[Milsurplus] More on the TCS Filter Adaptor

[Mike Morrow]

Dave wrote:

>This adaptor is very impressive.  And simple.
>I used the TCS set on the 160 meter contest last night
>and had several successful QSOs that would have been
>impossible through all that mess without it.
>The manual and schematics of two versions of 
>the adaptor are here:
>
>http://home.netcom.com/~arc5/FilterAdaptor/
>
>The adaptor is great, but the stock assembly is too tall
>(as you saw from the video) to fit inside the TCS.
>I intend to build a more compact adaptor.
>
>Are there any miniature, solder-in tubes that will 
>replace the 6BA6 and 6AU6? 

You might try using tubes with similar characteristcs of the type used in the AN/SRR-13* receivers, which last time I checked were easy to find new and inexpensive:

6AU6 is a sharp-cutoff pentode...so is the 5636 (used in SRR-13 IF stages).
6BA6 is a remote-cutoff pentode...the 5899 is semi-remote cutoff (used in SRR-13 RF stages).

The wire-lead 5636 and 5899 both have 6.3v 0.15a heaters, and typical plate voltage of 150v.

Mike / KK5F