Regarding accessory antennas... While it is impolite net style to add a "Me too." I'll risk it here as this is valuable information for perhaps many of us but I need help. Would one of you more knowledgeable posters give us some pragmatic instructions on making an extended antenna for in-camp emergency use. What materials should we use (coax, plain wire of what gauge?) How should the antenna be connected to the radio, how should it be deployed? Hung horizontally between tree limbs, vertically? A parts list and suggestions for places to obtain them would be a boon. Of course the formulas for length etc. would help too, along with any use advice regarding tuning (without additional equipment). Thanks for your guidance. Rich Mitchell Robert C. Cline wrote: > > >The problem is that VHF is vertically polarized so you would need to suspend > >the 1/2 wave dipole vertically, then feed it from the middle without > >compromising the radiation pattern. Then you end up with a 1/2 wave > >vertical. The yagi will provide significantly more gain over a > >dipole..usually 7 or 7 dB for 3 elements. > > Bob: Are there published documentation on the difference in gain between > horizontal and vertical polarization in VHF frequencies? At most amatuer > freq. range, I didn't notice significant problems communicating between the > two. > > Do you happen to have the formulas handy for both the j and the dipole? I > guess the best cut would be for Ch16. What are the dimensions for each? > If you've got the fomulas handy, that is. > > > > >The easiest antenna to use in the field is probably a J-Pole made from coax > >and twin lead for pennies. It can be suspended from a tree and will produce > >excellent results. > > Yes. I was thinking about carrying a spare antenna in the even I was > stranded somewhere...rather than trying to errect a whip on the boat itself. > > Robrt > > *************************************************************************** > PaddleWise Paddling Mailing List > Submissions: paddlewise_at_lists.intelenet.net > Subscriptions: paddlewise-request_at_lists.intelenet.net > Website: http://www.gasp-seakayak.net/paddlewise/ > *************************************************************************** Robert C. Cline wrote: > > >The problem is that VHF is vertically polarized so you would need to suspend > >the 1/2 wave dipole vertically, then feed it from the middle without > >compromising the radiation pattern. Then you end up with a 1/2 wave > >vertical. The yagi will provide significantly more gain over a > >dipole..usually 7 or 7 dB for 3 elements. > > Bob: Are there published documentation on the difference in gain between > horizontal and vertical polarization in VHF frequencies? At most amatuer > freq. range, I didn't notice significant problems communicating between the > two. > > Do you happen to have the formulas handy for both the j and the dipole? I > guess the best cut would be for Ch16. What are the dimensions for each? > If you've got the fomulas handy, that is. > > > > >The easiest antenna to use in the field is probably a J-Pole made from coax > >and twin lead for pennies. It can be suspended from a tree and will produce > >excellent results. > > Yes. I was thinking about carrying a spare antenna in the even I was > stranded somewhere...rather than trying to errect a whip on the boat itself. > > Robrt > > *************************************************************************** > PaddleWise Paddling Mailing List > Submissions: paddlewise_at_lists.intelenet.net > Subscriptions: paddlewise-request_at_lists.intelenet.net > Website: http://www.gasp-seakayak.net/paddlewise/ > *************************************************************************** -- Richard G. Mitchell, Jr. Department of Sociology Oregon State University Corvallis, OR 97331 U.S.A. (541) 752-1323 phone/fax mitchelr_at_ucs.orst.edu *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Tue Jan 12 1999 - 10:23:54 PST
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