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 Kriesler 11-20 White Bakelite, with unusual valve lineup
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 Return to top of page · Post #: 1 · Written at 9:37:00 PM on 28 February 2017.
JamieLee's Gravatar
 Location: Clare, SA
 Member since 27 March 2016
 Member #: 1894
 Postcount: 510

Yesterday the postman called with my latest acquisition, which I eagerly unwrapped during my lunchbreak and pulled apart once I arrived home from work, then spent my evening into the night recapping and fitting with a new 3 ply cotton power cord and plug, the original plug was unfortunately missing, having been cut off by the seller and was not sent with the radio, so I was forced to fit a modern plug. The dial pointer, to my dismay was also missing along with the dial cord.
Inside the radio, marked on the chassis "Model 11-20 6AN7 6AD8 6X5GT 6V6"

I am unsure of the date of manufacture and searching "Radio Museum" and several other sites, I found several schematics, one with a "dial Cord map" so I managed to re-string the dial cord using a generic spring which I fastened to the start of the cord as the anchorage point was missing.

I cannibalised a dial pointer from the Westinghouse (AWA B15), which of course I had to modify to run in the original dial pointer track, using some light garden variety fencing wire to fasten this to the dial cord, which runs 1.5 centimetres below. With a thin smear of grease in the track, I am pleased to say this arrangement works just fine and with some stiff foam cut thinly beneath the dial glass, new dial lamps, I re-assembled the radio and wired the aerial to my long wire antenna and plugged her in, switched on and twenty seconds later, she burst into song, loud and clear!

A very nice radio indeed.

However...
Luckily for me I have no problems , so it is not an issue, I could not find any schematic for, or ant reference to my particular valve line up.
I found 11-20a, b ,c, d, e etc. etc. but mine is simply 11-20
I wonder if it may be a rare bird or early model run? Any thoughts?

Kriesler 11-20 Mantel Radio


 
 Return to top of page · Post #: 2 · Written at 10:47:15 PM on 28 February 2017.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2011

From what I saw while searching around, there were 27 different valve lineups for that model.

The earliest were all octal types (ECH33, etc), to eventually all miniature. Yours would seem to be in the middle somewhere.


 
 Return to top of page · Post #: 3 · Written at 12:27:20 AM on 1 March 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

Welcome to your worst nightmare and its not the only one of them that has variations on the variant, which they varied frequently.

6AN7 started at 11-20K and was itself replaced with 6BE6. The rare one is model M (Metropolitan) as they only made 50 according to the Genuine Kriesler Sheet. Dial number would tell.

I have a sneaking suspicion having had a run of them, that its not an 11-20 but an 11-25E: It may have 11-20 on the cabinet? Frightfully expensive to retool for that.

All of the Krieslers are consistent. If it has a 6V6 its grid resistors are likely cactus. 50K resistors have an attrition rate& in some its not unusual to replace the lot. Leave any resistor unchecked at you peril. When they used rubber wire, it was nearly as bad as Astor,s: Tasma just overloaded it & cooked it.

Around 2 in eight will not have wiped out their speaker transformer (do you get the feeling I have seen more than one) Crack a 9V battery across the primary (pins 3 & 4) No noise: Worry & don't even think about powering it if that's proven open.

A good knowledge of circuits is desirable with this lot.

Marc


 
 Return to top of page · Post #: 4 · Written at 7:43:54 AM on 1 March 2017.
MonochromeTV's avatar
 Location: Melbourne, VIC
 Member since 20 September 2011
 Member #: 1009
 Postcount: 1179

I think it could be a 11-20T.

The Radiomuseum page for the 11-20T shows a different valve complement. However the source for this information came from a AORSM printed version of the various model changes which has a typo.

On the AORSM version the 11-20T refers you to 11-20R, which then refers you to 11-20. As the 11-20 doesn't use a 6M5, I can only deduce that there was a misprint & the 11-20 was meant to be 11-20K.


 
 Return to top of page · Post #: 5 · Written at 9:27:44 AM on 1 March 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

What is in a case marked 11-20 does not necessarily represent what is in it. Much of the information (representative of many Australian circuits) is often quite vague in respect of component changes made to compensate for the different parameters of substituted valves.

Eg. 6BE6 is closer to 6SA7 and 6SA7 is absolutely different to any of the other Pentagrids as it has no true oscillator grid (RCA manual): It is normally used with a a Hartley oscillator configuration. ECH33 /35 is closer to a 6J8 and has a separate Triode exciter. The latter will likely have a different coil set and the whole circuit around the valves will likely be different. 6A8 & 6J8 will normally work in the others socket unmodified, but don't expect it to track the same way.

What this means is that you do not dismantle any of it until you have photographed it to establish where everything currently is: Irrespective if its wrong.

You will need to get copies of the AORSM circuits and compare them, that aside from servicing a lot of them, is how I came to the conclusion that it is not an 11-20 despite the labels.


 
 Return to top of page · Post #: 6 · Written at 7:10:58 PM on 1 March 2017.
JamieLee's Gravatar
 Location: Clare, SA
 Member since 27 March 2016
 Member #: 1894
 Postcount: 510

That is very interesting, however not only the case but the chassis has 11=20 written on it, the chassis 11-20 plus the valve lineup! It exhibits no roblems as yet, I had it on for several hours last night after re-capping and it sounded great, lots of volume and clarity nd station sensitivity. Short wave works excellent as well. I think I have been very lucky with this one Smile
Wow 27 valve lineups!!! Phew! That would make it a handful indeed if it were playing up!!!


 
 Return to top of page · Post #: 7 · Written at 9:34:59 PM on 1 March 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5239

If the set has not been "got at", still has all of the green paint where it should be, and you have an understanding of how a valve radio works, then that gives you a good understanding as to why it won't, if it fails.

That knowledge also helps to determine what some Monkey has done prior to flipping, it to save the embarrassment, of being found out.

Just because there is no circuit does not always render it a write off & not fixable. You can reverse engineer it as I have done & one such set appeared in Silicon Chip, with appropriate warnings as to how the circuit was derived. I looked at the set originally having never seen an Autodyne (Screen Grid) radio in the flesh before and said it would never work as it was wired wrong. After making a circuit based on what was there as it was, that proved to be the case: In conjunction with some members of the Radio Club, the circuit was fixed then the radio.

I am still trying to identify that unknown I posted on recently, however, it has been sent out working. If we ever find out what it is & the circuit, perhaps I might get it back for a look at, but at the moment it ain't broke: No fix.


 
 Return to top of page · Post #: 8 · Written at 11:17:37 PM on 2 March 2017.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7290

Photo uploaded.

I should add that the bottom of the cabinet is stamped "11-20" as Kriesler did with several models of the 1940s though there were indeed close to 20 circuit variations during this model's lifecycle. The cabinet never changed though, that I know of. White is a rare colour in this model, with cream more common and walnut most common.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 9 · Written at 9:40:21 PM on 3 March 2017.
JamieLee's Gravatar
 Location: Clare, SA
 Member since 27 March 2016
 Member #: 1894
 Postcount: 510

Aha!!! Mine is an 11-20V apparently!

http://www.radiomuseum.org/r/Kriesler_11_20_v.html


 
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