2-Tube Transmitter

www.n9oh.com 


2-Tube Tuna Tin Transmitter 

Built by Steve Woodruff, N9OH

This page details my construction of the T5. The T5 is a CW transmitter designed by Steve Johnston, WD8DAS, which uses a couple of cheap vacuum tubes: a 6C4 and a 5763.

Original design/article appeared in the January 2003 issue of QST:    http://www.qsl.net/wd8das/TTTTT.html   Click here for the schematic.

The transmitter requires both 250 vdc and 6.3vac to operate and I built a power supply specifically for this transmitter. The details of this power supply can be found here.

And now some pictures. I really didn't take a lot of pictures during construction so you'll have to settle for some pictures of it mostly finished and then of it finished and hooked up to an OHR QRP Watt meter.

 


A mess of wires! No PCB here...


That giant capacitor on the right side got pushed over by my air variable capacitor during my first test and caused a capacitor and resistor to short out and burn up! The smoke test failed... and it smoked! So I replaced that big capacitor with a smaller (but lower voltage rating) capacitor. Now it can tune without shorting out other components. :)


It lights up!


The station...


A close up... labels applied

 
4 watts out? That's a little less than expected!


A little tweaking and then ahh... better. Close to 8 watts!!

 

What's next? Probably a tube regen receiver!

73, Steve N9OH

 

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