Re: {Collins} Need tube for 75S3B

[Chris Farley <kc9ieq@xxxxxxxxx>]

Hi Jeff,

There is really no difference between a 12AX7 and 12AX7a besides the "A" having a controlled filament warm-up time and having a slightly higher (20% if memory serves) max plate dissipation rating.  The mu of the two are the same.  

I don't have experience with the 75S3, but I don't believe it would really be that advantageous either way, although some claim the A is a bit quieter.  

Regards,
Chris KC9IEQ

--- On Fri, 9/4/09, Jeff Wayne <wayne4@xxxxxxxx> wrote:

From: Jeff Wayne <wayne4@xxxxxxxx>
Subject: Re: {Collins} Need tube for 75S3B
To: johnbess@xxxxxxxxxxxx, jmonk1@xxxxxxxxxxxx, collins@xxxxxxxxxxxxx
Date: Friday, September 4, 2009, 2:06 PM



Is there any advantage to using a 12AX7A over a 12AX7 in the 75S3B?

73,

Jeff, K1YLV




Jim,



The tube you need is available from Frank Krize, K5SVC, @ 601- 442-0973. He
has all of the tubes for Collins gear but supplies are limited.



73,



John??


-----Original Message-----
From: Jim Monk <jmonk1@xxxxxxxxxxxx>
To: collins@xxxxxxxxxxxxx
Sent: Thu, Sep 3, 2009 3:44 pm
Subject: {Collins} Need tube for 75S3B



Fellow CCA members......... I need a good 12AX7 vacuum tube for my 75S3B,
preferably a new one if possible.?
?
I would prefer an RCA or other USA manufacturer.........apparently these are
becoming hard to find. Any help out there??
?
73/jim/W0JJL ?
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SHARE THE FUN: JOIN THE COLLINS COLLECTORS ASSOCIATION TODAY !
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 NETS: Tues & Thur: 3.805 MHz-2000 Central + Fri: 3.895 MHz-2000 Pacific
  SUNDAYS: 14.263 MHz-2000 UTC  +  AM Net: 29.050 MHz-1200 Central
  1st Wednesday AM Net 3.880 MHz-2000 local (ET, CT, MT, PT)