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Painting an antenna? Bad idea?

Metal content to follow under the discone topic (I had to reach to get it in there ;-))

Ground plane first. Just get something working to start with.

J poles are a blast but a bit 'fiddley' as a first antenna in my opinion. That's what makes them a kick to play with.

Do your scanner as a separate antenna for now. (just get something working). A home brewed discone might be fun. but for now, how about another ground plane? A look at a discone will give you any number of ideas on how to get the ground plane elements at the right angle. An indexing jig on an angle table in the drill press would make a nice looking start.

I'm doing a bad thing and not getting involved in the rest of the discussion, but what you need is an antenna you can listen with while you're building the ultimate loaded happy hoohaa bedspring grounded gopher catcher. At least that way you have something to listen to, and compare the results of each of the new antennas with.

When you get your ticket, inverted V if you're on HF, and a ground plane for vhf. You'll find you end up hanging out on mostly the same area of a band, just tune them up, get em running, and build the ultimate wave catcher next weekend. in the mean time, you'll have something that you can listen to.

Humm,,, I guess from my stand point, just get something in the air, even if it's just a long wire into the trees. It's a lot easier to work on an antenna, or other project (even in the lathe) if you've a good receiver running in the back ground.

Now for all the other guys,,, just get something up for now, then as soon as you get your super special rig running you can always take the ratty old thing down.

Did I say just get something working? Good luck, have fun, and it's a hobby,,, it's supposed to be fun!

Reply to
Grif
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Styped

I'm an old guy who has asked probably more questions that you ever will. I have no problem with those who ask questions. I do have some information asking questions from which you intend to get educated. The answers you get about facts will be very difficult to distinguish from farietales when you submit the questions to either Internet news groups and/or HAM radio forums. Go to a HAM swapmeet and pick up a book, any book that is afordable and might cover the subject you have questions about. If you read the posts on the Antenna news group, you will find several really well informed guys who will communicate with you Off Line. That group is loaded with antenna guys who truely know their stuff. Several have published extensively on the Internet. Try contacting Richard Clark in the Antenna news group for decent guidance.

Jerry

Reply to
Jerry Martes

Yes. Smog interferes with it also. However not by much - would it be a transmitter - no big deal - a feeble signal receiver most likely.

Martin

Reply to
Martin H. Eastburn

Wow - used to consult with that group - 24 years ago has it been - Phew! Flew all over the U.S. installing computer systems for REA power / load control. Naturally it drove at least one Motorola transmitter.

Martin

Reply to
Martin H. Eastburn

Except for the fact that the skin is deeper for less conductive materials, the extreme being fully nonconductive materials like vacuum, where no skin travels (not counting electron emissions, but that's not a bulk conduction sort of mode). Or rather, I should say, the skin depth is full, being the electric field continues across it.

Which brings me to another point: insulation won't harm anything, because the electric field across the paint will be very low. (Most of the E-field 'voltage drop' occurs across the air.) To AC, an insulator of high dielectric constant (plastics go from say 2 to 10, paint might be 3 to 6, SWAG) looks like another piece of wire.

The worst combination would be a paint which has the right resistivity that a large portion of the current flows in it, while still being resistive to it. About analogous to stealth radar-absorbent material, but for your antenna (and at lower frequency). But since this layer is much thinner, especially with respect to the wavelength, I sincerely doubt you'll notice any difference whether the paint is a perfect insulator, resistor or conductor.

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

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Reply to
Tim Williams

Thanks for your help. I have been leanign toward the ground plane but have been confused at some of the articles I have been reading:

I have a radio shack antenna book that has a saple plan for building a small wire antenna directly to a pl connector. It says that radials for a ground plane are bent to determine the antenna's impedance. But I have seen some that were not bent.

I would like to build something I would not have to fool with once it is up because I plan to put it high atop my tv antenna tower and I am not crazy about heights!

The other thing that bothers me about a ground plane is I have not seen any plans for a dual band version and I would also like to get on 440. By the way, I have my license.

Reply to
stryped

It always warms the heart to see a troll's attempt get short-circuited.

Reply to
Dave Hinz

Ok, I'm sure that the right thing to do is get it right the first time. Have fun on your quest! I also enjoy the book/reading side of several hobbies. For me, that's a large part of my hobby life. The book/learning thing is a whole different track than my comments about getting something working. I'd be tempted to just buy a dual band vertical at one of the ham sites, or swap meets around whereever you are, and mount that on the tower.

I don't know of any DIY's that don't need a bit of tweeking/tuning to get working, or at least not with me putting them together.

If it's about $$, the ground plane bothers you, and you only want to go up the tower once, I'm out of suggestions, perhaps TV? but I still stand by my statement of having fun!

Reply to
Grif

Forgive my ignorance, but what is a "indexing jig" I wonder if I could make a discone that would be an all bander. I have plans for a uhf copper discone. I wonder if I could modify it to cover vhf too. I wonder if I could use aluminum elements instead of all copper flashing? WOuld there be a difference in performance?

Reply to
stryped

If you google for "indexing jig" you will be enlightened. Don't forget the quote marks.

Reply to
Dave Hinz

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