Luzon Island IOTA: OC-042
DU1IST's Home Call is JF1IST.
Log Search: ClubLog
Nao Mashita, 8-2-4-2A Akasaka, Minato-ku, Tokyo 107-0052, JAPAN
107-0052 東京都港区赤坂8-2-4-2A 間下 尚彦
My Shack (Operate Room)
Our family: Raiden and Ganta (one year old)
KOHJINSHA VERSA Beam: Model KA1-206X (6m 9ele, 10m-20m 6ele)
This is quite new antenna VERSA KA1 which was developped by Kohjinsha Co.,Ltd.
VERSA can cover 8 ham bands (40m, 30m, 20m, 17m, 15m, 12m, 10m & 6m) by one antenna.
All frequencies are adjusted by motor drive copper elements with digital control in order to get the best performance.
Excepting 40m band, the antenna works as a full size YAGI beam. 40m band is performed with center loading coil equipped into AEU (Adjustable Element Unit). It enables to shorten approximately 30% length of element. This is new technology of adjustable antenna in the world.
This antenna is great product which took 2 years development period to enable the best performance of adjustable antenna system by JH1ECG and their group.
5 element full-size yagi for 30 meters
EF-405XXLJ 5 element full-size yagi for 40 meters Boom length:23.5m
The antenna is designed to achieve superb front-to-back ratio.
Its driven element is designed to 7.200MHz and the box at its feeding point contains a couple of variable inductor coils which function to add element lengths. The box also contains another variable inductor coil which is used to adjust impedance. Utilizing CPU linkage, it can maintain, by step motors, SWR of 1:1.1 at 7.000 MHz through 7.200 MHz synchronizing with transceiver's frequencies.
The hot dip galvanized triangular cross section truss boom, made of lightweight steel pipes, is 23.5 meter long and weighs 98kgs.
1. Tuning circuit box
With the diven element being tuned at 7.200MHz, a couple of variable
inductor coils ( i.e right and left ones,) are provided to add extra length
for the element to cover up to 7.000MHz. 3 turns of the variable inductor
coils, which are generally available on the market, are utilized for this
purpose while the remaing turns of coils are shorted and unused. The other
variable inductor coil, positioned horizontal, is for impedance tuning.
Approximately 50 % of the coil is utilized. Behind this variable inductor
coil is located a 50 ohm 1:1 feeding balun.
2. Control box
The CPU enables the antenna to be tuned instantly to a transceiver's
transmitting frequency with a linkage to its VFO through the CI-V control.
Whenever the control box is switched on, the calibration will take place to
achieve stable operation of the antenna with preset data at every 25KHz
between 7.000MHz and 7.200MHz .
Boom lock device:
In a country where there are a lot of typhoons, it is important to prepare to protect antenna systems.
The auxiliary crank-up tower, located 7 meters from the principal crank-up tower, is equipped with a V-shaped device to lock the truss boom, in order to be prepared to avoid strong wind damages to the antenna or a rotator.
My house (DU1IST)
Security Guard dog for DU1IST. You can trust the brave. (15-year-old boss dog center)
Beverage ANT for EU
Beverage EU 400m, USA JA 350m
1873889 Last modified: 2015-04-14 21:13:41, 6599 bytes
You must be logged in to file a report on this page
Currently updating logbook display.