Rotating from the Bottom
Michael E. Perry (AL7F)
on
December 22, 2011
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I live in the Frigid North, to be exact North
Pole, Alaska. Nobody wants to climb the
tower when it's -40 or have their beam stuck
in the wrong direction for the winter, so I
mounted my rotator at the bottom of my Rohn
25 tower.
1 I used a flat top section at the top
with 2 thrust bearings to keep the mast
vertical. A pointed top section with one
thrust bearing placed at the rotator plate
would have worked just as well. I used
commercial chain link fence pipe the size of
my mast cut to 10 foot lengths. I took them
to a muffler shop and had one end of each
section of pipe expanded so they would slip
together and drilled a hole thru them so I
could bolt them together.
2 I used several pieces of 3/8 thick HMWP
plastic that I bored a 2" hole in to keep the
mast pipe centered in the tower. I spaced
them about every 20 feet up the tower.
3 I originally used a Tailwister rotator and
had to remove the diagonal bars for it to
clear and rotate. I've since changed to a
Alfa Spid and would have had to only remove
one of the braces. Just to be safe I added
three 3 foot pieces of 1 inch angle to the
legs where the braces were removed secured
with U bolts. Since the drive shaft is
supported entirely by the thrust bearings the
rotator can be removed and leave the shaft
hanging.
4 The torsion load has been eliminated from
the tower and placed on the drive shaft. The
tower is 80 feet high so the drive shaft does
have about 5 degrees of torsion twist in high
winds.
I did all this as I was installing the
tower and added a section of driveshaft as
each section of tower went up. It is working
GREAT and has been worth the effort.
73 from the 49th State
Mike Perry AL7F
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Rotating from the Bottom
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by KC4AF on December 22, 2011
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Very good idea. Thanks for the nice write-up and pictures. 73, Bob
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Rotating from the Bottom
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by KT4EP on December 22, 2011
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great idea! useful too for maintenance and not having to climb the tower for physical ailment reasons. I've never seen anyone talk about doing this.
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RE: Rotating from the Bottom
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by W7AIT on December 22, 2011
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I did a similar design with my VHF / UHF contest stack. Rotor at the bottom, thrust bearing, and used a collapsible 22 foot Buddipole mast. I can bring everything down to 5 foot height and work on everything - antennas, feedlines, rotor, without a ladder - being physically disabled.
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RE: Rotating from the Bottom
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by AA4PB on December 22, 2011
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Not to be negative, but I've read that Hygain does not recommend having a mast extend more than 2-feet below the thrust bearing because of the twisting forces placed on the rotor as the long mast twists in the wind.
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Rotating from the Bottom
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by TANAKASAN on December 22, 2011
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I wish I could remember the callsign but I remember seeing one installation where an amateur had rotated the whole tower rather than a shaft down the center. The large towers that have been on display at Friedrichshafen for the last two years also do this.
Tanakasan
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by KB1GMX on December 22, 2011
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I've seen this done many times before and it works very well. The biggest version of that was at the FAA Nashua NH where they turned a 50ft (or longer) LPA for the 4 to 18mhz aviation HF band. The tower for that was Rohn 55 sized and the mast was 6" steel tube.
The HighGain prohibition does not apply as there are several points of load bearing at the top and along the way down to avoid the mast whipping. The rotor has minimal side load as it can be aligned to the mast and no vertical load. The torsional load is the antennas and their boom length. But being close to the ground makes any maintenance issue trivial. Also you can turn the antenna without the rotor (power or rotor failure).
With all the forces concentrated at the base the
tower has less torque loading, also a good thing.
Getting a muffler shop to swage the tube is a great idea.
Turning the tower is harder but allows for side mounted antennas to turn. That requires far more power as the total weight is greater.
Allison
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RE: Rotating from the Bottom
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by WB4TJH on December 22, 2011
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It's a little extra hassle setting up, but it could save a LOT of tower climbing. The only real trouble I ever had with my tower setup was with the rotator. If I had had it set up this way at the bottom to begin with, I would seldom have ever had to climb mine.
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RE: Rotating from the Bottom
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by KO7I on December 22, 2011
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This is actually a very intellegent way of doing a rotor installation. Old timers used to extend the mast to the base of the tower using all forms of tubing mating with the mast up topside. This was the typical method of installing a arm-strong rotor. In the old days, hams would tie a rope to the base of the mast and to a old stiring wheel to rotate the beam to a desired heading. Hence the tirm Arm Strong. I first saw this done by Johnny Wattson W4GD in Memphis, TN a famus builder of 1 and 2 hole 4-1000 amplifiers. He used this system to rotate a 20M 3 el Telrex yagi at 70 ft.
The more common way I am hearing about this these days is to use grey electrical PVC pipe. This style of pipe provides a cushion for braking the antenna as it is swung. (but in environments with bitter cold, PVC would be a very poor choice for obvious reasons.)
I believe the claim that this results in higher levels of torque to be placed on the tower is bogus. by placing the rotor at the base of the tower, the rotational torque is transfered into the base of the tower and not distributed over the entire length of the tower because of the free wheeling behavior of the thrust bearings. I am going to use this technique on my upcoming installation (less the rope and a old stirring wheel.)
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by PD2R on December 22, 2011
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I like idea of having the rotor on ground level. Nice job.
At PI4DX we have two of our towers completely rotatable. If you look us up at QRZ.com you will see pictures of the towers. The two larger towers are both rotatable.
The biggest one is 100 feet tall and is turned by a 380V hydraulic motor. The ring it turns on is from an excavator and it handle the load without any problem.
One the side of that 100 feet tower we welded some rails. mounted to those rails is another 40 feet of tower on which we mounted all the antennas (4 el for 40, 6 el for 20 and 6 over 6 for 10 meters).
This section of tower containing all the antennas can be winched up to a total hight of 125 feet.
When the station is not in use or when high winds are expected, we lower the antennas to ground level.
Not only is this great for maintenance, it also keeps you antennas from getting blown to pieces when a storm hits the station.
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by AF6AU on December 22, 2011
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I like this tower/rotator installation. And in the way that Murphy's law works, because that rotator is within easy reach, it will probably never go out. It's the rotators that are 50 feet up that always die in late January, or the morning of some favorite contest, or hot DX band opening, right? So the only bug here is still having to climb the thing if the top side bearings seize, so with shields to keep rain out, and add some tubing and fittings so you could grease them from the ground as well.
So the only thing left is the antenna. Alaska is known for big birds, will your beam handle ice load + a big old eagle sitting on it? Always something...
Really nice application of thinking ahead to minimise issues common to your location. Well done OM.
JML
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Rotating from the Bottom
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by AE5QB on December 22, 2011
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I am not an engineer but the removal of the braces at the bottom concerns me. I understand that the author substituted 3 pieces of vertical angle for them, but my thought is that the original braces provided torsional resistance and the purely vertical braces do not. Just looking at the picture, I could see this section of the tower easily twisting with relatively little torque. So you engineers out there, is this a concern? I am always nervous about modifying the original design of a support structure, but maybe I am just overly anal.
Tom
AE5QB
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by W8ATA on December 22, 2011
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Nice job, pics and article. I have been doing this for about the last 6 years. I call it the "old farts" tower system. I had a friend make me a carrier bearing for mid-tower to take the flop out of the mast and of course a thrust bearing. One addition to consider is the rubber roof vent boots. The right size slipped down over the mast and taped keeps the ice out of bearings.
73 and Merry Christmas,
Russ
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RE: Rotating from the Bottom
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by AL7F on December 22, 2011
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There is NO torsion placed on the tower above where the rotator is mounted as long as the thrust bearings at the top don't seize. Rohn rotator sections from the factory already have the diagonal braces removed so that the rotators will fit and rotate.
73
Mike AL7F
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Rotating from the Bottom
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by AB9TA on December 22, 2011
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I'm with AE5QB on this one - It might be a good idea to find a way to replace the missing diagonals with something that's bolted or clamped on to reinforce that section of the tower.. After all, the manufacturer put those on for a reason. Triangles are a good thing..
I'm not so much worried about any torsion from the rotation of the beam, as I would be about wind loading and if the tower starts to oscillate under a high wind load. That could be the weak point.
Otherwise, that is a very nicely done job. Hopefully the bottom rotor idea becomes a lot more common, preferably standard, or at least a common option.
Great Article!
73!
Bill AB9TA
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by KD8MJR on December 22, 2011
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I would add some sort of clamp just above the rotator to lock that pipe down in case of a storm or heavy winds. I love your design but I am concerned about all that torsion being extended into a soupy twist during a storm.
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RE: Rotating from the Bottom
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by KC3JV on December 22, 2011
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Tom: You are correct. Removing bracing at the bottom where the load is highest is particularly bad! A thrust bearing and a right angle drive with anti-backlash gears would have solved the problem and allowed the rotator to be mounted even on the ground.
Mark Rothstein, P.E. (KC3JV)
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by KG4RUL on December 22, 2011
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OR a thrust bearing, chain and sprockets on the rotator and antenna mast allowing the rotator to be mounted outboard of the tower
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by KO7I on December 22, 2011
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Ol' Johnny Wattson's tower withstood many storms in tornado alley just fine.
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by G3LBS on December 23, 2011
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After WWII, prop-pitch motors off aircraft were popular. They were so heavy they HAD to be on the ground, outboard of the tower base. Anybody have any pictures of these please? W2/G3LBS
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Rotating from the Bottom
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by K7GLM on December 23, 2011
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Great idea. If you have a tall tower, remember to subtract the surface area of the mast from the rated antenna allowance. Shouldn't be much of a problem on a small tower with guy wires.
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RE: Rotating from the Bottom
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by AA4PB on December 23, 2011
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"The HighGain prohibition does not apply as there are several points of load bearing at the top and along the way down to avoid the mast whipping."
Okay but he indicated that there was about 5 deg of twist in the mast during high winds. This means that the antenna will have some momentum when the rotor break stops the movement. I'm not so sure that the High Gain prohibition doesn't apply.
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Rotating from the Bottom
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by K0AX on December 23, 2011
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Great article and great photos. I'm kinda wondering why we haven't always built them this way.
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RE: Rotating from the Bottom
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by AL7F on December 23, 2011
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All the torsion load is transferred from the mast to the rotator WHICH is BELOW where the diagonal braces have been removed. The mast acts as a 80 ft. long shock absorption device that prevents any sharp, heavy or quick twisting load from being placed on the rotator. The Alfa Spid rotator has a Ramp Up and Ramp Down, and doesn't use a brake( not needed as it is a worm gear drive system). In my case I also have a roof mount about 10 feet above the rotator, so the bottom of the tower can't rotate. I have had several friends that have EE and ME degrees go over this modification and they have not had any concerns. I believe in the KISS method. Keep It Simple S.
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by KL7JM on December 23, 2011
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I looked at Mike's arrangement and consider it sound with a house bracket above the rotor. I too was concerned about removing diagonal braces and the possibility of a thust bearing seizure causing torque at the rotor location. If the rotor were located so that the max diameter, 9.25" for a Tail Twister, is just below the top ends of the diagonal braces, no need to remove them. When Mike helped me install a Tail Twister in a Tri-Ex, now Tashjian, DX-86, we added a spacer to raise the rotor base plate about 2 inches to get the needed clearance for rotation.
Yep, the learning curve never flattens.
Best wishes for the Holidays,
Jim
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by KB1GMX on December 23, 2011
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RE: Rotating from the Bottom Reply
by AA4PB on December 23, 2011 Mail this to a friend!
"The HighGain prohibition does not apply as there are several points of load bearing at the top and along the way down to avoid the mast whipping."
Okay but he indicated that there was about 5 deg of twist in the mast during high winds. This means that the antenna will have some momentum when the rotor break stops the movement. I'm not so sure that the High Gain prohibition doesn't apply.
It does not apply in that adding mast is not the issue.
their prohibition addresses side loads and boom length of the antenna. Look at it this way if that tower had n antenna there would be no torsional load if the bearings were reasonable. there is no sideload as
enough bearing are used to insure the whipping of the mast cannot occur and the rotater does not have more than a few feet of movable pipe by virtue of:
quote> " used several pieces of 3/8 thick HMWP plastic that I bored a 2" hole in to keep the mast pipe centered in the tower. I spaced them about every 20 feet up the tower."
That does much to take out side loads often seen when there is only a top bearing and the next is the rotator.
Myself I'd like to have seen the cross braces remain or be replaced with a removable section. There is low torsional load on that tower so it works. I'd still only have removed one side for access rather than
three.
Then again once you have the mast and a bearing down low a standard gear motor can be used rather than a rotor. You can get a really robust gearmotor for the price of a rotor and chain and sprockets are also available. This of course goes back to the days of the prop pitch motor with its gear works.
Allison
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by W8AAZ on December 23, 2011
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Armstrong rotators arethe cheapest and usually reliable!
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by N4JTE on December 23, 2011
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Nicely done and great article, not easy to keep anything working up there, tnx for a very well done explanation and photos.
Bob
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by W6SDM on December 24, 2011
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We don't get much snow in the Arizona Sonoran Desert, but it is equally uncomfortable climbing a tower when it's 110 degrees outside.
Good article. Good food for thought for my nex antenna project.
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Rotating from the Bottom
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by KA4ETV on December 24, 2011
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This gentleman appears to be a lot smarter than I am. Nice piece.
I will be the one climbing mine to redo it like this.
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RE: Rotating from the Bottom
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by AL7F on December 24, 2011
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My final comment to the folks that question the removal of the diagonal braces that I removed for rotator clearance. If you take an empty Coke can and grab it at the top and bottom you can twist it and crush it. If you take three small pieces of angle metal and space them 120 degrees a part around the can secured at the top, bottom and middle to simulate the braces I placed on my tower. Then try to twist the can, it can't be done if taped properly. The angle pieces clamped on (my tower) sandwich the legs and are secured above, below and in the middle of where the braces a removed, preventing any twisting movement. Another thought, the diagonal braces on the tower all angle the same direction. Twisting a stock tower in one direction is trying to stretch the brace and would be very hard. Twisting the other direction pushes on the diagonal brace causing the brace to bow, not as hard to do. I have an old crank up tower and that is what happened to the top section. It twisted and bowed the diagonal braces, which all ran the same direction.
I've rambled enough about this and I'm satisfied that I've done what I needed to do to have a safe and secure tower modification.
73
Mike AL7F
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by KL7CW on December 24, 2011
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Mike,
I think your idea of moving the rotator down to a lower section is good and solves your problem. I probably would not worry too much about the long driveshaft or the missing tower diagonal braces for "REASONABLE" size arrays.
I solved the problem at my station by using a Prosistel rotator which can be placed inside ROHN 25 tower without needing to remove any diagonal braces. Several of their rotators fit inside of ROHN 25. At first I could not get it inside the tower, but after some trial and error at ground level I developed a scheme of how and where to insert and twist it into position. It was then easily installed at approximately the 55 ft level of a 60 ft tower. I used a rotator of more than adequate size for my yagi and changed out the lubricant to one with arctic specs. It has performed fine for 8 years, but only down to a balmy -30 degrees F, so no guarantees up further north in Alaska. So far I have never had a rotator fail, but all have been rated well above any expected load, but I am also prepared to climb my tower in the winter.
Rick KL7CW Palmer, Alaska
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by KO7P on December 24, 2011
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It is a great idea for cold climates. Even here in Idaho, it is no fun being up on a tower in the winter when the rotor fails.
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RE: Rotating from the Bottom
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by K2LGO on December 25, 2011
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Well by GOD this is certainly a great way to have your rotor where it is easy to work on...but it seems that is offset by the need for a guyed tower, that is put up section by section... I'm not sure I know of any amateur towers that are not telescoping, that can be laid over to work on, therefore in this gentleman's installation in order to work on the antenna he would have to climb to the top of the tower, somewhat offsetting the convenience of the rotor down below..Please believe me I admire the beautiful job he has done, but I ponder if having the rotor down low, is more useful than having the ability to have the antenna at ground level(along with the rotor)as in a telescoping, tilt over tower ????
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RE: Rotating from the Bottom
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by KB1GMX on December 25, 2011
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My tower does not telescope and in not guyed but it does tilt at the base. So doing that mod would means the rotor must be just above the base, not an issue. Since the tower tilts as whole a mast in the center is a only weight during the lift/lower process. I plan to make that change as it seems about every other year the rotor
gets attention while the tower is down for antenna updates and maintenance if only to prevent future failure.
In my case getting the rotor to the bottom is a great way to minimize headaches.
The great item gleaned from the article is how he got a 80-90ft long pipe! Getting a muffler shop to swage the ends of shorter sections is brilliance as getting long pipe sections as in over 10ft is not easy and a royal pain to transport.
Allison
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RE: Rotating from the Bottom
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by K2LGO on December 25, 2011
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Allison...
Not quite sure what this means "Since the tower tilts as whole a mast in the center is a only weight during the lift/lower process" Don't you consider the antenna load on the top of the tower as weight during a tilt over/lift procedure ??...I'm sure there are a few towers that can handle the stress of tipping them over with an antenna on top, but I think that is relative to what the antenna is...Put 50 or 60 pounds on top of a 60 foot tower, and tipping it over would require a stout winch, and a stout mechanism to hold the winch with a good back stay. and a very stout tower...As for the genius of getting the pipe swedged at a local muffler shop, yes I do agree that was genius...
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by KB1GMX on December 25, 2011
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>Not quite sure what this means "Since the tower tilts as whole a mast in the center is a only weight during the lift/lower process" Don't you consider the antenna load on the top of the tower as weight during a tilt over/lift procedure ??.<
Of course. However the mast up the center is additional weight.
>I'm sure there are a few towers that can handle the stress of tipping them over with an antenna on top, but I think that is relative to what the antenna is...Put 50 or 60 pounds on top of a 60 foot tower, and tipping it over would require a stout winch, and a stout mechanism to hold the winch with a good back stay. and a very stout tower..<
In this case we are not at 60ft so it's outside the actual case. With planning and preparation it's
doable. There are even utube videos of people
doing it.
This is only 30ft plus 10ft of mast plus VHF/UHF antennas, HamIV, and those considerations are part
of the design. The lift points, position of the
lift boom, and back stays are are critical to
making this lift system easy for me. The winchs in
the system are not stressed beyond a few hundred
pounds. It's been working for 5 years. If you pay
attention to those details first and design for them
then it's not much a problem.
Also consider a HamIV at the top and the weight that
is not there if moved to just above the hinge. Using
a longer mast is a weight gain along the total length
plus weight distribution recalculation with the rotor at the bottom.
Allison
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by K2LGO on December 25, 2011
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Reading the article carefully I see he says that the tower is 80 feet, and was put up section by section..
KB1GMX remarked that "This is only 30ft plus 10ft of mast plus VHF/UHF antennas" but that is clearly not the case in the original posters tower, as it clearly states 80 feet, and the top antenna looks like a small log periodic...If someone would try to duplicate this setup, and overload the top of the tower with antennas, with an inadequate tower it could be a disaster (in my humble opinion) I do take note of KB1GMX remark about the great reduction on the top by having the rotor on the bottom, and I say point very well taken..Might be OK for some, as long as proper engineering is taken into consideration...
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by N0UY on December 26, 2011
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Well everybody certainly has an opinion about how someone else modifies an original design . I imagine the poor fellow that came up with the idea for the wheel had to justify his reasons too. I am in agreement with the original poster that the forces are below the removed braces since the actual torsional load is delivered by the mast. He has added vertical strength with the angle irons. Now if he add added and outrigger on the tower with some sort of wind load mounted to it this would be a different story. That torsional load would be distributed directly to the tower and would require some sort of removable supports. The only issue I can see is the combined free play created over many years at each mast splice. Nothing a drill and a pile of rivots can't correct as it becomes necessary. I like it when someone thinks outside the box. I have been in manufacturing for 38 years. Ray
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by AL7F on December 26, 2011
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Hi Ray
Thanks for your input. I am amazed at how you guys from Mn. come up with so much of the out of the box thinking. IE. Polaris, Artic Cat. Tell John at Northern Crank, I said Hi.
73
Mike AL7F
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by N0UY on December 26, 2011
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Hi Mike,
You just keep doing what your doing and adapting to whatever the situation requires. This world is full of talented forward thinking people. I doubt if many of the best ones even have a degree in anything. God given ability and common sense goes a heck of a long way in most causes. Keep it simple has it's merits.
Merry Christmas, Ray
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by W7ETA on December 26, 2011
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Hi Mike
Thanks for a nice article; nice pixs.
Best from Tucson AZ
Bob
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by K2LGO on December 26, 2011
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Mike...
I want to apologize to you personally if you might have taken offense at some of my comments...believe me they we're comments, and not criticisms..Your article was well written, and greatly illustrated...
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RE: Rotating from the Bottom
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by KB1GMX on December 26, 2011
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Reply: K2LGO on December 25, 2011 Reading the article carefully I see he says that the tower is 80 feet, and was put up section by section..
KB1GMX remarked that "This is only 30ft plus 10ft of mast plus VHF/UHF antennas" but that is clearly not the case in the original posters tower, as it clearly states 80 feet, and the top antenna looks like a small <<
Absolutely correct his is 80ft, mine however, is not.
You failed somehow to miss the reference in an earlier response that I was looking to add this to my tower that is only 30ft. Someone commented I was missing the weight at the top and the ability to tilt it over.
I commented on the evaluation for MY tower. The author of the article did a service to tell us how he got 80ft of mast by having a muffler shop swage common fence pipe. That solved a problem for me, how to join the pipe cleanly.
Allison
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by NZ4AA on December 28, 2011
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A very nice article. I used to live on Eielson when I was a kid '77 to '81. A Ham in my housing court took his time to show a nosy kid his shack.
Thanks again for making me think of the memories.
73's Scott Jacobs NZ4AA
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by W9QR on December 31, 2011
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Nice ideas and good photos. I installed a TH7DXX on a 120 foot Rohn 25 in 1985. I was never able to get the thrust bearing to rotate freely. So I left it on the top plate with lots of slop so the mast could turn. I stacked a 5 element 6 meter yagi and a 13 element 2 meter on a 15 foot mast above the TH7. No problems after 26 years, but I have plans to change the configuration over to a side mounted arrangement. A local machine shop used the Rohn Work Platforms to mount the T2X rotor and a thrust bearing about four feet apart on the top 120' section. I am tempted to use this "Long Mast" method to bring the rotor down to within 20 feet or so of the ground. It will take 4 inch diameter irrigation pipe to resist the "twist",but that sounds better than climbing another 100 feet to extract a T2X. Thanks to all for the ideas and insights,
73, Larry, W9QR
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RE: Rotating from the Bottom
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by XV2PS on January 6, 2012
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Hello,
I did a "similar" system for my first antenna some 7 years ago. The reason? I had no rotator and had to do by hand. Rotator came later :-)
You can have an idea of the setting on this picture. Shaft is parallel to main supporting pipe.
http://i136.photobucket.com/albums/q193/XV2PS/lift.jpg
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Rotating from the Bottom
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by N5WBK on January 14, 2012
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Since I am getting close to retirement and my tower climbing days are about over. I went to Texas and bought 60' Rohn 25 with the rotor on the bottom section and a lifting fixture and hinge base. Through trail and error I have improved on his design. He also cut out the three diagonal braces out. I can show you what happens to when tower twist like a pretzel around a tail twister. I cut one brace in middle and used another brace ubolted it to the cut one. He had used 1&1/4" electrical counduit for the mast and had counduit unions to join them. They do not like the twist and torque of the wind. I used a foot of top rail off a chainlink fence and put inside and bolted them together. If anyone is interested I be glad to show you how I did it. You can see both of my towers and Mosley antenna farm on QRZ. Email is good there also.73 Fred N5WBK
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RE: Rotating from the Bottom
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by VE6KK on January 17, 2012
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With the help of a gracious ham (now SK), many towers in the Calgary area were outfitted with a central tube and rotator at the bottom. Most were self supporting stamped/riveted triangular towers like the Canadian Delhi (similar to Rohn BX or HBX). My was 56 ft. with a homebrew thrust roller bearing up top, triangular spiders (threaded rod to each leg) with copper inside steel pipe for sleeve bearings. My already old Ham-M was at 10 ft. This arrangement took the brunt of Chinook winds on a TH3 for 30 years. No rotor problems except the capacitor. Of course the pipe creates a tortional spring which depends on the stiffness and length of the center tubing, so there is some damped oscillation in stopping rotation and more than the usual movement in wind. But there is no more momentum than in normal rotation. (Momentum = mass x velocity.)
The only problems I could see after 30 years were in rusting of the bearing and the elongation of bolt holes in the tubing where spliced. I used 1.5 inch by 20 ft. steel tubing with "1.25 in" (i.d.) pipe inside at the joints. The swaged fence rail is a tremendous idea - it is galvanized, shorter to handle and the joint far superior.
So, is it worth going to this trouble? Maybe for a large beam or if you expect rotor troubles. But for my new hexbeam I won't bother. And if you have a guyed tower, why not set up torque extensions instead, cheaper. Remember too the extra wind load on the center pipe (offset by subtracting rotor area).
Now if I could only tilt the whole thing down to work on it...
73 VE6KK
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Rotating from the Bottom
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by W5XJ on January 31, 2012
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What a great innovation! Also thanks for all the pictures so we can see how you did it.
When i was up in Gustavus, AK i did not see many beams. Have fun on 160 this winter.
73 de W5XJ
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