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#11
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"JGBOYLES" wrote in message
... Some years ago experiments have be done using trees as antennas. Where can I find references about ? Do fellows here known about the results ? Seems like I remember an article in the 70's in 73 magazine (what else?) about this very subject. I don't have time to look back thru my old mags., but I bet the results indicated trees don't work well as antennas. If they did, a lot more hams would be using them. I don't think I have ever had a contact with someone using a tree. 73 Gary N4AST Maybe we can open a new branch of science, and solve some knotty problems. Please, don't say "What a sap!". This is serious: we've got a trunkful of knowledge here in the group, and we can put the crown on this whole idea. I'm not just barking at the moon. Bill |
#12
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Please, don't say "What a sap!". This is serious: we've got a trunkful of
knowledge here in the group, and we can put the crown on this whole idea. I'm not just barking at the moon. Bill Tough finding many different tree species in OK. But everyone enjoys OK's wide open spaces. 73, Chip N1IR |
#14
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On 18 May 2004 19:56:34 -0700, (k4wge) wrote:
From: (Prozma) Ah Yes, the Mutt of the Mutt 'n' Jeff comedy act. |
#15
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Many thanks for all the responses.
I remember that in the experiment I have mentioned, the coupling to the tree was via an toroidal coil which was mounted around the tree, the tree beeing in the axis. Sure, a tree cannot be a good antenna. Any "real" antenna will probably always be better. But often the question is: no antenna at all or anything which does not seem to be an antenna. Perhaps a tree can be such a thing. Further, in portable operation, it is not always easy to install a "real" antenna. Claude |
#16
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I regret I cannot give you an exzact reference but the WIA
magazine Amateur Radio, some years ago had such an article and the results thereof. It worked quite well for what it was (a tree) and there were even suggestions as to which species were better than others! AFAIK it wasn't an April edition. Some of the gum trees here are 150+ feet high and the trick seemed to be tapping in at the right level from the ground. Some unhelpfull folk later suggested the 8' of coax to the matching network was the radiator :-( I have no way of finding this info - maybe you can search the net? Cheers Murray vk4aok Claude Frantz wrote: Many thanks for all the responses. I remember that in the experiment I have mentioned, the coupling to the tree was via an toroidal coil which was mounted around the tree, the tree beeing in the axis. Sure, a tree cannot be a good antenna. Any "real" antenna will probably always be better. But often the question is: no antenna at all or anything which does not seem to be an antenna. Perhaps a tree can be such a thing. Further, in portable operation, it is not always easy to install a "real" antenna. Claude |
#17
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Sure, a tree cannot be a good antenna. Any "real" antenna will probably
always be better. But often the question is: no antenna at all or anything which does not seem to be an antenna. Perhaps a tree can be such a thing. Further, in portable operation, it is not always easy to install a "real" antenna. Claude Trees are, as already noted, usable as VHF antennas when properly 'fed'...whether you should or shouldn't use a tree is your decision. It is hardly a new idea. Certainly placing a bona fide VHF antenna--in the clear--on top of the tree is the better of the two options. The interesting question is: how does a tree compare to a ground-based monopole? There is a reason why VHF monopole antennas are not on the ground, whereas MF ones are. Experiment for more info. Many have been down this path before. I don't know a sap or a chump in the bunch. 73, Chip N1IR |
#18
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Claude Frantz wrote in message ...
Many thanks for all the responses. I remember that in the experiment I have mentioned, the coupling to the tree was via an toroidal coil which was mounted around the tree, the tree beeing in the axis. Sure, a tree cannot be a good antenna. Any "real" antenna will probably always be better. But often the question is: no antenna at all or anything which does not seem to be an antenna. Perhaps a tree can be such a thing. Further, in portable operation, it is not always easy to install a "real" antenna. Claude I've seen advertising in QRT for the latest new miracle sticks: *SAPSUCKER 2000T®*. and the mighty: *BARKBURNER 9000TRX-DX®* Note that the ground qualities will enhance automatically by using such an treetenna. That is because most all dogs will stop and urinate against the base of said device. Add a few beer drinking buddies to the party, and you will be a dx chipper in no time. Squirrels can add nests, which will act as additional top loading. Beware of tree beetles, infections, etc.. After a while the treetenna could become a: *STUMPSTICK* Gasp! These have been proven to be inferior radiators due to the *stumphole effect* to the rf as it encounters the many rings in the tree stump. These proceed to turn the rf round and round ,like flushing a toilet, and ploink, you blow the finals in your rig, due to a massive *wormwood* pulse that flows back along your feeder to the rig and your operating position. Usually a desk or table made of wood, which further increases the potential of damage to the station. MK |
#19
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On Tue, 18 May 2004 10:26:59 +0200, Claude Frantz
wrote: Some years ago experiments have be done using trees as antennas. Where can I find references about ? Do fellows here known about the results ? Claude enter "tree antenna" into GOOGLE GROUPS, 17 000 hits, needs some additional filtering , but here we go! I used them trees, while I was a boy, to listen to medium wave radio stations with my diode detector, a 60 mm nail, a hammer, some wire, worked great, nail them in about 3 meters height. S9 + 20 dB, for sure :-) w. |
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