Connect up your Paraset to an appropriate supply, connect an antenna, switch on and try the receiver first. With any luck it will work first time.

To test the transmitter connect a dummy load...a 50 ohm or so resistor will do, go to transmit and key the rig. You should be able to make both light bulbs glow by peaking the tank circuit first and then the aerial circuit. Of course it won't work if you forgot to plug in a xtal ! If you don't have a dummy load then just short out the antenna terminal to the earth terminal and key down anyway. The antenna light bulb will soon show you if the Paraset is transmitting. If you do have another receiver then listen to the transmitted signal. It should transmit a clean, almost if not, completely chirp free signal. Remember some xtals are reluctant to key well.

If either the Rx or the Tx doesn't work. Check the wiring against the drawings and of course the components to see if you have missed anything. We might have made a mistake and forgotten something so if you are still having trouble now check through the entire Paraset against the main schematic. It won't take long to find out where you or we have gone wrong.

If you carry out a power test then please send in your results....read about the data-base on this web site before sending in details.

You now need to download the appropriate tuning chart from this web site and calibrate your receiver. If you want to band spread your receiver then look on this web site elsewhere for help on this. Parasets work quite happily on 40, 80 and 160m. In due course we will provide details of coils should you be interested.

The Paraset in it's original format switches both HT and antennas when going from transmit to receive. The antenna will of course need to be switched over from receiver to transmitter and since the switch has the capability to do this properly this is left as originally designed. However switching the HT over does give rise to a couple of problems. The first one is a crash in the headphones....tolerable....but this can be removed easily. However when switching from transmit to receive the HT to the detector valve takes a little while to become steady (capacitors take time to charge) causing the Rx to drift a little. This is enough to loose the contact in a busy band momentarily. Not good. The answer is simple. Use the other half of the transmit/receive switch to short out the phones on transmit. No crash in the phones no....only silence. Feed the detector with HT all the time from the screen of the 6V6. This IS good because now the detector is fed with well decoupled and smooth HT. By the time you have stopped sending and changed over to receive the Rx is already on station. What is more if there was any hum on your power supply HT line it does not get to the detector as this extra decoupling/smoothing of the HT is very effective. You may like to increase the 6v6 screen decoupling to 0.1uF to be really effective. You will notice that this also means several resistors and capacitors from the original design are now redundant.

Whilst on the subject of redundancy you will also notice that the second 6SK7 valve is triode connected and only has a resistor in the anode circuit. Why? Simple, it means several components from the original design are not needed and the performance IS just as good as the original. One also does not need an RF choke in the detector anode or the rf decoupling capacitor here, this small capacitor in particular can be a source of scratching noises in the phones....if you don't believe me see for yourself. These two parts are also redundant.

You will now find the Paraset RX to be very quiet when no signals are present. A good improvement.