Manned Experimental Propagation Transmitter for Manned Experimental Propagation Tests.

A new MEPT band, for me 160 meters. I could build the same tried and tested design for all bands but the fun is in the experimenting. This Transmitter uses only 2 Transistors. NPN Crystal Oscillator DC coupled to a PNP Output Amplifier an ideal use for the old BFX29 transistors in the junk box.

Based on an old design from G3MY called the Pippin it is capable of more power than needed for a QRP Propagation Beacon. I used a DIP Switch to select collector load resistors. power levels from 5mW to 400mW are possible. The Crystal available needed pulling low, determined to use the bits from an Energy Saving Lamp I wound the inductor on the toroid former which saw previous life as the Lighting Pulse Transformer. The output capacitor and some decoupling came from the same source.

The other variation that can be made is in the construction method, I have used the Pad on Earth Plane method for VHF PA construction, it lends itself well to this project at the other end of the frequency range. I piggy backed my old test PIC Keyer to FSK via a Black LED once again used as a Varicap Diode.

Once complete I put it on test running 100mW to my 40m 1/2 wave Doublet, my e-mail being down I could not ask for reports, it would need to be spotted by a keen Top Band monitoring station, this was a week day and the week ends are more popular for 160m experiments.

When I managed to get some incoming e-mail a couple of days later I was pleased to see.

[Knightsqrss] who is on 160m? G6AVK

Later he searched the Captures for the most readable segment and deduced the call and QRA Locator. Well done and thanks Colin.