Strad PW461 - Copper Foil? - UK Vintage Radio Repair and Restoration Discussion Forum

Stuart R · 26th May 2019, 9:40 am

Hello,

I'm taking a look at a Strad PW461 for a friend.

On dismantling the set, I've noticed a sheet of copper foil is taped inside the bottom of the Bakelite case, it sits below the valve holders, rather than the IF/RF section which has its own metal screen. Don't be fooled as I was by the smaller brown rectangle, that's my table cloth!

Smoothing caps don't want to reform fully, but after tacking on a new coupling cap to the output valve, bypassing the open circuit mains switch and repairing a broken wire in the speaker loom, I have some sounds.

There isn't much mention of these of the forum. Does anyone know if the copper foil is original, or an add-on? I can see the phantom twiddler has been at the MW oscillator!

Thanks & Regards,

SR

Electronpusher0 · 27th May 2019, 5:58 pm

That looks like a later add on using masking tape.
Peter

Andrewausfa · 27th May 2019, 7:37 pm

I believe it's an original part, mine show remnants of where the foil was glued.

Andrew

vidjoman · 27th May 2019, 9:41 pm

Looks like it’s a screen as it seems to connect to the chassis

Added - when the chassis is screwed in place. You can see the bright copper where the chassis brackets were touching it.
It may have been glued in at some time but later someone added the masking tape to stop it curling up.

Electronpusher0 · 27th May 2019, 9:49 pm

Ok, so the masking tape is later.
(sounds of man eating humble pie)

Peter

Stuart R · 27th May 2019, 11:10 pm

Thanks Andrew, hope your set was already dismantled for the photograph, I'm grateful for you taking the time to post it.

No need to eat your humble pie, Peter. Being held in with crudely-torn masking tape I wondered if it was an add-on, coupled with the fact there's been some tweaking, maybe this set had (or will have) some issues.

Yes vidjoman, the chassis has two metal bars along the bottom that will make good contact with the foil when everything is screwed in. The big problem is getting the chassis out as the heavy end with the mains transformer catches on a bit of foil every time. Maybe time for some new masking tape with neatly-cut edges?

Will probably be a while before there's an update, but was pleased to get a few stations on 2 of 3 wavebands the other night, means that most of the hard-to-source wound components are intact.

Regards,

SR

Andrewausfa · 27th May 2019, 11:44 pm

No problem Stuart, it was taken a few years ago when I was restoring my one. One of my favourite radios actually, it looks like an old radio if that makes any sense. There's just something about the PW461 which strikes a chord with me.

Andrew

Herald1360 · 28th May 2019, 9:41 am

Restick it invisibly with Evostik or maybe double sided mounting tape neatly round the edges plus a bit or two in the middle.

Or perhaps replace it with adhesive copper tape?

AC/HL · 28th Jul 2020, 2:54 pm

Thread reopened.

Stuart R · 28th Jul 2020, 5:52 pm

Thanks Bill,

I managed to flatten the worst of the creased foil by smoothing it out on my plastic work tray with the long edge of a square of plastic (large cable tie base).

Then stuck it down at the edges using the automotive foil tape used in previous projects as a in-cabinet aerial.

Looks a lot neater but care is still needed easing the heavy chassis in and out over the foil edges.

The set is back with its owner now, it's taken over a year to sort. Hopefully I'll have time to write a bit more about it if I get a quiet evening.

SR

Gabe001 · 28th Jul 2020, 6:39 pm

Does it make a difference to the set's performance? I didn't put one in my set - didn't know about it
Gabriel

Stuart R · 28th Jul 2020, 7:02 pm

Hello Gabriel,

I'm not sure that it made any noticeable difference to the performance.

I worked with the chassis out most of the time and the set's performance wasn't that great on the kitchen table with my usual washing line antenna.

I didn't hear any improvement when re-assembled, but the set worked better when moved upstairs with a few feet of wire strung around the window.

I was impressed with how quickly your restoration was completed!

There will be more to follow.....

Kind Regards,

Stuart.

Gabe001 · 28th Jul 2020, 8:32 pm

Thanks Stuart. The Strad was my first restoration and it remains my wife's favourite set. I found reception to be pretty good but it does suffer from a lack of tone control IMO. It cuts off the high frequencies a bit too aggressively I think, good for AM radio but less than ideal for modern tunes.

26th May 2019, 9:40 am	#1
Stuart R Heptode Join Date: May 2011 Location: Letchworth Garden City, Hertfordshire, UK. Posts: 693	Strad PW461 - Copper Foil? Hello, I'm taking a look at a Strad PW461 for a friend. On dismantling the set, I've noticed a sheet of copper foil is taped inside the bottom of the Bakelite case, it sits below the valve holders, rather than the IF/RF section which has its own metal screen. Don't be fooled as I was by the smaller brown rectangle, that's my table cloth! Smoothing caps don't want to reform fully, but after tacking on a new coupling cap to the output valve, bypassing the open circuit mains switch and repairing a broken wire in the speaker loom, I have some sounds. There isn't much mention of these of the forum. Does anyone know if the copper foil is original, or an add-on? I can see the phantom twiddler has been at the MW oscillator! Thanks & Regards, SR Attached Thumbnails

27th May 2019, 5:58 pm	#2
Electronpusher0 Nonode Join Date: Jun 2016 Location: Bognor Regis, West Sussex, UK. Posts: 2,296	Re: Strad PW461 - Copper Foil? That looks like a later add on using masking tape. Peter

27th May 2019, 7:37 pm	#3
Andrewausfa Octode Join Date: Dec 2010 Location: St Ives, Cambridgeshire, UK. Posts: 1,180	Re: Strad PW461 - Copper Foil? I believe it's an original part, mine show remnants of where the foil was glued. Andrew Attached Thumbnails __________________ Invisible airwaves crackle with life. Or they should do. BVWS Member

27th May 2019, 9:41 pm	#4
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Strad PW461 - Copper Foil? Looks like it’s a screen as it seems to connect to the chassis Added - when the chassis is screwed in place. You can see the bright copper where the chassis brackets were touching it. It may have been glued in at some time but later someone added the masking tape to stop it curling up. Last edited by vidjoman; 27th May 2019 at 10:11 pm.

27th May 2019, 9:49 pm	#5
Electronpusher0 Nonode Join Date: Jun 2016 Location: Bognor Regis, West Sussex, UK. Posts: 2,296	Re: Strad PW461 - Copper Foil? Ok, so the masking tape is later. (sounds of man eating humble pie) Peter

27th May 2019, 11:10 pm	#6
Stuart R Heptode Join Date: May 2011 Location: Letchworth Garden City, Hertfordshire, UK. Posts: 693	Re: Strad PW461 - Copper Foil? Thanks Andrew, hope your set was already dismantled for the photograph, I'm grateful for you taking the time to post it. No need to eat your humble pie, Peter. Being held in with crudely-torn masking tape I wondered if it was an add-on, coupled with the fact there's been some tweaking, maybe this set had (or will have) some issues. Yes vidjoman, the chassis has two metal bars along the bottom that will make good contact with the foil when everything is screwed in. The big problem is getting the chassis out as the heavy end with the mains transformer catches on a bit of foil every time. Maybe time for some new masking tape with neatly-cut edges? Will probably be a while before there's an update, but was pleased to get a few stations on 2 of 3 wavebands the other night, means that most of the hard-to-source wound components are intact. Regards, SR

27th May 2019, 11:44 pm	#7
Andrewausfa Octode Join Date: Dec 2010 Location: St Ives, Cambridgeshire, UK. Posts: 1,180	Re: Strad PW461 - Copper Foil? No problem Stuart, it was taken a few years ago when I was restoring my one. One of my favourite radios actually, it looks like an old radio if that makes any sense. There's just something about the PW461 which strikes a chord with me. Andrew __________________ Invisible airwaves crackle with life. Or they should do. BVWS Member

28th May 2019, 9:41 am	#8
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Strad PW461 - Copper Foil? Restick it invisibly with Evostik or maybe double sided mounting tape neatly round the edges plus a bit or two in the middle. Or perhaps replace it with adhesive copper tape? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

28th Jul 2020, 2:54 pm	#9
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Strad PW461 - Copper Foil? Thread reopened.

28th Jul 2020, 5:52 pm	#10
Stuart R Heptode Join Date: May 2011 Location: Letchworth Garden City, Hertfordshire, UK. Posts: 693	Re: Strad PW461 - Copper Foil? Thanks Bill, I managed to flatten the worst of the creased foil by smoothing it out on my plastic work tray with the long edge of a square of plastic (large cable tie base). Then stuck it down at the edges using the automotive foil tape used in previous projects as a in-cabinet aerial. Looks a lot neater but care is still needed easing the heavy chassis in and out over the foil edges. The set is back with its owner now, it's taken over a year to sort. Hopefully I'll have time to write a bit more about it if I get a quiet evening. SR Attached Thumbnails

28th Jul 2020, 6:39 pm	#11
Gabe001 Octode Join Date: Oct 2019 Location: Stockport, Greater Manchester, UK. Posts: 1,641	Re: Strad PW461 - Copper Foil? Does it make a difference to the set's performance? I didn't put one in my set - didn't know about it Gabriel

28th Jul 2020, 7:02 pm	#12
Stuart R Heptode Join Date: May 2011 Location: Letchworth Garden City, Hertfordshire, UK. Posts: 693	Re: Strad PW461 - Copper Foil? Hello Gabriel, I'm not sure that it made any noticeable difference to the performance. I worked with the chassis out most of the time and the set's performance wasn't that great on the kitchen table with my usual washing line antenna. I didn't hear any improvement when re-assembled, but the set worked better when moved upstairs with a few feet of wire strung around the window. I was impressed with how quickly your restoration was completed! There will be more to follow..... Kind Regards, Stuart.

28th Jul 2020, 8:32 pm	#13
Gabe001 Octode Join Date: Oct 2019 Location: Stockport, Greater Manchester, UK. Posts: 1,641	Re: Strad PW461 - Copper Foil? Thanks Stuart. The Strad was my first restoration and it remains my wife's favourite set. I found reception to be pretty good but it does suffer from a lack of tone control IMO. It cuts off the high frequencies a bit too aggressively I think, good for AM radio but less than ideal for modern tunes.