Once more, I come on bended knee to seek the collective wisdom of this forum.

My Model 11 has what appears to be a trimmer capacitor between the antenna and first coil (L-1). Rider has no value on this capacitor. This capacitor shorted, causing my set to be inoperative.

What value and what kind of replacement do you suggest? Where can I get it? Because it's adjustable, I presume it has some role in alignment. Rider is silent on the alignment procedure, too.

I assume that you are talking about the two unmarked condensers that are connected to the long ant./short ant. terminals (switch...whatever it is). Personally I do not see why the radio would not perform at all if one of these was shorted, and if one was shorted, why you couldn't get the receiver to work by using the other connection (if long is shorted, use short connection as temporary). If the trimmer you speak of is not one of these, then please correct me. This trimmer serves to match the antenna to the radio circuit, and should simply be adjusted for loudest reception on a quiet station at 1400 KC.

Trimmers are usually fairly easy to repair if they are of the compressed leaf variety. Simply remove the center screw and carefully separate the leaves. There are several different methods of construction. Some will require you to bend metal tangs on the ends of the plates in order to separate the plates. Carefully disassemble and remove the mica plates. Inspect the mica for missing pieces and/or cracks. Try repairing with super glue. If a piece of mica is missing, try substituting a spare piece of mica of the same thickness if you have some available. If not, try obtaining a very thin piece of plastic and use this as a substitute. Even if this piece of plastic is somewhat off, if the trimmer consists of several plates of mica, one piece being somewhat off should not harm adjustment much. Be reasonable in your selection of plastic. Remember that you are dealing in thousandths of an inch. Just because a selected piece is thin does not automatically qualify it for the job. You could also use a piece of wax paper as a temporary sub, though this may absorb moisture at times and spoil set operation.

When reassembling the trimmer, be very careful with the mica and its placement. Be sure that none of the plates touch or are capable of touching. When the screw is reinserted, it should only touch mica. The holes in the metal plates should allow ample clearance. Ideally there should also be a mica or plastic washer between the screw head and the top plate, even if this was not originally done. The plastic or mica washer should have a thin metal washer above it for distribution of force, and above this should be the screw head. Tighten down the screw until it is just snug and test with your meter for shorts. Loosen the screw and check for shorting.

As for the adjustment of your radio, it appears to me that it is of the TRF (tuned radio frequency) type. This type of radio usually requires no special alignment procedure. Simply tune the radio to about 1400 KC and adjust all of the transformers for maximum output at this point. Try to pick a quiet station. The station you pick should align with its spot on the dial. If not, be sure that the dial stops on the stop marks (if provided) and then go back to the station you were using. Edge the dial off of the station towards where it should be and realign the transformers for this new position. Keep doing this until the station falls where it should. Check all other spots on the radio with local stations and see to it that the radio pulls in stations well at all points. Check distance sensitivity and selectivity. The better the alignment, the more selectivity you will have (stations will overlap less).

Thomas

Thanks, Tom. I'll try to fix that trimmer.

I was surprised, too, that it made the radio dead. I used the antenna as a signal generator. I got a good signal at the grid cap of the 1st RF tube but no signal at the antenna post. I worked backward from the grip cap to the antenna. Everything checked out fine except for the trimmer. When I substituted a cap (250 mmfd), the set came alive with the antenna hooked up to the antenna post.

If you can connect the antenna directly to the grid and get a signal, or directly after the trimmer, then is the trimmer perhaps open somehow? When you say shorted, you do mean that there is a metal to metal contact through the device, right? When a condenser is shorted, you can test it on your ohm meter and are able to get a reading (needle moves towards zero). I think that a trimmer is more likely to short than open up, though, so you are probably using the correct terminology for what you are saying. A trimmer is usually too ruggedly constructed to open up. In order to open up, all of the leaves on one side or both would have to disconnect from the terminals.

That said, though, if say the long antenna trimmer is shorted, can you use the short antenna trimmer instead (temporarily)? Disconnecting the antenna from either the long or short antenna trimmer should leave the trimmer all alone and not part of any circuit (like a wire hanging off of something that does not go anywhere else).

Well, whatever the case may be, good luck repairing the trimmer.

Thomas