Wurlitzer 1100 Interference or scratchy sound

[gordo]

Hi,

I realise this is an almost impossible question, but I'll ask anyway.

My Wurlitzer 1100 has an annoying scratchy sound at times.
Not always. It comes and goes, but usually once with every record.
It sounds like running my finger lightly across the needle.
To me, it sounds like an electrical interefence. 

The sound continues if I disconnect the tone arm wire.

I have:
Had the amp recapped, tubes and resistors checked and replaced as required.
Replaced the tone arm wire all the way to the amp.
Lubed the mechanism.
Changed the needle.
Disconnected all the lights.

My pre-amp does not have the dome (shield) covering the 6SN7 tube. I think this may be called 'the bombshell'.

Any suggestions greatly appreciated.

Kind Regards

Gordon..

[Ron Rich]

Hi Gordon,
Try a metal 6SN7 ?? Ron Rich

[gordo]

Thanks Ron,
I'll see what I can find.

They can be very expensive.
I have found a used one on eBay.
I'll see if he will ship to Australia.

Regards
Gordon...

[Ron Rich]

Hi Gordon,
I MAY have a NOS one--I will look later when it's "light" in the storage area-- Shipping, as you know is the "killer", as your Govt. won't allow anything to be shipped from here, except by (VERY expensive) overnight post ! You might also look for that "cover" ? Ron Rich

[mikeman1]

Hey Gordon, I know you said you checked/replaced the tonearm wire but on my W1100 it was shorting inside the RCA jack periodicially, i unsoldered it, put heat shrink tubing going into the rca jack (male end) , resoldered it on and problem was solved. i dont recall if it was wire from tonearm to preamp or preamp to amp. i wiggled wiring by rca jacks and that is how i found the problem.

[gordo]

Thanks, I'll check.

Gordon...

[Ron Rich]

Hi All,
Gordon sent me a PM-- His son built a grounding cover for that tube--problem solved. Ron Rich

[gordo]

Yes, Ron is correct.

My son made me a simple grounding cover, resoldered one of the tone arm wires and separated how the braided cable travels though the jukebox.
Away from other leads etc.

All working well.

Lesson learnt for me. I did not think that a cover would make a difference.

I'll watch it for a while and try to get a permanent fix.

Thanks for your help.

Regards

Gordon...