[Boatanchors] National SW-3 variations

[RJ Mattson]

Al
I have a blank hole (never used - no scratches) like Vic where your B+
switch is.
In the universal AC/DC models that position has a switch to go between AC
and DC tubes.  The chassis must be punched for all versions.
Again, there were probably many commercial contract versions not documented
and many user mods.
bob...w2ami


----- Original Message ----- 
From: "Vic Rosenthal" <vic@rakefet.com>
To: "Al Klase" <skywaves@webex.net>
Cc: "RJ Mattson" <rjmattson@hvi.net>; "Boatanchors List"
<boatanchors@mailman.qth.net>
Sent: Wednesday, March 31, 2004 12:16 PM
Subject: Re: [Boatanchors] National SW-3 screen resistor


> Al Klase wrote:
>
> > Now you've got me going.  This set has 237 stamped on the audio tube
> > socket, and 5-pin unlabled ceramic sockets ('36) in the other two
> > positions.
>
> Mine is the same.
>
> > The power cable is a 5-conductor affair with a separate lead
> > for the screens.
>
> The previous owner of mine replaced the cable, but this is the way it is
> currently hooked up.
>
> > B+ is controlled by a long-shafted rotary switch mounted vertically on
> > the chassis just in front of the antenna and ground terminals.  You need
> > to lift the lid to get to it. All looks original.
>
> I have seen SW-3's with this switch, which I think is to switch between
> battery and AC operation.  My chassis has a hole (apparently original)
> there, and it doesn't look like a switch was ever mounted there (no
> scratches).
>
> The front panel hole on my radio is on the left, not the right as I've
> seen in pictures, and is slightly higher than the hole for the antenna
> trimmer.  As I said, it looks ham-made, but of course it could have been
> enlarged.  It is 1/2" diameter.
>
> -- 
> 73,
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco
>
>
>