A few months ago when I went to Ross for an amateur radio weekend, and discovered the SGC-237 antenna tuner. This unit is designed to tune antennas of all kinds and has a very good reputation. I decided to take a chance given that if it works the way its supposed to, it would make life very easy when it came to carrying and erecting antennas for frequencies that usually require very long lengths of wire.
The specifications call for the usint (which is waterproof) to be mounted under a cover to keep the sun off it. I decided to fit the unit inside a metal box on the back of the bus, but having done this, had to get heavy coaxial cable and a 12 volt line from the box to the front of the bus to the small bench that I made to hold the radio.
The pic below shows the box mounted on the rear of the bus. You can see the cables coming out the bottom of the box. The white insulator on the top was made for me by David Wilson of ttssystems. David also sold me the SGC tuner and when I couldn't find the high voltage insulator I needed to get the antenna wire out of the box, made it for me. Thanks Dave.
The metal loop to the right of the box is where the 10 metre telescopic fibreglass squid pole slips into. The squid pole support 65 feet of antenna wire which the tuner makes resonant.
The pic below is a close-up of the antenna tuner in the box.
This unit has 12 volts to it from the front of the bus. The reason for this is that it needs to be switched off when not in use to save the battery. The running of the coax cable and the 12 volt cable was an 'under the bus' job, so I called upon one of the best 'under the bus' people I know, Lucy. she spent a couple of hours trying to avoid getting stuck again like she did before. Managed OK this time, but there was a fair bit of complaining.
The pic below shows the location of the switch. I ran the 12 volts from the panel that I made earlier un the cupboard that he radio sits on.
Earlier today, we put the squid pole up and gave the tuner a test run, On 40 metres a contact S9 to Queensland, then to the US Canada border on 20 metres, also S9. The antenna and the tuner work really well.
Only 5 days to go before I leave. Still lots of little jobs to do including the installation of the voltage sensetive relay to charge the house battery off the alternator. That's tomorrow, we'll see how I go.
