Welcome to the JA2TKO

QSL card

My hobby is Ham Radio....This is my QSL card(My home and antenna tower)

My shack

This is my shack

Toyota-city 50 anniversary commemoration station
8J2OOI/2 On air souvenir picture/ Mar 11. 2001

On air: Mar 3. 2001---Mar 10
The result: 566Station/SSB
Itemization: 3.5MHz 114 Station. 7MHz 289. 14MHz 110(DX16). 50MHz 48(DX3). 144MHz 5.

My antennas

These are my antennas


1. Introduction of JA2TKO

  1. Personal Data
    • QRA : Full name: Kunio Okada, Handle: kuny
    • Born: 1938 in Tokyo Japan.
    • Nationality: Japan.
    • QTH(Present Address): Toyota City Aichi-Prefecture Japan.
    • E-mail: ja2tko@sun-inet.or.jp
    • URL: http://www.sun-inet.or.jp/~ja2tko/

  2. Memories of my boyhood
    I caught fish in the rivers day after day and also I played sandlot baseball, until sunset. and also I enjoyed BCL and SWL with the shortwave receiver of homebrew.
    And I tried amateur radio. However, I did not succeed.
    This experiment was A3 modulation of 7MHz Band and homebrew transmitter was running 10watts to 807 in single in the final.
    The time of this experiment was in 1954 of 2 years after the ham was resumed in Japan after the end of the second world war.
    Furthermore I devoted to volleyball. And, I participated in the all-Japan high school title convention in 1955 and the 10th nations physical education convention.


  3. Activity of my amateur radio
    • From 1952 to 1957.....I enjoyed BCL and SWL with the shortwave receiver of homebrew.
    • 1969/01... JA2OSO opening, 50MHz Band On air with A3.
    • 1969/10...Call sign were changed to JA2TKO. On air to SSB of HF & 50MHzBand.
    • 1971/01..The 2nd class ham radio license acquisition.
    • 1971/10 ... The completion inspection pass of output 100W.
      and DX QSO was started.
    • 1978/11 ...WAC(Worked-All-Continents)
    • 1981/03....The winner of Warld Wide WPX-SSB Contest.
      (Single operator 14MHz Band at JA station )
    • 1987/08/15...Satellite communication experiment start of via JAS-1.
      The first communication orbit No 4557.
    • 1987.....The 435MHz. F9.FAX sending and receiving experiment
      by NTT discharge FAX reconstruction.
    • 1996...I introduce used personal computer PC-9821AP and Turbo HAMLOG Ver 3.4
      and the computerization of LOG BOOK.
    • 1997...The YAGI Antenna simulation soft introduction.
    • 1998......DXCC 100 Country achievement.
      Wkd/Cfm 3.5MHz band=1/1,7MHz=17/9,14MHz=135/83,28MHz=29/12,50MHz=14/8
    • 1999/2....Opening of the JA2TKO's homepage on the Internet Web.
    • 2001/3....On air with Toyota-city 50 anniversary commemoration station 8JQOOI/2.

  4. Equipment&Antennas
    • HF band: IC756,IC720A,FTDX400
    • VHF band: 50MHz IC-756.IC551D. 144MHz band:FT-726
    • UHF band: 435MHIC-38FT-726& MobileIC-2700D 144/435 F3
    • Antenna Tower: made in USA, Tri-Ex LM-470D(Crank up,self-supporting Tower, 21.3m Height)
    • Antennas: 3.5&7MHz...Full size IV-Vee,14/21/28MHz...AS-33(3ele tri- bander),
      50MHz... CL-DXX 7ele,.144MHz... F9FT 13ele, 435MHz... F9FT 21ele & 144/435/1200MHz 3Band GP(Diamond X6000W)

  5. Ham club
    • JARL(Japan Amateur Radio League) life member.
    • JA2YIM, ex "Toyota Motor Corporation amateur radio club" member.
    • JA2ZXW, "Toyota on air ham club" member.
    • JA2YZC, "Toyota-City Amateur Radio Club" member.


2.Antenna tower construction description
(From June,1995 to Nov,1995)

As for the antenna tower construction of JA2TKO this time is the 3rd with the ham life for about 30 years. The first time built the pole of 8m on home made ANT rotator. I raised Yagi ANT of 5ELE for 50MHz. The 2nd time builds of home made in 18 m tower that cranks up and used for 24 years.(A square tower + sliding pole. photo reference)
And I built the tower that cranks up 4 steps the self-supprtimg of 21.3 m of model LM-470D a long-awaited Tri-Ex company(USA) this time, at the opportunity of the reconstruction of the own house. I report the situation. It is for the ham that builds an antenna tower from this.


"This is the boasted tower that used it for 24 years.And the height is home made with 18 m "

It had been decided to reconstruct the home where constructs with this boasted tower and passed in 25. The reason is due to the ground sinking of a defect development housing lot. Thereupon, I fixed it to that builds the 3rd tower to this opportunity. I selected the tower of the Tri-Ex company (USA) production.The reason is cheaper than Japanese production with strong yen. The introduction model is the tower that cranks up 4 steps self-supporting with LM-470D. The purchase price was about 800,000 yen ($6000). The place of the tower construction in this time needed to build the tower before building the house. I decided the time for delivery of the tower in accordance with the schedule of builder. This tower had trouble adjustment very much for convenience' sake of shipping service, with the importation from U.S. Accordingly I should have done the order of the tower earlier.




"This is the foundation of the tower that was excavated"

I was afraid of the foundation removal of this tower. However, digging up it from periphery with the power shovel of middle size it ended safely. I did not think to dream that it excavates it such early, when this foundation is made. And, I knew the power of the power shovel again.




"Arrival of the tower"

The tower arrived with the truck that the construction work general manager of the FTI company of Hachiouji-city(The suburbs of Tokyo) drives.




"Tower arrival souvenir picture"

I shot one and souvenir picture of Mr. Abe, I, the FTI staff of the construction work general manager from the left. The tower that arrived was a tower, motor, control box, wire complete set and was the condition of operation confirmation, adjustment completion. Furthermore, I asked to send the foundation part of the tower in the advance in relation to the construction work schedule.




"Arrangement the tower foundation part vertically"

This photo takes out the level where I asked to send in the advance with the tower foundation part from the FTI company and be the photo for explanation. This is very important know-how in order that it builds the tower vertically. Three direction level checkers of the vinyl hoses of the transparency are enclosed. Binding this to the foundation parts of 3 corner towers water is able to be been. And a vertical level is monitored. It fixes it firmly beforehand so that the foundation part does not decline when concrete is pour.




"Foundation work situation (No 1)"

The foundation work of this time fixed the tower at the weak place of the foundation. For that I struck the post of 5m for the ground sinking measure of the own house right under tower foundation. Delving the round about 1.8 m I struck the ground stick. And I got tower foundation. I fixed firmly and poured it concrete. The subsidence, earthquake and also typhoon measure of the tower are completion with this construction work. I advanced this construction work in a parallel fashion with the foundation work of the house. The central round thing is the head of a post. The green cable of the top is a ground wire.




"Foundation work situation (No 2)"

The concrete construction work of the foundation part combined at the time of the foundation work of the house and did it.B Putting the model frame made of the iron plate of the just good height, width concrete was poured. It is the finish finishing remarkable the surface with a trowel in the evening.




Hanging the tower with a crane (No 1)

I did the tower construction work with my direction before building the house. I requested it to the crane construction work near my house. And giving hang the tower it had. I hang and think the balance, so as not to hurt the tower and pay attention did it. I advanced it with the responsibility of all the selves.




"Hanging the tower with a crane (No 2)"

521 kg of towers went up to the air safely. And, the connection of the foundation and tower are my job. Power entered into the hand that the time tightens the bolt. It was the moment of excitement.




"Hanging the tower with a crane (No 3)"

The connection of the tower and foundation gave tighten 15 places firmly with the bolt and nut of 3/4 inches. And, that looks at the tower from the place where parted a little and stood straight was confirmed.




"Attachment of the work stand"

It is the attachment of a work stand subsequently. The work stand is set up to LM-470D with an option. I requested it to the FTI company. I had the handrail to this work stand added as a safe measure. It is my job even to attach this work stand to the tower. This work was very difficult. However, I make efforts and attached. It is from this experience. I recommend this work stand attach firmly before lifting a tower. The handrail of this work stand was saved very much in the antenna attachment work after that. There was not work anxiety. I was saved very much.




"Trial run of the crank up tower"

After the crane truck came back, I did the trial run of the tower that cranks up promptly. The power supply is AC100V. It is SW-on of excitement. When I turn on Key the red pilot lamp of the control box is lighted. The tower there was not sound and went up smoothly. I was able to judge even the operation in nighttime as OK. I raised the tower to the top and confirmed the operation of limit SW. I rested while feeling realistically the height of 21.3 m. When look at from everywhere and see it is the good height. However, it was good slender. There was not a coercion impression. It was as I expected. And it is crank down completion in several minutes. It was the wonderful day when I should commemorate.




"My house and antenna tower"

The tower of the hobby I was completed before building the house and was laughed to everybody. However, I climb to the tower in the day when builds the house and visit and also could enjoy and also take the photo.




"Antenna rose before moving-in "

The own house construction is completion at the end of the year starting at the end of June. I fixed it to that raises an antenna in these 6 months. As for the reason a lot of antennas had been put in the garden. It became obstructive. It is because I wanted to raise it before I becoming cold, with that tidies up it. This photograph is when moving is ended. The attachment of the time antenna had already ended.




"Finish the reconstruction of the tower"

I thank for, The Tri-Ex Tower Corporation/CA USA,the FTI company/Hachioji Tokyo japan and other many persons concerned that received cooperation from the tower construction in this time. I report this antenna tower construction description at the opportunity of homepage opening. After already the tower even is could 4 years passed.And, enjoyable ham life could be spent. I report the result that used this tower actually.
(1)The biggest advantage in safety can lower the tower right away to the information of thundercloud approach. I go out as I always raised the tower. My wife is afraid of falling of a thunderbolt very much. My wife can lower this tower safely. Therefore, my wife is said to be merciful and convenient.
(2)The biggest advantage for the ham is to be also able to raise all the antennas to the height of 20 or more m safely easily. This is that the matching of all the antennas become easy. Incidentally SWR drops easily to 1 when even IV-ANT of 3.5MHz hooks to this tower and raise to the height of 20 m. The reception sensitivity and transmission performance are preeminent. Accordingly, even the report from each station is mistaken with high-powered station of linear amplifier use. I was able to feel realistically importance to raise an antenna than I raise power.
(3)The maintenance situation for 4 years of this tower was 4 years later 1 time the tension adjustment of the wire ,2 years later 1 time the tension adjustment of the V belt. Even, either adjustment work is not a height. It can easily while having fun if the work is one of a ham.
(4)What was anxious about it a little is the waterproof of the motor made in U.S. Pulling the power supply the cover made of the iron plate has tightened in the that terminal with a screw through rubber packing. A lot of water appeared out of the cover if I try to open this cover. This is because there is not the hole without water in the lowest place of the cover. I opened the small hole promptly, and prevented recurrence.
This is the report of my antenna tower use result. If it becomes your reference it is great pleasure.
I write in the days of Sep 15,1999 old person.




Return to Top Page of English ****** ******