160/80/40/30 Meter Paraset Qrp Battery Powered Ham Radio Receiver/ Transmitter

  

This item has exposed high voltage underneath the chassis. Handled carelessly, this circuit can kill you! Once powered on, the no load dc operating voltage produced by the 12 volt inverter power circuit is over 250 volts DC!

The high voltage circuit works only in send mode. This is a Homebrew QRP 160/80/40 and 30 meter ham radio transmitter/regen receiver, similar to the WWII Paraset, in that it employs two 6SK7's for the receiver and a single 12V6 tube for the CW transmitter. The radio you receive will look similar to the photos, except that for this model I use plug-in coils, for extended coverage of the 160 and 30 meter bands.

So this version will have a plug-in coil on the chassis top. This radio was constructed on a 3D printed chassis. The 3D prints are never perfect, but as you can see, it's quite presentable, in overall appearance. You'll need batteries or well filtered external power supply sources for this item.

A 12 volt car, motor cycle, golf cart or wheelchair battery will work fine for the filaments and power inverter circuit. Four 9 volt rechargeable transistor radio batteries are required for the receiver. No batteries or other power sources are provided with this listing. Power output from the transmitter is about 5 to 7 watts, depending on crystal activity. Four QRP crystals (one for each band) are included, along with a Piezo headset, like the red ones that you see pictured on some of my listings.

The headphone output impedance is high, in the ballpark of 2 to 4k ohms. QRP crystals can have a hint of chirp when pressed close to their operating limit, but typically I've been able to tune the tank circuit for a decent sounding cw tone.

The full power FT-243 type crystals will sound better if you happen to have some of those on hand. For 160 meter operation, all I have are the 1843 khz QRP crystals, so that's what you'll receive for that band. I have many different frequencies for the 80, 40 and 30 meter bands. Operating controls are PA and antenna tuning for the transmitter, plus main tuning, fine tuning and regen action. On/off switch on the regen pot, plus a send/receive switch on the upper left front panel.

A hand-sketched schematic will be included with this item. I guarantee this radio will work if hooked up properly to a respectable antenna system.