1928 SOLODYNE - Peto-Scott design ? - UK Vintage Radio Repair and Restoration Discussion Forum

RadioHist · 24th Mar 2014, 2:32 am

Of all things... My first exhibition of my McMichael Screened Dimic 3 last Thursday in Charlotte, NC, USA has me dumb founded by discovering in the conference flea market this definitely British made "1928 SOLODYNE" - Ugly and then some on the outside but amazing inside. A set containing TWO S625 screen grid valves - fantastic!

The plug-in coils are LEWCOS and they plug into receptacles branded Peto Scott. There appears to be a regenerative detector with feedback controlled by a small variable condenser mounted on the front panel.

It appears to have originally had a pentode output valve that was rewired slightly for a triode.

It will be more than interesting to trace the circuit and see if the S625's are operated at very low voltage like the SOLODYNE circuits that were written up here in the USA in the 1924/27 time frame. (They were usually for headphone only operation...)

Have you seen such a beast in collections on your side of the pond? This set has been in the USA since at least the mid 1970's. It is going to be a challenge to get this set properly cleaned & documented but I sure hope I can make that happen in time for the AWA Conference in Rochester, NY during August.

jonnybear · 24th Mar 2014, 2:37 pm

If is a solodyn R.056? it was made around 1927 according to the net, it uses RE144 RE144 RE054 RE054 RE054 RE134 valves, and was made by Zenit Prelouc in Czechoslovakia.
May be someone has a better idea.
John

Mr Moose · 24th Mar 2014, 3:17 pm

Hello,

Lots of different manufacturers in several countries seem to have models called Solodyne.
( It originally seems to have been used for models using a single battery for HT and LT.)

The only British one I can find is this one but the description does not fit yours. http://www.radiomuseum.org/r/bligh_9_solodyne.html

This Australian one does use two double ended screen grid valves http://www.radiomuseum.org/r/crammon..._solodyne.html but from its name would appear to be in a metal cabinet.

Looking at the internal construction and the somewhat varied use of different manufacturers parts it is possible that it is a homebuilt set in a proprietary cabinet.

Yours, Richard

RadioHist · 24th Mar 2014, 4:44 pm

Thanks for the Australian tidbit.... I have a guy down there who might be able to get the newspaper reference....

The panel is engraved, and has Peto Scott special sockets.
The great book Setmakers by Geddes w/ Bussey comments. pg36
"Peto-Scott specialized in making up receiver kits for designs published in constructors' magazines."

I have a fair stash of Wireless Worlds from 27/28 maybe I'll get lucky and find a write-up there.... Of course, any information from this forum is most welcome. I really enjoy the back-story to this hardware. It is essential to proper exhibition which I dearly love to do.

BTY - The S.G. valves are S625 - I thought I'd never find one over here, much less a whole set!

Robert

RadioHist · 25th Mar 2014, 8:36 pm

Well I did go through my 20 or so Wireless Worlds from 1927 to 1928.... No references to a "1928 SOLODYNE"... I have the January 1927 issue of Wireless Magazine... That publication seems much more likely to have had such a constructors article. Alas, I have only one issue.

It is not mentioned in the first 20 years of the BVWS Bulletin...

Robert

RadioHist · 31st Mar 2014, 2:29 pm

A friend in Oz found a reference in the Brisbane, Sunday Mail 11-November-1928 saying that the 1928 Solodyne construction article first appeared in the UK publication Modern Wireless - It calls it a LEWCOS 1928 SOLODYNE. (And my set does have LEWCOS coils.)

Anyone know of a stash of Modern Wireless? There is also some mention elsewhere that the 1928 SOLODYNE was an improvement of a 1927 circuit.

Just pulled the chassis out of the cabinet for detailed photos before tearing into it for cleaning. There are definitely extra screw holes in the audio section suggesting modifications. Vintage documents are surely going to be necessary for proper restoration.

Robert

RadioHist · 13th Apr 2014, 4:58 pm

From about the other side of the globe comes some great info on the Screen-Grid SOLODYNE.

The Queensland Radio News 1-July-1929 has a receiver review for the Crammond All-Metal Screen-Grid Solodyne. Unfortunately the ‘ump-teenth’ generation Xerox copy makes OCR impossible and even a couple of paragraphs are unreadable, it sure looks to be a very close relative of my “1928 SOLODYNE”
Ditto for the version shown in Wireless Weekly for 7-Sept.-1928. Their version now has single dial tuning.

The major differences seem to be in the brand of components and circuits used in the audio section. I’m sure that the interstage audio transformer was changed at some point and I very much want to find out what the original part was in the U.K. Modern Wireless issues – (especially the Jan. 1928 issues).
There appears to be variation in the coupling between the detector and first audio.

Four features I find interesting…

1. Much is made about the tunable notch filter in the antenna circuit to prevent overloading from your local station.
2. The R.F. coils are ‘Astatic wound’ half the primary and secondary windings wound in the opposite direction from the other half of the windings. This is reportedly done to reduce the shielding requirements and provide for close coupled coils that would match the high impedance output circuits of the screen grid valves.
3. There is a two position plug board that permits the selection of leaky grid or anode bend detection.
4. There is a provision for regeneration but it states that it is virtually unused for other than the most extreme DX operation. Also it states that the two dial tuning could be dispensed with if there were no interest in the extreme DX.

Robert

RadioHist · 29th May 2014, 3:52 pm

Well after three full weeks of afternoon work I've got the 1928 SOLODYNE chassis cleaned up pretty good I think considering the original condition.

I find the oxidation on sets from the UK to be especially difficult to remove even with the commercial grade ultrasonic cleaner I've used for years... Must be the character of the pollution and average humidity and temperature of the last 80 years in your part of the world.

The only thing keeping me from exhibiting the set is finding three appropriate triodes to replace the 'modern' ex GPO found in the set.... I need equivalents to the OSRAM DEP610 (2x) and one OSRAM DEL610 with the original style glass bulbs circa 1928 - I only care about how they look. Open filament or zero emission would be just fine for me. (These are 6 Volt valves.)

To take pictures, I put in some 2 Volt valves on hand...

I found the MODERN WIRELESS January 1928 article at the New York Public Library and for $25, they sent me a scan of the pages. From that article I now see that I need to have them look in 1927 issues for an earlier version of the SOLODYNE.

In the radio I was happy to find a cardboard sleeve of an original Siemens 1.5 Volt grid bias cell... With a little on-line detective work I was able to recreate the battery with a high degree of accuracy.

Now on to making repairs to the cabinet.... There are two missing wood feet and a missing strip of the bottom molding. First is just finding a piece of mahogany that comes close to blending-in to what is there. (No small task.)

Robert

Herald1360 · 29th May 2014, 5:32 pm

That's a work of art! Well impressed.

SeanStevens · 29th May 2014, 7:35 pm

Stunning - looks like a millionaires toy from back then!

SEAN

peter_scott · 30th May 2014, 9:20 am

Hi Robert,

I have some earlier Modern Wireless. It looks as if Peto Scott started advertising in about 1924 providing kits for John Scott Taggart designs.

Peter

RadioHist · 30th May 2014, 12:57 pm

I've known about Scott-Taggart for some time and know that there were at least a couple of books by him.... A year or two ago I was in the Book Fair at the AWA Conference in Rochester and found one of his books on offer and thought I'd pick it up for maybe $30 or $40... I was shocked to have the dealer ask (I think) $160

---- So no S-T book on my library shelf yet...

Robert

HamishBoxer · 30th May 2014, 2:21 pm

One the subject of S625 valves i have single valver homemade found in Gainsborough,Linconshire UK.

AC/HL · 30th May 2014, 4:56 pm

A Peto-Scott advertisement in a 1933 Practical Wireless I have states that they started in 1919

RadioHist · 23rd Aug 2014, 4:34 pm

Folks,

My 1928 Solodyne had its first outing at the Antique Wireless Association Conference near Rochester, New York last week... It did get a first place ribbon in it's category.

If you have the interest, you can go to this web page and download an 11 page .pdf document that I included in my exhibit. There are many other pages and photos in my notebook, but no time to post them now...

http://kd4hsh.homestead.com/1928-Solodyne-00.html

I also exhibited my McMichael DIMIC III.... At this point I do not have a .pdf document available for download.

The only task left on this project is to complete fulfilling my parts trade with Phil Taylor. Without his help I could not have made the Solodyne ready for exhibit.

Robert

24th Mar 2014, 2:32 am	#1
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	1928 SOLODYNE - Peto-Scott design ? Of all things... My first exhibition of my McMichael Screened Dimic 3 last Thursday in Charlotte, NC, USA has me dumb founded by discovering in the conference flea market this definitely British made "1928 SOLODYNE" - Ugly and then some on the outside but amazing inside. A set containing TWO S625 screen grid valves - fantastic! The plug-in coils are LEWCOS and they plug into receptacles branded Peto Scott. There appears to be a regenerative detector with feedback controlled by a small variable condenser mounted on the front panel. It appears to have originally had a pentode output valve that was rewired slightly for a triode. It will be more than interesting to trace the circuit and see if the S625's are operated at very low voltage like the SOLODYNE circuits that were written up here in the USA in the 1924/27 time frame. (They were usually for headphone only operation...) Have you seen such a beast in collections on your side of the pond? This set has been in the USA since at least the mid 1970's. It is going to be a challenge to get this set properly cleaned & documented but I sure hope I can make that happen in time for the AWA Conference in Rochester, NY during August. Attached Thumbnails

24th Mar 2014, 2:37 pm	#2
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	Re: 1928 SOLODYNE - Peto-Scott design ? If is a solodyn R.056? it was made around 1927 according to the net, it uses RE144 RE144 RE054 RE054 RE054 RE134 valves, and was made by Zenit Prelouc in Czechoslovakia. May be someone has a better idea. John

24th Mar 2014, 3:17 pm	#3
Mr Moose Octode Join Date: Jul 2008 Location: Gloucestershire, UK. Posts: 1,043	Re: 1928 SOLODYNE - Peto-Scott design ? Hello, Lots of different manufacturers in several countries seem to have models called Solodyne. ( It originally seems to have been used for models using a single battery for HT and LT.) The only British one I can find is this one but the description does not fit yours. http://www.radiomuseum.org/r/bligh_9_solodyne.html This Australian one does use two double ended screen grid valves http://www.radiomuseum.org/r/crammon..._solodyne.html but from its name would appear to be in a metal cabinet. Looking at the internal construction and the somewhat varied use of different manufacturers parts it is possible that it is a homebuilt set in a proprietary cabinet. Yours, Richard

24th Mar 2014, 4:44 pm	#4
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? Thanks for the Australian tidbit.... I have a guy down there who might be able to get the newspaper reference.... The panel is engraved, and has Peto Scott special sockets. The great book Setmakers by Geddes w/ Bussey comments. pg36 "Peto-Scott specialized in making up receiver kits for designs published in constructors' magazines." I have a fair stash of Wireless Worlds from 27/28 maybe I'll get lucky and find a write-up there.... Of course, any information from this forum is most welcome. I really enjoy the back-story to this hardware. It is essential to proper exhibition which I dearly love to do. BTY - The S.G. valves are S625 - I thought I'd never find one over here, much less a whole set! Robert Last edited by RadioHist; 24th Mar 2014 at 4:52 pm.

25th Mar 2014, 8:36 pm	#5
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? Well I did go through my 20 or so Wireless Worlds from 1927 to 1928.... No references to a "1928 SOLODYNE"... I have the January 1927 issue of Wireless Magazine... That publication seems much more likely to have had such a constructors article. Alas, I have only one issue. It is not mentioned in the first 20 years of the BVWS Bulletin... Robert

31st Mar 2014, 2:29 pm	#6
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? A friend in Oz found a reference in the Brisbane, Sunday Mail 11-November-1928 saying that the 1928 Solodyne construction article first appeared in the UK publication Modern Wireless - It calls it a LEWCOS 1928 SOLODYNE. (And my set does have LEWCOS coils.) Anyone know of a stash of Modern Wireless? There is also some mention elsewhere that the 1928 SOLODYNE was an improvement of a 1927 circuit. Just pulled the chassis out of the cabinet for detailed photos before tearing into it for cleaning. There are definitely extra screw holes in the audio section suggesting modifications. Vintage documents are surely going to be necessary for proper restoration. Robert

13th Apr 2014, 4:58 pm	#7
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? From about the other side of the globe comes some great info on the Screen-Grid SOLODYNE. The Queensland Radio News 1-July-1929 has a receiver review for the Crammond All-Metal Screen-Grid Solodyne. Unfortunately the ‘ump-teenth’ generation Xerox copy makes OCR impossible and even a couple of paragraphs are unreadable, it sure looks to be a very close relative of my “1928 SOLODYNE” Ditto for the version shown in Wireless Weekly for 7-Sept.-1928. Their version now has single dial tuning. The major differences seem to be in the brand of components and circuits used in the audio section. I’m sure that the interstage audio transformer was changed at some point and I very much want to find out what the original part was in the U.K. Modern Wireless issues – (especially the Jan. 1928 issues). There appears to be variation in the coupling between the detector and first audio. Four features I find interesting… 1. Much is made about the tunable notch filter in the antenna circuit to prevent overloading from your local station. 2. The R.F. coils are ‘Astatic wound’ half the primary and secondary windings wound in the opposite direction from the other half of the windings. This is reportedly done to reduce the shielding requirements and provide for close coupled coils that would match the high impedance output circuits of the screen grid valves. 3. There is a two position plug board that permits the selection of leaky grid or anode bend detection. 4. There is a provision for regeneration but it states that it is virtually unused for other than the most extreme DX operation. Also it states that the two dial tuning could be dispensed with if there were no interest in the extreme DX. Robert Attached Thumbnails

29th May 2014, 3:52 pm	#8
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? Well after three full weeks of afternoon work I've got the 1928 SOLODYNE chassis cleaned up pretty good I think considering the original condition. I find the oxidation on sets from the UK to be especially difficult to remove even with the commercial grade ultrasonic cleaner I've used for years... Must be the character of the pollution and average humidity and temperature of the last 80 years in your part of the world. The only thing keeping me from exhibiting the set is finding three appropriate triodes to replace the 'modern' ex GPO found in the set.... I need equivalents to the OSRAM DEP610 (2x) and one OSRAM DEL610 with the original style glass bulbs circa 1928 - I only care about how they look. Open filament or zero emission would be just fine for me. (These are 6 Volt valves.) To take pictures, I put in some 2 Volt valves on hand... I found the MODERN WIRELESS January 1928 article at the New York Public Library and for $25, they sent me a scan of the pages. From that article I now see that I need to have them look in 1927 issues for an earlier version of the SOLODYNE. In the radio I was happy to find a cardboard sleeve of an original Siemens 1.5 Volt grid bias cell... With a little on-line detective work I was able to recreate the battery with a high degree of accuracy. Now on to making repairs to the cabinet.... There are two missing wood feet and a missing strip of the bottom molding. First is just finding a piece of mahogany that comes close to blending-in to what is there. (No small task.) Robert Attached Thumbnails Last edited by RadioHist; 29th May 2014 at 3:55 pm. Reason: comment about valves used in photo

29th May 2014, 5:32 pm	#9
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: 1928 SOLODYNE - Peto-Scott design ? That's a work of art! Well impressed. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

29th May 2014, 7:35 pm	#10
SeanStevens Octode Join Date: Sep 2009 Location: Bath, Somerset, UK. Posts: 1,033	Re: 1928 SOLODYNE - Peto-Scott design ? Stunning - looks like a millionaires toy from back then! SEAN __________________ There are only 10 types of people, those who understand the binary system, and those who don't.

30th May 2014, 9:20 am	#11
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,274	Re: 1928 SOLODYNE - Peto-Scott design ? Hi Robert, I have some earlier Modern Wireless. It looks as if Peto Scott started advertising in about 1924 providing kits for John Scott Taggart designs. Peter Attached Thumbnails __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos

30th May 2014, 12:57 pm	#12
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? I've known about Scott-Taggart for some time and know that there were at least a couple of books by him.... A year or two ago I was in the Book Fair at the AWA Conference in Rochester and found one of his books on offer and thought I'd pick it up for maybe $30 or $40... I was shocked to have the dealer ask (I think) $160 ---- So no S-T book on my library shelf yet... Robert

30th May 2014, 2:21 pm	#13
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: 1928 SOLODYNE - Peto-Scott design ? One the subject of S625 valves i have single valver homemade found in Gainsborough,Linconshire UK. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

30th May 2014, 4:56 pm	#14
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: 1928 SOLODYNE - Peto-Scott design ? A Peto-Scott advertisement in a 1933 Practical Wireless I have states that they started in 1919

23rd Aug 2014, 4:34 pm	#15
RadioHist Pentode Join Date: Aug 2009 Location: Charlotte, NC; USA Posts: 165	Re: 1928 SOLODYNE - Peto-Scott design ? Folks, My 1928 Solodyne had its first outing at the Antique Wireless Association Conference near Rochester, New York last week... It did get a first place ribbon in it's category. If you have the interest, you can go to this web page and download an 11 page .pdf document that I included in my exhibit. There are many other pages and photos in my notebook, but no time to post them now... http://kd4hsh.homestead.com/1928-Solodyne-00.html I also exhibited my McMichael DIMIC III.... At this point I do not have a .pdf document available for download. The only task left on this project is to complete fulfilling my parts trade with Phil Taylor. Without his help I could not have made the Solodyne ready for exhibit. Robert Attached Thumbnails