THE MYSTERY OF THE ALL-WAVE 27 EXPLAINED – MAYBE!

[David Wilson]

I use my holidays to catchup on my hobbies and my research, I’ve done a couple of resent posts here, one on AW 27 ownership showing some of the cabinets and phono options they came with and I also posted an early 1937 Scott AW 23 price list. This early 1937 price list was produced as Scott was changing over their AW 23 production to the production of their all-new Philharmonic. The Philharmonic was a major production change over for Scott as you know because they were switching from the turret system they had been using going back to the original AW 12. A production change over like this require much more tooling, which takes more time. The AW 27 (Baby Quaranta) was produced in this early 1937 production change over period. The final AW 23 price list I posted here earlier may holds some clues to why Scott produce the AW 27 and why so few exist today.

 

What makes the early 1937 AW 23 price list interesting is a few things. First, the cabinet lineup changes from the old standard cabinets that Scott offered with their AW 23 starting in 1935. Cabinets like Imperial Grande, the Nelson, Valencia, Lido and others were dropped from the price list. In 1936, Scott offered a staggering 32 cabinets including some cabinets with size variations to accommodate certain record players. The cabinet lineup in this early 1937 price list show here was cut to only 8 cabinets. The next Scott price list, which came out around April or May of 1937,  would introduce the Philharmonic with the same 8 cabinets that were in the last AW 23 price list plus two more, the all-new Secretaire and they brough back the popular Tasman rounding their cabinet lineup to 10. Scott started to trim the number of cabinets the offered their customers toward the end in 1936.   In the Scott March of 1936 news letter Scott would introduce  their Volume Range Expander used with their AW23.  The company promoted heavy in their 1936 price lists from March on this AW 23  Volume Range Expander. What’s even more interesting is in this early 1937 price list the Volume Range Expander is no longer offered as an option when ordering an AW 23. You can see this transition to the Philharmonic line start at Scott in this short window from the beginning of 1937 to April of 1937 starting with the same cabinet being introduce in the two price lists. Keep in mind, Scott had to start bringing the Philharmonic production online and at the same time continue to the production of their popular AW 23 model. Change overs like this were a challenge for the manufacture and normal production procedures were often modified to accommodate the change-over in models.

One thought that could explain why the Volume Range Expander not offered in the early 1937 AW price list could be that Scott had produced several extra tuners chassis for their top of the line 40 tube Quaranta models. These were produced for a very limited market with their $2,500 price tags. If Scott had several of these Quaranta tuners in their inventories as the Philharmonic came online, they may have been looking for creative ways to use these left over Quaranta chassis. One way the could have moved slow selling or extra inventory like this was  if an AW 23 customer wanted the Volume Range Expander, which was not currently offered in the most current 1937 price list, Scott would switched these customer to the  Quaranta chassis designed to accommodate the Volume Range Expander. Thus the AW 27 (Baby Quaranta) could have been invented out of a process invented to eliminate excess inventory during Scott’s major production switch over to the Philharmonic. It would have been a no brainer to do, especially if you were looking for way not to have produce more AW 23 chassis at the time.

 

I could be totally wrong on this theory but with only one surviving, complete Quaranta found to date a couple of less compete examples out there and only 20 of the AW 27s found to date this would help explain the scarcity of the AW 27s. It would also help explain why these AW 27s are not listed in any of Scott promotional materials. There were a limited number of Quaranta chassis left over and Scott put them to good use up selling their AW 23 customers, telling them for a little more money they could get the same tuner used in their $2,500 Quarantas.

[David Wilson]

Norm ... if you compare the AW 23 schematic with the Quaranta in the set folders in Kent's Scott Info Archive here on the Enthusiast site the two chassis are for the most part are the same electronically except for the Quaranta tuner having the expander built into its tuner circuitry. What are the electric differences between the AW 27 tuner and the Quaranta tuner, is it in the additional amp hook-ups?

Norman S Braithwaite said:

Physically it is the same.  Electronically it is different.

Norman

David Wilson said:

It's the same tuner used in the Quaranta Bruce.

[Norman S Braithwaite]

Eight wires to the mid-amp and isolated bass circuit.

[David Wilson]

Makes since, thanks!

Norman S Braithwaite said:

Eight wires to the mid-amp and isolated bass circuit.

[David Wilson]

Yep ... McMurdo really know how to get under Scott's skin. That's a great piece of history you dug up there Kent! Quite the battle of words going on at that time. I think it was Richard Majestic who pointed out to me that McMurdo's bass boost circuit on their V look a lot like the on circuit Zenith use on their 1935 Stratosphere. I checked out the expander first used on the Mills Studio jukebox and it looks like it came out in their 1937 Studio model. So they lifted the expander idea from Scott as well. You know you're doing things right when everyone is coping your ideas. When your close competition is coping your ideas, like McMurdo did to Scott, it becomes person. I think McMurdo must have been to taking sales market share away from Scott with his V and McMurdo's marketing claims like this was like throwing salt in open wound to Scott. 

Kent King said:

So I did some digging - you got me thinking about things I had read...I've located the following:

The first letter I have describing the Volume Range Expander is dated Feb 15, 1936

From "What's the Answer - An Open Letter to McMurdo Silver" dated Oct 7, 1936:

I will take just a few of these so called "New Engineering ideas never before found in any set,"

and call your bluff on them.

"NEW-Built-in Electronic Volume Range Expander for Radio and Phonograph reproduction."

You are just about eight months too late to describe this feature as "New", for volume range expansion operating on both radio and phonograph, was first built into and sold in a Scott Receiver in 1935. The Scott Expander uses a special push pull circuit which was developed in our own research laboratories,
and is not simply a Chinese copy, like yours, of the circuit and tubes used in the R.C.A. D-22, which was brought out many months before the Masterpiece V was announced. I will donate $100.00 to any charity you name if you can prove a Scott did not have built-in volume range expansion for use on both radio and phonograph reproduction in 1935.

and from a letter dated Oct 25, 1937:

The 23 TUBE SCOTT has been designed for those who do not desire the Program Volume Range Expander or the Scratch Suppressor built into the PHILHARMONIC, features that require six extra tubes. It is used by distance fanatics in every part of the world, and I have in my files hundreds of enthusiastic letters telling of the marvelous DX reception it is providing its owners. Being equipped with variable Selectivity and variable Sensitivity controls, it is particularly suitable for those who are interested in DX reception, especially on the broadcast band. The tonal range of the 23 TUBE SCOTT is identical with that of the PHILHARMONIC, being capable of reproducing the complete audible range from 30 to 16,000 cycles, and it has an undistorted
output of 35 watts. This is the receiver for those who are looking for a super-powerful, super-sensitive receiver, but who do not desire the Program Volume Range Expander or Scratch Suppressor features.

The last letter certainly indicates he was selling AW23 sets without the expander at the very end of its life.

[Y2K Bruce]

This has turned into quite an historical and intriguing discussion. I am glad we have captured it here on Kent's site for future radio researchers.

[Norman S Braithwaite]

More information on volume range expanders (VRX) along with identification of other sets employing VRX circuits can be found at the link below.

https://www.antiqueradios.com/forums/viewtopic.php?t=267049

Norman

[Kent King]

I believe I have located the first magazine article on volume expanders in Radio, May 1935. Link here:

https://worldradiohistory.com/Archive-Radio/30s/Radio-1935-05.pdf

Page 19...

Kent

[Norman S Braithwaite]

C.G. McProud was the founder and editor of Audio Engineering Magazine starting in 1947.

Norman

[David Wilson]

This is a great article! Thanks for looking and posting it it Kent! 

Kent King said:

I believe I have located the first magazine article on volume expanders in Radio, May 1935. Link here:

https://worldradiohistory.com/Archive-Radio/30s/Radio-1935-05.pdf

Page 19...

Kent

[Kent King]

Slight change on this same topic: You all got me to pull out my AW27 chassis. It hasn't been playing exactly right for a year or so, and all this talk made me decide to get it working right. I had worked on it a LONG time ago (more than 20 years) so my skills have improved a lot. When I restored it last, I did restuff all the original caps and all, I'm going to retest them but it <looked> good and played with great sound on AM. I never used it on SW much.

Anyway, ahead to today: when I opened it up, I immediately noticed the coil wheel was different. 

The coil on the left is from a normal 23/late. The one on the right is out of my 27. Note the wave coils for the band above AM. There is nothing on the left coil and the right coil is clearly wound very differently, finer wire, many more turns. I haven't had a chance to test what frequency range it runs - if it works at all. 

Anyone have any ideas on the mods (different trimmer caps too). I may try operating the 27 with the other coil wheel (with an alignment)....this is going to take some time to test.

Kent

[Kent King]

One other thing I discovered this evening. I have a special supply for testing AW23 tuners, I can set the B+ and bias voltages precisely, allowing for very stable testing. This unit also monitors the current draw through the B+. I've restored enough AW23 sets to know that the tuner usually pulls about 75mA at 250v. The AW27 is pulling close to 150mA. I am not sure why it is so much greater, again, more testing this weekend.

Kent

[David Wilson]

I'm still digging to find my AW 27 restoration specs. I did find my AW 15 info. It will be later in the day or tomorrow, I have to replace a fuel injector O rings on my Expedition today.

Kent King said:

One other thing I discovered this evening. I have a special supply for testing AW23 tuners, I can set the B+ and bias voltages precisely, allowing for very stable testing. This unit also monitors the current draw through the B+. I've restored enough AW23 sets to know that the tuner usually pulls about 75mA at 250v. The AW27 is pulling close to 150mA. I am not sure why it is so much greater, again, more testing this weekend.

Kent