First Contact with an Antenna Made in a Hurry

I'm a radio amateur newbie and I've struggled to get on the air with my shortwave BITX40 radio and my 20m long wire antenna on my balcony. For a long time I've also owned a Baofeng UV-5R+ handheld radio for the VHF/UHF bands, but never actually used it. It's very cheap (about $25 when I bought it), doesn't have many bells and whistles, but still as a lot of bang for the buck.

Compared to shortwave, VHF/UHF is much easier to get into. No need for a huge wire antenna. The tradeoff is that you only are limited to line of sight range, compared to the bounce-off-the-ionosphere action that allows shortwave to reach between continents. On the other hand you have VHF/UHF repeaters on hilltops that have powerful radios and good antennas (and this very good range). These allow people to talk to each other using the repeater as a hub.

One evening I programmed the freqencies for the repeaters in my area into my handheld and listened in on a conversation. I thought I recognized one of the guys from an antenna day in Motala the year before. Maybe it was him... Another night I felt it was time to call CQ and see if anyone would answer. Lo and behold, the same guy answered my call! Well, he heard that someone was trying to call, but he said he couldn't read the call sign.

I had heard that the stock antennas for handhelds like mine weren't very good. Mine was about 10cm long. This was the 2m band, so a quarter wave antenna ought to be about 50cm. Maybe I could build a 1m long half wave dipole antenna really quick? That would be 10x the length of the stock antenna, so surely that ought to be much better. I'll just take two wires and connect them to one of the BNC to terminal block adapters I have...

Figure 1. Picture of the improvised antenna

Said and done. I put the terminal block adapter on a piece of wood, added a bamboo stick from the garden shed and taped the wires to it. I also put three small ferrite beads at the terminal block as a common mode choke. I have no idea if those small beads made much difference in the end. Didn't hurt though.

I trimmed the antenna to make it resonant at 145 MHz by cutting and bending the ends of the diple legs. I used my NanoVNA (one of my favorite tools!) to measure the antenna impedance and SWR. It was very satisfying and I was happy to see that I got good SWR on the whole 2m band.

I connected the antenna to the radio and tried calling CQ again. The same guy replied this time too! He could read my call sign this time and we ended up having a long pleasant chat. And he turned out to be the one I was I thought I had talked to before on that antenna day. At the time he was a pretty new radio amateur and had built a cool moxon antenna. I consider this to be my first successful (non-preplanned) QSO, and I'm very happy with how it went!


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