Valves. Some questions.

[Morningside]

I have stripped an old Oscilloscope and it has given me about 30+ of them.
Some are Marconi and some are Mullard. Does it really make any difference to the value if they of a certain make?

Also they were VERY dusty and needed a clean, so I put a cloth over them and to my shock and horror the lettering came OFF!

So how do I clean the writing?

Here they are:



After a couple of days I am still at it. Dismantle time:
http://www.datasilo.co.uk/?p=537


Now I also thought of another question. These valves have sleeves to reduce interference.

Should home hi-fi ones also be screened as well to improve sound quality?

[Toffer]

Tony Sale can answer any valve related questions...he can be contacted at Bletchley Park.

[Smiler.]

I love stuff like this.

Why did you strip the oscope?

Where did that come from?

[Morningside]

Tony Sale? Thanks, I shall look it up.

Smiler. said:

I love stuff like this.

Why did you strip the oscope?

Where did that come from?

It came from the local car boot. From a house clearance I was told, so I presume it was some 'old boy' collector who has gone silent key.

Saw it sitting on the ground and it was always my intention to strip it. Some old equipment can turn up some surprising stuff

For example, I found a couple of KT66s in some old 60s test equipment.

Mainly, I wondered if some valve (manufacturer names) are more worthy than others and if so why?

Edited by Morningside on Monday 15th August 23:25

[phumy]

Theyre worth something if they work and even more if you have the original boxes.

[5705]

Morningside said:

Mainly, I wondered if some valve (manufacturer names) are more worthy than others and if so why?

Mullard (or any other brands that have the same Blackburn factory codes screenprinted on them). Very popular types like ECC83, EL84, EL34 (etc) should sell well, if that's your plan. Even untested.

[Morningside]

5705 said:

Morningside said:

Mainly, I wondered if some valve (manufacturer names) are more worthy than others and if so why?

Mullard (or any other brands that have the same Blackburn factory codes screenprinted on them). Very popular types like ECC83, EL84, EL34 (etc) should sell well, if that's your plan. Even untested.

Ah, I wondered what those codes were! I thought they were month/date.

Anyhow I have put them on eBay. Oddly the ones I thought were worthless are getting the most bids.

So why is the silk screening coming off when I clean it? What did they use back then as it must have been weak paint.

[rsv gone!]

How much do they typically go for? (Can't see ebay at work).

I'll tell my dad to have a clear-out. He has quite a few.

[5705]

The Blackburn code is an alphanumberic code that always starts with a "B".

There may also be other codes for the version number (such as "XF2" for EL34s).

Don't bother cleaning them. In your Ebay advert show the equipment they came from (adding to provenance).

And if you're Ebaying Blackburn-made Mullards (or Telefunken or old RCA, Philips, etc), make sure to include worldwide shipping, as the deepest pockets for these seem to be in the Far East, Germany, USA.

[Morningside]

Thanks for that. As for eBay prices I cannot really say (7 days to run) but they have only been on for a day and the 2 ECC81s are making £10.50!

Too late, I cleaned the ones not in the screened can. Yes, you are right about the far east! So far someone from China has bid on most of them.

I understand they love (Engish?) retro stuff.