Allwave 15 Dial lamp

[Frank Shafer]

Well, I finally got up the courage to put together my 1934 Allwave 15 and fired it up. To my amazement it picked up my AM Transmitter and played pretty well with just a 10 foot piece of wire attached.

There is a slight hum but I'm not sure if that is due to electronic issues or interference from the electrical panel in the same room where my workbench is or other issues like maybe not being grounded (I powered it up through my isolation transformer/variac) the first time.

The dial light does not work which means that of course the tuning meter doesn't either. I removed the dial lamp and found that the one installed was a jury rigged bulb that had the base of one bulb soldered to another so that it would fit.

Does anyone know what bulb this set is supposed to use? That information is not in my documentation. There are a couple of other differences in the set from the manual I have too. It shows a "bass" control on the back of the chassis that I am not sure that is there.

 

I was told that this Scott had been restored by the previous owner and was a working set but you never know what to believe. In this case though at least it does play and I am thankful for that. I guess I need to do a little more investigating and troubleshooting before I decide what to do next but I obviously will need the bulb so if anyone knows which one it uses I would appreciate the info.

 

Thanks,

Frank

[Frank Shafer]

I posted a couple of pictures, one of the bulb and another of the back of the chassis. There are two switches and I am not sure what each does. The manual says that there is a bass control on the right and according to there diagram it should be just to the left of the switch that is on the right hand side. Mine has an opening tthat has some kind of screw driven control there, is that the bass control?

 

Thanks,

Frank

[Angelo]

Hi Frank try the 44 or 47 bulb for the dial light.Angelo

[David C. Poland]

Hi Frank,

 

The Allwave 15 uses 2.5 volt tubes in the receiver chassis, and so too is the dial lamp which is wired into the filament string.. Should have a screw base socket  and use a 2.5 volt  #41 lamp.

 

The tuning meter operates separate from the lamp. The lamp merely projects the shadow of the tiny tuning meter pointer on to the dial strip, and ultimately on to the multi-color dial insert if you have a cabinet (or wood panel). 

 

The Allwave 15 seemed to continuously evolve, and there are 5 different diagrams reflecting a variety of changes to the curcuits, controls and of tubes for the 1st and 2nd detector. Only the last 2 diagrams are in Riders and both show the type 55 second detector. The 3 earlier diagrams  all use Arcturus' blue glass Wiunderlich tube for the 2nd detecter. A number of the earlier Wunderlick sets were subsequently converted to use the 55 tube because Wunderlick tubes became scarce. The 2 nd detector (as you face the front of the receiver) is the 3rd tube back on the left. If the tube type 55 is embossed on the socket you probably have a later set. But if that socket has no number embossed and the center button is a dark red color, your set has the Wunderlich, unless it was converted to use a 55  and a grid cap wire added for the 55 grid cap.

 

The tone control would be on the back far left of the receiver, if yours has one - some versions did not.  I have never seen a toggle switch used for tone. I have an AW-15 with a tapered tone control and another with a 5 step tone control.

 

The hole with the screw adjustment is to adjust the tone when you push in the BFO switch (the push button below the band switch).

 

A toggle switch in the middle of the back suggest an earlier version set with the pair of red  antenna posts for a separate short wave antenna,  in addition to the regular black antenna post and black ground post. The toggle switch changes from one antenna input to the other.

 

Hope this helps. 

 

[Frank Shafer]

Thanks David, The set does have the Wunderlich tube in it,I know that much. I am very onfused about the dial lamp though. This one is set up with a bayonette base as you can see. I wondered about that because I read in the literature that came with this swet that to change the lamp you need to unscrew it and that didn't sound like a bayonette type bulb. So I guess someone down through the years must have converted the lamp base?

Also,you are correct,this set has the two red antenna posts and the two black antenna posts as well so that must be what the toggle switch in the back is for.

 

You have provided me with a wealth of information is one short post and I can't thank you enough.

Do you know where I might find the correct schematic for it or a proper dial lamp socket?

 

Thanks again,

Frank

David C. Poland said:

Hi Frank,

 

The Allwave 15 uses 2.5 volt tubes in the receiver chassis, and so too is the dial lamp which is wired into the filament string.. Should have a screw base socket  and use a 2.5 volt  #41 lamp.

 

The tuning meter operates separate from the lamp. The lamp merely projects the shadow of the tiny tuning meter pointer on to the dial strip, and ultimately on to the multi-color dial insert if you have a cabinet (or wood panel). 

 

The Allwave 15 seemed to continuously evolve, and there are 5 different diagrams reflecting a variety of changes to the curcuits, controls and of tubes for the 1st and 2nd detector. Only the last 2 diagrams are in Riders and both show the type 55 second detector. The 3 earlier diagrams  all use Arcturus' blue glass Wiunderlich tube for the 2nd detecter. A number of the earlier Wunderlick sets were subsequently converted to use the 55 tube because Wunderlick tubes became scarce. The 2 nd detector (as you face the front of the receiver) is the 3rd tube back on the left. If the tube type 55 is embossed on the socket you probably have a later set. But if that socket has no number embossed and the center button is a dark red color, your set has the Wunderlich, unless it was converted to use a 55  and a grid cap wire added for the 55 grid cap.

 

The tone control would be on the back far left of the receiver, if yours has one - some versions did not.  I have never seen a toggle switch used for tone. I have an AW-15 with a tapered tone control and another with a 5 step tone control.

 

The hole with the screw adjustment is to adjust the tone when you push in the BFO switch (the push button below the band switch).

 

A toggle switch in the middle of the back suggest an earlier version set with the pair of red  antenna posts for a separate short wave antenna,  in addition to the regular black antenna post and black ground post. The toggle switch changes from one antenna input to the other.

 

Hope this helps. 

 

[Kent King]

Frank - I can email you schematics for this, however!! The AW15 is transitional, and there are a lot of variations in the sets. I have two different schematics for a Wunderlich version, you'll have to look to see if either of these match your set. Work with whatever is most like your set, and if you find differences, bring them here and we can work through it. I'll email the diagrams to you in a little while...

 

Kent

[Frank Shafer]

Thanks Kent, I appreciate it.

Kent King said:

Frank - I can email you schematics for this, however!! The AW15 is transitional, and there are a lot of variations in the sets. I have two different schematics for a Wunderlich version, you'll have to look to see if either of these match your set. Work with whatever is most like your set, and if you find differences, bring them here and we can work through it. I'll email the diagrams to you in a little while...

 

Kent

[David C. Poland]

Frank,

 

I emailed Kent last evening that you could use diagrams for the Wunderlich AW-15 versions. Keep in mind, E H Scott was a custom radio producer, and was leading edge technology and, so,  he incorporated running changes as he went along, and only introduced a "new " model when he made a really major change.   I am aware of 5 circuit diagrams for the AW-15, of which 2 show the Wunderlich tube, dated 4/10/1934 and 5/7/1934.  But there are 4 Wunderlich variations seen among several collectors as of a couple years ago. Your version may have elements that depart from either of the 2 diagrams.  As a start, here are some differences to look for on your AW-15 Wunderlich set:

 

-Transition of the mixer: 57, then 58,  58 again, then 2A7. (both  Wunderlich diagrams show the 58.)

-The 2 early versions had a 5 position static switch on the front left;  and the next 2 versions of the Wunderlich sets had a continuously variable sensitivity control on the front left. 

-Version 3 (of the 4) had no tone control on the back, but had an outboard static switch (twisted wires to a toggle switch that mounted on the cabinet .... maybe that explains your 2nd toggle switch if it was relocated to the chassis back.)

 

And so on. Identify which diagram most closly  describes you set, and then keep notes on any differences.

 

I suggest you use a long wire to the black antenna post (and a ground wire if that helps) and leave the toggle switch (near the chassis cable) in which ever position works, and don't bother with the red antenna posts.

 

The Wunderlich tube is an interesting tube. The secondary of the last IF transformer is center tapped. Each end of that IF coil runs to the two grids in Wunderlich  tube. The two tube grids are inter wound around the cathode. The tube operates a bit like a full wave rectifier to detect the audio, and this tube also amplifies the audio. The center tap of that IF coil secondary feeds  the AVC circuit.

 

History:  Scott began use of the Wunderlich tube late 1932 with the 2nd version of the 12 tube Deluxe making it his first radio with automatic volume control. The AW-15 evolved in February 1934 from the 12 tube  Allwave Deluxe with AVC by adding a 56 tube for the BFO,  a 56 tube for the tuning meter, and a 56 tube to make the 2nd AF push-pull -  and the amp from push-pull 45's to more powerful 2A3's and upgrading from 80 rectifier to 5Z3.  Sometime after mid 1934, Scott moved from the Wunderlich tube to using the 55 tube.

 

More history:  The old 2-dial 12 tube set was revised in May 1932  and renamed the Deluxe by virtue of the new internal coil changing wheel (like your AW-15 uses) and a single tuning dial. It used 24A type tubes, a 51 RF amp and the new 56 triodes but had no AVC.  The next AW-12 version December 1932 was the Deluxe With AVC that introduced the Wunderlich and upgraded from using 24A's to 58's and a 57 mixer. The early version AW-12 with AVC had twin speakers (by Rola) until Scott changed to the Jensen 12 inch pedestal early 1933. As a caution: although they look much alike, the amps for the AW-12 and AW-15 are not interchangeable, nor are the Jensen speakers. The AW-12 would be a nice addition to your collection - they play well.

 

Jim Clark's E H Scott Radio Collector's Guide is a very good identification guide to all the pre war Scott's. I don't see it listed by Radio Daze nor ARC now, but it does show up on ebay. 

 

Regards,

[Frank Shafer]

David, In your opinion,what is the best sounding Scott. I am interested in these radios for performance more than anything else. I want to have a set that really stands out and not just because it is rare. I bought this one because I had heard so much about Scotts being great radios but I really didn't know enough to decide which one I thought I would want before this one presented itself to me at an auction and I didn't expect to get it for the price I paid.

David C. Poland said:

Frank,

 

I emailed Kent last evening that you could use diagrams for the Wunderlich AW-15 versions. Keep in mind, E H Scott was a custom radio producer, and was leading edge technology and, so,  he incorporated running changes as he went along, and only introduced a "new " model when he made a really major change.   I am aware of 5 circuit diagrams for the AW-15, of which 2 show the Wunderlich tube, dated 4/10/1934 and 5/7/1934.  But there are 4 Wunderlich variations seen among several collectors as of a couple years ago. Your version may have elements that depart from either of the 2 diagrams.  As a start, here are some differences to look for on your AW-15 Wunderlich set:

 

-Transition of the mixer: 57, then 58,  58 again, then 2A7. (both  Wunderlich diagrams show the 58.)

-The 2 early versions had a 5 position static switch on the front left;  and the next 2 versions of the Wunderlich sets had a continuously variable sensitivity control on the front left. 

-Version 3 (of the 4) had no tone control on the back, but had an outboard static switch (twisted wires to a toggle switch that mounted on the cabinet .... maybe that explains your 2nd toggle switch if it was relocated to the chassis back.)

 

And so on. Identify which diagram most closly  describes you set, and then keep notes on any differences.

 

I suggest you use a long wire to the black antenna post (and a ground wire if that helps) and leave the toggle switch (near the chassis cable) in which ever position works, and don't bother with the red antenna posts.

 

The Wunderlich tube is an interesting tube. The secondary of the last IF transformer is center tapped. Each end of that IF coil runs to the two grids in Wunderlich  tube. The two tube grids are inter wound around the cathode. The tube operates a bit like a full wave rectifier to detect the audio, and this tube also amplifies the audio. The center tap of that IF coil secondary feeds  the AVC circuit.

 

History:  Scott began use of the Wunderlich tube late 1932 with the 2nd version of the 12 tube Deluxe making it his first radio with automatic volume control. The AW-15 evolved in February 1934 from the 12 tube  Allwave Deluxe with AVC by adding a 56 tube for the BFO,  a 56 tube for the tuning meter, and a 56 tube to make the 2nd AF push-pull -  and the amp from push-pull 45's to more powerful 2A3's and upgrading from 80 rectifier to 5Z3.  Sometime after mid 1934, Scott moved from the Wunderlich tube to using the 55 tube.

 

More history:  The old 2-dial 12 tube set was revised in May 1932  and renamed the Deluxe by virtue of the new internal coil changing wheel (like your AW-15 uses) and a single tuning dial. It used 24A type tubes, a 51 RF amp and the new 56 triodes but had no AVC.  The next AW-12 version December 1932 was the Deluxe With AVC that introduced the Wunderlich and upgraded from using 24A's to 58's and a 57 mixer. The early version AW-12 with AVC had twin speakers (by Rola) until Scott changed to the Jensen 12 inch pedestal early 1933. As a caution: although they look much alike, the amps for the AW-12 and AW-15 are not interchangeable, nor are the Jensen speakers. The AW-12 would be a nice addition to your collection - they play well.

 

Jim Clark's E H Scott Radio Collector's Guide is a very good identification guide to all the pre war Scott's. I don't see it listed by Radio Daze nor ARC now, but it does show up on ebay. 

 

Regards,

[David C. Poland]

Frank, a the risk of offering too much info.....

 

Scott made major efforts in pioneering home high fidelity.  Scott collectors focus on two models in particular as tops: the AW-23 (1935-37) and the Philharmonic AM 30 tube (1937-40). Until you are familiar, I would suggest you limit yourself to complete sets with a proper cabinet. I have both models in my collection.

 

Both models are true high fidelity, with the optional pair of Jensen tweeters. Both use 4 output tubes in push-pull parallel class A in the final audio: the AW-23 at 35 watts using 2A3's and the Philly at 40 watts using 6L6's. Both claim 30 to 16,000 hertz nearly flat with less than 1% harmonic distortion.  Both have large 6 tube amps at 5 1/2 x 22 inches. 

 

The 23 tube Allwave Hi Fidelity Allwave (AW-23) is the successor to your AW-15. It has much in common: general appearance, same dial arrangement, coil wheel inside and wave change switch. But is updated with 6 volt tubes in the receiver. Additional controls include variable selectivity with an arrangement that detunes the IF amps for wide band to receive the new experimental hi-fi stations  of the mid 1930's. The audio circuits had separate treble and bass controls , including bass boost.  Voltage regulation for the oscillator. Magnavox 12 inch pedistal speaker. The optional tweeters were the Jensen Q series with field coils (again, 2 versions-  early and late). There are a handful of tricked out factory models with 27 tubes, and a very few with 40 tubes and more (the Quaranta - one known complete example currently). There are over a dozen different furniture grade Scott cabinets originally priced at from $20 to over $200 in addition to the radio itself - the most common is the Tasman. The early version AW-23 is known as the "5 knob" and the later version in 1936-7 the "7 knob"  with two small additional controls below the bass and sensitivity controls. 

 

The AM Philharmonic is a total redesign. It has been termed the greatest radio ever built. ( some McMurdo Silver collectors may argue the point)  It has all those features of the AW-23 plus controls for 1) volume expansion and  2) scratch suppression at low volume.  The Philly has  a 15 inch Magnavox main speaker. The optional tweeters were Jensen with permanent magnets instead of field coils. The Philly has all octal tubes except for the 5Z3's and 2 magic eyes indicators. It has broadcast and 5 SW bands and an 8 inch round dial, usually green. Again there are a couple evolutionary changes during the run that altered the control and dial configurations a bit. A few of the earlier model cabinets styles were enlarged to accommodate the Philharmonic, the most common seems to be the Warrington, and a few new ones added over time. Eventually in 1940-1, there was an AM/FM 33 tube Philharmonic without the volume expansion feature, but it is obsolete pre War FM and having portions of the FM circuitry on top of the AM circuits, maintenance is more demanding.

 

Spend some time monitoring ebay to accumulate some familiarity with these models and costs. And John Slusser's Collectors Guide has a Scott section with photos. Also, Slusser's revised "Dean of DX"  is an outstanding book on Scott and his radios. Scott pricing has 2 main components: the radio and the cabinets. Chrome condition maters. Cabinets range from the common to the seldom seen and very upscale. When you get an opportunity, visit folks who have one or more.

 

Be happy to talk with you sometime. These sets sound great with a modern FM or CD player into the phono input.

[Frank Shafer]

There is a Scott Allwave 23 on Ebay now--  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290559325045...
Is this one of the suggested models that you are talking about? Would it be the type that you would consider buying to get a strong performing set?

 

Thanks,

Frank
David C. Poland said:

Frank, a the risk of offering too much info.....

 

Scott made major efforts in pioneering home high fidelity.  Scott collectors focus on two models in particular as tops: the AW-23 (1935-37) and the Philharmonic AM 30 tube (1937-40). Until you are familiar, I would suggest you limit yourself to complete sets with a proper cabinet. I have both models in my collection.

 

Both models are true high fidelity, with the optional pair of Jensen tweeters. Both use 4 output tubes in push-pull parallel class A in the final audio: the AW-23 at 35 watts using 2A3's and the Philly at 40 watts using 6L6's. Both claim 30 to 16,000 hertz nearly flat with less than 1% harmonic distortion.  Both have large 6 tube amps at 5 1/2 x 22 inches. 

 

The 23 tube Allwave Hi Fidelity Allwave (AW-23) is the successor to your AW-15. It has much in common: general appearance, same dial arrangement, coil wheel inside and wave change switch. But is updated with 6 volt tubes in the receiver. Additional controls include variable selectivity with an arrangement that detunes the IF amps for wide band to receive the new experimental hi-fi stations  of the mid 1930's. The audio circuits had separate treble and bass controls , including bass boost.  Voltage regulation for the oscillator. Magnavox 12 inch pedistal speaker. The optional tweeters were the Jensen Q series with field coils (again, 2 versions-  early and late). There are a handful of tricked out factory models with 27 tubes, and a very few with 40 tubes and more (the Quaranta - one known complete example currently). There are over a dozen different furniture grade Scott cabinets originally priced at from $20 to over $200 in addition to the radio itself - the most common is the Tasman. The early version AW-23 is known as the "5 knob" and the later version in 1936-7 the "7 knob"  with two small additional controls below the bass and sensitivity controls. 

 

The AM Philharmonic is a total redesign. It has been termed the greatest radio ever built. ( some McMurdo Silver collectors may argue the point)  It has all those features of the AW-23 plus controls for 1) volume expansion and  2) scratch suppression at low volume.  The Philly has  a 15 inch Magnavox main speaker. The optional tweeters were Jensen with permanent magnets instead of field coils. The Philly has all octal tubes except for the 5Z3's and 2 magic eyes indicators. It has broadcast and 5 SW bands and an 8 inch round dial, usually green. Again there are a couple evolutionary changes during the run that altered the control and dial configurations a bit. A few of the earlier model cabinets styles were enlarged to accommodate the Philharmonic, the most common seems to be the Warrington, and a few new ones added over time. Eventually in 1940-1, there was an AM/FM 33 tube Philharmonic without the volume expansion feature, but it is obsolete pre War FM and having portions of the FM circuitry on top of the AM circuits, maintenance is more demanding.

 

Spend some time monitoring ebay to accumulate some familiarity with these models and costs. And John Slusser's Collectors Guide has a Scott section with photos. Also, Slusser's revised "Dean of DX"  is an outstanding book on Scott and his radios. Scott pricing has 2 main components: the radio and the cabinets. Chrome condition maters. Cabinets range from the common to the seldom seen and very upscale. When you get an opportunity, visit folks who have one or more.

 

Be happy to talk with you sometime. These sets sound great with a modern FM or CD player into the phono input.

[David C. Poland]

Frank.

email me at [e-mail]