VHF beam and automated mast control

In early 2018 I made an Enfield Yagi to the specification of G6ODA.  It is a 6 element yagi for the 2M band with an SWR of less than 1.1:1 across the whole band – great for working SSB and CW.

Enfield Yagi

I purchased a Hilomast pneumatic mast from one of the UK online flea markets which was hurriedly mounted next to my shed – thanks to a supportive neighbour who manufactured some custom steel mounts for me.

As the mast was well away from the shack, and I was overcome by a serious case of laziness, I decided to automate the raising and lowering of the mast by adding two solenoid valves (here on Amazon), a two relay control board (here on Amazon), a NodeMCU ESP8266 board (here on Amazon), a small bowden tube quick connect fitting (here on Amazon) and a short piece of PTFE tubing.  I wrote a small web based application to run on the ESP8266 providing control of the solenoid valves (the Arduino sketch is attached to this post).  I could now easily add and release air from the mast at will!  As the ESP8266 board and valves were located inside the shed, I fed the thin PTFE tube out through a small hole in the shed 1) to release the air in a controlled manner and 2) to eject any unwanted H2O out of the shed (rather than splattering all over the wall and floor – that was my first attempt!).

Hilomast (in background)
Enfield atop mast

The Yagi was providing me with some great VHF activity in the early part of the year.  During the summer I decided to extend the scope by adding a 6m Moxon, trying to get a bit of the magic band during some of the great openings we had.  Unfortunately this was too much for my immediate neighbour who thought the Moxon was “an eye-sore” and suggested I only raise the mast in the dark – hardly useful for 6m sporadic-E!

I decided to err on the side of caution and keep the neighbours happy – they’ve been living in the house 12 years and I’ve not had any complaints before and I didn’t want to start a local feud.  The whole setup went on the flea market site and in 2 days was sold.

The final straw

It was great fun while it lasted, great experimentation and good playing around the automation of the mast control system.  I’ve switched back to the original 2M halo I had but barely have time for the local QSOs these days – HF and D-Star is my new home!

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