From: jlloyd@aristotle.cs.clemson.edu (John LLoyd) In article bfp@mace.cc.purdue.edu (Bryan Putnam) writes: >In article <2obijc$caj@hubcap.clemson.edu> jlloyd@aristotle.cs.clemson.edu (John LLoyd) writes: >> I would like to thank Dan Hughes and Werner Funkenhause for >>their instructions on building a "homemade select-a-tenna". I > >Could you repost those instructions? Thanks. > Message-ID: NNTP-Posting-Host: 142.156.2.13 There's been some exchange on this group as well as on FIDO shortwave echo about the "Select-a-tenna". This is a passive, inductive-coupling loop designed to be used with receivers having internal antennas. I think it costs about $50 in the USA and can be had from various sources. Anyone can build something that works equally well with just a bit of effort and a whole lot less cost. Get a 12x14 inch wooden picture frame, take out the glass but leave the fibre picture backing in place. Notch the corners and drill two small holes (from outside to inside) at opposite corners. Wind 14-15 turns of thin wire upon the frame the draw each end through one of the drilled holes. Mount a 365-500 pf capacitor dead centre in the fibre backing card (if you use a small Poly-pak type it can be epoxied into place) and solder one wire end to rotor and the other end to the stator of the capacitor. Make a small support to hold the whole thing upright and place it near your radio. Tune the capacitor for maximum signal on the radio and experiment with placement for best results. Originator: dhughes@firefly.prairienet.org The formula for number of loops is 242.3 divided by the square root of the area of the loop in square inches. So if you use a square form here are some values: Number of loops Length of each side of form 8 30 5/16" 9 26 7/8" 10 24 3/16" Double the number of loops; halve the length of each side if you want to use a smaller form. So 20 loops for a side of 12 3/32", for example. -- John Lloyd Computer Science Dept. Clemson University Clemson, South Carolina, USA