Don, G4LOO began the evening with a quick run down of the RTTY contest of the week end. The score looks good and we await the final results.

The main programme started with Don’s explanation of his Weekend Project. The original details were published in PW June 2016. The item was an entry in the 2015 Hackaday one square inch competition.  Much later, Don acquired a commercially made board and started collecting the parts. The main delay in the building was the unavailability of a 74VHC4052 IC.  Upon completion the unit was plugged into an NTL dongle to up convert  HF frequencies to VHF

The Kit Construction project explained next was Don’s Iceni 432MHz Transverter designed by Sam Jewell G4DDK.  Don added a 30W Power Amplifier and control circuitry to the complete the project.

The Major Project was a 70MHz 300w Linear Amplifier which Don started with a part assembled kit from Enigma Components Ltd. Combined with a 48v and 12v power supply with coax changeover relays and LCD display controlled by an Arduino control unit, the finished project can handle an SWR of more than 65:1. It has been tested into open and short circuit loads at the output without damage. With efficiency of about 70% at 350W with 48v the power gain is more than 22dB equal to 2W input for 300W out. The harmonic output is less than 70dBc at 140-150MHz.

It’s no wonder Don had been chosen as winner in all three categories in this year’s construction Contest!