The ‘White Knight’ 144/432MHz dual-band antenna
Tim Kirby GW4VXE looks at a low-profile antenna suitable for 2m, 70cm and a range of other frequencies.
Regular readers of PW will be familiar with the ‘RadioGeeks’ brand of antennas and perhaps will remember the reviews of the innovative, inflatable antennas that they produce.
The antenna I’m looking at this time is not inflatable, but rigid, designed for base use. It’s the RadioGeeks ‘White Knight’ antenna, described on their website as an ‘All-in-one base antenna’. In reality, although it may receive over a white range of frequencies, it’s designed to transmit on the 2m and 70cm amateur bands. It’s a half wave on 2m and two times 5/8th wave on 70cm.
RadioGeeks’ publicity describes the antenna as
• New design ‘All In One’ Antenna, will Tx & Rx on 2m/70cm Ham Bands,
• Power 150 watts
• VSWR <1:3:1
• No ATU required
• 3dB gain on VHF, 5dB on UHF
• 3ft length
• Military grade solid stainless steel thick whip
• IP Rated, fully waterproof, multi band tuned coiled base unit with SO239 at base
• Supplied with wall fixing bracket
• Will superbly receive all Military & AirBand frequencies and will also cover Marine, TETRA, PMR & FM broadcast frequencies
Unpacking the antenna from the tube (slightly tricky because the plastic end pieces had been stapled into the cardboard), the first impression is of a nice piece of stainless-steel for the antenna whip, with a coil half-way down the whip. The base is slightly larger than an old 35mm film container, feels well made and appears waterproof, Fig. 2. The antenna is rated as IP67/IP68 and is also anticorrosion proof. An SO-239 connector protrudes from the underside of the base, which can be secured into the supplied wall fixing bracket. Some people might like the option to have the antenna supplied with an N-socket, perhaps.
Testing
My first test of the antenna was to detach the wall fixing bracket, pop the base into the centre of a picnic table and try it as a ‘portable’ antenna, Fig. 1. Although 2m and 70cm conditions were noticeably above normal when I tried it, it was clear that the performance of the antenna was very respectable on both 2m and 70cm, with signals 4 or 5 S-points better on both bands, compared to a rubber duck on the handheld at the same height. I was able to access the EI7MLR 70cm repeater at Mount Leinster using the ‘White Knight’ whereas I could not using the rubber duck, over a distance of around 85 miles. The GB7PD 2m repeater at Maenclochog, over a hilly path from me, was around S5 whereas it was inaudible on the rubber duck.
In the same configuration, I tried the ‘White Knight’ on the marine band, with my Standard Horizon HX370E marine handheld and it produced decidedly more traffic than when using the rubber duck supplied with the HX370E. Similarly, on the air band, using a Yaesu FT-2DE for receive, good results were achieved using the ‘White Knight’. Curious about the resonance of the antenna, I popped it on the NanoVNA to