1934 AW 15 Electrical Restoration, Questions Please

[Jon Ketron]

Hello all,

I am new to this forum and somewhat new to E.H. Scott Radios.  I have about 10 years experience collecting, restoring, and rebuilding pre WWII radio's back to factory specs., or as close as possible.  I am excited to start an electrical restoration on this early version AW15.  My goal is to re-stuff each and every bathtub style capacitor which will include drilling out each rivet and re-installing new rivets.  I will also re-stuff all electrolytic cans.  The end goal of this restoration is to have an electrically restored factory looking set.  

Has anyone re-stuffed these bathtub style caps before?  Could you please give me any pointers or advice for this procedure?  What style of rivets are used for re-installation and what would be the best tool to use for this as there will be many awkward angles?

You may notice the Olympian cabinet this radio resides in has short legs.  Upon close examination, Norman and myself have decided this cabinet had a new set of legs and stretcher installed at some point during the radio's life.  Whether at the beginning or sometime mid point, I don't know.  The legs and stretcher look to be a custom job and the quality shows as this modification looks to be neat and very difficult to spot upon preliminary inspection.

I would like to thank all of you for any help provided, this looks to be an excellent forum!

Thanks,

Jon

 

[Norman S Braithwaite]

Place the bandswitch in the broadcast band position and note the position of the turret.  Do not rotate the bandswitch while the turret is removed and replace the turret in the same position as it had been when removed.  Rotation of the bandswitch while the turret is removed may damage the antenna switch linked to the bandswitch above the chassis as well as result in misalignment of the turret when re-installing.  That's it!

Norman

[Jon Ketron]

Thanks Norman.

Jon

[Jon Ketron]

Per the parts diagram, there looks to be several wax paper caps that will need to be changed on the top side of the chassis.  One cap resides within just about each coil shield.  The grid cap lead looks to be soldered to the supporting tab.  Is there a special way to remove the top side coil shields for this model?

Thanks

Jon

[Thomas Day]

Jon: Unsolder the cap and gently pull the lead thru the can while lifting the can from the chassis. On my Allwave 23 the cans are a pretty tight fit. I added a length of wire to the lead to put it back thru the can, then unsoldered the extra wire and re soldered the cap. I used Turtle Wax chrome polish on the cans. I see that your wires are shielded, they are not on the Allwave 23

[David C. Poland]

Jon - have you printed/read the 14 page Technical Service Data on the AW-15? 

It is in Scott Info Archives in the set folder for the AW-15.  It mentions a number of things including removal of the coil wheel.

To repeat Norman's direction, put the wave change in the Broadcast position before removing the coil wheel and leave it there until you re-mount the coil wheel. Broadcast band is the extreme counter clockwise position (which is about 8 o'clock position). Failure to do this risks breaking the switch in the antenna coil above the coil wheel.

[Jon Ketron]

Thank you Thomas, I will do this.  Looks as though the tab that protrudes from the can is soldered to the braided strap.  I will de-solder this section as well when disassembling.  Everything is shielded so well!  Such an excellent quality set.

Jon
 
Thomas Day said:

Jon: Unsolder the cap and gently pull the lead thru the can while lifting the can from the chassis. On my Allwave 23 the cans are a pretty tight fit. I added a length of wire to the lead to put it back thru the can, then unsoldered the extra wire and re soldered the cap. I used Turtle Wax chrome polish on the cans. I see that your wires are shielded, they are not on the Allwave 23

[Jon Ketron]

Thank you Dave.  I have printed and read the 14 page technical service data.  It is very detailed and labels everything to a "T".  Thank you for the direction on the coil wheel.

Jon
 
David C. Poland said:

Jon - have you printed/read the 14 page Technical Service Data on the AW-15? 

It is in Scott Info Archives in the set folder for the AW-15.  It mentions a number of things including removal of the coil wheel.

To repeat Norman's direction, put the wave change in the Broadcast position before removing the coil wheel and leave it there until you re-mount the coil wheel. Broadcast band is the extreme counter clockwise position (which is about 8 o'clock position). Failure to do this risks breaking the switch in the antenna coil above the coil wheel.

[Jon Ketron]

After a bit of patience and carful work, I was able to remove all grid caps and coil shields.  All 5 original wax/paper caps were removed and replaced with modern Polypropylene capacitors.

Jon

[Jon Ketron]

After re-installing the grid caps and coil shields, I completed a final polishing of the tuner chassis.  The chrome really stands out once polished.  I must say, it took hours doing it by hand.  A labor of love I suppose!

Jon

[mike hadley]

Hi Jon,

If I send my chassis over could you do the same for me,

Nice work, your chrome looks much better than mine, (stored damp, lots of rust) I also found that the two 3uf caps to be in good order, not bad for 83 years, have you stuffed the bathtubs yet ?, there was two that I did not touch, the first audio and oscillator cathode bypass, the push pull driver would have to come out in order to get to the rivets, (these caps are the ones located to the right of the right hand contact assembly in your photograph), as this would require major surgery and the set is working I made a tidy job of fixing the replacement caps in their correct places,

not long now until You hear the song of fifteen tubes i think.

[Jon Ketron]

We now arrive at the final part of this AW-15 electrical restoration, the underside of the tuner chassis.  After removing the coil wheel I noticed a small chunk of the supporting bracket missing (right side of the shaft).  I found the missing piece else where in the chassis.  The loose piece is a perfect fit and I plan on gluing it back in place.  Do any of you recommend a good adhesive?  I was thinking JB weld.  Did the early Scott AW-15 models have pot metal assemblies?  What is the story on this if any?  Overall integrity of this bracket is great, no cracking or any damage other than the missing chunk.

Jon

[Norman S Braithwaite]

The bandswitch gear boxes employed in the Allwave Deluxe, Allwave Fifteen, and Full Range High Fidelity (AW-23, AW-27) receivers are chrome plated pot metal.  Most were cast using a good alloy but some made during the run of Allwave Fifteen receivers were cast using a bad combination of ingredients.  The broken stop on your gear box is likely due to a combination of a marginal alloy plus an attempt to rotate the bandswitch too far.  It will likely work satisfactorily if you cement the stop using two part epoxy.  If you want to replace the top piece of the gear box or the entire gear box, I have good ones available.

Norman