In the spirit of "some antenna is better than no antenna at all," I'm going to add a base loading coil to for 160m to my 40 foot vertical (http://www.n3ox.net/projects/lowbandvert). I know it's a sub
Why not make the coil from small aluminum tubing without leaving the form in place? It would be easy to adjust. 73, Keith NM5G In the spirit of "some antenna is better than no antenna at all," I'm go
Why not use copper tubing which is available at those 'despot' type stores? Copper is much easier to work with [and solder taps where needed] than aluminum. Don N8DE _________________________________
I've used a fair amount of PVC pipe over the years for insulators and here are my observations: The exterior color says nothing about what's actually inside the pipe wall. I turned some White PVC dow
And MUCH more expensive. Aiee.. I just bought some 1" pipe elbows $4-5 each! I'm keeping that 100 ft spool of tubing hidden away. _______________________________________________ _____________________
I bought seven 100' coils of copper tubing about 5 years ago .. hidden in the garage .. but available, if anyone else needs some, LOCALLY. Don N8DE _______________________________________________ ___
Self supporting coils are a decent idea but I don't have the materials like I do with the PVC/wire coils. Also, the coil needs to be pretty dimensionally stable, which I think would require pretty su
I used gray PVC for the insulator on my 160m vertical and it works fine. I see no reason not to use the material that you have. You don't mention what power level you intend to transmit with, but per
You are going to need something more than just a loading coil to match it. A 40 ft vertical with an 80 uh coil at the base, using #14 wire, should be resonant on 160 meters but the feedpoint impedanc
How does the program calculate the loss and change in resonance with the form? I assume that the loss would be from the parasitic C, since there's low loss from the magnetic fields? The change in tur
This doesn't relate to the original question about inductor forms (see link at end), but matching 12 ohms is quite easy with a simple "hairpin" match. It just requires that the antenna (including any
It's not immediately obvious as to what is going on with these coils. The additional loss is from the dissipation factor of the dielectric which is a function of the electric field strength. Also the
Hi All, I have a Force 12 EF180S rotatable dipole for 80 meters. The 1 3/4" dipole element is insulated from the mast plate using gray PVC tubing. A matching box allows coils to be placed in series w
Well, it seems from all the advice I've recieved that PVC is *marginal* as a coil form. I've gone and built the thing anyway; did it last night, but since I'm running low power and other system loss
Author: "WA3GIN @ Arlington County, VA" <wa3gin@erols.com>
Date: Tue, 05 Dec 2006 16:45:01 -0500
HI, I think the voltage concern is going to be at the top of the antenna but I could be wrong. The electrical (gray) PVC holds up well outside in UV. But one can always paint the plastic black which
With 1500 watts to Dan's 40 foot vertical on 160m (assuming 10 ohm equivalent ground resistance), the voltage across the loading coil would be about 9.5 kV rms. That drops to only 2.5 kV rms at the 1
Which is why I assumed the parasitic capacitor got about twice as big (frequency ratio of 0.70 is about doubling the LC product, and the L's just not changing much). To get twice the C with essential
"And 14.3 watts more than I can radiate on 160m" Yeah, if I find I can *hear* anything on 160 with this thing, I'll pursue more efficient loading schemes so I don't lose so much in the ground. Dan __
I'd say that PVC is a fine material for coil forms, if it works. My experience with using it has been generally good, but unpredictable (that is, every once in a while you get a piece of junk). It's
Author: "WA3GIN in Alex. City, VA" <wa3gin@erols.com>
Date: Tue, 5 Dec 2006 19:55:00 -0500
I run 7 watts into a 50ft center-loaded helical and use a common MFJ tuner to match the input. I have gotten good reports from stations as far as Ontario, Canada. He might do just fine with 14 watts.