Enter the Transverter

Since my Yaesu FT-991a radio isn't able to operate on the 1.25-meter band, I spent some time looking for solutions to getting onto said band. This led me to the Q5 Signal L22-28HP transverter, which maps 10-meter on the radio side to 1.25-meter on the antenna side.

Q5 Signal L222-28HP

Back side of the transverter, showing the various ports

But since I didn't have an appropriate antenna for 1.25-meters, this also prompted experimentation into loops of proper sizes (which also included more playing around with 70cm).

Pair of aluminum loops for UHF

NanoVNA: SWR of 2.661 @ 260.5 MHz, 60.76-j55.13Ω

Loop antenna hanging indoors with a feed attached

NanoVNA: SWR of 1.663 @ 408.5 MHz, 50.4-j25.81Ω

At this point, I'm not sure why I started playing around with alternate feed point designs, but here are photos of what I ended up with.

PVC strip with two brass strips as the starting point for a new feed

New feed made from the above parts, with a UHF connector in the center

UHF loop with the new feed

NanoVNA: SWR of 2.168 @ 427.4 MHz, 53.23-j40.6Ω

PVC pipe with the UHF loop and NanoVNA attached

NanoVNA: SWR of 2.402 @ 422 MHz, 43.81-j41.87Ω

It was at this point where I was starting to get strange readings with the Amazon Special SMA to SMA coaxial line I'd been using, so I finally built a new line using LL-240 coax and higher quality connectors.

SMA to UHF coaxial cable and SMA to SMA coaxial cable

UHF loop connected to the new SMA to UHF cable and NanoVNA

NanoVNA: SWR of 2.008 @ 425 MHz, 99.97-j971mΩ

Much better!

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