanks to everyone helping me to reach the goal of a model number and a schematic! Ian.

14th Dec 2009, 11:00 pm	#9
mickjjo Rest in Peace Join Date: Jul 2004 Location: Dartford, Kent, UK. Posts: 1,661	Re: Armstrong Radio Hi Ian, I've attached an Armstrong ad from October 1947 with various model numbers listed, after late 1949-50 they started using miniature valves so I would think your chassis dates from 1947-8. Regards, Mick. Attached Thumbnails

15th Dec 2009, 10:33 am	#10
SeanStevens Octode Join Date: Sep 2009 Location: Bath, Somerset, UK. Posts: 1,033	Re: Armstrong Radio Unless I cannot count, I think you have an 8 valve model. So it must be either: EXP83 - 10 Watts - AC Mains or INI-83 - 8 Watts - AC & DC Mains So, if you can tell if it will take DC (or not), you know which model you have. Hercule Poirot AKA Sean __________________ There are only 10 types of people, those who understand the binary system, and those who don't.

15th Dec 2009, 12:52 pm	#12
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Armstrong Radio Sometimes though, magic eyes and rectifiers were not taken into account when counting valves. Either way, an intesting set though. It would look a lot more pleasing if the escutcheon weren't so wide. I wonder whether the cabinet was purchased empty as surplus, post-war. I don't know what the normal lifespan of a radio was back then, but it would seem odd to have used a relatively new set merely as a cabinet donor. Nick.

15th Dec 2009, 4:16 pm	#13
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio Hi Nick, well now having removed the radio from it's cabinet, I can clearly see that the cabinet was not intended for this radio. A piece of the plastic trim fell off and underneath were the holes for whatever chassis had been in there originally. In addition, the speaker baffle, which was missing has been used as the base to the cabinet. There is a large hole in it suitable for an 8 inch speaker. Additionally, now I have it out of the cabinet, another valve has been exposed. It's a little metal 6K7 hidden in between two IF transformers. So now the valve cmplement is: CV281 (X61M), 6K7, 6K7, CV1100 (KTW62), 6Q7, 6J5, 6V6, 6V6 and GZ32 rectifier. The magic eye is a 6U5G. If they are counting the magic eye as a valve then that makes a total of 10 valves. I guess it could be the RF103 as a pair of 6V6 are capable of 10 watts output and the O/P tranny is rated at ten watts. Maybe it's been cracked and it is the RF103. Thanks all for the help so far. Ian.

15th Dec 2009, 5:16 pm	#14
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Armstrong Radio A tabletop set with 10W output and 8" speaker could sound rather good.

15th Dec 2009, 6:32 pm	#15
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio I agree with that Nick. It should sound wonderful. It's got all manner of tone controls fitted . Any way with the set off, I removed the rectifier valve and fed in 200 volts to the HT line from my variable PSU and the current taken was negligable. A quick and dirty test for leaking decouplers. Replaced rectifier, gradually brought up the mains from a Variac and it wasn't long before I was greeted with horrible crackling. Measured the grid volts on each of the 6V6s and each time it cracked up went the grid voltage. Turfed out the caps fitted by a previous owner replaced them with my stock 0.1 at 630 volt. Replaced a couple of electrolytics because they were. Did the same test again and this time I was greeted with smooth noise. Tuned around with my wire aerial connected and found many stations on both LW and MW but nothing on SW. Fitted new magic eye as old one shot but I have no AGC by the looks of things as the eye doesn't move when I tune through a station. Need to look at that but at least I can see the wood for the trees now. Still hopeful that someone can come up with a schematic but at least I have something going without it. Ian.

16th Dec 2009, 3:47 pm	#17
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: Armstrong Radio Chris, you may well be right as it wasn''t a cheap set by any means. Especially as you had to provide your own cabinet or other housing. However, I can confirm that it is an RF103 because written in tiny letters at the bottom of the tuning scale it says "RF103/2CP" So thanks to all especially Mick who submitted the cutting that helped so much. It's working well, AGC problem sorted (Leaky mica cap) and it's beginning to look very nice. Got to find some knobs now. Ian