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THE AM BULLETIN BOARD => QSO => Topic started by: K1JJ on December 28, 2014, 04:38:40 PM



Title: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: K1JJ on December 28, 2014, 04:38:40 PM
https://www.youtube.com/watch?v=T_g2tnCRO9k


These Russian "amateurs" near Moscow have really raised the bar.

Check out this 75' boom full size 3el 75M Yagi. Notice that the telescoping tower goes up by adding sections at the bottom. Massive rotator at the top.

Weight: 1900 lbs at 135' high. Flat elements with no droop. Very FB mechanical engineering. Good use of military surplus.

I've heard these guys on before. They are among the loudest stations coming out of Europe on 75M.

T


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Steve - K4HX on December 28, 2014, 07:04:29 PM
Overhead guying.

It's amazing the number of Russian stations that are running big antennas like this on 80 meters. Such a thing was almost unheard of not many years ago. Gotta love the BAs these guys have.


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: K1JJ on December 28, 2014, 07:47:10 PM
Yep, they certainly used trussing to their advantage. That antenna can take sideways, down and underneath gusts due to the 3-d trussing.

Here's another monster creation....  40 elements on 15M.  Eight 5el Yagis on an eight-H-frame.  I've never seen anything quite this big on 15M.   The tower is 230' tall and rotates.  

Horiz beamwidth is <30 degrees.  The vertical takeoff angle is probably down under 7 degrees I wud guess.

Near the end of the video he tests it on the air and sees about 10dB over his old triple stack of tri-banders.

My only concern would be servicing the antennas. It looks near impossible to access each antenna if need be by climbing - only using a crane bucket.


Imagine using this on 15M:

https://www.youtube.com/watch?v=Z9fDlbIFhMs


T


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Steve - K4HX on December 28, 2014, 08:01:33 PM
Geez! That puts most VHF/UHF arrays to shame. That's about as close to a laser beam as you'll get on HF.

Crazy Estonians.  ;D


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: W2NBC on December 28, 2014, 08:04:45 PM
Yes.. 3 FULL sized elements on 80/75 ..

Memory lane, and his last name was "Tamchin" ..



Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Steve - K4HX on December 28, 2014, 08:16:29 PM
IIRC that was a linear-loaded beam, not full sized.


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: K1JJ on December 28, 2014, 08:24:05 PM
Wow, that was an old tape, probably in the early 80's before we got privileges below 3800.  As Arnold said, "It's good to be king".

Arnold ran a "4el" KLM linear loaded beam.  It was really a 3el but had a dual driven el for bandwidth.  It came down in the mid 80's in a storm when the boom broke.

Interesting thang is Chuck put up his own 3el KLM two weeks before Arnold's crashed.

Arnold then put up a delta loop at 230' ?  and never had the same signal into Eu afterwards. Chuck and I had our way with him from then on.... :-)

T


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: KL7OF on December 28, 2014, 08:38:32 PM
Nice dog...


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: W2NBC on December 28, 2014, 08:58:26 PM
Thanks Steve, T, for the clarification on Arnold's loaded KLM..

I DO remember him touting his "FULL" sized 75 meter beam on the air..

The thing I remember most about his DX calling was that he seemed to hog almost all the activity..

Power CAN corrupt..  ;)


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: flintstone mop on December 28, 2014, 09:23:37 PM
TOM
These guys are trying to out do YOU and your BA signal.
I wonder if the OH8X 80 and 160M antenna will ever be rebuilt.
I hope they had insurance
Fred


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Steve - K4HX on December 28, 2014, 09:42:26 PM
Our pal Jaakko - OH1TX, has a 3 element up on 80 meters. That's why he's so loud when we work him cross band (80/75 meters) on AM.

http://qrz.com/db/oh1tx


http://amfone.net/Amforum/index.php?topic=22519.msg163513#msg163513


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Chuck...K1KW on December 28, 2014, 10:15:32 PM
Never thought I'd see so many folks put up rotary yagis for 75/80M.  Full sized ones no less!

I put my 3E KLM 75M yagi up 2 weeks before hurricane Gloria hit in September 1985.  That was the storm that took down Arnolds beam.  He and I had about 2 weeks of overlapping time to compare signals on 75M.  We were about the same into the Carribean but I had him a bit into Europe.  He was quite the gentleman and congratulated me on the signal.  We only did that a few times before the hurricane hit.  My antenna survived it since the winds peaked  about 100 MPH here and on LI they were much worse.

I took that antenna down 10 years later after getting tired of climbing the tower and fixing something almost every year.  I managed to wipe out a rotator about every other year.  I rebuilt the beam but never put it back up.  Sold it to Carl, KM1H who may still have it.

Chuck


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: K1JJ on December 28, 2014, 10:32:36 PM
OK on the two week overlap and hurricane Gloria. (my poor memory) Good we don't get those storms too often.

Yeah, those were fun times back in the 80's and 90's. It was so busy that the pile-ups sometimes lasted for minutes at a time.  Now I tune down and hear spotty activity - sometimes nothing.  Still, I want to get on there soon and hold court again. The antennas are still up and working.

The last I spoke with him two years ago, Carl still had your old KLM.

Steve: Yep, Jaakko is a crazy man too. Quite a nice station. Those old recordings are classics. How often does anyone work Europe on 75M AM?


T


Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Steve - K4HX on December 28, 2014, 11:08:49 PM
Not very. I was licensed close to 30 years before I did. Lots of fun though. Kinda like working those 10 watt UK stations on slop bucket.  ;D

Those recordings were from January of 2010. Here are couple from Feb of that year. Again, Jaakko is working USA split on AM.




How often does anyone work Europe on 75M AM?



Title: Re: Amazing homebrew 3el 75M rotary Yagi with telescoping tower
Post by: Pete, WA2CWA on December 29, 2014, 01:17:08 AM
OHow often does anyone work Europe on 75M AM?

T

Over the last several years, a number of us during the winter months have worked into Europe around 3705/3710.
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