Re: How to ruin a 535...

Robert Morein <morepub@...>

If you do that, you should know that the 6BQ7A may have been an older tube that had a mechanically fragile structure. Simply moving the scope around could cause tube failure. The later "frame grid" tubes were an advance in shock resistance.

I can't remember for sure whether the 6BQ7A is the problem tube, but I encountered this with a 545.

----- Original Message -----
From: Tony Denning
Sent: Wednesday, January 21, 2004 8:16 PM
Subject: [TekScopes] Re: How to ruin a 535...

--- In, "Craig Sawyers" <c.sawyers@t...>

I bought a scope on eBay which had all the 6BQ7A's replaced with
6DJ8 - the Amperex "Orange Globe" variety - which from my cursory
research, seem to be fetching a premium on eBay. Can't understand
it myself... but anyway, it looks like there's some money to be made
here. I'll pull all the 6DJ8s and replace them with some JAN
6BQ7A's that I bought for next to nothing, and sell the 6DJ8's to
some audiophile nutter... that should cover my original investment
in the scope and repair parts (and repair parts for the next 40


>> Yup. I've seen a few on eBay sans tubes over the last year.
Suppose the
> equation is that the 18 or more 6DJ8's are worth a mint to the
audio folks
> (perhaps $20 each), whereas a fully working 5xx series scope will
only get
> $50 maximum.
> Very glad that my 545A has the full complement of firebottles!
> Craig

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