[time-nuts] Loran, GPS, Lightning, Timing

Bill Hawkins bill at iaxs.net
Wed Jun 25 22:29:13 UTC 2014


The Boonton (later HP) model 260A Q meter used such a tube for a 100
megohm VTVM.
The tube was specially made for Boonton as the 535-A.
There are also references to the 1659/535-A.
If you search for it, use "Boonton 535-A" to avoid the Tektronix 535
scope.
The Q meter manual has a picture of it.

Bill Hawkins


-----Original Message-----
From: Poul-Henning Kamp
Sent: Wednesday, June 25, 2014 3:45 PM

Somewhere, sometime, I saw an homebrew article for a lightning detector
which was based on some obscure valve/tube that had grid on the top
terminal.

A wire from the grid electrode ran to a porcelain isolator and from
there to the wire antenna, in order to get the highest possible imput
impedance.

I have no idea where I saw that article, but some HAM magazine or
possibly Elector about 10-20 years back is a good guess.





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