Neutralizing SB-401 6146A finals

[Stu Lyon]

Comments interspersed
73, Stu W6CUX
Winnetka, CA
w6cux at earthlink.net

----- Original Message ----- 
From: "Robert Myers" <rsmyers at ROGERS.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Saturday, July 23, 2005 5:17 PM
Subject: [HEATH-TEMPE] Neutralizing SB-401 6146A finals


> Hi,
>
> Is there an easy way to neutralize the SB-401 finals without an RF probe?
> For example, by only using the front panel meter settings (grid current,
> plate current, relative power, etc.) and a dummy load?

There is the very frustrating technique of adjust for simultaneous min
plate - max output. This is described in the SB-102 manual (pgs 103/104) as
providing "adequate neutralization". Unless you want to go completely crazy,
the method still requires an external power meter of some kind. If your
dummy load is an original Cantenna, the penthouse detector circuit should be
adequate. Set the -401 meter on "Plate" and adjust for a plate dip. Then
readjust for max power out. Keep tweaking the neutralizing cap until the two
above criteria occur at the same setting of the plate cap. Sounds as bad as
it really is.

> For that matter, does anyone know who is selling 6146A's (not B's or W's)
> these days?  Anyone at all?
>
Ebay produced several interesting hits including this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5791068387&category=48710&ssPageName=WDVW&rd=1
I just searched for " 6146". Also found some interesting Chevy valve covers.

>
> Thanks,
>
> --- Rob VE3 JQL
>

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