Hi fellow Radio enthusiasts.

My latest debacle is recalcitrant Kriesler 11-81, which I bought on Ebay as "fully working", however when I tested it, it was getting stations ok, but very quiet.

I today proceeded to replace all paper and electrolytic capacitors and out of spec resistors.

Still whisper quiet...

Checked voltages, about 20v high (220v where I should have 200v) but only 85v where there should be 100v.

Well I've nearly replaced every resistor in the damned thing and it's still whispering at me.... Gone over every solder joint, checked output transformer for continuity, seems ok, changed output valves, 6Q5..?

I have an 11-80, which isn't working properly either after hours of replacing bits, all scratchy and generally unlistenable..

As much as I liked the look of these things, I'm wondering if they are a cruel mistress?!?! (I think I'd enjoy one of those more perhaps lol)

Sorry to be a bother, but what could I possibly have missed? Any Ideas very welcome!

Cheers

If you inject audio into the wiper of the volume pot do you get a loud response?
JJ

As much as I liked the look of these things, I'm wondering if they are a cruel mistress?!?!

Jamie,

If you want to continue restoring old sets, I think you'd do yourself a large favour if you bought a book or two on radio repair, wherein you'll learn the professional approach to fault finding.

It's not a scatter gun process. There's a logical and well trodden path to doing this stuff and, once you've followed it a couple of times, you'll be less frustrated and have less need to ask for ideas at the fundamental level of fault finding, plus you'll gain a sense of achievement from having nutted it out yourself.

Plenty of us here are willing and able to help with the curly issues, but the basic stuff just needs to be learned by reading and doing.

11-80: does the volume of the crackling vary with adjusting the volume? If not, disconnect one end of C11 (150pf) and C14 (100pf). If this stops the crackling, replace them.

11-81: output valve is 6AQ5, not 6Q5. If you hold a screwdriver blade to the PU jumper, turn the volume all the way up, and touch the blade, do you get a loud hum, or a soft one? Can you receive all the stations, but at reduced volume, or can you only get the closest stations? The answers will determine where you should be looking.

Ok Robbb, I'll report back after work, when I'll pull them apart again. Funily, I've had great success unexpectedly with non workers, it's the ones supposedly working which give me heartburn!

However your suggestion is a very good one GTC! Do you know of or recommend one or more particular books, and where I can buy them?

Do you know of or recommend one or more particular books, and where I can buy them?

I have a few stored upstairs somewhere, but with a bad knee at present it'll be murder getting to them. I'll let you know as soon as I'm more mobile -- hopefully in a day or so.

Okay, now that I'm able to climb again I have listed titles in a new thread here:

https://vintage-radio.com.au/default.asp?f=2&th=736

Jamie: I would recommend the first two titles to start with.

Thanks also from me about the book link. I would like to find those two as well.

Cheers Keith.

Quite true regarding methodology. There is always a set sequence of events before you even think about powering a set. Quite often I will do some of this sequence and not even bother to power it as its just too dangerous.

I would refer to my "prophesy" post to see an example of what can happen and why, when you ignore the sequence. Do be aware that you need to understand the voltmeters of yesteryear and those of today and how their differences can lead to wrong conclusions and serious errors.

+/- 20% is considered normal variance in voltage. I commercially fix so I am less tolerant of resistors that have drifted. In the set I mentioned, several of the resistors from its last service are now not in it, along with the paper caps that should not have been left in it.

One of the greatest causes of "deafness" in a radio is actually the meddlers when things go wrong and the actual act of changing parts throwing things like IF transformers off frequency (and the Monkeys tampering with their adjustments).

Manufacturers do recommend re-alignment after the RF has been repaired. Also check for wrong parts.

Generalising: Over voltage can be the wrong tap on the transformer, or a valve/s not drawing the right current and failed / wrong filter caps.

Marc

Well these are sitting on the backburner with the Astor Mickey, I've bought both of those books and read most of one, I'll tackle these troublermakers again soon. Great books, much more is clear to me now as to how radio's actually work. So thank you for the suggestions! Cheers.

It has always been one of my pet statements; "that if you gain an understanding of how a radio (and many other things) work. Then you also gain an understanding of why they don't.

Studying these forums you will get an understanding of some of the things like the old and unused, electrolytic capacitors, that will fail when unused, just due to their construction & how they work.

Rats & other forms of vermin chew components & wiring and deposit other corrosive stuff and some wiring deteriorates anyway. Aside from that, the Monkeys do all sorts of horrid & bizarre things to sets and most importantly many of these sets died and were replaced.

So as you have no idea with,an unknown set, which of these scenarios apply, you have to look before you leap.

I still have not identified the unknown set, but I know a lot of it is wired wrong. The tone does not work & I know why and the audio is crap. Now that it is able to run I can measure a few voltages & get a signal generator & Oscilloscope to work in there. The RF is working but I do not as yet know the IF frequency. They are bottom trimmer IF's & EMMCO used & made them for one.

Naturally to help things the speaker is poling & is bypassed onto a permanent magnet one.

This is what to expect with a hacked set, even the power cable is new. You don't rush in: Exuberance can do a lot of damage and I have seen plenty of it. Last week 1 x #80 for starters.

Beware of the internet, there are some morons on ego trips passing themselves off as experts.

I wont be doing that, My main field of training is technically Chemistry.

Marc