Noone has raised the issue of how long 6JB6s last.

If they are used with caution they last for a long time, but if one =
tries to squeeze the last watt out of them (and the 6JB6s invite you to =
do so, thanks to their strong cathode emission) they can last for a VERY =
short time.

The 6146 have a lower cathode emission and do not then lend themsleves =
to be squeezed so badly as the 6JB6s. So there is less harm to =
inadvertently destroy them.

To my experience the Sylvania 6JB6s (those sold by Drake as spares) =
perform better than the GE 6JB6s, and are are easier to neutralize. The =
RCA 6JB6s, luckily much less common, were no good.

73

Tony, I0JX

------------------------------------------------------
Antonio Vernucci, I0JX US call: K0JX
50-MHz beacon: 50.004 KHz FSK 10W 5/8 vertical antenna
home page: http://www.qsl.net/i0jx
e-mail: k0jx {at} amsat {dot} org
------------------------------------------------------
"RadioGuy" ha scritto nel messaggio =
...
The thought came to me the other day whle thinking about the cost of =
6JB6's
nearly $100 for a set; I paid $18.00 for a matched set of three at =
AES back
in the 1970's and I got plenty of spares. Why did Drake use those =
cheap ass
sweep tubes in their final instead of the old standard 6146 to begin =
with?
=20
Sure, back then it seemed in vogue to use sweep tubes in amateur gear =
(yea,
sure, Swan gear...) but as I recall, we thought that Drake was kinda =
cheesy
to use those tubes anyway. I gonna stick my neck out and say Drake
engineering wasn't the end all that the youngsters think nowadays.
=20
(Yes... I have a complete Drake station (including amplifier)---the =
whole
line-up in pristine, vitrually unused condition in crisp factory =
cartons
including accessories, catalogs and a handful of the right-angle =
Switchcraft
microphone (black cap) and key (red cap) plugs that Drake originally
supplied not that PL-whatever. Original owner---me---so it's not sour
grapes.)
=20
RG
=20