What did Pye use to coat/seal transformers etc? - UK Vintage Radio Repair and Restoration Discussion Forum

Cruisin Marine · 8th Mar 2022, 9:16 pm

In old PMR gear like the Vanguard, Cambridge and Westminster, used in particular on audio transformers and LF chokes etc.
It looks like an orange colour, like a "tropicilisation" treatment.
It has certainly lasted VERY well.

CambridgeWorks · 8th Mar 2022, 10:00 pm

Always reminded me of toffee apple coating!
Fixed station equipment had the same coating. Even up to the 400& 4000 series base stations of the 1980s.
All I can say is that the transformers in their pmr gear were extremely reliable.
The only one I had to replace several times in my 20 or so years was the mod transformer (part # AL21219) on the W15AM Westminster. Fault being extremely low mod caused by shorted turns.
Rob

Sparky67 · 9th Mar 2022, 12:05 am

That smell when you lifted the top cover off a warm Vanguard as well...!

If I get a whiff of it now it takes me straight back to servicing P-band AM25HO and high-band FM25B Vanguards on the bench in the 1970s.

Martin
G4NCE

Cruisin Marine · 9th Mar 2022, 12:39 am

That smell when you lifted the top cover off a warm Vanguard as well...!

If I get a whiff of it now it takes me straight back to servicing P-band AM25HO and high-band FM25B Vanguards on the bench in the 1970s.

I know EXACTLY what you mean! It is amazing, smell is probably the strongest of all senses that evoke memories.
Old comic's is a smell takes me right back to the sixties.

Refugee · 9th Mar 2022, 1:53 am

Does this stuff look anything like it?
It has been used to seal the calibration parts on an elapsed timer from the period.

Cruisin Marine · 9th Mar 2022, 2:34 am

Does this stuff look anything like it?
It has been used to seal the calibration parts on an elapsed timer from the period.

It does look VERY much like that.

CambridgeWorks · 9th Mar 2022, 8:07 am

Istr at Haig Rd factory, Cambridge back around 1968 the transformers were baked in a large oven to complete the process?
Rob

joebog1 · 9th Mar 2022, 11:13 pm

I know the "stuff" you are talking about, but never knew what it was. The better shortwave radios produced in Au used this technique for the various coils in the radio. It melts at a very low temperature though, so it's "not really" a varnish, at least as I know it.

It would be nice to know what it is, and how it's made. To me it looks like some sort of "hardener" is added to beeswax. ( I keep bees and have used beeswax as n insulation.) I think beeswax is too "organic" for long term service, although it does last thousands of years in dry cool temperatures.

Joe

Jon_G4MDC · 10th Mar 2022, 10:01 am

I don't recall the Pye stuff melting easily.

Each transformer had a sheet for winding which gave all the core & wire part numbers along with how to many turns to which pins. It would also have the information about the varnish.

There were thousands of such hand drawn sheets which were eventually all transferred to microfilm. There was a fiche of cards where you could find your part number and obtain a print of it from a machine to the side. The whole Pye world was in there.

Some manager probably ordered it to be dumped. How I would love to have access to it now. Today they would call it their IPR.

M0FYA Andy · 10th Mar 2022, 11:40 am

The stuff in post #5 looks like shellac varnish.

Andy

beamcurrent · 10th Mar 2022, 8:13 pm

Quote:

There were thousands of such hand drawn sheets which were eventually all transferred to microfilm. There was a fiche of cards where you could find your part number and obtain a print of it from a machine to the side. The whole Pye world was in there.

I too would love such a list! I would be happy with just a list of what "ALxxxxx" transformers did and their windings.

I do have a lot of Pye television equipment in the tvcameramuseum collection, In a world of infinite time I could list the transformers in them, but there is no time....

joebog1 · 10th Mar 2022, 10:32 pm

Is there ANY coil winding data left online?. I have seached for our Australian AEGIS coils and can find nothing. They made almost every coil you could imagine. I still have some of their Pi wound RF chokes which are a thing of great beauty. I would still play with radio if I could get the coils, OR the data to wind them. I still have a large collection of IFT's made by Aegis all 455 Khz, which was Australias most common IF frequency for normal sets.

Joe

8th Mar 2022, 9:16 pm	#1
Cruisin Marine Octode Join Date: Jul 2018 Location: Worthing, West Sussex, UK. Posts: 1,003	What did Pye use to coat/seal transformers etc? In old PMR gear like the Vanguard, Cambridge and Westminster, used in particular on audio transformers and LF chokes etc. It looks like an orange colour, like a "tropicilisation" treatment. It has certainly lasted VERY well. Last edited by Cruisin Marine; 8th Mar 2022 at 9:38 pm.

8th Mar 2022, 10:00 pm	#2
CambridgeWorks Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,859	Re: What did Pye use to coat/seal transformers etc. Always reminded me of toffee apple coating! Fixed station equipment had the same coating. Even up to the 400& 4000 series base stations of the 1980s. All I can say is that the transformers in their pmr gear were extremely reliable. The only one I had to replace several times in my 20 or so years was the mod transformer (part # AL21219) on the W15AM Westminster. Fault being extremely low mod caused by shorted turns. Rob __________________ Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd

9th Mar 2022, 12:05 am	#3
Sparky67 Heptode Join Date: Feb 2008 Location: Great Barr, Sandwell, West Midlands, UK. Posts: 589	Re: What did Pye use to coat/seal transformers etc. That smell when you lifted the top cover off a warm Vanguard as well...! If I get a whiff of it now it takes me straight back to servicing P-band AM25HO and high-band FM25B Vanguards on the bench in the 1970s. Martin G4NCE

9th Mar 2022, 12:39 am	#4
Cruisin Marine Octode Join Date: Jul 2018 Location: Worthing, West Sussex, UK. Posts: 1,003	Re: What did Pye use to coat/seal transformers etc. That smell when you lifted the top cover off a warm Vanguard as well...! If I get a whiff of it now it takes me straight back to servicing P-band AM25HO and high-band FM25B Vanguards on the bench in the 1970s. I know EXACTLY what you mean! It is amazing, smell is probably the strongest of all senses that evoke memories. Old comic's is a smell takes me right back to the sixties.

9th Mar 2022, 2:34 am	#6
Cruisin Marine Octode Join Date: Jul 2018 Location: Worthing, West Sussex, UK. Posts: 1,003	Re: What did Pye use to coat/seal transformers etc. Does this stuff look anything like it? It has been used to seal the calibration parts on an elapsed timer from the period. It does look VERY much like that.

9th Mar 2022, 1:53 am	#5
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,554	Re: What did Pye use to coat/seal transformers etc. Does this stuff look anything like it? It has been used to seal the calibration parts on an elapsed timer from the period. Attached Thumbnails

9th Mar 2022, 8:07 am	#7
CambridgeWorks Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,859	Re: What did Pye use to coat/seal transformers etc. Istr at Haig Rd factory, Cambridge back around 1968 the transformers were baked in a large oven to complete the process? Rob __________________ Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd

9th Mar 2022, 11:13 pm	#8
joebog1 Banned Join Date: Jun 2015 Location: Mareeba, North Queensland, Australia Posts: 2,704	Re: What did Pye use to coat/seal transformers etc. I know the "stuff" you are talking about, but never knew what it was. The better shortwave radios produced in Au used this technique for the various coils in the radio. It melts at a very low temperature though, so it's "not really" a varnish, at least as I know it. It would be nice to know what it is, and how it's made. To me it looks like some sort of "hardener" is added to beeswax. ( I keep bees and have used beeswax as n insulation.) I think beeswax is too "organic" for long term service, although it does last thousands of years in dry cool temperatures. Joe

10th Mar 2022, 10:01 am	#9
Jon_G4MDC Nonode Join Date: Nov 2015 Location: Welwyn Garden City, Hertfordshire, UK. Posts: 2,015	Re: What did Pye use to coat/seal transformers etc. I don't recall the Pye stuff melting easily. Each transformer had a sheet for winding which gave all the core & wire part numbers along with how to many turns to which pins. It would also have the information about the varnish. There were thousands of such hand drawn sheets which were eventually all transferred to microfilm. There was a fiche of cards where you could find your part number and obtain a print of it from a machine to the side. The whole Pye world was in there. Some manager probably ordered it to be dumped. How I would love to have access to it now. Today they would call it their IPR.

10th Mar 2022, 11:40 am	#10
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: What did Pye use to coat/seal transformers etc? The stuff in post #5 looks like shellac varnish. Andy

10th Mar 2022, 10:32 pm	#12
joebog1 Banned Join Date: Jun 2015 Location: Mareeba, North Queensland, Australia Posts: 2,704	Re: What did Pye use to coat/seal transformers etc? Is there ANY coil winding data left online?. I have seached for our Australian AEGIS coils and can find nothing. They made almost every coil you could imagine. I still have some of their Pi wound RF chokes which are a thing of great beauty. I would still play with radio if I could get the coils, OR the data to wind them. I still have a large collection of IFT's made by Aegis all 455 Khz, which was Australias most common IF frequency for normal sets. Joe