Tom G3OLB wrote:
Confirming our contact today as follows:
[ . . . . .]
Comments: Congratulations Steve on an excellent 5 watt QRP signal and
your first LF/QRP QSO!
Tom, many thanks for QSO and for the e-QSL! I was very excited
to make the contact - so I'm sorry that my morse was a bit
shaky!
I had been constructing the new QRP TX during the past week, and
decided to give it a try during the 136 Activity Period this
morning (Sunday). The TX uses: a FET VFO (2 x 2N3819 FETs in a
source-coupled oscillator, using a 4.7 mH RF choke in the tuned
circuit); FET buffer; 2N2222 amplifier + BC212 keying transistor;
2SC2166 driver; 2 x 2SC2166 PA (the two transistors connected in
parallel, with individual one ohm emitter resistors, each
decoupled by 22 uF). As my breadboarded circuit is still without
a heatsink on the PA transistors, I have to keep the overs short!
A picture of the TX can be seen at:
http://www.alg.demon.co.uk/radio/136/pictures/qrptx_1.jpg
After my QSO with Tom (97 km), I later had more QRP QSOs with
G3YXM (105 km) and G8IK (101 km) - all using 5 watts RF to my
simple 12 m vertical (no top loading).
I believe that a simple low power transmitter for 136 kHz would
make an excellent club project, with the very real prospect of
not just making LF QSOs across town - but with other countries
too!
Regards to all,
Steve GW4ALG
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