ELECTRICAL RESTORATION: All Wave 12 Deluxe

[Jon Ketron]

Hello all,

I have started another E.H. Scott restoration and wanted to share my progress for those interested.  Pictured is an early version AW12 Deluxe with AVC (Wunderlich tube) housed in an early version Tasman cabinet.  Upon receipt of the electronics, the set was wired for use with an 1930's era PM speaker.  The original E.H. Scott speaker was missing.  I purchased the set with a correct and working pair of E.H. Scott Rola twin speakers.  This Rola speaker setup has been seen and documented on early examples of the AW12 Deluxe chassis, which this set appears to be:

Serial number F-78

The All Wave 12 chassis/power supply and Rola speakers were added to this Tasman cabinet upon purchasing.  All is period correct thus showing an proper example as to what a complete set may have looked like brand new upon purchase via the Laboratory in the early 1930's.  Please feel free to comment as the restoration progresses.  I look forward to making this beautiful AW12 operational again!

Jon

 

[Y2K Bruce]

I have the 3rd version with the dual speakers and the blue Wunderlich tube. Interestingly there is no tone control on the back of the chassis. My serial no is F-99

[Jon Ketron]

Thank you Dave for sharing this information!

Jon

[Jon Ketron]

Bruce,

Thank you.  I appreciate you sharing your serial number.  I find E.H. Scott production run changes fascinating, so many variables.  This AW12 also has AVC within the circuit utilizing a Wunderlich tube.  My serial number is very close to yours! 

Jon

[Jon Ketron]

The replacement power transformer to be utilized came from an 2-dial AW12 power supply.  Findings indicate the 2-dial AW12 power transformer is electrically identical to the later Deluxe AW12 single dial power transformer.  Tube line up on both power supplies are identical.  Both have close to identical electrical layout with several differences present.  Findings indicate these differences will not affect power transformer performance.

Cosmetically, the replacement power transformer does not have a chrome cover over the exposed laminations.  This cosmetic feature is one that E.H. Scott added to Allwave sets post 2 dial version.  Rivets hold the power transformer covers together.  It is possible to break these rivets to add in the missing chrome cover.  I have decided to avoid performing this procedure for fear of damaging.  The replacement transformer will not have a chrome cover over the exposed laminations.  An enthusiast could perhaps detect the difference, those whom don't have a trained eye will hardly notice!

Replacement 2-Dial AW12 power supply:

Patent date stamped into AC power Plug with Chicago address (Sept. 22 1931):

 

[Jon Ketron]

The replacement transformer has been removed from the 2-dial AW12 power supply:

[David C. Poland]

Bruce - My remaining AW-12 DELUXE AVC with Jensen speaker is a very late version DELUXE AVC Wunderlick model. The audio path is revised.

- Jon's example (and most other AW-12's) use a 5 wire receiver cable with plug pin 6 unused. So, Jon's  2nd AF plate is both fed B+ through the interstage primary to receiver cable plug pin 3 to the receiver and carries the audio back to the amp through the interstage primary.  

- Mine uses pin 6 together using pin 3 as part of the revised audio path separating the 2nd AF audio path back to the amp's interstage transformer. So, both my amp and the receiver are a partial redesign. All this is factory in as much as Corby Dawson has the same late version AW-12 Deluxe and he posted his adjusted receiver diagram in May 2012 on this Scott site on a thread.

- Thus, Scott radios can be an interesting restoration challenge. No Scott factory diagram has yet turned up for my version receiver (Ser# W-114)  and amp. Always pays to explore a Scott project set before beginning any work.

[Jon Ketron]

I agree Dave!  Thanks for the info too!

Jon

[Thomas Day]

Jon

Thanks to a member of this list, I was able to have a power transformer reproduced for my 

Allwave 23. The company is Heyboer transformer co. in Grand Haven Mi.  It took a couple of months to have it done and there is a small size difference from the original, but otherwise a very good result. Very reasonable cost for a one off product.  They are a small company and the reason it took so long is that they do this work in between their regular production work. 

Thom

[Jon Ketron]

Thomas,

Thank you for informing me of Heyboer Transformer co.  Fellow collectors have mentioned Heyboer and services they provide.  I hear they do great work.  I will keep this information in mind should I need such a service performed in the future!

Jon

[Jon Ketron]

The 2 dial AW-12 power transformer is now installed on the deluxe power supply.  A controlled power up monitoring wattage and voltage proved to be successful as the set came to life instantaneously.  All tubes lit, stations were pulled in on all four bands utilizing a 30 ft. indoor antenna!  I absolutely amazed once again with the quality E.H. Scott put into his products.  I checked alignment on all four bands, dead on accurate to the dial scales!  All bands above broadcast can be deciphered utilizing an E.H. Scott provided "Station Finder".  Upon the introduction of the Allwave 15, a "Station Finder" was no longer needed.

My evaluation of performance:  Once again E.H. Scott comes through with perfection!  I have worked on over 100 pre-1935 radio circuits since starting this hobby ten years ago.  With respect to 1932 year radio sets, this E.H. Scott will blow away all competition offered in 1932 (from my restoration experience).  1932 Philco and RCA sets (from my restoration experience) don't stand a chance to the crisp clear powerful audio this AW-12 two speaker system provides.  Selectivity, sensitivity, and fidelity are the finest I have ever come across on a circa 1932 circuit.  DX'ing, also the finest for the year this set was introduced to the public.  Most general consumer radio sets circa 1932 didn't offer 4 band Allwave performance.  Opinion:  E.H. Scott receivers are the finest I have ever worked on.  Performance is unmatched to any manufacture with respect to year introduced.  The Allwave 12 is a fine set to work on and enjoyable to listen to as well!

This concludes the AW-12 Deluxe electrical restoration.  Final restoration pictures shown below:

[David C. Poland]

Ah - you have the metal version of the station finder. There is a heavy yellow paper version too.

The Scott AW-12 Broadcast band is calibrated in kilocycles, one of the first radios to do so. But the 3 SW bands are calibrated with a 1 to 100 scale. My paper version shortwave station finder translates SW dial number to meters for each band.

[Jon Ketron]

Dave,

After seeing your two versions I started the hunt to find both myself.  I was lucky finding this brass version on the internet several months ago.  Thank you for the information regarding.  Question:  Which station finder came out first, brass or paper?

Jon