[Boatanchors] 1930's era cw transmitter

[Al Klase]

Gang,

With any of the popular one-tube circuits, I'd add a #49 (2-volt, 60-mA) 
pilot lamp in series with the crystal socket.  The lamp is quite low 
resistance when cold, but the resistance increases as the crystal draws 
current, and keeps things under control.  I did this in a TBX-6 years 
ago after pondering the heat sinks on the original TBX crystal holders.  
I had no problems with FT-243's.

The early TBX is an interesting circuit, probably more elaborate than 
most ham applications.  Crystal control or tunable, 9 watts CW, 3 watts 
supressor-modulated AM from a single 837.  Someday I'll build a clone.

Al

On 6/1/2013 4:27 PM, David Stinson wrote:
> ......I built a single-tube, crystal-controlled power oscillator using 
> an 814.
> Only ran 550 V on the plate for 35 watts out and it is tough on crystals.
> FT-243 won't work- too much current......
>
> Please help support this email list: http://www.qsl.net/donate.html

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