Testing the Diamond RHM-8B portable screwdriver antenna

By Steve (MW0SAW)

I have seen many amazing K4SWL SPOTA pileups on YouTube using the AX1 antenna and the extension coil. I have fancied trying a small walkie talkie style whip antenna for a while now.

I have a AX1 and KX2, but my Yaesu FT-818 was the radio with a fully charged battery. So I pulled out The Diamond RHM-8B, an antenna I purchased a while ago but never used in the field. It has a BNC fitting and you tune the antenna by sliding the coil up and down for loudest signal and best SWR. They make one very chunky walkie talkie together! Diamond products do have a fantastic air of quality about their construction.

Radio conditions weren’t great, and bands were busy being the weekend of the CQ WW CW contest. So decided to go the my nearest summit that’s amount 12mins in the car and about a 25mins hike up. This was GW/SW-034 Garth Hill. On a clear day you can see out over the Bristol Channel into England, but mist/fog were the order of the day.

I wore the FT-818 and rubber duckie around my neck with the neck strap for a couple of 2m FM contacts, before setting up on 40m SSB sitting on the ground. Without a tablet or chair with me I found it most comfortable to support the radio between my knees.

I was really pleased to get 9 QSOs in the log, some 59 reports, some difficult contacts. Moving on to CW I managed another 8 QSOs with an S2S into Germany.

All the QSOs were UK and mainland Europe, but I was more than happy with the haul for such a small antenna.

So conclusion about the Diamond QRP antenna.

Can you qualify a SOTA summit on a short 1.5m whip antenna? Absolutely, no sweat!

Does it work as well as a full size wire antenna? Of course not. Nowhere close.

However, its makes such a great rapid deploy, ultra packable option with the Yaesu. Not quite as small as a AX1 but you have the bonus of not requiring a tuner. Definitely something for a travel bag if you own a FT-817/818.

Equipment:

Best 73
Steve
MW0SAW/P

One thought on “Steve tests the Diamond RHM-8B during a SOTA activation”

Steve,
Very interesting article, I enjoyed it and always enjoy reading about QRP / portable kit. I am just about feeling confident enough to get on the air on CW, I ll listen out for you.
I live in North Devon, not too far from Exmoor. Dunkery Hill, Exmoor s highest point, looks over the Bristol Channel into Wales. If conditions aren’t great I could possibly shout to you.
Regards
Alan 2E0EUZ