Fw: [Collins] 6AQ5 v. 6BF5?

[David Knepper]

Also see Don Kang's article on solid-stating the audio circuit, replacing
the 6BF5.  This article is on the CRA website at:

http://www.collinsra.com/cra_album/0202/cra_0202.html


David, W3ST
Publisher of the Collins Journal
Secretary to the Collins Radio Association
To Join the CRA go to www.collinsra.com
Nets:  3805 Khz, Monday/Wednesdays 8 PM EST and 14250 Khz Saturday, 12 Noon
EST

----- Original Message -----
From: "Glen Zook" <gzook at yahoo.com>
To: "Gerald" <geraldj at ispwest.com>; <collins at mailman.qth.net>
Sent: Tuesday, April 26, 2005 8:53 PM
Subject: Re: [Collins] 6AQ5 v. 6BF5?


> To use the 6AQ5 in the Collins S-Line receivers
> requires some modification of the circuitry.  There
> have been articles on this in several amateur radio
> publications.  If you do not make the modifications
> the 6AQ5 runs even hotter and the audio distortion is
> considerably greater.
>
> All in all, if a 6BF5 is available it is usually best
> to leave things alone.
>
> Glen, K9STH
>
>
> --- Gerald <geraldj at ispwest.com> wrote:
> I don't see typical operating conditions for the 6AQ5
> at 110 volts on the plate which is the typical
> condition for the 6BF5. For the data given the 6AQ5
> needs 12.5 volts grid bias and the 6BF5 needs 7.5
> volts bias. So it may be that the 6AQ5 will draw more
> than typical plate current when biased as a 6BF5. With
> the difference in heater power, the 6AQ5 may still run
> cooler.
>
> I'm sure the 6AQ5 has been run in 6BF5 sockets.
>
> Glen, K9STH
>
> Web sites
>
> http://home.comcast.net/~k9sth
> http://home.comcast.net/~zcomco
>
>
>
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