Scott Allwave Deluxe 12 - Cap replacement

[Jeff Buda]

Hello all,

Picked up an Allwave deluxe 12 over the weekend. I was told it was a display/demo unit used at Sprague in N. Adams back in the day. The older woman I bought from said it was her Dad's that worked there. I live in Beverly, Mass.

Anyway, I'm curious what the consensus is regarding Capacitor replacement in the main chassis...Meaning, the small square cans riveted to the side of the chassis. I am aware of how to "re-stuff" them, but really do hate to drill the rivets out for this procedure.

thank you, Jeff Buda

[David C. Poland]

The 3 larger metal bathtub caps across the chassis rear apron have both a cap and a coil in them, potted in pitch. Low voltage application, so I have left them alone. ( I have restored 3 of the 12 tube Alwave Deluxe model)

But all the other metal bathtub caps should be rebuilt,  or in my case, disconnected and bridged by modern caps.

CAUTION: there is a specific procedure to remove the coil wheel inside - in particular, position the band switch to broadcast position and do NOT move the band switch until the coil wheel is re-mounted. Take a photo of it before dismounting it. The coil wheel button detents are spring loaded. The danger is breaking the switch in the antenna coil can above the angle drive gear that also rotates the coil wheel. Go to SCOTT INFO ARCHIVE above, then open SET FOLDERS and find ALWAVE DELUXE. Print the Technical Service Data, and if you need an Owners Manual, print that too.

WARNING: Scott was a custom set builder. He made refinements during the couple years of production, as he chased improved performance and audio quality. So, the circuit diagram may not exactly match your chassis. Let actual construction be your guide, and proceed carefully where you see past repairs. The single dial 12 tube DELUXE was introduced Spring 1932. The AVC model using the Wunderlich tube as 2nd detector was introduced December 1932, at which time the tube line up changed a bit. The change from the twin speakers to the pedestal speaker occurred Spring 1933. Audio path to back to the amp (early 1934?) changed to use the #6 pin of the set cable Jones plug.  

The blue glass Arcturus Wunderlich tube is dual grid for push-pull detection, but this tube became unavailable, so,  some sets were modified to use a type 55 tube. The Wunderlich is a long life tube, and they do turn up if you need one.

A search for "Deluxe" may yield helpful threads. Good Luck.

[David C. Poland]

Oh - and please post the serial number of your receiver for the ongoing project to determine total production of the various pre-war Scott models 

[mike hadley]

If you are interested here is the insides of a larger bathtub,

the cap is on the left and the coil on the right, the junction of the two is marked with a red dot.

[Jeff Buda]

Hello David and Mike,

thank you for your excellent information!

David, based on your writeup, I have a Deluxe / Single Dial / Wunderlich Tube / Twin speakers. Serial Number: D 111...I am new to the website so please post for me.

That was good information about the 3 larger bathtubs. I will leave those alone. Since I don't have any way of knowing what band Im on, maybe you could advise on coil wheel location before I remove.

[David C. Poland]

Read the Factory Tech manual I mentioned from this Scott site archive. 

The coil wheel hides a couple caps you need to replace. The wheel fits a flat sided shaft and only fits two ways 180 degrees part. Hence, turn the band switch to full counter clockwise to Broadcast and before your dismount the coil wheel ... Note the position of the wheel ... and do not touch/turn the band switch until AFTER you re-mount the coil wheel.

Probably assume the wheel is correctly positioned, in as much as you acquired it from a technical person's wife. But cross check with info in the tech manual anyway. The owners manual (also from this Scott archive) has several pages of operating instructions including about the 4 position band switch.

The manual with the gothic cabinet pictured on the front cover should be a good match to your twin speaker AVC Scott Deluxe.  One speaker field is in the B+ high voltage circuit. The other speaker field coil is in the output tubes' bias circuit. Notice the dial strip only has calibrated broadcast band, and 1 to 100 scale for the 3 short wave bands. There should be a tuning meter behind the dial, and the little meter pointer shadow plays across the dial strip to indicate signal strength. 

Tube numbers are embossed on the tube sockets, except for the Wunderlich tube socket having a dark red center.

Which cabinet do you have? post a photo and we can tell you.