Anyone know how to load up a flagpole?

[AJ1G]

I have been thinking about how one could do a temporary non-invasive JS arrangement to load up the flagpole down at Stonington Point by attaching some radials to its base, throwing them over the rocks into the ocean (only a few feet away) and gamma matching at some point up the pole.    It is steel and not fiberglass.  My rough guess is that it is about 50 feet high - will use the old scout pace and pencil trick to get a better estimate.  Anyone ever tried this trick on a flagpole and have some rough dimensions re a tap height and gamma match capacity, or can steer me to info on same?  Would like to try on 80/75 and 40. Or maybe I can use the flag halyards to hang a sloper toward EU and/or VK/ZL.

[WA1LGQ]

   Chris, maybe you could try backing up the car so that the ant is almost touching the pole. The proximity will detune the ant. Try getting as close as possible while still being able to retune the ant. I have tried tried this with mixed results on a parking lot light pole. Another trick that you might know about is to find an overpass that gives a boost in signal when you are underneath it, and park there for a while, on the shoulder until a cop kicks you out. Don't know if this works on 40M, but it does work on 75...........Larry

[Carl WA1KPD]

Chris,
Dont know if this would work but when I had the screwdriver on the car I used to notice that going under highway bridges signals on 40 and below would peak noticeably and that the swr would shift.

On a whim K1VYU and I backed the car up to a large lamp pole at a gas station and noticed that the received signal came WAY up. We did not have time to experiment, plus the station owner was looking at us a bit strange, so I don't know how much the coupling would have worked on xmt, But it would be an unobtrusive way to try it.

Carl
/KPD

[kb3ouk]

I'm with everyone else. Try backing the car up to the flagpole and see what happens. It sounds like there is some kind of coupling going on between the antennas and the poles, overpasses, etc. I was thinking about a similar idea of taking a mobile antenna such as a hamstick and mounting it near something like a tv mast or other large piece of metal with the idea that the antenna would couple to the mast or whatever and hopefully improve the signal.
Shelby KB3OUK

[kb3ouk]

It seems to me like it is similar to gamma matching, except with a gamma match there is a connection between the gamma match and the antenna. With the mobile antenna and pole situation, the mobile antenna is somehow inducing RF into the pole, allowing it to radiate part of the signal, without a physical connection. It would be interesting to see what the pole's heights were, because it is possible that the poles could present some kind of resonance at that frequency that allowed that effect to happen. Just an idea.

[WU2D]

Chris-- What a MOBILE ANTLER! YEAH BABY

I like that Gamma match idea - it should work.

Is the flagpole grounded for lightning at least?

Keep your Gamma feed point away from the grounded base of the flagpole by about 10 to 20% of the estimated height of the pole. The feed wire can slope back directly to the rear of the vehicle where your mobile antenna mount (and tuner) is located, say 10 feet away.

Getting good contact with the pole by drilling and blasting is probably a bad idea - what about cap coupling?

I would couple with collars made of aluminum with PVC or Tarp material for insulation and giant hose clamps. Wrap it around and tighten. Even a small 4 inch collar will give at least 1000 pF when tight.

Mike WU2D

[AJ1G]

Just tried backing up as close as possible to a big light pole in a shopping center parking lot - as close as I could get was the right corner of the rear bumper about 1 foot away - caused the Hamstick SWR indication to go up a bit, but still less than 2 to 1, no notable change in received signal strengths.

Interesting on the underpass effect - maybe you are making a big RF directional cavity?  I remember the article in ER about the guy who built a huge HF exponential horn antenna for the military - hooked his mobile rig to it and was 40 over 9 in Hawaii from the DC area on 20!!!!

[AJ1G]

Way cool Mike! - was just typing my latest post when you posted.  The foil ring cap coupling idea sounds workable - guess I would put one at each connection, at the bottom for the coax shield and radials to dump into the ocean, and one at the feed point....probably would want to use a tuner at the feed point to match the antenna to the 50 ohm feed from the Yaesu.

Don't know if the Point flagpole is grounded or not - I would deploy a counterpoise into the ocean which is only about 5 feet away on the other side of the pole.

[flintstone mop]

Just tried backing up as close as possible to a big light pole in a shopping center paking lot - as close as I could get was the right corner of the rear bumper about 1 foot away - caused the Hamstick SWR indication to go up a bit, but still less than 2 to 1, no notable change in received signal strengths.

Interesting on the underpass effect - maybe you are making a big RF directional cavity?  I remember the article in ER about the guy who built a huge HF exponential horn antenna for the military - hooked his mobile rig to it and was 40 over 9 in Hawaii from the DC area on 20!!!!

AND WOW!!!! that was a great article too. The antenna was huge and 20M band to boot.
Fred

[K5WLF]

I remembered this from ARRL a while back:

http://www2.arrl.org/news/features/2008/06/12/10155/

Happy New Year!

[flintstone mop]

QUOTE: Just tried backing up as close as possible to a big light pole in a shopping center parking lot - as close as I could get was the right corner of the rear bumper about 1 foot away - caused the Hamstick SWR indication to go up a bit, but still less than 2 to 1, no notable change in received signal strengths.

 I almost thought that maybe you were able to "couple" into the flagpole with your procedure mentioned above. I wonder if that is a possiblity??
Fred

[AJ1G]

No can do Fred - there are a couple of granite benches around the pole that prevent snuggling the car up to it.  I'm seriously thinking of trying WU2Ds ideas above...

[Gito]

Hi

Maybe a stupid Idea from me.
Why don't You try to wind several turns of isolated cable/maybe ten or twenty turns on  the  flag pole/making the flag pole as the form, maybe at the bottom of the flag pole,  than connect this coil,using a feeder cable to your antenna tuner,so You are link coupling to the flag pole.
Actually the flagpole is an inductance ,and can be coupled with link coupling.

Gito

[AJ1G]

Found a couple of big rolls of heavy duty wide aluminum flashing material at the town dump free reusable shed this morning...just the thing to make the WU2D capacity coupling straps - just need some thin plexi sheet and some BIG hose clamps.....

Worked down to VK this morning on 40 CW from the Point with the  Hamstick mobile whip.

[flintstone mop]

The coupling idea might not be as crazy as some might think!
Just imagine pulling up to a light pole, the type used on interstates or the tall buggers that light up those cloverleaves??? They must be over 100 feet tall.
Have a quick deployment of ground radials......kinda wonder about that!!

Fred

[Ed/KB1HYS]

Rapid Radial Deployment Cut some radials, solder together at one end. Wind on a big spool. Attach the soldered end at the flagpole. Walk it out. Spread by walking the ends.

Tangling will be an issue.

[AJ1G]

I have made such counterpoises just as you described - all soldered together at one end with a single short pigtail lead to the feed point.  I wind each lead on its own winding frame - then wrap the bundled frames with tape for storage.

Minimizes tangling.

As a lot of the radials will likely end up in the ocean I will put heavie weights on the far ends so they can be tossed out into the drink.  Will put breakaway links at the weights so if they foul on a rocky bottom, I can at least retrieve the wire.

[W2PFY]

Along the same lines are HV transmission lines. Near my camp there is a 115 KV 3 phase line. At the top there are two wires that are at ground potential. Each pole has a # 4 hard drawn copper wire going down the entire length of the pole and buried to the depth of the pole in the ground. Someone suggested that this would make the best 160 meter antenna in the world. I guess the wire going up the pole could be be shunt loaded. My worries are even if it worked, is the fact that the power companies I'm told, send VLF signals on the same wires for control of the network and that if a person did something like this, the system could be disrupted. I've heard of old buzzard tales of people doing this.  

# 1 question, would it work
# 2 question, how much prison time is dealt for doing something like this?

[flintstone mop]

Messing with the electrical grid could be considered an act of terrorism. Stay away from those muthas.

Fred

[N2DTS]

I would think all you would hear is electrical noise!

Brett

[W2PFY]

I would think all you would hear is electrical noise!

The suggestion was for transmitting only.