The Fine Things are Always Hand Made
I just got into this fascinating hobby. Just redid a couple of radios I grew up with - a Majestic 1941, and Philco Model14 - 1933, chassis only. Now working on a Philco 96, 1930. I decided I needed a real radio and found a Scott 16 in an Acousticraft cabinet. It's not in the greatest shape as there is a fair amount of chrome damage and it is missing a few parts. The receiver, power supply and speaker are intact and fairly unmolested, but I need knobs, the large dial pointer and a replacement plastic dial cover. Are there reproductions of these parts? Or, in particular, does anyone have a pointer they might want to sell? I guess I can live with non original knobs and I think I could vacuum form a new dial cover. I couldn't find anything at Radio Daze.
This project will be on the back burner for awhile, especially as I research dealing with the rust areas in the chrome. Not sure I want to completely strip the chassis and have it re-plated. I guess it depends on what it's value might be completely restored.
I've done a little research on the 16 in the forum's archives. I'm not really sure of what I've got. I don't know how popular the 16 was or how it performed compared to the other Scott models. Any input would be appreciated.
Thanks David. I've tried the 6K7's in every possible combination. Not much change in the hum level. I've got some NOS 6k7's coming soon and hope that I can find a quiet one for the 1st AF. I may see if I can get a couple of NOS Sylvania's as they, perhaps, have what Scott wanted in a filament. The RCA 6J5 I bought for this set has a spiral filament. Maybe their 6K7's do too.
I ordered and tried both the 8.8 and 8.6 and neither work. In both cases, the belt climbs up one or both pulleys and will not stay in the groove. I cut and spliced an O-ring that is about 2.5" inner diameter. It works, but is kind of stiff, plus I would not trust a Crazy Glue joint to last (and this is a customer repair). I have found suppliers of thinner O-rings, but most of these suppliers require huge minimum orders and cost. I would need a selection of thinner rings near the 2.5" inner circumference. I attached a photo of my dial assembly. It looks to have been heavily modified. And the remnants of a tensioner are still there, so a cloth belt is not an option. Any suggestions? Thanks!
Robert Feenstra said:
I found a belt that seems to work well. It's a flat belt that is almost 1/4 inch wide. I thought I might have to trim it but it just fits between the flanges. Ordered a 9" circumference, an 8.8", and an 8.6". The 8.8" seems to be perfect. They have lots of sizes.
Elliott Electronic Supply
If the belt is climbing out of the pulleys, then they are way out of alignment. Might want to see if there is a way of correcting that.
There are 2 belt numbers, so evidently there is an early and a late dial for the Scott Sixteen.
General Cement Guide: circumference around pulleys Cut length. inches
Type one: #119 9 17/32 " 9 23/32"
Type two. #152 10 1/2" 10 11/16"
Probably avoid the NOS old belts - pretty stiff and dry now.
Are the GC belts mentioned new cloth or rubber? The belt tensioner appears to have been removed in my radio, so Zenith type cloth belts cannot be used. I tried trimming the width of the 8.6" Elliot Electronics belt (quite difficult) but there was no change. There really is no way to adjust the alignment of the pulleys, except for the small drive pulley which can be moved about 1/8" total. I did find that an O-ring works perfectly, but to use it I had cut to length and splice using super glue (diagonal splice). I have had cut joints fail in the past. So I found a supplier (Grainger) that stocks many thicknesses, materials, and inner circumferences (non-stretched diameter needed is about 2.75"). I ordered inner circumferences from 2.5" to 3". They arrive in 2-3 days. A bag of 10 O-rings is only $2-$3 (plus postage).
My 16 did not have a belt tensioner either but the belt stays perfectly centered on the 2 pulleys. The slight domed shape of the pulley between the flanges helps to keep it that way. Are the two shafts perfectly parallel or is there, perhaps, a lot of wear in the drive mechanism causing the pulley to be at a slight angle?
There is a slight amount of play (wiggle) in both pulleys. It is difficult to determine if the two shafts are parallel by eye. The two plates are definitely firmly attached by the 4 studs so no relative movement of the plates should occur.
In your picture the belt is riding up on the flange away from the tuning knob. I would loosen the screws holding that assembly and try some thin metal shim stock under just the edge of that assembly to get the belt to ride towards center. If you have a set of feeler gauges, those would be perfect.
Try Kent for a belt tensioner from a parts chassis?
The model Sixteen is the only E H Scott using a dial belt.
The GC belts are a laminated combo of cloth and rubber layers.
+1 on Scott's suggestion.
I did add shims to the bracket holding the tuning shaft pulley using my stock of thin brass of various thicknesses. I could tilt the pully either up or down a small amount. It made no difference, except which side of the pulley the belt climbed. The tuning capacitor shaft and pulley cannot be shimmed to change the tilt in my radio. Also, when I was able to shim the tuning shaft pulley so that the belt stayed in the groove, it still would climb the sides of the tuning capacitor pulley (larger pulley). FYI the belt cut length is 9 23/32".
I will try using the O-rings that I have ordered ETA Wednesday. If that does not work, I may have to find a replacement belt tensioner and use one of the GC belts.
Thanks to everyone for the suggestions.
Interesting dilemma, but I still see it as an alignment problem or possibly the circumference of one edge of the belt is slightly different from the other one.