Home |
Search |
Today's Posts |
#10
![]() |
|||
|
|||
![]()
It's a new hole -- two days old now though. I am using an MFJ-1623
tuner which also includes tuning for the counterpoise ground which I'll be using. The wire will be enough to hold one small bird -- if necessary I can always rebuild with heavier wire (the MKII version I mentioned before)! I checked carefully before I drilled and missed the glass entirely which is unusual because Murphy lives with me! I've never seen him, but his influence is always around! The magnetic loop would not be using the window frame -- I have some 1/2 inch flexible copper tubing which I brought from my condo (which will officially be off my books at noon today!) Last week we had a flea market in Calgary. Having given away all my precious ham radio parts (aka junk) I was in dire need of a roller inductor and a variable capacitor or two to build (if necessary) an artificial ground, or a matching device of some sort for whatever purpose I might dream up. I walked into the market, paid my admission, and the first thing I saw was a box (about 4 cu ft) of variable caps of assorted shapes and sizes. I bent down to have a closer look since I could hardly believe my eyes, and asked the seller 'How Much?' At the same time, I noticed another box of the same size full of assorted inductors, some roller inductors, some coil forms, some coil stock and such. It was like a dream come true. The seller responded '20 bucks for the whole box' and I asked 'How about 20 bucks for both boxes' and he accepted! Talk about a lucky find -- some of that stuff is hard to find nowadays, and to purchase would cost a fortune. I have both boxes in the trunk of my car as there is little room in my suite to allow me to start collecting parts aka junk! I've brought the cream of the crop up to my suite and have cleaned them off using an electric toothbrush and a mildly abrasive cleaner -- they look like new. I now have sufficient L and C, both fixed and variable, or every sort and description to keep me happy for a long while. The rest I will store in my brother's garage until the next flea market where I intend to recoup my $20 bucks plus the admission price! I've tested the MFJ-1623 and it will work 80 thru 10M with the wire -- the wire is basically the same as the 12 foot whip only longer but thinner. If it doesn't, I have another MFJ-949E which I got as junk because the coil switch was burned (I replaced it in an hour with a new single pole 12 position) and it's been tested and used by a friend of mine for the last couple years. If one or the other works or doesn't, I've got all that LC stuff from the flea market so if necessary I can put together enough to load a wet noodle. I did load a wet noodle once, and worked from Penhold AB to Red Deer AB (about 10 miles) just to show it could be done! I love antennas. Does anyone recall reading a book on antennas that had a Chapter subtitle saying 'Antennas are Funny People!'? I'd love to find the book again. My carpeting is wall to wall, so the chicken wire ground would have to be on top of the carpet. I'm sure though, that if anyone asked, I would simply explain 'I'm a Ham' and they would shake their heads understandingly and not ask any more foolish questions! One way or the other, with the planned setup, I intend to get some signals out -- come hell or high water. I don't give up on my hobby after all these years, and I've helped many a ham get on the air under worse (but not much worse) circumstances. Gotta get downstairs and vote -- we are having our provincial election today! 73 Irv VE6BP "Jeff Liebermann" wrote in message ... On Sun, 22 Apr 2012 23:18:17 -0600, "Irv Finkleman" wrote: I just want something quick and cheap so I've ruled out anything like copper clad steel and such. Will your 25ft span of copper wire support a few birds? If not, please reconsider copperweld. Just to clear things up on the geometry, the wire will run out the window horizontally to the tree (about 25 ft) and then drop vertically (another 25 ft approx) through the tree to just above the ground. Sort of an inverted letter "L". It is just a random wire, and the best I can do at the moment given my current situation. Do you have an antenna tuner? The FT-817ND does not have a built in antenna tuner. You're going to need one with your random wire and random configuration. The hole through the window frame is too small (1/4 in.) for conduit but I plan to use a heavy plastic kids drinking straw, tilted down on the outside, and plugged with some silicon seal at each end where the wire enters and exits. Ummm... is this an existing hole are you going to drill a new hole? The modern windows that I've seen have the glass extend almost to the edge of the frame with only a sheet rubber spacer in between. You're highly likely to drill through the glass if you decide to drill the frame. I may even try loading the window frame (aluminum, 5 ft x 5 ft (approx)) using a handy sheet metal screw for the connection. With 5 watts, that might work. Forget about building a magnetically coupled loop. You would need to split the frame at some point, and install a variable capacitor. That's probably not going to happen. If your window proves to be uncoated glass (unlikely), you might consider two squares of aluminum foil on both sides of the window to couple through the RF via a ladder line. You won't get much capacitance so it won't work on the lower frequencies, but should be tolerable for the higher bands. A reminder -- the ground system will be tuned counterpoise wires running along the wall inside my apartment. I have an MFJ-1623 tuner which will handle tuning the antenna and the counterpoise in a very nice compact arrangement with only one meter to watch! Good, you have a tuner. However, that's designed specifically to handle a 12ft balcony mount HF antenna. I don't know what it will do with a longer antenna. Looking at the schematic: http://www.mfjenterprises.com/pdffiles/MFJ-1623.pdf it seems to be a crude L match, which isn't going to match every combination of reactance and frequency. The meter does NOT indicate VSWR, so you really won't know if the tuner is effective. My guess(tm) is you're going to purchasing a more elaborate antenna tuner, a VSWR meter, or using a 12ft piece of wire. I once used a large sheet of WELDED chicken wire under the carpet for a "ground". It has to be welded to prevent the galvanizing from forming diodes. It sorta worked but nobody wanted the lumpy carpet. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Some ideas ... | Antenna | |||
5/8 over 5/8 over 5/8.. On 2m - Looking for ideas | Antenna | |||
Any ideas of the best value -vs- money for 6 and 2M? | General | |||
Heathkit HW-32A Ideas | Boatanchors | |||
Heathkit HW-32A Ideas | Boatanchors |