AR15.Com Archives
 Help with HF multiband yagi suggesions
SandHillsHillbilly  [Team Member]
2/19/2012 5:20:05 PM
The New QTH has room enough for me to put up a 50 to 70 free standing tower.

Many years ago I use to a HyGain TH6DX and have used a Cushcraft AB-34

Loved the TH6 was excellent antenna but tornado decided it liked it better.

I am looking for a multiband yagi for the new QTH Really size does not matter. Tower can handle anything I can fit on top. No wire type yagis. I will be stacking a 6m and 2m yagis on top of this.

I am gun shy of the new Hygain TH7 and TH11 since MFJ bought them out. Cushcraft doesn't offer what I consider a large yagi also in same boat with MFJ.

Gave thought to the StepIR.They are nice but to me too many parts to fail and even being multiband is a compromise on element spacing. Also cost begins to become a fact. Hard to justify a $4000 a compromise antenna with moving parts that could fail at any time.

Mosley makes what appears to be something to compete with the HyGain TH7 and TH11 but I don't know of anyone using one.

Looking for something that I can install and forget about for years. Getting too old to keep wrestling antennas on and off a tower.

Looked thru Eham reviews and little to no help as popularity is based more on price than actual performance.
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ColonelPanic  [Member]
2/19/2012 6:59:05 PM
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.

Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...
K9-Bob  [Member]
2/19/2012 7:07:01 PM
Mosley beams are built a tank....have you checked them out?
KB7DX  [Team Member]
2/19/2012 7:09:10 PM
Mosley hands down. We have taken two tribanders down in the last year that had been up since the 70's. Both still had a good SWR and performed well. One of them needs some new insulators (available from Mosley) before it goes back into service but still works. I'm in the same boat as I don't climb towers and I want something to last.
Mosley's are expensive and the wait time can be long for them to build it for you, but worth it.
What kind of freestanding tower are you going to put up?
KB7DX  [Team Member]
2/19/2012 7:12:28 PM
Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.
Too heavy for the elements to support.
Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...

Huh? A Yagi will SMOKE any wire antenna when it comes to gain, not to mention directionality and rejection figures.
ColonelPanic  [Member]
2/19/2012 7:42:18 PM
Originally Posted By KB7DX:
Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.
Too heavy for the elements to support.
Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...

Huh? A Yagi will SMOKE any wire antenna when it comes to gain, not to mention directionality and rejection figures.


Well, a single, long wire dipole is more efficient than a yagi, so arguments concerning gain/directionality needn't be considered, let's just talk gain...

Is 4dB that big of a deal in the Ham world? As I mentioned above, I am not a Ham and 4dB in HF for me is a decent amount, but all things considered, isn't the end of the world. Is it that big of a deal in your world? Or are you talking some nice sized yagis with over 9dBi of gain (I'm assuming around 5dBi of gain for some dipoles)? In my world (MW/MMW), 4dB of excess gain between two antennas isn't 'smoking'.

And why would the elements need to support the PVC??? I was speaking of basically building a box for rigidity. If you can't visualize, I can MSPAINT something fierce

And what type of rejection are you speaking of? OOB? Polarity?

Edit: Had a dBi instead of dB...
SandHillsHillbilly  [Team Member]
2/19/2012 7:44:43 PM

Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.

Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...
Finding a TH6 these days would be like looking for a Model T Ford. Considering the age all the plastic trap covers would need replacing without even looking at them. The TH6 design is at least 40 years old. The new models TH7 and TH11 often better gain and band coverage. Just not keen on trusting MFJ QC on a product of this type.

I already have a Carolina Windom 80 that I may use possibly using one tower leg for support. If I was going to use T2FD design I would go ahead and just build a Sterba Curtain. I need something steerable and with some significant gain.

The new QTH sits in the middle of 300 acres of pasture land. It is split with a public dirt road. I still have the plans and design notes my dad made on a steerable 80 meter Rhombic he built back in the late 50s. Don't think the local farmer would enjoy telephone poles planted in his pasture.
SandHillsHillbilly  [Team Member]
2/19/2012 7:47:00 PM

Originally Posted By K9-Bob:
Mosley beams are built a tank....have you checked them out?

Yes been looking at them. They do look good. I did have one of their verticals that was very well built and worked comparable to any other mutliband vertical back in the late 70s.
ColonelPanic  [Member]
2/19/2012 7:50:08 PM
Originally Posted By SandHillsHillbilly:

Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.

Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...
Finding a TH6 these days would be like looking for a Model T Ford. Considering the age all the plastic trap covers would need replacing without even looking at them. The TH6 design is at least 40 years old. The new models TH7 and TH11 often better gain and band coverage. Just not keen on trusting MFJ QC on a product of this type.

I already have a Carolina Windom 80 that I may use possibly using one tower leg for support. If I was going to use T2FD design I would go ahead and just build a Sterba Curtain. I need something steerable and with some significant gain.

The new QTH sits in the middle of 300 acres of pasture land. It is split with a public dirt road. I still have the plans and design notes my dad made on a steerable 80 meter Rhombic he built back in the late 50s. Don't think the local farmer would enjoy telephone poles planted in his pasture.


Gotcha. And I guess having a complete metal-working shop at your beck and call along with several antenna design engineers spoils you to "eh, if you can't find it, just make it"

And I wasn't aware that many private Americans had 80m rhombics, so yes, you are correct, you are talking about ACTUAL gain here... My misunderstanding.
SandHillsHillbilly  [Team Member]
2/19/2012 8:22:08 PM

Originally Posted By KB7DX:
Mosley hands down. We have taken two tribanders down in the last year that had been up since the 70's. Both still had a good SWR and performed well. One of them needs some new insulators (available from Mosley) before it goes back into service but still works. I'm in the same boat as I don't climb towers and I want something to last.
Mosley's are expensive and the wait time can be long for them to build it for you, but worth it.
What kind of freestanding tower are you going to put up?

I have been eying the Pro 67C3. It is a little higher priced but no other antenna comes close to what it offers. One thing it will allow is that now instead of building a 40 meter 4 square array, it offers 3 elements on 40 meters so I would actually be money ahead with the same amount of gain and rejections and better steering. Question is can I plant the tower in the middle of the 80 meter 4 square array without causing ill effect. I don't think that will be possible.

Tower is an unknow commercial tower. See if I can describe it as best as possible cause I don't have pics of it. Typical triangle shaped, spread between legs is approx. 18 inches. Each leg is made from 2x2x1/4 angle iron. Zigzag is made from either 1/2 or 5/8 round stock never measured. Each section is 10 feet long and HEAVY!! I can tell it was professionally made cause each side the zigzag bar is one continuous piece bent with radiused 90 degree bends welded to the inside of the angle iron. No flat structure to stand or climb on so its going to be uncomfortable. This thing was welded in a fixture. No way the average welder decided to make a tower like this. I currently have 50 feet of it but have a local fabrication shop willing to make more sections if I want them. I don't have any desire to go any higher than 70 feet not knowing any specs on the tower. On one end of each section is a larger size angle iron stub for overlap the next section. Each side of the angle iron stub is then bolted with 2 bolts to the next section. So 4 bolts per leg.

I do have the flat top section to mount the thrust bearing, The guy that had it before me made a rotor shelf about 3 feet from the top. I plan on using a longer mast and bring the rotor plate down about 20 feet. Don't know yet is I will need a center bearing or not.

I do have a PRE MFJ Hygain TX2 rotor. It is in working order but think I will go thru it and replace the bearings and make sure the brake is in good condition. Going to change out the wiring connection to something more weather proof.


Sorry for being so long winded. Been collecting bit and pieces over the years till I could have a QTH that I can put a nice antenna setup on.
SandHillsHillbilly  [Team Member]
2/19/2012 8:26:13 PM

Originally Posted By ColonelPanic:
Originally Posted By SandHillsHillbilly:

Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.

Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...
Finding a TH6 these days would be like looking for a Model T Ford. Considering the age all the plastic trap covers would need replacing without even looking at them. The TH6 design is at least 40 years old. The new models TH7 and TH11 often better gain and band coverage. Just not keen on trusting MFJ QC on a product of this type.

I already have a Carolina Windom 80 that I may use possibly using one tower leg for support. If I was going to use T2FD design I would go ahead and just build a Sterba Curtain. I need something steerable and with some significant gain.

The new QTH sits in the middle of 300 acres of pasture land. It is split with a public dirt road. I still have the plans and design notes my dad made on a steerable 80 meter Rhombic he built back in the late 50s. Don't think the local farmer would enjoy telephone poles planted in his pasture.


Gotcha. And I guess having a complete metal-working shop at your beck and call along with several antenna design engineers spoils you to "eh, if you can't find it, just make it"

And I wasn't aware that many private Americans had 80m rhombics, so yes, you are correct, you are talking about ACTUAL gain here... My misunderstanding.

While I don't actually own one now Dad did way back then. I just have his plans and design notes. If I owned the whole 300 acres I would give the rhombic some serious thought. When I say steerable I only mean about 90 degrees. Manual steering using ropes and pulleys to swing it between telephone poles. LOL something that does not work from the comforts of the shack but back then was typical of what a real ham did.

SandHillsHillbilly  [Team Member]
2/19/2012 8:52:00 PM
Here are the specs on the Mosley Pro 67C3. It can be ordered with a 2 inch boom instead of the 3 inch. Stepping up to the 3 inch is cheap insurance.
Not concerned so much with 30 meter band.

Frequency, MHz
28, 24, 21, 18, 14, 10, 7
Power Rating, watts CW
2500
Power Rating, watts SSB
5000
Power Rating, AM/FM
600
Power Rating, RTTY/AMTOR
600
VSWR at frequency
1.0/1 to 1.6/1
Forward Gain, dBd 10 meters
9.3
Forward Gain, dBd 12 meters
8.3
Forward Gain, dBd 15 meters
8.3
Forward Gain, dBd 17 meters
8.3
Forward Gain, dBd 20 meters
8.2
Forward Gain, dBd 30 meters
0.0
Forward Gain, dBd 40 meters
6.8
Front-to-Back Ratio, dB 10 meters
25
Front-to-Back Ratio, dB 12 meters
15
Front-to-Back Ratio, dB 15 meters
24
Front-to-Back Ratio, dB 17 meters
25
Front-to-Back Ratio, dB 20 meters
24
Front-to-Back Ratio, dB 30 meters
0
Front-to-Back Ratio, dB 40 meters
24
Boom Length
24ft 7.32 m
Maximum Element Length
43.75 ft 13.34 m
Turing Radius
23.67 ft 7.21 m
Mast Size hardware (equipped)
2 in 5.08 cm
Assembled weight
133 lbs 60.33 kg
Wind Surface Area
12.1 sq ft 1.13 sq m
Wind Load, EIA Standard 80 MPH
330 lbs 149.69 kg
Warranty
2
Recommended Coax
Belden RG-8 / RG-213
Options (E-mail for details.)
2" OD boom available.


HomeSlice  [Team Member]
2/19/2012 8:57:22 PM
I'm going to put a Tennadyne T6 on top of my tower when it goes up. Does it have to be a yagi for some readon, or will a LPDA work?
SandHillsHillbilly  [Team Member]
2/19/2012 9:30:44 PM

Originally Posted By HomeSlice:
I'm going to put a Tennadyne T6 on top of my tower when it goes up. Does it have to be a yagi for some readon, or will a LPDA work?

While it is a good broadband antenna that is useful over a broad spectrum that is it's major downfall. To cover this much spectrum it is compromise. Broadband vs Gain. Generally speaking you can't have one without sacrificing the other. I have no need or desire for coverage outside the ham bands. If you are, are you wanting to use it for receive only purposes outside the band? If so then reconsider. Although a typical yagi is designed to work with a set of frequencies it would still work outside the ham bands for receive purposes.
HomeSlice  [Team Member]
2/19/2012 10:19:49 PM

Originally Posted By SandHillsHillbilly:

Originally Posted By HomeSlice:
I'm going to put a Tennadyne T6 on top of my tower when it goes up. Does it have to be a yagi for some readon, or will a LPDA work?

While it is a good broadband antenna that is useful over a broad spectrum that is it's major downfall. To cover this much spectrum it is compromise. Broadband vs Gain. Generally speaking you can't have one without sacrificing the other. I have no need or desire for coverage outside the ham bands. If you are, are you wanting to use it for receive only purposes outside the band? If so then reconsider. Although a typical yagi is designed to work with a set of frequencies it would still work outside the ham bands for receive purposes.

Im only going to use it for the ham bands. It's in the right price range for me, and one of the only antennas I could find that would cover 20,17,15,12,&10m that wasn't a mechanical/electrical kludge, at least in the eyes of my limited knowledge. My tower is only supposed to support a 10' beam, so even this is a stretch for me.
A_Free_Man  [Team Member]
2/20/2012 2:40:39 AM
Just last summer I assembled a Mosley 20-15-10 meter Tribander. The city crew came by with a couple of bucket trucks and put it up for us on a 60' Rohn tower behind the club station.

It works great. Like you wanted, we have a 2m beam on top of that.

If you get the Mosley IM me and I'll send you some detail pics on assembly and hookup.

AFM



Oldford  [Team Member]
2/20/2012 8:16:38 AM
Originally Posted By HomeSlice:
I'm going to put a Tennadyne T6 on top of my tower when it goes up. Does it have to be a yagi for some readon, or will a LPDA work?


I have one up at 50 feet. I am very happy with it. For the $, it is hard to beat.

Best Regards, Eric
KB7DX  [Team Member]
2/20/2012 9:58:46 AM
I have been thinking about the same thing kind of. I have a 56 ft freestander that is slated to go up to the BOL and wanted to put it in the middle of a 160m loop. I'm sure it would mess with a four square, but not sure about a loop. The 80m four square is smaller than the 160m loop so I'm sure there will be interaction between them.
As far as a Yagi vs. wire, I have run alot of antennas in my 20+ years of hamming and nothing I have tried has even come close to the performance of a Yagi. Forward gain, F/B ratios etc.. a Yagi has it, a wire, not so much. Now I realize there is some compromizing with a multi band Yagi, but they still have the advantage over a wire.
SandHillsHillbilly  [Team Member]
2/21/2012 6:20:12 AM
I have been doing some reading about having a tower with yagis in the middle of the four square array. Generally as long as the tower system is not resonate with the four square there will be no loss of gain and a slight loss of front to back rejection. This was on systems that use wire verticles with 12 feet verticle and rest sloping inward towards tower. To me its worth the chance. To have about 7db gain and 20-25db reject on 80 meters is considered major gain. When using modeling software the appears to be a thicknon-resonant wire.

Will have to be careful that tower grounding doesn't interfere or connect to vertical radials.
SandHillsHillbilly  [Team Member]
2/21/2012 6:37:51 AM
http://lists.contesting.com/pipermail/towertalk/2010-December/121692.html

http://wiki.contesting.com/index.php/KG5VK_four_square

http://www.arraysolutions.com/Users/ni1n.htm


DanishM1Garand  [Member]
2/21/2012 7:17:54 AM
Originally Posted By SandHillsHillbilly:

Originally Posted By ColonelPanic:
What's wrong with another TH6DX? You could probably buy some pvc to protect it a bit better without seeing much, if any, performance hit. If you get creative, you could build a "rather" rigid structure immediately around the elements with a couple hundred $$ of pvc. Nothing that will withstand a tornado, but better than slapping that sucker on a pole all naked like.

Also, out of curiosity, why not some long wires (BTFD/T2FD-types) ? The gain difference isn't all that much from some yagis, is 4dB less gain detrimental to your needs? I'm not a HAM so I may not understand your specific requirements...
Finding a TH6 these days would be like looking for a Model T Ford. Considering the age all the plastic trap covers would need replacing without even looking at them. The TH6 design is at least 40 years old. The new models TH7 and TH11 often better gain and band coverage. Just not keen on trusting MFJ QC on a product of this type.

I already have a Carolina Windom 80 that I may use possibly using one tower leg for support. If I was going to use T2FD design I would go ahead and just build a Sterba Curtain. I need something steerable and with some significant gain.

The new QTH sits in the middle of 300 acres of pasture land. It is split with a public dirt road. I still have the plans and design notes my dad made on a steerable 80 meter Rhombic he built back in the late 50s. Don't think the local farmer would enjoy telephone poles planted in his pasture. All you can do is ask him. He will say yes or he will say no. You might as well try


SandHillsHillbilly  [Team Member]
2/21/2012 2:30:29 PM
Besides the "DO WHAT? Have you lost your damn mind look on his face?" There is also the problem of getting the feedline across or under a public dirt road with overhead powerlines. LOL It would be nice though. He only uses it for pasture land for horse and cattle.
NAM  [Team Member]
2/21/2012 4:53:11 PM
Originally Posted By SandHillsHillbilly:
Besides the "DO WHAT? Have you lost your damn mind look on his face?" There is also the problem of getting the feedline across or under a public dirt road with overhead powerlines. LOL It would be nice though. He only uses it for pasture land for horse and cattle.


No culverts in the area? run some direct bury coax through the culvert...

Not sure of the legality, but realistically speaking, who'd know?
SandHillsHillbilly  [Team Member]
2/21/2012 10:11:39 PM
Originally Posted By NAM:
Originally Posted By SandHillsHillbilly:
Besides the "DO WHAT? Have you lost your damn mind look on his face?" There is also the problem of getting the feedline across or under a public dirt road with overhead powerlines. LOL It would be nice though. He only uses it for pasture land for horse and cattle.


No culverts in the area? run some direct bury coax through the culvert...

Not sure of the legality, but realistically speaking, who'd know?


Nope no culverts haha there aren't any ditches it is a dirt road.

Road gets grated regularly by county DOT.
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