Tennadyne Antennas

[wa2pjp]

I was wondering if any has had any dealings with Tennadyne? I have been trying to order a new T-8 log for about two months now and I get no return phone calls or e-mails. I spoke to that guy Roger once, it was the only time he called me back, to place an order with some upgrades I wanted and never heard back from him. Is this company still in business? or is this a reputable company? because I don't think I would now purchase from them or recommend them, or maybe they don't need the money?

[WA1GFZ]

Joe,
I have a very modified T12 from the old owner. Electrical very good but the old mechanical design sucked. Chuck told me he bought some custom T12s with better components. One Saturday we both worked Dean in Az. on 10 through 20 meters to compare performance of his stack. I think I doubled the weight. I know Roger uses a stronger boom than my ant. I had sleeves tig welded in the boom and added 1/4 inch fiberglass  plates around each element at the boom. My T12 has been up since '97. I thought the old owner was an AH.
I had the feeling I could have saved a lot of money if I built it myself from amuminum stock. The boom and element segments are too short because it ships in a 6 foot long box. I think you would get better VSWR performance with the T10 or T12. I ended up not using about 1/2 the element material and built my own.
The stock antenna has problems with the longest element ripping out of the boom due to heave ice load. Ask WA1IWQ who has a broken T10 at the top of his tower.
I am very happy with the electrical performance

[K1JJ]

Joe,

As you remember, you, Huzman, Todd and I stopped by Chas' house and checked them out a few months back.

For others' information:  Chuck recently bought four T-12's? and had them modified for better strength by the factory. He said to axe the guy for the extra $300 K1KW mods if interested. Chuck said the guy will know what you mean.

The mods are probably akin to what you did to yours Frank.

He also mentioned that the logs were mechanically redesigned since the new guy took over the company. Adding the additional mods put them over the top, according to Chas.

Joe, with your abilities, you would probably do better building your own. A few years back I built two big logs for 10-20M. One was on a 60' boom and weighed about 300 pounds. I used scrap aluminum from the scrap metal yards. If you catch the right yard, some will have stock from many many years hanging around. I cleaned out all the tubing they had for $1 a pound.

BTW, Chuck plans to mount four on a rotating tower. Now that oughta be some pattern.

T

[wa2pjp]

The whole point of what I was saying is that it seems Tennadye does't care about selling products, after calling and leaving many messages and e-mails with no return calls, it seems to me like they are out of business. And Tom your right, I would just be better off building my own which I think I'm going to do anyway because of the fact that most af the commercial antenns are mechnically very poor design.

[K1JJ]

Joe,

In these times of deflation and impending depression, it would not surprise me to see many high profile ham operations drop out of the picture in the next six years.  It's been a relative cakewalk to this point.

I would try one last time and send him a copy (or link) of these postings.  I'll bet that will get his attention.  At this point it's still positive and he could erase all potential questions by a reply to you.

Yes, building your own will instantly free you of dependence on antenna manufacturers. You will have the confidence to build ALL of your Yagi-type antennas afterwards. It's really easy once you do the first one, OM.

Get a copy of YagiStress to easily model antennas mechanically in a simple Windows format.  There are plenty of log design programs around too - or just copy the Tennadyne electrical plan. Axe Chuck for a copy of his antenna stuff A-Z.

T

[WA1GFZ]

Joe,
I'd be glad to share my design changes so you could build it to stay in the air.
My T12 has been up since '97 with no issues. It has been iced a number of times and seen plenty of wind. I have a number of pictures. I think the T12 electrical design is very good with a 30 foot boom. The weight was around 100 pounds. I received a 57 pound box of crap from the first owner. I would have never let my kids play under it. All you really need is the right drill bits to drill the holes in the boom. Then the tig welded sleeves make it a lot stronger.   

[KL7OF]

Do any of the homebrew antennas you gentlemen are talking about have the elements welded to the boom?  I have thought about doing it that way but I wonder if the welded joints would stand up to the stress without cracking...6061 T6 tubing? Just curious   Steve

[WA1GFZ]

Steve,
The Tennadyne uses a pair of square booms that serve as the feed line.
Each element half plugs into a hole in the side of the boom. A 10-24 SS screw and lock nut mounted vertically hold the element into the boom. 1 friggen screw. I had sleeves tig welded into the boon in addition to the screw. Also added a horizontal screw through the element a foot or so out from the weld. The longest sleeve was about 3 feet long for the longest element half of 19 feet.
My longest elements are 3 telescoped tubes near the boom to make them stronger. Tennadyne had a 3 inch overlap and a sheet metal screw at the joint. Very JS. The longest element had a 7 segement joints with plenty of sag. POS.  I scrapped all that crap and built real elements. What a waste of money. The basic design was cool but JSed to death to make it cheap.
Knowing what I know now I would have bought 6- 12 foot long sections of square tube and some 1/4 inch fiberglass plate and built my own. The joints of the stock boom were joined with a hunk of aluminum angle, not square tube. I added square tube at the joints inside the boom. My boom is .062 wall thickness. Chuck told me the new guy upgraded it to 1/8 inch making the antenna heavier and a lot stronger.  The electrical performance kicks butt.
I did not change anything electrical because it worked so well. I built the antenna stock and worked plenty of DX at a height of 5 feet off the ground. Then I started doing my mods. 

[k7yoo]

I had a T-10 up for several years with no problems. Like most hams I did some tweaking of the mechanical structure (boom to mast mount). I sold it and purchased a T-8 which is still new in the box. I have several friends that have used them with no problems. If I ever get my tower back up the T-8 will be on it. I have had no dealings with the current Tennadyne owner so I can't answer to that. I do know that when I purchased the T-8 4-5 years back it was a good transaction. I have have had pretty much all of the typical trapped antennas, including the old Telrex beams and even several quads--none of them were perfect. I am a "little gun" so the expense of big arrays and top of the line antennas is out of the question. Based on the cost of aluminum, and the performance of the antenna, and assembly time I think the "kit" is a good deal.
Skip

[K1JJ]

Do any of the homebrew antennas you gentlemen are talking about have the elements welded to the boom?  I have thought about doing it that way but I wonder if the welded joints would stand up to the stress without cracking...6061 T6 tubing? Just curious   Steve

Hi Steve,

Yes, most commercial ham beams are built like toys. Even the 60' boom 6el 20M mono bander "Big Bruiser" I bought from M2 used a small 1/4" thick aluminum mast to boom plate. It was a joke. After seeing how that first Yagi was made, I didn't even put it up - just used the aluminum to build my own from that point on.

On my 60' boom log I used a standard 4" telescoped to 3" round 3/16" boom.  I used flat fiberglass boom to element plates that u-bolted on the insulated elements.  I then used a pair of close-spaced  1"X 1" angle aluminum rails that ran the length of the boom to feed the elements.

It had side and overheard trussing.  On all elements I used double thickness sleeves where the elements mounted to the fiberglass plates to insure mechanical strength at the boom to element strees points.

No problems with winds or ice for about 8 years.  Finally tore the logs down and built up mono-band Yagis.
I did like the logs for performannce, but if I did it again, I would go with the three or four 24' boom smaller logs in a stack.

T

The homebrew 10-20M log shown below weighed 300 pounds on a 60' boom. It was turned by a prop pitch at the top of a 110' Rohn 45 tower.. I later added a 20M log at 60' - it was identical to the top one but missing 10-15M. I put it up myself, but it was way too much to handle. This is the log that snapped a tag line and slid all the way down the tramline and buried some of its elements in the ground.  I was taking it down anyway, but was a dangerous antenna to work with. The close spaced elements made it especially difficult to keep clear of guy wires and tower stuff...

[Steve - WB3HUZ]

There was a nice design for a HF log in QST few months ago.

The whole point of what I was saying is that it seems Tennadye does't care about selling products, after calling and leaving many messages and e-mails with no return calls, it seems to me like they are out of business. And Tom your right, I would just be better off building my own which I think I'm going to do anyway because of the fact that most af the commercial antenns are mechnically very poor design.

[WA1GFZ]

My T12 is set up to swing it vertical if I ever need to service the elements.
I mounted the insulator block to a 3/8 inch plate with a 1/2 inch bolt through  it and the mast. I put it up vertical to clear the guy wires then my brother and I flipped it horizontal and added the 4 mast clamps. At close to 100 pounds we could handle it ok. Tom likes to drop element diameter 2 sizes at each joint. I did one size which makes the elements heavier or sag more. I think 2 sizes that Tom did makes more sense.
My mast is 2 inch OD and 1/2 inch ID with dual thrust bearings. I used a bunch of different diameter pipes to make the section of mast going through the bearings. I did a dual over head truss spread about 5 feet apart at the top.

[WBear2GCR]

I'm curious to see what these ants are all about - they escaped my radar... any links/pix?

               _-_-bear

[Pete, WA2CWA]

I'm curious to see what these ants are all about - they escaped my radar... any links/pix?

               _-_-bear

Google is your friend



Here's one working ground wave:



Here's one doing a wind dance:



Hang some balls and garland on this one and you're all set for the holidays:

[SV2GWY Demetrius]

73s from SV land,
My name is Demetrius and my callsign is SV2GWY. I plan to make by myself a 6 element Log periodic for 10~20m. I wonder if anyone can help me giving me details for T6 :

Boom        length :
elements diammeter :
#1 element length :
#2 element length :
#3 element length :
#4 element length :
#5 element length :
#6 element length :
Spacing 1-2 :
Spacing 2-3 :
Spacing 3-4 :
Spacing 4-5 :
Spacing 5-6 :
 
          Thank you in advance,
 
                                             de SV2GWY / Demetrius

[w3jn]

Hi Demitrius - there are several forum members that have home-brewed HF log periodics - Frank WA1GFZ and Tom K1JJ.  Hopefully they'll see your post.

[Steve - WB3HUZ]

There was a nice design for a HF log in QST few months ago. It even covered 6 Meters!

[WA1GFZ]

T12 longest element is 38 feet and they get 9% shorter as you go exept for the last small element which is a bit shorter that 9%.
The boom is 30 feet but I forgot the sequence. I think the first to second is 4.5 feet. I'll check at home to see if I have the demensions. The diameter to length ratio was way off but still worked. I changed it to make it much better.
I think it was around 100% and I got it down to around 30%.
The mechanical design of the stock antenna was junk but electrical was very good. I added close to 40 pounds to mine with some welding of sleeves into the boom at each element. Also added fiberglass plates between boom at each element. I would make the booms from 1/8 inch wall square tube 1 1/2 inch by 1 1/2 inch spaced 1/2 inch apart. The old owner used .062 wall. The new owner used 1/8 inch.

[WA1GFZ]

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=16289

this does all the work for you

[wa2pjp]

I finally got in contact with Roger at Tennadyne, I told him that I purchased a T-10 and would like to get some parts and upgrades, he promised me he could sell me what I needed and never came through...... after tons of e-mails, no returned calls and complete wasted time, I have given up on Tennadyne. Just poor service and empty promises. I would not recommend them to any one at this point.

Joe  WA2PJP

[WA1GFZ]

Joe,
So you bought that T10. Does it have the .062 wall boom?
I suggest you assemble it in the back yard. (once the roof is done) and put you hot rodder hat on. When you understand the electrical design you will be able to make it better. Put it up about 10 feet and work a few contacts.
Electrical performance is very good.

[wa2pjp]

Hey Frank,

Yes got a great deal on  a T-10, new in the box for half the new price and it was the latest version with the heavier boom and choke support. I wanted to buy Extra clam shells and make up a larger center insulator for better support and add an overhead truss. I called that guy Roger, got ahold of him once, told him what I needed, said he would get right back to me and never did. Sent a number of e-mails to him along with countless phone calls, he told me when I did talk to him, that he never got any e-mails or phone calls from me.......he's got to be kinding !!!! That guy is a real flake and if I didn't get this antenna new for half the price......I would never order one from him or recommend that anyone else order from him.

Anyway, won't be doing any antenna work for a while, when I was roofing the rear shop, I trpped with a bundle of shingle on my shoulder going down slope and went off the egde of the roof, landed on my side and broke my hand. I'll be in a cast for 4 to 6 weeks.......Can't beleive it.......

[w3jn]

Ouch!  Could have been a lot worse though, Joe - although walking around with a busted wing is no fun, I'm glad it wasn't a lot worse.

[KA0HCP]

Good thing you were carrying 40lbs of shingles to break your fall!!

Get better soon, B.

[WD8BIL]

Joe, Joe, Joe.
When are we gonna learn???

But...... I can't talk now. I gotta climb this tower!