Then, there is something missing
You probably guessed what: some kind of transmitter. I have had my share of both kWatts and kVolts so now it's time to try QRP.
A few months ago while browsing the net I found several simple low power rigs. The soldering iron is hot so here we go.
Just a warning: Really Uggly Construction Technics [RUCT™] to follow ...
Dark pix, sorry
This is part of a slightly modified "Fireball40", an 80m xtal controlled tx.
A DIL xtal oscillator at 28.322 MHz and two 74LS74 dividing with eight should give some 40 mW on 3.540 MHz. In the original schematic the oscillator was keyed on/off. As this might give some chirp I prefered to have it run all the time and to key the last divider on the preset pin. At keyup, when the last divider is not running, there is no output whatsoever on 3.540.
Bandpass filter and amplifier with 2N3866 is added. Something is very wrong as the output is meassured to 20mW.
Stay tuned for the next episode.
A working QRP Tx
Late autumn 2008 The digital signal source is abandoned and a vfo plus a buffer substituted. Also an amplifier and a low pass filter added.
QRP breadboard tx (
Click for larger view.)
A pin-diode T/R-switch and some components for Rx muting included. This rats nest gives 2W rf on 80m and with a simple wire, 21m long and 4m above ground.