Okay so ive been in and had a bit of a look see and removed one end of each resistor to allow for proper testing.Ive measured 4 resistors.
R17 which is Red Violet Yellow silver in machine and
R19 which is the same. Both are 270k so I measured on the 2M setting of my multimeter. R17 came back at .396 and R19 .314. When I used the multimeter at the 200k setting the R17 came in at 1 and the same with R19.
Then I measured what I believe is R16 and R18 and these are Brown Red Yellow black in machine. Both are 120k so I measured on the 2m setting and the R16 came in at .194 and the R18 came in at .216. So I set multimeter to 200k setting and R16 came in at 67.3 and R18 was 139.8 wanting to rise. So thats where I'm at.

Any thoughts?

im not a 100% sure that my resistor descriptions are spot on as they maybe round opposite. R19 maybe R17. or R16 maybe R18. but all 4 are right on top of one another and all 4 are hanging round together.

Im a Diesel Fitter by trade and a Pressman so ive got two trades and I cant read a multimeter or understand it even though I'm trying to.haha thats hopeless.

Ian or someone will tell you which resistors are more likely to cause a crackle in your sound .
It's old and you allow 20 percent give or take in readings.
Some resistors may be bad but maybe in a circuit where its not a issue.
This is why you need someone to point out the likely suspects.
Hang about !

Hi Padge, Hint:

When measuring high value resistors, say above 50K keep your fingers off the metal probes or wires.
Your skin resistance will parallel the resistor and give a false reading low.

In an old radio most resistors you test will have gone high in value sometimes to silly values.
The answer really to which resistors can cause noise can be technically answered but in the end, REPLACE ALL.
I know you can usually leave in wire wound and low value (less than 1k) and plate and screen resistors are the most suspect for noise but just cut the things out and replace. There is so much emphasis on "recapping" but how about "reresistoring"?

The only reason a lot of resistors still work ok is the tolerance of the circuits may allow plus/minus 20% of centre values.
Yes I have deliberately made a superhet using only carbon resistors and wax capacitors just for the hell of it but I tested a mound of parts to find the 20 or so needed. That means about 80% of the parts tested were useless. That means about 80% of the parts in a typical old chassis are unserviceable!

Guys that repair old sets for a living don't crap about they replace most parts (pick up the 80%) using experience ( hi Marc) as to what is safe to leave in. That means no after sales warranty needed!

Fred.

Shane, here is my 11 77 chassis I restored.
Pete . Note the chassis was not quit finish when that photo was taken ,I then did the mica caps

Where did photo send to pete.

Thanks for that Fred. I will at least change these 4 resistors that I measured.
Pete do you have four of those resistors I mentioned in my comments mate. If so happy to pay for them we can do it through email and I can just transfer money to you and postage mate.

Re-post here in case you missed it:

Most likely NOT the resistors. Do the test!

The colour the valves glow is irrelevant. The colour of the pins is irrelevant, they use a nickel alloy.

You 11/77 is too new to have these 6M5s and so is not affected.

The 100pF caps are mica, not paper. They are there to ensure high frequency stability in the amplifier, google Barkhausen's stability criteria for an explanation.

In that position and that age, silver migration is a definite possibility inside the cap.

As I suggested before, pull the 12AX7 out while the unit is running (perfectly safe to do this, although it will make a loud bang in the speakers) and see if the noise is still there or gets worse.

Another way you can test the 100pF caps is to measure the voltage across the 270k resistors with the 12AX7 unplugged and the chassis powered. There should be zero volts across those resistors. Any voltage you measure is caused by leakage in the 100pF caps.

Shane,yes I have parts.
No charge for a hand full of resistors,
But you need to follow ians intructions to find out what components need replacing .

Pete

Thanks Ian.Yes I have just done the test. When I turned it on the noise was there. I then removed the 12ax7 in operation the noise went and when I replaced it the noise came back. So is it those 2 mica caps which you said right at the beginning of this whole thread? Or do I need to now measure the voltage across those 2 270k resistors? I guess that is a double check. cheers Ian

Thanks Pete, yes I will follow his instructions.

Hey Ian I tested the two 270k resistors with the 12ax7 removed and both had voltage. One was 0.55 the other 0.25 so I guess then I will wait for your reply and see if it is what you think. Oh and the power was off too..

Replace the resistors. One of them is noisy. You would be wise to replace the two micas as well.

https://www.altronics.com.au/p/r7075-270k-0.25w-carbon-film-resistor-pk-10/

https://www.altronics.com.au/p/r2882-100pf-3kv-y5p-5mm-ceramic-capacitor/

That capacitor is a bit of overkill but it will do the job. High voltage small value through-hole caps are rare now.

Photo uploaded to Post 64.

Thank you Brad for the fast photo upload,
Thanks pete

Hey Vintage Pete,
The original wiring was never that neat!
JJ