Dipole antenna

"Anthony Fremont"

YOU can go to HELL - IDIOT.

........ Phil

"Anthony Fremont"

Explains it all really.

....... Phil

"Anthony Fremont"

= autistic, illiterate bloody IDIOT

Explains it all really.

....... Phil

It depends on which kind of "electrically short" you mean. If the antenna is exactly tuned to resonance, then it will present a resistive impedance of, I guess, 72 or 77 ohms, something like that, AKA "radiation resistance" - it is the "load" that consists of the power it takes to send radio waves out into space. That might appear as an "electrical short" relative to a high impedance source. The other thing is, dipole antennas aren't actually a physical half-wave long, because of "end effects" - like its own inductance, its capacitance to the surroundings, and that sort of thing, but that's rarely referred to as "electrically short".

It could very well come from that mnemonic about standing waves in a transmission line, "Our Commander Sucks Lemons", or OCSL: Open, Capacitive, Short, Inductive. This is how tuned impedance transformers are made. (I don't know why 'L' stands for inductance.)

See if you can find a copy of the ARRL Handbook, or better, the ARRL Antenna Book.

Or google on "antenna impedance" or "half-wave dipole" or whatever you want to know about. Maybe "standing waves". Go to the "Search" part of google.

And why did you post this three times?

Good Luck! Rich

I think even a newbie - even a googlegroupie [ ;-) ] should be able to discern that Phil's reaction here isn't really worthy of note.

I know some theoretical stuff about antennas, and when I was about 12 I got my novice license, WN0GJS, and put a 40-meter folded dipole with twin-lead feedline up on the roof of the house. I actually made some contacts - I forget the jargon at the moment - I had a collection of about 3 ~ 4 QSL cards. ;-)

The transmitter had a pi-net output, and I stuck the twin-lead into a PL-259; used a knife switch for a T/R switch. So, I know enough about antennas to know that that one worked, although I did feel a little skittish about driving twin-lead from an unbalanced output. :-)

Cheers! Rich

On Tue, 10 Jan 2006 13:09:35 +1100, Phil Allison trolled:

Allison, you never have anything of value to contribute, do you? What do you get out of sitting there calling people names? What's the payoff for you?

I just can't imagine what you get out of getting into those pissing contests with him. In some circles, that's called "trollfeeding," which you may have noticed in my other post as The Pig Bladder On A Stick. ;-)

Cheers! Rich

Why don't you take your childish attitude somewhere else? You were wrong....so what....it's not like it was the first time. Now please try to get over it and move on with your life.

right...

which

;-)

I actually derive some deviant form of pleasure out of watching him blow his top. I figure that I've earned a special place in phil's list of usenet enemies when every response is just more vulgar tripe and nary a shred of logical argument. It seems to me that once you acheive that form of response from him, you have beaten him. ;-)

Admittedly, I love a good argument, but smart as phil is, he just can't reciprocate.

"Anthony Fremont"

......... Phil

"Pig Bladder"

.......... Phil

" Anthony Fremont "

Plus a full on usenet criminal.

One really evil dude.

....... Phil

Do a Google search on "electrically short " and " antennas ".

The term has been in wide use for many decades.

So have "electrically short" antennas.

Apologise to me and the OP any time.

.......... Phil

" Anthony Fremont "

Plus a full on usenet criminal.

One really evil dude.

....... Phil