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Author Topic: New T2FD Antenna Construction and Performance  (Read 33055 times)

Offline ChrisSmolinski

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Re: New T2FD Antenna Construction and Performance
« Reply #60 on: June 20, 2020, 1523 UTC »
I played around with antennas on the Kiwis and ended up with the 120 ft T2FD on http://sdr.hfunderpants.com:8073/ and the 500 ft beverage on http://sdr.hfunderpants.com:8074/

The 120 ft really works well overall, from MW up through HF and is not even that bad on 11 meters.

Yes, the spacing for the T2FD antennas is scaled based on the length.

I found (and some websites with T2FD info/modeling confirm this) that the ideal orientation is really vertical vs tilted, you tilt only because your trees are not tall enough for the antenna length  ;D
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline syfr

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Re: New T2FD Antenna Construction and Performance
« Reply #61 on: June 20, 2020, 1734 UTC »
Thanks Chris. How high up is the 120' T2FD  (tilted?) I'm really impressed at its s/n even with stormy wx here in SE
Kiwsdr x 2. TenTec Paragon/NRD535

Offline ChrisSmolinski

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Re: New T2FD Antenna Construction and Performance
« Reply #62 on: June 20, 2020, 1906 UTC »
Thanks Chris. How high up is the 120' T2FD  (tilted?) I'm really impressed at its s/n even with stormy wx here in SE

It's installed going down a hill, roughly to the east. The high end is maybe 85 ft up and low low end is perhaps 5 ft high, the bottom of the hill is perhaps 20 ft lower than the top. So at roughly a 45 degree angle. Obviously my trees were not tall enough  :)  But I wanted something significantly longer than the 58 ft to make it worth installing. I will say that 120 ft is probably the upper end of what is feasible before it becomes completely unwieldy (I think I mentioned this before). Also you really need a support rope down the center to take all the stress off the wires.

But yes, it's a great performer, and I am glad I built it. It's significantly better than the 58 ft T2FD. Much more than just twice as good.  Someone out west with a 200 ft Redwood needs to put up a real T2FD  ;D
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline syfr

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Re: New T2FD Antenna Construction and Performance
« Reply #63 on: October 13, 2020, 2223 UTC »
I may have to settle for the smaller T2 that you describe, although I think I could fit a 90' version in between the trees. 

I was surprised that my RTLSDR doing 10M QRSS decodes managed to live though a very stormy summer season here with no damage (I choked the DC feed and put gas discharge devices on power and RF input).

Too bad that they're so poor at direct sampling .  I'm hesitant to potentially sacrifice a kiwi but I might but a RSP1 out there and let it go.

I"m using a 30M ammo can to house the radios and the PI that is beaming the data in to the house via a RF transparent window I cut and covered in the mil can. So far, so good including a 2 month straight run with no downtime.  The can is bolted to the ground rod with the radio and computer inside.

I'm just using a 10M dipole which works well, but I'm thinking of the T2FD for multiband SWL only .
« Last Edit: October 13, 2020, 2239 UTC by syfr »
Kiwsdr x 2. TenTec Paragon/NRD535

Offline syfr

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Re: New T2FD Antenna Construction and Performance
« Reply #64 on: October 13, 2020, 2236 UTC »
Cool. Definitely the future of wire antenna deployment!

Str.

I do the sling shot, fishing reel and monofilament with a small fishing sinker. I've gotten pretty good at it though there's a fair share of marooned sinkers in various trees. I too use it to pull a heavier "haul line" back over.

Eucalyptus are good in the sense that they're mostly vertical as opposed to more low, globe shaped trees. Kinda surprised to find that they're found out your way
Kiwsdr x 2. TenTec Paragon/NRD535

Offline syfr

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Re: New T2FD Antenna Construction and Performance
« Reply #65 on: October 26, 2020, 1134 UTC »
Received some bamboo "spreaders" Friday. Will get to work on one of these before long.

I found the original CQ article (1956?) about these in my old magazine stash.
Kiwsdr x 2. TenTec Paragon/NRD535

 


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