EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

Anyone care to detail the disassembly and implementation for the AW23 voliume expander accessory box? This is one tight package.

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Hello- I am now at the stage where I too need to disassemble and restore the Volume Ranger Expander for my AW23 and remembered having seen an inquiry about it.  This is it but there are no responses.  Does anyone have any suggestions?  I have removed all the screws in mine and absolutely nothing in it wants to budge or come apart in any way.  Very reluctant to force anything for fear of causing damage or finding out there is an effective method that just isn't obvious or apparent.  Seems clear that this was an accessory that Scott did not want anyone to tinker with. 

I have a copy of the original instructions, which clearly state that the tubes in this accessory are only to be ordered from the laboratory, since they claim that most new tubes lack the correct characteristics for proper operation.  Obviously I cannot order specially tested tubes directly from Scott anymore.  Has anyone with experience with these devices found a need to be especially choosy with replacement tubes?

And what are the values of the capacitors inside the box?  My plan was to see what was in there and make my own list to order, but as I cannot get the box apart, this has not worked out so well.

Thank you and best regards-

Troy

i never disassembled but there’s a center plate with holes to retain the tubes vertical along with the bottom Insert with pin sockets. Corrosion was only thing keeping these from separating from the basic box shell. There’s two different layouts in the archive section as a I recall 

Kent commented to me -  fashion a couple long hooks using coat hanger wire. 

Use the hooks to draw out the innards with even pressure to avoid the little chassis getting stuck.

Not that I have any personal experience with the outboard volume expander.

Hello-

Tonight I finally succeeded in disassembling my AW23 Volume Range Expander and can provide some pictures and some experiences with DO NOTS that I figured out the hard way in the process.  The ultimate objective is to remove what I will call the "tube socket assembly" from the chrome box.

First off:  All of the screws that hold the tube socket assembly are the ones around the outside of the chrome box.  Those must be removed to get the assembly out of the box.  DO NOT unscrew the four screws at the corner edges on the bottom of the box.  I unscrewed mine and they just simply fell inside the unit to rattle around.  More on that in a minute.

Also there are three round-head screws visible next to the tube sockets as you peer in from the top.  DO NOT try to unscrew these either.  These are rather long screws with nuts and sleeves that are used to support the different layers of components that make up the tube socket assembly.  Trying to unscrew them will not help release the assembly from the box.  Also DO NOT try to push the assembly up from the bottom by sticking anything through the four holes on the bottom.  All you will do is cause damage to the internal pieces that is likely to be irreparable.

Next, document the wiring for the grid caps sticking through the top sheet metal piece that is located near the top of the box and then unsolder it such that you can pull that piece out by itself.  I had to unsolder several joints here.

With that top piece out of the way, you will see two 'lugs' sticking up just inside the edges of the outermost tube sockets.  You will also see the three screw heads that DO NOT need to be removed.  I used these two lugs as lifting eyes to yank on with bent clothes-hangers snaked through the eyes.  However, it was a real chore to get that assembly pulled out, at times the hangers got "unbent" and pulled through.  I used a couple of rectangular pieces of wood that were just slightly larger than the inside width of the box and twisted them to slightly bulge out the sides of the box.  This helped break the socket assembly from the sides of the box. 

But the whole mess was so tightly packed in there that I literally had to hold it on the floor with my feet and draw up with the clothes hangers.  I found it easier to 'rock' the tube socket assembly out rather than pull evenly, which proved to be pretty much impossible for me.  Please note:  The cloth covered harness with the big socket on the end MUST be fed through the hole into the box as you draw the tube socket assembly up.  Otherwise it will bind and probably yank off some connections.  I was fortunate to catch this before it happened to me.

By rocking with the coat hangers I finally got the assembly out of the box.  Pictures are below.  There are nine capacitors inside the layers of the tube socket assembly as follows:

.01uF @ 600VDC, QTY 1

.05uF @ 200VDC, QTY 2

.05uF @ 600VDC, QTY 3

.25uF @ 200VDC, QTY 2

.5 uF @ 200VDC, QTY 1

Hope this is clear enough to be of use to someone else.

Troy:

Thank you for posting guidance for servicing the volume range expander.  I've been there but did not take notes to pass along to others.

Norman 

Sorry I've been too busy to write mine up, I have a series of pictures and detailed notes on this process. I'll try to take your notes and mine and create a good service guide.

Kent

Troy: possibly because the 6a7’s would need to be matched for proper operation.

The 6A7 tubes need to be WELL matched.  Also, going from recollection, the EH Scott Radio Laboratories recommended the spiral filament version for reduced hum.

Norman 

Hi Troy-In case you do not have the bezel for the knob control of the VRE on the side of your cabinet there was a bezel that said expander sometimes used and I think most of them had a bezel that said volume same as a front control bezel.

The "expander" escutcheon was used on the early Philharmonic as well as on the AW-23 accessory.  They are not easy to find but not impossible either.

Norman 

Hello-

Finally got a chance to follow up on the comment I made about the screws on the bottom of my VRE falling through when I tried to remove them.   I believe that these four screws originally attached some sort of feet in the four corners.  However, the material they were composed of did not age gracefully and so they had deteriorated into crunchy bits.  I am not sure what they are supposed to look like, or what a suitable replacement would be.  If anyone could post a picture of either original feet in good condition or else provide information about what they used for replacement, it would be much appreciated.  Just got the capacitors needed to restore mine on order, so hoping to get that project done shortly after they arrive.

Oh, and yes, I do have the "EXPANDER" escutcheon on my Warrington cabinet.  This is what clued me in to the fact that my set originally had one installed.  It is listed as "discarded" on the sheet of information dated October 1948 included with the radio when I bought it.

Thank you and best regards-

Troy Taylor

Edmonds, WA

The feet were conventional runner feet.

Norman 

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