[R-390] Re: Small Voodoo Antennas

[Rbethman]

Hello!

    I am a LIVING experiment of BPL!  Manassas, VA is running it 
currently.  I hear EVERY burst from 2Mc up through 30Mc!

    I HAVE to get out the reel to reel tape deck and start recording for 
both the ARRL and the City Council.  Maybe even the FCC!  It very 
DEFINITELY detrimental to the HF bands as a whole.  FEMA definitely WILL 
have problems, along with us.

    I agree that almost ANYTHING makes one darn good receiving antenna.  
My own little arrow shaft vertical was more tham proof to me.  The thing 
that started that project was looking at the collapsible whip on TOs and 
my Mohican.

Bob - N0DGN

Bob Camp wrote:

> Hi
>
> The wire wound arrow shaft antenna working well  is actually a proof 
> of Maxwell's fifth equation which more or less states "the antenna you 
> count on the least will always work the best".
>
> Most of us go (myself *very* much included) go overboard on  receiving 
> antennas most of the time.
>
> Transmitting antennas are a bit of a different story. A lot of the 
> theory we are taught applies only to a transmitting antenna. Which 
> parts of the rule book apply to which kinds of antennas is rarely made 
> clear either in the text books or in class. Often the reaction of 
> anybody who has used an antenna is "electromagnetic theory is bunk". 
> It's not bunk, it's just so complex that they rarely teach it in a 
> comprehensible fashion.
>
> If you sprinkle a bit of salt (maybe a bit more than most people would 
> ....)  on a  damp piece of yarn (say very damp) looped over the back 
> of a chair (a large chair)  and hook it to your R390 whip antenna 
> input. It is acting as an adequate antenna *if* the radio noise level 
> (front end noise + antenna noise) rises when it is connected to the 
> radio.  It may not be the best antenna you could have but it is doing 
> a job for you. For the full recipe and other exciting details on this 
> dish please visit our web site ....
>
> A lot of modern antennas are amazingly small by the standards of days 
> gone by. One excellent example of this is an amplified whip antenna 
> that a bunch of the guys from this list came up with. It uses a very 
> expensive FET running hot enough to cook an egg. Very good performance 
> from sub 100 KC up through 30 MHz (it even does that little trick as 
> well ...). Most loran-C antennas are *very* small when you consider 
> the wavelength of a 100KHz signal.
>
> Most of us have more trouble from local noise than we used to. A small 
> antenna located far from, or maybe at right angles to a noise source 
> may be a better bet than a nice big one that runs right into the noise.
>
> Soon by virtue of broadband over power lines we all will be able to 
> get a *lot* more experience with this sort of thing. Or I suppose we 
> could just stop playing with radios. Then we could turn this into a 
> full time humor list ....
>
>     Take Care!
>
>         Bob Camp
>         KB8TQ
>
>
>
> On Jul 10, 2004, at 5:07 PM, Rbethman wrote:
>
>> Hey Gang!
>>
>> Take this in another direction.  Using one of those 50 ohm antenna 
>> connectors, I attacged two fiberglass arrow shafts.  I joined them 
>> together with a 1/4" dowel.  I wound its length with #26 enameled 
>> wire VERY tightly and closely wound.
>>
>> I have NO idea as to its impedance.  BUT - my den is mostly below 
>> ground level.  The recption ia AS GOOD as an outdoor antenna of 
>> either dipole or ant other I've strung!
>>
>> The R-390A loves it and performs flawlessly.  YMMV.  But it sure 
>> works for me!
>>
>> Bob - N9DGN
>
<                      Bob Bethman - N0DGN
+-------------------------------+----------------------------------+
| N0DGN AMRadio Manassas, VA    |    REAL Tube Radio and AM        |
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|       Manassas Radio - Home of Homemade Kielbasa & Pirogi        |
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| Bob Bethman                \\\|///     " The absence of a danger |
| rbethman(at)comcast.net   \\ ~ ~ //      signal does *NOT* mean  |
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| 1 BC-610I w/BC-614I,1 T-213/GRC-26 w/BC614I 1 '51 Collins R-390A |
| 1 '67 EAC R-390A, Heathkit DX-60, Apache, Mohawk, SX-101, HT-32A |
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|           Amateur Astronomer - Celestron Nexstar 8               |
|             12" f5 Dob coming soon!  Being built                 |
|                  Meade ETX-60 (Got it back!)                     |
|               38 Deg 46.8' N - 77 Deg 28.5' W                    |
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