Good job Jim. This type of restoration is one that I find very satisfying. I started my electronics hobby with little money but I was blessed with a wonderful mentor He was an old radio man who moved into television repair. When he retired he started buying old radios and restoring them for resale. He took the time to teach me electronics, shop techniques, wood working and veneering. I could buy rare radios that were in terrible shape and bring them back. When you finish you will have a great SX-11 and a finished project to be proud of.

Jim,
Would you have an interest in a parts set? It's no prize rusty chassis top and bottom. Shoot me a pm.

Terry N3GTE

Yes please - PM sent.

Love it when a plan comes together. After drilling out the setscrews in the main tuning dial, and liberal applications of Kroil and heat gun, the main dial came off without having to resort to any kind of pullers. Front panel comes off next.

The set is getting lighter, also shown are the front panel parts that have been removed and set aside:

Watching this post closely and looking forward to updates. Hope to learn something from your efforts!

So far so good. Power transformer continuity seems good. Notice the tone control at the far left of the photo above, the poor shaft came out when the knob was extracted. Also the AF gain control seems to be pretty well locked up. So those are going to need replace or rebuild. The AF gain in particular is problematic, it has a centertap for the tone control.

Thankfully the band switch is in good shape.

The BFO pitch control variable capacitor had been replaced with a trimmer, that's on my list to replace. Visible at the far right. I am going to re-stuff the filter capacitor, which is marked as 8 uFd
(two sections) whereas the schematic has 16s called out. But the one can I took out does seem original.

Another interesting feature is, the three gang tuning condenser has been soldered to the chassis at one point near the back. Could be factory original, not sure.

The temptation here is to get the set in working condition and then decide how far to take the cosmetics.

Next step I think is to begin checking all components to see what's in spec, and what's not.

Tone control and AF gain control:

As mentioned the AF gain control had the shaft frozen in place inside the body of the unit. Also the entire shaft for the tone control was gone, having been removed during the knob extraction.
Both of these are unique items, the AF gain has a loudness tap, and the tone control has the power switch for this radio, so I wanted to save these if possible.

First picture is the dismantled AF gain control. I had to use a large amount of force and lots of heat to remove the shaft. After cleaning up the shaft with a wire brush, and passing a half inch reamer through the brass bushing, it went back together fine.

The tone control needed to have a new shaft manufactured, and riveted onto the wiper unit. Second photo is that unit apart, with the stock used to make the new shaft. Next one shows the new shaft in place.

And finally, both controls finished and ready to use.

Comments about these variable resistors: I've never seen ones like this before. The resistance element is carbon on fiberboard, and inside of that circle of material, is a thin metal shim strip, bent into a circle. The metal shim strip is the wiper. Then there is a pusher, attached to the shaft, which is what seems to be a tiny wood (oak?) block, that forces the shim into contact with the resistance element. The wiper assembly with the wood block on the end, is spring loaded to press very hard on the metal shim strip. I cleaned the inside the metal shim (old grease) and put a tiny bit of low vapor pressure grease back on. I used a very thin cotton swab (no solvents) to wipe particulates off the inside of the resistor elements. The pots read properly at all positions. They're both log taper apparently.

The RF gain control and the BFO injection control will probably be cleaned up the same way.

Once I had all the knobs off the front panel, I was able to get a good look at it. I did remove the two escutcheons from the panel, one for the bandspread dial and one for the eye tube. These were held on with tiny spiral drive screws, which could be driven out from inside.

I cleaned up some of the filth on the panel, and a few things became apparent. It's brass, and the paint, which appears to be textured, is not actually. The brass panel has been apparently chemically etched to give the textured surface seen once painted. The next item is that the lettering on the panel is not paint, it's not decals. The lettering actually has been formed on the surface by the same etch process that formed the texture. The lettering is white because it is probably Nickel plating, and there was probably some kind of photo-lithographic process involving and etch resist, to form the lettering. The entire backside of this panel is smooth and seems to be plated with some white metal, possibly Nickel. The front and back of this panel were probably the same to start, and the front was etched to give the lettering and the texture. The resolution of the process was pretty darn good, as seen in the hallicrafters logo on the front panel.

The final interesting feature is, the paint around the controls is actually worn away in many places. I suspect this radio had a lot of use over the years, to the point where the owner's fingers simply wore the paint away. Photos:

Hi Jim,
My HRO Sr used similar pots, and was exposed to almost as much moisture as your S-11 has. I had similar difficulty removing the set screws from the knobs. I like your fixture method, which looks like it was a necessity in your case. Because I didn’t have a fixture (didn’t think of it) I resorted to a left hand twist drill bit, with the idea of using an easy out on the set screws. I applied Kroil for several days before starting the process. Fortunately, when drilling, each one of the set screws backed out of the knobs before I had to resort to the easy out.

The control pots, I figured were a lost cause, with all the rust and corrosion. I really had nothing to loose, and had some new pots on order. As it turned out, the resistive elements were still good, so I disassembled them as best I could, and threw them in the ultrasonic cleaner with hot water and Simple Green. It removed much of the surface rust, and cleaned them right up. The were reassembled, lubed, and checked out without any skipping when sweeping the wiper pad thru the arc of the control. With these pots, as long as the resistive element is not open, they are pretty robust. I only had one pot on the HRO that I had to replace.

Great job, and thanks for posting.

So others have been through this before, too!

On this set, the setscrews were only the opening act. The knobs would not come off at all, once they were drilled out, took some major effort to pull them off.

Did you actually put the resistive elements in the U/S cleaner? I only used hot water wipes, and a toothbrush, to clean the dirt off the exteriors. They
actually were not that badly scuzzed up.

Yes sir. Like I said, I figured I had nothing to loose, so was willing to try anything. I should add that I put them in a low oven for several hours to dry, after rinsing in warm water first.

So, if I understand correctly, that interior metal strip is only pushed against the resistive element at one, moving point, by the moving insulative "wiper", and nothing actually "wipes" against the element at all? That's ingenious! I have an 11 in the stack of Hallicrafters awaiting attention, I'll have to dig it out for a look. Those controls do sound eminently servicable. Did any other Hallicrafters models use them? Who made them?

Bob, yes that is the way they work. I am not at home right now to provide the manufacturer's name, but it is a common one. I have seen ads for them in the magazines of the day. As I recall they are wire wound pots. One of the tricks is to get the right lubricant on the rubbing block so that it slides easily. I have heard that the rubbing block is made of wood, so perhaps it is lignum vitae, which is self lubricating. It could also be leather. I have used Super Lube Grease, very sparingly on the slider, which seems to work. There may be other lubes that work better.

After thinking about it, I can see one possible drawback to that method of contact, in that the control would not be self-cleaning by turning back and forth, since nothing wipes the contact path to push debris and corrosion out of the way. Still, wear of the resistance element should be less, although I guess you could eventually wear holes in the metal contact strip...tradeoffs, tradeoffs!

(By the way, nice Model A in your avatar! I have my dad's '27 Model T in the garage, I need to reregister it and get some driving practice in on it!)

I'm pretty sure the block is oak, end grain on to the pusher point. Could be some other wood of course.

I had the pleasure of meeting Jim and his wife this afternoon. They came down to pickup the S-11 that I had. Unfortunately they were a mission and had a head out pretty quickly. Was glad to pass it along to someone that could use it. I thought I might have serviced it but have many other projects and was unsure if I would get around to it.

Safe travels back up to NY tomorrow!

Terry

(Shame) the set is still in the car. Took longer to get back than expected - forgot this was a long weekend!

Photos to come.

As promised, photos of the second, parts set, S-11. Looks aren't everything:

Front panel is pretty much unmolested.
Came with a full compliment of (apparently good) tubes.
Has the correct case.
IF transformers look nice.
BFO tune capacitor, and the housing, are present (missing from the other set)
Bandspread dial looks to be in good shape.
Main dial nice condition.
The knobs have the correct pointers!
Phone jack present (also missing from the other set)

The bad: mouse attack!

I think I just threw up a little.

I look forward to your wonderful work continuing and the completion of this wonderful receiver!