ARRL VHF June Contest 2020

It has been a while since I have obtained a new SDR (Software Defined Radio) Unit made by Analog Devices, called "ADALM PLUTO".

This is actually a learning module, capable of operation in a frequency range (after a simple hack) from 70MHz to 6GHz. There are several software programs able to work with PLUTO, I am using the SDR Console (note that this software does both, receive and transmit).

I am usually operating from outdoor locations, sometimes as a "rover". That brings a big challenge - how to squeeze everything inside one car? I have used this year's ARRL VHF June Contest to test my idea of using the PLUTO with simple wide band amplifiers and antenna for multi-band operation.

The antenna used for this VHF contest was a logarithmic-periodic PCB antenna made by Kent WA5VJB.

This antenna gives me access to all HAM bands between 900MHz and 6GHz. During this test, I have concentrated on 1296 MHz, 2304 MHz and 3456 MHz. I have also used the PLUTO on 222 MHz, but that was a different antenna.

I have obtained a cheap RX preamp from eBay (35dB gain / 2.5dB noise). I know this is not the greatest, but is was cheap, quick and simple.

The TX exciter (used as a PA capable of up to 100mW here) with GALI84 was from eBay too.

Along with these modules, I also used RX-TX Relay (cheap version on W1GHZ board) and USB-controlled relay board to switch the antenna relay and power for RX or TX amplifiers.

During the contest, I made 14 QSOs during its first 2 hours - 8 of them using the PLUTO. Distance covered by these QSOs was around 4.6 km, the station worked was Harry WA0CNS. However, we have made a test with Zack W9SZ one week before the contest (see here) and made a contact on 2.3 GHz SSB over 24.3 km with good signal.

I believe that the PLUTO is a good way how to improve VHF and microwave activity on HAM bands. I will work on improvements and post them here after next contest.

As for the lower bands, I have used FT857D and ring antennas installed on my car. The multiband microwave antenna was inside the car on the dashboard.

Harry WA0CNS used his home made transverters and antennas on azimuth rotor installed on his car.

My dog Darcey (on last picture) supervised the activity and made sure we followed the contest rules :-)

73 Herbert
AF4JF