Last Updated on December 1, 2025 by John Berry
The VHF Station (50MHz and 144MHz) comprises antennas for two bands – 6 metres and 2 metres, on a winch-up 15 metre mast.
50MHz
The 50MHz station is simple. It’s a 6-element Yagi from Antennas-Amplifiers at about 15 metres connected to the IC-7300 via Westflex 103 semi-rigid coax. The coax loss is as good as possible considering the need to drop the mast from time to time and hence flex the cable. A flexible RG213 tail is used from antenna to masthead to allow rotation.
Since the environmental electrical noise is very low at my location, I also use a mast-head low noise pre-amp from SSB-Electronic. If the noise level was higher, this would be pointless, since I would just be amplifying the noise.
The rig is an IC-7300 with a BLA600 Amplifier giving around 500 Watts from the shack.
144MHZ
The 144MHz is similar but with an 11-element Yagi. Again I’ve used an SSB-Electronic pre-amp.
The 144MHz rig is the Icom IC-9700. I’ve used a 100W power amplifier in the shack. The amp is in circuit pending replacement with something more powerful in the future. Since I use an amplifier, I need only run 20W or so from the rig.
Sequencing
I need a sequencer a) to delay the transmit RF on TX-key until the pre-amp is powered down and put in by-pass mode and b) to delay powering the pre-amp and coming out of by-pass until the RF power from the transmitter and power amplifier has dropped away. I’ve used two SSB-Electronic sequencers to power and sequence each mast head pre-amp.
