EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

Good morning everyone,

           This is my first time posting so please forgive me if I mess something up. I have recently purchased the radio stated in the subject line above and please see the attached pictures. Single tuner, Serial M-99, single speaker, and AVC with the Wunderlich tube. Before powering up the radio on a dim bulb tester, I notice the 80 rectifier tube was in one of the 45s' socket and the 45 was in the 80 socket. I decided I better start checking underneath the power supply before applying power. I noticed filter caps have been changed out in the past and some soldering on wires in different locations. I pulled the tubes out in the power supply and began tracing wiring and taking resistance measurements. The biggest GOTCHA so far is what I understand to be the audio interstage transformer. Please correct me if this is not the correct terminology. My Fluke meter shows an open circuit on all connections. I have never seen a transformer open like this. Anyway, I need a replacement. Performing research by looking at the grid and plate characteristics of the 45 and 56 tubes. I believe this transformer from Antique Electronic Supply could possibly work.

 https://www.tubesandmore.com/products/transformer-audio-interstage-...

P-T156

Any advice will be greatly appreciated letting me know if this part would work or I'm totally out in left field. I'm in and out of the house today so it may take time for me to respond. 

Thanks!

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Yes, I looked at the RCA manual for the 56. Ideally I suppose I would have several chokes to try in circuit, see which performed best - but I'll try the one I ordered and see how things work. I have a couple other chokes (vintage, non-Scott) here, I may test with them as well. Obviously, the original is a high-failure item, so finding a good substitute is going to be helpful to others. 

Good evening Scott collectors. Kent, did your choke arrive and did it work for the unit? If you have not had time to install the choke, no worries, I'm working on the top end of the chassis in the IF sections. Out of 4 58 tubes, I had to reattach the grid caps on three out of the four. I was lucky that enough wire was protruding from the glass in order to solder on the top cap. I even got lucky in that all tubes tested very well. Thanks.

Good evening Scott collectors. Kent, did your choke arrive and did it work for the unit? If you have not had time to install the choke, no worries, I'm working on the top end of the chassis in the IF sections. Out of 4 58 tubes, I had to reattach the grid caps on three out of the four. I was lucky that enough wire was protruding from the glass in order to solder on the top cap. I even got lucky in that all tubes tested very well. Thanks.

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I have received the choke from AES, but have not had a chance to test it. I've got an AW23 on the bench right now, will be there for a couple more weeks I expect...I'll let you all know.

Kent

No worries. I have plenty to do until then. Thank you for the update.

Good evening everyone,

        I have decided to restore the cabinet. The cabinet has issues such as veneer separating from the wood, missing veneer on the feet, and brush marks in the clear on the radio cabinet. After searching for professional restorers, my wife referenced me to a gentleman she knew who was in the furniture restoration business. I spent a half day at his shop and I'm convinced he will be able to restore the cabinet.

https://www.harmisonfinefurniture.com/

Noel and I were discussing what type of glue was used to glue in the speaker grille cloth. We believe it is hide glue and we were attempting to decide what would be the best way to dissolve the glue in order to remove the speaker grille cloth. I have read people using 50/50 mix vinegar and water or just warm water. We will be able to recreate the saw kerfs. Does anyone have experience at removing this glue cloth from this time period? I have attached a picture of the back of the cabinet. Thanks

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The grill cloth should not be glued, it is held in by the wood splines pressed into the notches around the edge. You have to remove the strips (they will break, almost unsaveable)). I replace them with screen door spine when putting the cloth back on.

Kent

Lance Hughes said:

Good evening everyone,

        I have decided to restore the cabinet. The cabinet has issues such as veneer separating from the wood, missing veneer on the feet, and brush marks in the clear on the radio cabinet. After searching for professional restorers, my wife referenced me to a gentleman she knew who was in the furniture restoration business. I spent a half day at his shop and I'm convinced he will be able to restore the cabinet.

https://www.harmisonfinefurniture.com/

Noel and I were discussing what type of glue was used to glue in the speaker grille cloth. We believe it is hide glue and we were attempting to decide what would be the best way to dissolve the glue in order to remove the speaker grille cloth. I have read people using 50/50 mix vinegar and water or just warm water. We will be able to recreate the saw kerfs. Does anyone have experience at removing this glue cloth from this time period? I have attached a picture of the back of the cabinet. Thanks

Some secured with both hide glue and splines.  Sometimes grill cloth in good condition cemented with hide glue in can be carefully pulled off the baffle board without damaging the grill cloth.

Norman 

Hello-

Hide glue is used extensively in player piano restorations (another hobby of mine) so I have lots of experience using it.  If you need to remove something that is glued with hide glue, it will soften and let go with the application of gentle heat and, if possible, light moisture.  I use a travel-size clothes iron on low-medium heat for removing old pneumatic cloth from wooden parts.  Lightly moistening the cloth will help it let go.  Obviously be aware of what you are doing and do not scorch anything.  Keep the iron moving.  Note that the cloth may shrink or stretch as you heat and pull on it and/or apply water, so be careful.  You may want to start in one corner and just gently peel it up as it softens in small sections, rather than try to warm and soften everywhere at once.

For reference, glue pots are generally kept at 140-150F when applying glue, so this is all the heat you will need to soften and remove old glue.

I should add that I will sometimes use a piece of aluminum foil between the iron and the cloth being removed.  This added layer, provided you do not let it slip around while ironing, will help prevent any glue that seeps through the cloth from getting stuck to the underside of the iron and getting smeared around as you iron.  The glue will not stick well to the foil, as it is non porous.

I am not familiar with using vinegar, so cannot speak to usefulness of that being added.

Wood glued to wood with hide glue can also be separated with the application of heat.

Real hide glue is completely water soluble, even after 100+ years.  This is why it is still the preferred glue for restoration of player pianos, since it can be removed and re-re-restored indefinitely in the future.  If glue becomes (or remains) impregnated in the cloth, it will dissolve in warm water and can be rinsed out.

You can find considerably more information on the use of hide glue by visiting the archives of the Mechanical Music Digest at https://www.mmdigest.com/ and looking at the subjects relating to hide glue.

-Troy

Edmonds, WA

Troy, I too used to play with player pianos.  Have an Ampico A and B and Steinway DuoArt.  All grands.  Is player piano co still in business?  where do most supplies come from these days.  I know this is off the subject but but you piqued my interest!  I too have my home made hide glue pot.  I haven't used it in years and none of the pianos are playing.  Friend request sent.

Thank you gentlemen for the prompt and great responses. Whether it is unfortunate or not, my grille cloth is held in by both the wood kerf and the glue. The wood kerf strips in certain areas are falling out just by the touch of a finger. The glue is hanging on. I like the idea of the travel iron and aluminum foil which will probably be used in an attempt to remove the grille cloth. Thanks again and I will keep everyone updated.

Why do you need to remove the speaker cloth? It is usually attached to the speaker baffle board, not to the cabinet.

Your cabinet has original speaker cloth. Hope you can keep it.

With regard to installing speaker cloth, I have had varying success extracting the wood strips and areas where the glue was a problem. Hope Troys suggestion works.

I clean out the residual glue in the saw kerfs with the table saw - carefully so as to not widen the kerf, but a tad deeper is OK. 

Screen door spline comes in 2 diameters, the smaller .125" should suffice. Use the inexpensive tool  - I prefer the one with plastic/nylon wheels rather than metal wheels. Easy to pull out portions of the spline to correct cloth alignment and cloth tension. The speaker baffle screwed against the cabinet front helps hold the cloth and spline in the long term.

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