This is such a great looking little radio with a lot more room to work in than the HMV portable I have just put aside. And the circuit looks pretty easy to navigate after scanning through the schematic I got from Radiomuseum. Although it did mention there are 27 different versions of this set. I am two days in and nowhere near putting power on to the receiver. After hours of searching I have determined that I have version 11-20X. That has the same valve set as mine (6AN7,6AD8,6M5) with the only difference being the rectifier tube.Mine has a 6V4 and the X model has an EZ82. A quick check shows that the two should be interchangeable (I think). Unfortunately there is no schematic that I can find for the X model. Radiomuseum has most versions listed but when you look for the schematic it just comes back with a note saying except for tube xxxx being changed for tube xxxx it is identical to model xxxx. And this goes on through each preceding model until you get to the schematic I have which by now has a completely different valve set. Never mind at least I have a complete radio to work with. And a schematic that should be somewhat correct ( Am I wrong in this asumption? Probably). I started at the two electrolytics and to be honest I have not got anywhere really. The first one, listed as C53 looked to be in the right place on the schematic and was listed as 8mfd 350 volts going to ground. What was actually in place was a larege 8mfd electrolytic but it had a wax .05mfd 400 volt non polarised cap piggy backed to it in parallel. This has me stumped. My instinct is just to replace it with an 8mfd electro and move on. But this could be totally wrong. The second electrolytic is even more confusing. It has two inlets or positive leads and just one outlet or negative. it is listed as C110 and is linked with a weird wire wound resistor. This resistor has three green leads. One at each end and one in the middle. The schematic shows it as two resistors R176 and R179. I would like to say that the schematic looks correct as far as the relationship between these resistors and the two electrolytics goes. But try as I might I get lost along the trail every time. I still don't know if C110 is two caps in one body or it is just one cap with a complicated wiring to the wire wound resistor or should that be resistors?
If anyone has a good understanding of this circuit I would greatly appreciate some guidance. Particularly around those two electrolytics and the wire wound resistor.

Yes dual axial electros existed. As did wire-wound resistors with two or more segments. When you look at how they are made (wound with wire) you can see the attraction to the idea.

The reason for the .05μF cap in parallel is to provide better bypassing at radio frequencies and is a common technique, even today. Once you go up in frequency above about 500kHz electrolytics stop working as capacitors!

Kriesler were known for changing designs frequently for supply reasons. They weren't the only ones.

Thanks for the info Ian. When you say "wire wound resistors with two or more segments". Does that mean there are two separate resistors on the same core? There are just three wires on the resistor. One at each end and one in the centre. Like a centre tap. And the dual axial electros. There appears to be two wires at the positive end but only one wire at the negative end. I can see how that would not be an issue if the caps were connected to ground but that is not the case here. I can't figure out what's going on. Any ideas? Thanks for the info regarding the piggyback caps. I will replace the same as the original. Don't know why it wasn't shown on the schematic.

I don't have a 11-20, but I assume this resistor is probably green and long, and has a kind of ring around it in the middle, where a wire joins to it, also with a wire at each end.

If so, it's often called a "dropper", and some of them can have multiple taps to extract various voltages. They have a tendency to go open circuit, especially at the taps, because the wirewound wire becomes disconnected or corroded.

The double capacitor is quite a common thing. The negative wire goes to ground, while one positive lead goes to the rectifier cathode, and the other positive terminal goes on B+ just after the filter choke/resistor (a resistor according to the blurry schematic). It's just 2 capacitors in one can.

Hi Robbbert. Yes that's what I thought regarding the output from the double electrolytic. Except this ones output does not appear to go to ground. As far as I can see it goes back to that wire wound resistor. I am really stumped trying to figure this out. Hopefully someone with detailed knowledge of the 11-20 circuit can put me right.

The best circuit is this, https://www.kevinchant.com/uploads/7/1/0/8/7108231/11-20.pdf.

The set is a reflex type. It is back biased and the first cap of the filter goes neg to the centre tap, the other, positive to cathode. The second filter electrolytic after R176 neg goes to ground.

There is a tapped resistor R146, A, B & C. One end of R146 goes to the centre tap via R179 and the back bias resistor R148, also comes off that end of R146.

AORSM circuit is a horror. I would replace both C110 and C53 filter electrolytics, with separate capacitors. I prefer 500v caps not 450v too many fails.

Thanks Marcc. Unfortunately the link you supplied no longer works. I get a page not found 404 error. I have been at it this morning before I saw your reply and I can trace the red wire from the output transformer through the wire resistor (R176 according to my schematic) top and bottom then on to both C110 (the dual cap) input and the cathode of the rectifier tube (6V4). The second electrolytic (C53) taps off before R176 and goes to ground. this is the one that had the piggyback .05 cap that Ian explained. Hope that makes some sense. In any case it appears that the schematic I am using is not right. Now that I have your explanation I will use that to try and figure out what's going on. I will report my progress. I could really use that better schematic if anyone has it on file.

You may have to go direct to Kevin Chants website; Choose Australian radio circuits, Kriesler & then download yours. The data there also has alignment etc. That is the superior info, I do have that pdf downloaded.

It from cathode The first Ecap goes from cathode to CT the second Ecap 53 taps off after 176 (load side) and goes to ground. The 0.05 cap gets replaced with 0.047μF 630V (473 nF).

That is a decoupling cap & often up the RF end of the B+ Rail. It is to get rid of RF riding on B+ as Electrolytic caps do not decouple RF very well. So it should be there.

Thanks Marcc. I have been to the Kevin Chant website several times but the only schematic I can find is the 11-20 (issue 2) which has a completely different tube lineup to my set. When I trace throught the circuit starting from tube 1 there are so many discrepancies that it is not much use to a beginner like me. I do understand what's going on with the second Electro cap C53 and its companion. replacing that will be no problem. But I am no closer to understanding the wire wound multi tap resistor and the other Electro C110. As I mentioned earlier there are two inlets to this cap but only one outlet. Also both schematics list resistors 146 a,b and c as 1meg half watt carbon resistors. I don't think they are tapped resistors in my set. Am I confusing the wire wound tapped resistor which I think is shown as R176 and R179 with R146a,b,c? In other words are you saying that R146 a,b and c are that big black wire wound resistor on the top part of the chassis? This is probably starting to frustrate you as much as it is me. But please don't give up on me. The penny will drop eventually. Cheers Ray.

The big long black notoriously unreliable is 146 A, B, C. They are often used as voltage dividers for either negative for different bias voltages Or alternatively in positive dividers for different HT voltages. Americans often refer to them as candohms.

They have a notorious habit of going open circuit, frying, or if they have clamps for tapings: They corrode & go open circuit. C110 because its back biased has to go back negative to centre tap. It cannot in any way be grounded. In the 11-20 circuit Kevin or AORSM's have. If the dual cap has been replaced it may be wrong. The body of an aluminium can is usually negative, There is a possibility that C110 has two wires an C53 has one and the case.

The whole dilemma can be solved by using individual caps wired as per circuit. R179 (150 Ohm) & R148 (35 Ohm) I would expect to be individual resistors however, they may be part of the end section of the candohm and vulnerable.

So the candohm may go tap 146 A, tap, B, tap C, tap then R179, tap to CT then R 148, tap to ground

Do note mods G & H further on. In and just after the war lots of changes were made due to availability of parts and W^D scarpering of with them.

There were plenty of sets made where tube numbers & bases changed, not their electrics. It was never unusual for Kriesler to recycle a cabinet & put different chasses in them, While the original chassis number was on the cabinet. So, what the cabinet says is an 11-20 of 1949 is actually a fifties chassis.

OK its not an 11-20

11-38 has sw so 11-36,11-37, 11-48, 11-49, That is possibly stamped on the chassis

EZ 82 & 6v4 same thing

11-48 looks like it has a Candohm of three resistances

Thanks Marcc. Flying (glider) today. I will digest all that and have a look for a better schematic based on your model info. C110 in my set is a paper electro and I could only find a chassis number stamped on the set but I will have amnother look tonight.

I prefer flying a plane with an engine albeit I have been in a glider.

There is often a date on an original speaker or speaker transformer, not withstanding only around 2 in 10 have an operational one, or it has already been replaced.

OK.I think we are making progress. My set does have shortwave and it has the identical valve compliment as the 11-38. Marcc I think you may have found my model. Unfortunately neither Kevin Chant or Radiomuseum have a schematic for that model. And nothing comes up on an internet search. Radiomuseum listed AORSM Volume 12 , 1954 page 224 as having the schematic. I wonder if the Mitchell library would have those service manuals. If so I could go in and have a look and maybe even take a copy. Other than that an appeal to the membership here might work. I will put something in the general discussion section and see what happens. If anyone is reading this and has that schematic I would love to get a copy. My email is unhidden.
I looked over the chassis again this evening and found this. The number 148839 stamped on the chassis. A cardboard tag rivetted to the back of the chassis has No: 90272 printed on it. No other explanation. Just a number. The speaker is a Rola 5C and has 26F1 printed on the frame. That is all I can find. Can any of these numbers be used to identify a particular model?

I would have got back to you sooner, however I have changed to the other computer & the site loaded on it.

11-38 has mods but the circuit in AORSM has the double cap negative to CT and its positives across the 1500 Ohm resistor there is an 8 & 16μF cap in that pair which it seems not to have marked. I will assume 8μF first to 6V4 cathode?

It has the abc candohm. I note negative feedback from the speaker and note that its phasing is critical.