New member needs help

[Zachary C. Fridman]

Greetings from Greece. My name is Zachary C. Fridman.
Trying to restore a Allwave 15, I discovered your excellent site.
I need some information dating the radio. For this reason I have upload some photos.
The radio has the Wunderlich Arcturus tube for detector, and the 58 tube
for mixer, instead of the 2A7.The number in the rear plate is F-421.
In my opinion is a export model.
The cabinet is from a local Greek manufacture around the year 1925-1935.
Any help will be appreciated. Thank you.

Zachary

[David C. Poland]

You have an earlier 1934 version Wunderlich tube model of the ALLWAVE FIFTEEN. Scott made running changes during the production of the AW-15. You will find the 5 known (so far) circuit diagrams, along with owner manual versions. Scott changed from the Wunderlich tube 2 nd detector to the 55 tube in later 1934 into mid 1935. On this Scott site,

click on the SCOTT INFO ARCHIVE
select SET FOLDERS
select ALLWAVE 15
open the various documents.

Review for diagrams and manuals showing the Wunderlich tube to print. Collectors have found more than 5 variations, so yours may have be a transition between 2 of the diagrams. Also look through the Scott News issues for detailed Alwave Fifteen articles in 1934 issues of the Scott News. Export models should be very close to the domestic model, except for maybe the the power transformer and the dial strip markings to accommodate country of delivery.

Good luck.

[David C. Poland]

Your photos show you have a complete example in very nice cosmetic condition - with correct amp and speaker. Be very careful with the coil turret inside. Look for specific instructions in the technical document if you dismount the coil turret in order to avoid breaking the switch in the antenna coil can above. The 2 red short wave antenna posts confirm an earlier version Wunderlich model. The toggle swiitch below the antenna posts selects the red or black antenna posts. The optional antenna switch attached to the rear tube cover went with the Scott Super Antenna which was introduced later in 1934 after you radio was built.

[Zachary C. Fridman]

Thank you very much for your reply. The radio had a problem in the fourth position of Short Wave. After cleaning the contacts and because the problem remained, I put small washers under the switches in the chassis, to increase the contact pressure. Now the radio is working in all bands. A broken wire in volume control, it was an easy fix. I change all the paper capacitors due to high leakage.

I check all the tubes in my Hickok 752 (except 2A3 and Wunderlich), found to bee in excellent condition. The only problem is the lack of sensitivity in Medium Wave. Only with 15-20 foot of outdoor antenna wire, was possible to hear local stations (not in high quality). In Short Wave behave much better. This is the short story of the restoration. Again thank you for your input.

David C. Poland said:

Your photos show you have a complete example in very nice cosmetic condition - with correct amp and speaker. Be very careful with the coil turret inside. Look for specific instructions in the technical document if you dismount the coil turret in order to avoid breaking the switch in the antenna coil can above. The 2 red short wave antenna posts confirm an earlier version Wunderlich model. The toggle swiitch below the antenna posts selects the red or black antenna posts. The optional antenna switch attached to the rear tube cover went with the Scott Super Antenna which was introduced later in 1934 after you radio was built.

[David C. Poland]

If the radio is receiving stations on any band, the Wunderlich tube 2nd detector is probably OK. Don't drop it as it is not well supported inside and once bent may be ruined. Designed for automatic volume control, it is a full wave detector, audio amplifier and the AVC is driven off the center tap of the last IF transformer. The polishing pads on the coil change turret should keep the silver contacts in good condition once clean. Operate the short wave pointer back and forth. Be careful with that cast metal band change pointer as it is pot metal and prone to breaking after all these years. If you dismount the turret, be careful with those silver contacts - clean them with alcohol, nothing more abrasive.
A 40 to 70 foot long wire antenna to the black antenna post should give good results. The antenna toggle switch attached to the tube cover is the first version switch for the Scott Super Antenna, a double dipole antenna with twisted lead-in. The antenna toggle switch has a coil inside and must must be in the Broadcast position for the white broadcast band and the part of the blue short wave band, It must be in the Shortwave position for the red and green higher wave bands. Otherwise the switch blocks reception. For the blue band try both positions however.
Many but not all versions of the Fifteen have a tone control on the left rear , but I see your version does not. The light rust on your amp should clean up well with an automobile chrome polish.

[Zachary C. Fridman]

The switch inside the antenna coil can is OK.

Trying to boost the reception, I make a new antenna coil with 50 turns, and I put it INSIDE the coil in the central antenna coil.With trial and error, I found the best position between the two coils, and this help a lot the reception in Broadcast. But I believe that the radio has more  potential.

[Kent King]

I can add that F-455 (an AW23) was built 15-Oct-35. So I'd guess this set was built mid-1935...

[David C. Poland]

Kent - 1935 seems seems pretty late for a Wunderlich AW-15. I would think no later tan Summer 1934.