08-10-2016, 07:25 PM
Hi.
Made up a very simple pantry transmitter using a 1566Khz Crystal, one valve and 6 passive components. The valve works best with G2 & Anode strapped, the crystal is connected between Anode and G1(1) a 5.6meg is between this grid and F-. on the opposite G1(2) audio is applied via a 1000pf cap and 47k series resistor at line level, the grid is returned to F- via a 4.7meg, the G3 is returned to F-.
The Anode & G2 is fed via an HF choke to HT (9v)
Too long an aerial and the circuit stops oscillating but with a couple of meters of wire off the anode you get about the same in range, feed it to my frame aerial and tune it up then the range goes to 15 meters outside, audio quality is reasonable so long as you dont go over 80% modulation.
It really needs a buffer to work correctly and a proper Tank arrangement.
