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 Kriesler 11-97 Sound
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 Return to top of page · Post #: 16 · Written at 10:29:24 PM on 4 June 2023.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5461

That's one of the reasons why I collect the junk radios, often they have valves to add to the unsorted collection if you remove them. I did sit down one day with a TV collector and a box full. He got the TV ones I kept the radio ones with the exception of 6CK6 which is only different than 6M5 in its suppressor being on pin6; Whereas 6M5 is internal connection.

Most are transformer and never the one you want. Anything I can get rid of that is never likely to be fixed is a good move. There is a 1940's console. Internals restored has a cabinet & some Goose made the gearbox casing of the turntable out of diecast. Bad move.

There's a collection of Stereo speaker boxes to be gotten rid of; I was going to create space by removing the speakers & using the rest as room warmer.

Transformer is likely to be a drop in fit but give less voltage.


 
 Return to top of page · Post #: 17 · Written at 1:59:01 PM on 6 June 2023.
Monaro's Gravatar
 Location: Brisbane, QLD
 Member since 24 October 2013
 Member #: 1439
 Postcount: 131

Sure sounds handy to have that many spare parts!! I can imagine all the speaker boxes and consoles take up stacks of room - they were all so bulky! although I think that's what makes them sound so nice - the big enclosed wooden cabinet reverberates the sounds.

Ok well I'm in Melbourne at the start of July so if I can't get an 11-97 transformer by then I'll touch base with you to come grab it if you don't mind?

In the interim I've been tinkering on an old HMV 61-51 which has been problematic....I recapped the radio but it had a bad buzzing on AM probably needed realignment so I gave a tiny tinker to the IFs and in flipping it over to do top and bottom the sound dropped right off and I thought I must have stuffed one of the IFs.

So I had a spare parts chassis here so I thought I'd swap over the transformer (was no good on the spare parts chassis) and as I had just about finished I noticed that the ground on the output transformer was loose! Ahhhh I must have knocked it so here I was thinking it was an IF but it was just that......Well I was too far in to things to stop so I finished putting the spare parts chassis together and it worked - but it would only work intermittently and then stop.....well I spent hours on the damn thing but I ran out of parts to replace. So I figured I'd put it all back into the original......and guess what....went to swap the 6av6 back over and noticed the base had a crack! I (THINK) that was the problem with the spare parts radio.....so just ordered a replacement.

So seems I've wasted a whole day swapping an entire power transformer over just because there was a loose output transformer ground....and then wasted another day swapping it all back just because there was a cracked tube.

Ahhhhh vintage radios!!


 
 Return to top of page · Post #: 18 · Written at 2:12:15 PM on 6 June 2023.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5461

Some lessons are learn the hard way. I will go around every visible connection with a marker when I am finished to ensure every one is properly soldered. The marker makes the ones you missed obvious.

Its amazing what you see if you do that, albeit there are surprises. I got a restoration (DIY= Destroy it yourself) with seven dry joints one short and mains wiring of the standard that burnt down Notre Dame. Never unusual to find a factory dry joint in a radio which has been repaired and they missed it.


 
 Return to top of page · Post #: 19 · Written at 2:36:03 PM on 6 June 2023.
Monaro's Gravatar
 Location: Brisbane, QLD
 Member since 24 October 2013
 Member #: 1439
 Postcount: 131

Ah that's a good tip I will have to buy one!

Very good DIY acronym.....sounds appropriate for me so far on these projects lol

One thing you would know how hot can resistors safely get? I noticed in this hmv that the 3 resistors connected in parallel across the 2 electrolytic caps got really hot to touch after a few minutes operation.....so much that I replaced them (15k 1w) and still gets just as hot. I added a 4th but it didn't make much difference.....perhaps will be different with a new 6av6 tube in it....


 
 Return to top of page · Post #: 20 · Written at 11:49:08 AM on 7 June 2023.
Monaro's Gravatar
 Location: Brisbane, QLD
 Member since 24 October 2013
 Member #: 1439
 Postcount: 131

Actually one other question - in my Kriesler which drops a turntable channel sometimes, I'm looking to replace some caps and resistors in the preamp stage.

Just wondering can I replace the styroseals with film caps? The styreos are apparently rated at 600v and 120pf / 220 pf / .0022μF so easily to obtain in 500v mica's and can probably get 630v ones too which are better suited to the voltage rating.

Just wondering if there's anything special about styros?

Thanks!


 
 Return to top of page · Post #: 21 · Written at 3:33:36 PM on 7 June 2023.
Irext's avatar
 Location: Werribee South, VIC
 Member since 30 September 2016
 Member #: 1981
 Postcount: 485

In my experience Styro caps virtually never fail (I've never replaced one).
By all means test them with a capacitance meter but I think you'll find them to be o/k.
WRT the buzz on radio reception LED lights cause no end of interference.
I have a magnifying lamp with a ring LED array and it causes a loud buzz through any radio I'm working on.


 
 Return to top of page · Post #: 22 · Written at 4:48:19 PM on 7 June 2023.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5461

I have taken several LED flood lights back to point of sale. Once upon a time we had RFI regulations: No more. The country is going down the gurgler.

In many cases the use of voltage regulators & switch mode power supplies in lights insane. I do wonder at the overall cost making and using such units when technically you could use a cheap barretter in it. bearing in mind an incandescent bulb is pretty much 100% recyclable (glass can be re-used) and it is an RFI clean pure resistive load.

To calibrate anything here One has a symphony orchestra from lighting (got rid of one) Wireless NBN, one older computer, and the UPS. One has to turn all of them off. The bench desk lamp is Halogen & that keeps one warm in winter. Fortunately it is a mild winter and it only takes a 1000 watt heater to keep the (insulated walls & roof) workshop 30ft by 14ft walls 8ft at around 15 degrees.

I do not use a magnifier light I prefer the head type like a tennis shade. The one from a certain purveyor is not what I call a quality item. But gives better depth of field and corrected vision can be worn.

The pretty little Styroseal caps can be "made to fail" by soldering close to their body. Normally a haemostat is advised. The Caramel Polyesters can crack if under mechanical stress. The most important test for paper caps and suspects (not electrolytic) is leakage and that is done at rated voltage, or working voltage, using DC. Any that leak here are binned.

Often turning on and off to make it go is a "dry joint".

Marc


 
 Return to top of page · Post #: 23 · Written at 9:12:31 PM on 7 June 2023.
Monaro's Gravatar
 Location: Brisbane, QLD
 Member since 24 October 2013
 Member #: 1439
 Postcount: 131

I’ve had a brief further look over the pre amp circuit but I can’t find anything obvious. Tested the resistors they all appears on spec except one that was high but upon retest it was back on spec….so I don’t know what is up there I may replace it anyway. Cleaned switches again and aux inputs too. Will leave the styros then - if they rarely fail I think I should rule other more likely culprits out first.

Incidentally I also found the 25μF 25v electros I couldn’t locate 1st time…small blue canisters. Haven’t ordered those yet will see what change they bring if any when I can get some next. One doesn’t look great - like it has some paper sticking out one end - although that’s the left channel which is the good channel! They sure don’t look like normal electros & would be easy to miss. Can’t seem to find an exact transformer replacement yet though…the old 11-97’s don’t seem to pop up often anymore.

New tube for HMV arrives tomorrow would be nice to have at least one going for the weekend…!


 
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