So I decided to sell of some gear and buy the Icom IC-705 and it’s matching tuner the AH-705. I initially hooked it up to my home QTH antenna, a 43 foot vertical with my existing Icom AH-4 tuner. It worked great of course, but being a home station isn’t really the intent of the radio now is it!
Not so Random Wire
While the instructions with the the AH-705 are vague, like the AH-4 I think it’s really intended to be used with random wire antennas. There is a ton of information and recommended lengths out there so I chose a couple to try and settled on 41 and 84 feet for the radiator with 17 feet for the counterpoise. There are longer and shorter lengths, but these two were fairly common in the POTA/SOTA community posts I found.
The Field Test
I don’t know if you could call it a field test, but I wanted to at least get outside of my house with the new radio to see how well it would work. I took the 41 foot wire and the 17 foot counterpoise and setup on my back patio by the pool. We have a Japanese Maple in the back yard right off the patio so I coiled the wire and threw it over by hand. The tree couldn’t be more than 20 feet tall and I ran the other side through the umbrella on the patio table. The counterpoise was just ran along the ground under the radiator.
The Results
The 41 foot wire tuned quickly on every band 80m-6m. It tried on 160, but just couldn’t get there. My AH-4 with the 43 foot vertical can’t do 160 either though so I wasn’t surprised. The sun was setting and I was already on 20m so I gave a quick CQ and checked the RBN. 4 hits with 6-13db. Not bad for a wire that I had just cut and lazily drooped over the shortest tree in the neighborhood! I listened for a bit and was very happy with the noise level and signals coming in. Switching over to 40m the band was packed. The antenna tuned up quickly, and I forgot to try a CQ for the RBN because I heard K2G with the 13 Colonies special event station. They were calling CQ so I replied and they came right back to me the first time! We exchanged 599’s and they went on to work a few million more stations.
This blew me away for a few reasons. The first being that this was my first totally head copy QSO ever and I did it at 20wpm. I almost forgot to write it down even! It was almost too dark to see my notebook at this point.
This was also pretty amazing to me because I was only using 5w on the 705’s internal battery. The antenna was stupid easy to deploy!
QRP… who knew? Uhhhh like everyone 😉 I’m hooked!
72 – KK9U
One reply on “IC-705 and AH-705”
Thank you for the direction! I was looking for a setup I could take flying without causing a bunch of issues (I have a mag loop and BuddiStick). I ended up with a 21’ wire and a 42’ wire. Initial testing with a counterpoise, I was able to tune 80-20m with the 21’ wire. Now to go find a tree and test the 42’. Thanks again!