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I¡¯m considering putting up the subject antenna. ?KLM is no longer in business to ask them for information. ?Does anyone know the wind load rating and survival wind speed?
Also, this antenna weighs 24 lbs. ?What would be the best non-guyed tower to use?
Thank you.
73,
Michael Smith, N4KZO
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I believe M2 can help with that.
?
73, W8GYV
On Thursday, January 25, 2024 at 01:11:34 p.m. EST, Michael Smith via groups.io <tw8kcabpilot@...> wrote:
I¡¯m considering putting up the subject antenna. ?KLM is no longer in business to ask them for information. ?Does anyone know the wind load rating and survival wind speed?
Also, this antenna weighs 24 lbs. ?What would be the best non-guyed tower to use?
Thank you.
73,
Michael Smith, N4KZO
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I forgot to mention the height. ?My understanding is that a 50 foot tower height is a standard height. ?Being this is approximately 15 meters, a full wave length height for the 15 meter band, the lowest frequency band in the range of this log periodic antenna, and above obstacles around me, I expect a 50 foot tower would be a good choice. ?Concerning a rotator, I need recommendations also. ?Please help if possible.
Thank you.
73,
Michael Smith, N4KZO
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Hi Mitchel,
?
There isn¡¯t a standard height, but my guyed Rohn towers range from40 feet to 70 feet.? While I have two Yagis per band 20, 15 and 10m, plus one on 40m, on long
skip the 20m Yagi at 70 feet is at least 1 S unit stronger on average on long skip (1000 miles +) than the one at 40 feet.? I am in rural Colorado with flat terrain with 100 feet difference in elevation. ??
?
A 50 foot free standing tower will be more expensive than guyed, but installation and maintenance will be easier. Are you talking about a crank-up tower or
a fixed self-supporting tower?
?
I have two Orion 2800 rotors for my larger Yagis and four Yaesu 2800 rotors for the other Yagis.? They have all worked flawlessly for about 5 years replacing
six TailTwisters.?
?
Due to RFI from home appliances, my towers 200 to 350 feet from my house are quieter than the ones within 30 feet of the house.? You may not have an option
as to where to locate a single tower.?
?
In general I would suggest 70 feet, but do what makes mechanical and cost sense.? I wish my 40m Yagi was at 130 feet but it isn¡¯t !? I struggle breaking EU
pile-ups in contests being in Colorado with a Yagi only at one half wavelength.
?
Photo attached, all Yagis are mono-band.
?
Nothing is more significant than the best antennas you can install over any modern or even vintage Drake transceiver or twins.?
?
My 5-element Yagis are between 65 and 70 feet, and my 12m Yagi is at 80 feet simply because it is mounted 10 feet above the 40m Yagi.
?
73, Rob, NC0B
?
?
?
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From: [email protected] [mailto:[email protected]]
On Behalf Of Michael Smith via groups.io
Sent: Thursday, January 25, 2024 12:37 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] KLM 20-30-6LPA Wind Load Information and Tower Recommendation
?
I forgot to mention the height. ?My understanding is that a 50 foot tower height is a standard height. ?Being this is approximately 15 meters, a full wave length height for the 15 meter band, the lowest frequency band in the range of this
log periodic antenna, and above obstacles around me, I expect a 50 foot tower would be a good choice. ?Concerning a rotator, I need recommendations also. ?Please help if possible.
Thank you.
73,
Michael Smith, N4KZO
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Bill,
M2 did not have any information on this legacy antenna, but this was a reasonable try. ?I had a response via qth.com with wind load information, but not survival wind speed.
Thank you for the response.
73,
Michael, N4KZO
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Hello Rob,
Good to hear from you. ?I sense a 50 foot tower, non-guyed, would serve me for antenna performance and ease of use. ?I prefer not to climb, so a crank-up of some kind would be best to make antenna maintenance easier. ?I recall seeing an advertisement for a tilt-over using a wench, long ago; I don¡¯t know if they still exist or the feasibility of using one. ?So, based on these parameters, I am looking for make and model advice based on performance ¡ª ease of use, mechanical integrity, and longevity. ?I wanted to get some advice before I start shopping.
Thank you.
73,
Michael, N4KZO
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That tilt-over with a wrench, well, make sure the person doing it is strong like bull..
On Thursday, January 25, 2024 at 09:06:02 PM EST, Michael Smith via groups.io <tw8kcabpilot@...> wrote:
Hello Rob,
Good to hear from you. ?I sense a 50 foot tower, non-guyed, would serve me for antenna performance and ease of use. ?I prefer not to climb, so a crank-up of some kind would be best to make antenna maintenance easier. ?I recall seeing an advertisement for a tilt-over using a wench, long ago; I don¡¯t know if they still exist or the feasibility of using one. ?So, based on these parameters, I am looking for make and model advice based on performance ¡ª ease of use, mechanical integrity, and longevity. ?I wanted to get some advice before I start shopping.
Thank you.
73,
Michael, N4KZO
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Wench not wrench.
73,
Michael, N4KZO
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So, a wench is a girl that serves drinks. ?I meant to type winch.
73,
Michael, N4KZO
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Knowing what alloy and what the various diameters of the tubing that make up the eles and also the boom, and also the wall thickness, and also including any double or tripled walled sections ...then plugging all that info into the DXE ....' yagi mechanical' software? ?will spit out max survival speed.? ?It will do it for various standards.? ?I typ use the....'no spec'? which is what you will get when using a wind tunnel...and that's good enough for me.? It's very accurate.??
?
I got into this many times with Ken Garg? (who owns? JK ants)? and he concurs.? If using the old 'C spec', the C spec results will spit out slightly higher wind survival ratings.? ?When using the software,? you have to? do it for the boom, with boom broadside to the wind.? ?Then again, for each ele, with each ele? broadside to the wind.? Typ the boom has the strongest wind survival.? When dealing with monoband yagi's, it's typ the REF that has the lowest wind survival rating.?
Using the software, it's a simple matter to see where the weak spots are in any ele, and where extra re-enforcement is required.?
?
Beware, on older ants...like F12, ( and others) F12 used 'effective ant area', instead of 'projected ant area'.? ?On all F12 ants, you have to multiply by 1.5? to get projected ant area....which is what all tower manufacturer's use.??
K6MYC is still around, and may well have the info you seek.?
?
Jim? VE7RF
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Good to know. ?Thank you, Jim.
73,
Michael, N4KZO
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Two places to look:
See MODS.DK
They have manuals from many pieces of ham stuff; radios, accessories, and antennas.
Also, the Yahoo groups TOWERTALK may be a good source for antenna info.
Just FYI that I hope helps....
73
KF6JS - Tony
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Thank you, Tony. ?I¡¯ll check it out.
73,
Michael, N4KZO
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Rob Sherwood
Tony Yamin