The other day, when I visited a local OM house, I mentioned that I was planning a solo trip to Michinoku Mobile during the summer vacation, saying, “If you go anyway, you should get out of 18MHz or HB. I’ve been looking for an HB mobile ANT that can QRV while driving.
At first, I thought it would be nice to have an HM6 that can produce a lot with one car, but I gave up knowing that I couldn’t do QSY without getting out of the car one by one. I thought I would be a mono bander if I got off the car anyway. When I was thinking, “I think it’s definitely MD for performance, but I can’t afford to have all the coils …”, COMET’s HA750BL was recommended. It was painful that 10MHz, which is indispensable for mobile CW, is out of the standard, but the total length is 2.4m, which is about twice as long as it is an improved version of HA750B. In the worst case, I compromised because I thought it would be possible to put it on my Kranishi MTU.
<Characteristics of each band SWR>
On the way home, park the car in the middle of the rice field in the neighborhood, assemble the elements, connect to the 857 without adjustment, and check the SWR of each band. 7, 14 to 50MHz on the spec is about 1.2 with RIG’s SWR meter. It was like sending to a dummy load. (Maybe in a sense.) I tried 10MHz, which I was worried about, with no use, and it was about 1.7. “Maybe you can use 10MHz? I called the Miyakojima City Mobile Bureau in Okinawa Prefecture, and there was a one-time response. The opponent’s S wasn’t swinging, but if it wasn’t piled with the same PWR, it would be possible to get it. (10MHz is out of the manufacturer’s standard, so please take your own risk.)
<Communication result (7MHzCW)>
HB seemed to have poor CONDX and could not QSO with anyone, but I tried to issue CQ with 7MHz CW. It was about 30 minutes in the evening, but I was able to communicate with 10 stations. I wasn’t called anymore, so when I issued a CQ while driving on my way home, I was called by the Mito station. (However, when I got home, the hatchback base was moving without being able to withstand the wind. Hi)
After returning, I plotted the QTH of the communication station on a map and imagined the path of ionospheric reflection.
-Performance is good for mobile ANT. (It’s only
7MHz . Some people have a maximum of + 20dB.)・ QSY is easy anyway.
・ SWR 1.5 or less (excluding 10MHz) from 7MHz to 50MHz ・ No
need to worry about wraparound. (It seems that grounding is unnecessary, but the base is grounded.)
・ Is 50MHz a bonus? (It was about S3-5 different
from SG9700 .)・ Not suitable for hatchback base (base height 1.5mH + L = 2.4m = 3.9m, so it is too long and dangerous while driving. )
* Please note that this is a subjective impression after a short operation of about 30 minutes.
In the end, the original idea of HB ANT, which allows QRV while driving, was missed, but I am very happy to be able to come out easily. In the future, I would like to try it in each band and accumulate results.