[Milsurplus] TBX various questions

[Al Klase]

Ian,

A comment on the crystal:  Hiding a modern crystal inside the vintage 
holder might not do the trick.  The early TBX uses a single pentode in 
the TX.  I suspect the current in the crystal can be quite high under 
some circumstances, hence the crystal holder with the heat sink in 
contact with the chassis.  When I operated one of these years ago, I 
used the old Indian trick of putting a #49 pilot lamp (2 volts, 60 ma) 
in series with a more common FT-243 rock.  The lamp is low resistance at 
low current, and the resistance increases significantly with RF current, 
and protects the crystal.

YMMV,
Al
.

On 4/29/2010 11:12 AM, Ian Wilson wrote:
> I have a TBX-5. A few questions:
>
>    - I'd like to double in the final so I can work 40m (much better antenna
> here, etc). Anyone know
>      details of the final LC tuning components?
>
>    - anyone have a schematic for the EL (AC-powered receiver power supply)?
>
>    - looking for a 4-pin female power connector
>
>    - looking for a cover for the accessory box
>
>    - looking for one large Bliley xtal container
>
> 73, ian K3IMW
> ______________________________________________________________
>
>    

-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/