The Fine Things are Always Hand Made
I just posted some questions about the Allwave 12 I bought last weekend and wanted to ask some questions about a second Scott radio I was offered, but turned down because I have some reservations about its degree of authenticity (it has obviously been modified), and whether or not it would be possible to restore it to it's original configuration.
The second radio is an Allwave 23 and I was all set to purchase it too, but then I took a look at the back of the cabinet and noticed the cover panel was attached with phillips-head sheet-rock screws. I removed the screws and saw a large mystery box of components and modern wiring, and a terminal strip of wires going everywhere stuck in the bottom of the cabinet. Some of the wires lead to a large MAGNAVOX speaker that had been shoved in there. Obviously someone has removed the correct speaker and replaced it with this albatross substitute, and then created some sort of Frankenstein contraption to work around the electrical differences between the factory speaker and this substitute. I do not have any pictures of this conglomeration, but it is definitely not original factory work, or the work of someone that shares my belief of the necessity of maintaining originality when working on vintage items.
Although it might be functional, or made to be functional, as-is, I am only willing to buy this radio if I discover it is possible to 'unmolest' it and return it to the correct configuration and components it would have had when built.
At the very least it will need a replacement speaker of whatever variety is correct for this radio. (However, I do not know what kind of speaker this would be.) Probably everyone wants these speakers for something, so I have little confidence in finding one, but if it is possible to do so, I will reconsider purchasing this radio if I can be sure it is restorable. I would like to restore this radio correctly, but I have little interest in one that has been butchered in this manner if proper restoration is not possible.
Thank you and best regards-
Hard to tell. The build date seems to be 9th week of 1949, which was getting close to the end of EM speaker production. It could be that the person who replaced the original was able to find one with the right voice coll value and close to the right field coil value. Magnavox built speakers for many different companies, including Hammond organs and Leslie speakers. I have two of the 31 A/H series Leslies from the 1940's, and one of them has a Magnavox 15 inch field coil speaker and the other a 15 inch Jensen field coil speaker. I have had both re-coned and the Leslies will rattle the windows. Both Leslies use quad 6L6 output tubes. This speaker could very well have come from a Leslie speaker system. Leslies are 16 ohm and most use 15 inch woofers. Some use a pair of 6550 output tubes so these would handle the power of a quad set of 2A3s.
As I am due to be furloughed from work next week due to the major dip in aerospace manufacturing presently occurring, I am considering a new project with my AW23. I have obtained a NOS Amphenol Magic Eye Socket Assembly that will allow me to add an eye tube to the Scott. I would not consider doing this except for the fact that it will be a non-destructive and completely reversible operation to the radio.
My plan is to route the wires through the existing hole in the chassis presently used for the dial lamp (there is enough room if I use plastic-insulated wires) and to make a wooden housing for the tube/socket assembly that will sit on top of the Warrington cabinet. I won't be drilling any holes in the chassis or cabinet. This will be connected via a detachable "umbilical cord".
Since I am unlikely to ever have a Philharmonic or other Scott that is factory equipped with a 'magic eye' tube, this seems like a reasonable substitute, especially because the original AW23 tuning meter is frankly uninspiring to look at.
But I have a few questions before I even attempt getting started on this project. Please note that I am including photos of the Amphenol instruction sheets for reference to what I am asking about.
-I understand all the wiring instructions _except_ I am not clear where the yellow wire should be connected in the AVC circuit. I do not know what point on the AW23 schematic could be called "the diode load" or, alternatively, points X or Z as shown in the photo of the sample schematic. Does anyone have any suggestions on this? See the photos of the instruction sheet for clarification.
-Is there any way to know which eye-tube would work better? According to the box, either the 6E5 or 6G5 can be used. I know these are not identical tube types and not directly interchangeable.
-Taking into account that I won't do this if it will cause damage or require any irreversible modifications to this radio, is there any reason that this is a terrible idea?
Thank you and best regards-
I did a small writeup on the two tubes a while ago, it's here
the 6G5 has a greater negative bias on the grid for full shutoff
For the yellow wire...connect it to the grid lead of the 76 tube that acts as the tuning meter amplifier. That grid is connected to the diode load (AVC). It should give good action on the eye.
You could remove the 76 tube completley and make up a plug to fit the socket, as all of the signals are there.
All you would need to find is a chassis point for the eye tube cathode, completely reversable with no modification.
I used the socket from a broken 24A tube to make an adapter plug to fit in the tuning meter 76 tube socket for the magic eye kit. This socket gave me filament power, the necessary grid connection, and B+ voltage. Then I used the existing ground lug on the chassis for the fifth wire and powered up the AW23 with the magic eye installed. And it works great! I am using a 6E5 in the socket.
By using the tuning meter 76 socket, I was able to install this kit without adding any soldered connections to the chassis anywhere. Didn't even have to take the chassis out of the cabinet. Removing the magic eye will be as simple as pulling out the adapter plug and reinstalling the 76 tube! The wires coming from the plug even fit in the slot on the side of the original tube shield typically used for grid wires, so I was able to put the shield back in place too. Everything is completely reversible.
All I have to do now is figure out a way to dress the wires so they look better. The wooden 'case' I made doesn't match the original cabinet color as closely as I hoped, but have been making do with what materials I have around the house already. It does look closer in color in person than the picture shows though.
Thank you Mike and Kent for the advice on getting this kit installed!
and no modification to the radio.
Definite LIKE...very nicely done!