Alejandro Lieber wrote in news:i4h24t$1rl0$1
@adenine.netfront.net:

....
and take Rl=5 ohms for 8 radials of 8 feet each

That specifically escapes me.

Owen

On 08/18/2010 02:49 PM, Owen Duffy wrote:
Alejandro wrote in news:i4h24t$1rl0$1
@adenine.netfront.net:

...
and take Rl=5 ohms for 8 radials of 8 feet each

That specifically escapes me.

Owen


The 8 radial can be as short as 4 feet long for the same results.
I came to these results from R. J. Edwards (G4FGQ) program ENDFEED.EXE
It's interesting to note, that radial longer than 1.3m (4 feet), always
increase earth looses.

The complete modeling results can be seen at:

http://1fcr.com.ar/endfeed.pgn

Alejandro Lieber
Rosario Argentina
LU1FCR

http://1fcr.com.ar

--- news://freenews.netfront.net/ - complaints: ---

On 08/18/2010 06:16 PM, Alejandro Lieber wrote:
On 08/18/2010 02:49 PM, Owen Duffy wrote:
Alejandro wrote in news:i4h24t$1rl0$1
@adenine.netfront.net:

...
and take Rl=5 ohms for 8 radials of 8 feet each

That specifically escapes me.

Owen


The 8 radial can be as short as 4 feet long for the same results.
I came to these results from R. J. Edwards (G4FGQ) program ENDFEED.EXE
It's interesting to note, that radial longer than 1.3m (4 feet), always
increase earth looses.

The complete modeling results can be seen at:

http://1fcr.com.ar/endfeed.pgn

Alejandro Lieber
Rosario Argentina
LU1FCR

http://1fcr.com.ar

--- news://freenews.netfront.net/ - complaints: ---

Sorry:

the link to the results is:

http://lieber.com.ar/enfeed.png

Alejandro Lieber

--- news://freenews.netfront.net/ - complaints: ---

On Wed, 18 Aug 2010 18:21:08 -0300, Alejandro Lieber
wrote:

the link to the results is:

http://lieber.com.ar/enfeed.png

Not Found
The requested URL /enfeed.png was not found on this server.

Always use cut/paste from a browser actually viewing the page you wish
to share with others.

73's
Richard Clark, KB7QHC

On Aug 18, 2:21*pm, Alejandro Lieber wrote:
....
Sorry:

the link to the results is:

http://lieber.com.ar/enfeed.png

For what it's worth, the link works fine for me.

Cheers,
Tom

Alejandro Lieber wrote in
:

....
The 8 radial can be as short as 4 feet long for the same results.
I came to these results from R. J. Edwards (G4FGQ) program
ENDFEED.EXE It's interesting to note, that radial longer than 1.3m (4
feet), always increase earth looses.

The model sensitivity to radial length suggests that the radials are
modelled as short transmission line immersed in a lossy medium, in which
case, the assumptions about soil conductivity and permittivity are very
important to the model accuracy. It is unlikely though that shallow
buried radials are very consistent in behaviour due to the effects of
rainfall.

It would be interesting to measure the antenna and compare it with your
model predictions.

Owen

On Sat, 14 Aug 2010 21:49:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Owen Duffy wrote:

The article also shows a BNC connector option which IMHO is superior to
F connectors.

BNC compression connectors are available. They are much harder to install
properly than F connectors, but once you "get the hang of it", they work fine
and are sturdy. BNC to UHF adaptors are also available, and the ones I have
seen are better quality than the F to UHF ones.

I don't know if they are as water resistant as the F connectors designed for
outdoor use, but UHF (PL-259) connectors are in comparison sponges, so if
you are used to them, you should be able to deal with BNC connectors.

Note that there are different connectors for RG-59, RG-6 (not quad
shield) and RG-6 quad shield, and they can not be used on cables they
are not designed for. Either they don't fit on properly and don't make
connections, or fall off. :-(

You can buy a package of compression 50 BNC connectors and the appropriate
tool with international postage for about $50 on eBay.

There are three kinds of compression connectors I have seen so far.
One is a one piece solid connector, which when compressed, the back end
folds into itself (think of a metal accordian). The second is made from
two pieces fitted together, and when you compress it, the part in the back
is compressed into the front.

Both work well, and if you get the trimming right, will fit well. I found
on the two piece verisions I have, the center conductor has to be trimmed
to 3mm. 4 or more and they fall off. :-(

Note that when I say two piece, when you get them they are both one piece
and can not be separated. It's just obvious that not counting the ring,
they were made from one or two pieces.

There also is a third kind I have so far only seen in F connectors where
the front pushes into the back. I tried many in all sorts of ways and cables,
and either end up with it falling off, or making a solid fitting but no contact
to the shield (ground). :-(

I use a lot of compression F connectors that are truly 2 pieces with
the back piece being pressed into the front.
The front part has an extension that *just* fits over the foil and
under the braid and jacket. The back part is a snug fit on the jacket.
When the back is pressed into the front the forward part with a soft
plastic gasket compresses down on the jacket and braid giving a strong
connection to the braid and foil. The center of the coax (RG6) forms
the center pin of the connector. I just leave it long until after the
connector is installed. Then trim it off about 1/16th inch in front of
the connector. You can go a good 1/8th inch or cut it flush so there
is lots of leeway.

I use a commercial pair of pliers made for installing these, but it
would be fairly easy to make up a set of pliers if need be.

73

Roger (K8RI)
Any advice on how to get them to work would be appriceated. I still have
around 30 of them.

Geoff.

On Wed, 18 Aug 2010 19:45:37 -0700, Richard Clark
wrote:

On Wed, 18 Aug 2010 18:21:08 -0300, Alejandro Lieber
wrote:

the link to the results is:

http://lieber.com.ar/enfeed.png

Not Found
The requested URL /enfeed.png was not found on this server.

Likewise I get: " Sorry, the page you were looking for could not be
found"

73

Roger (K8RI)


Always use cut/paste from a browser actually viewing the page you wish
to share with others.

73's
Richard Clark, KB7QHC

Roger wrote in
:

On Wed, 18 Aug 2010 19:45:37 -0700, Richard Clark
wrote:

On Wed, 18 Aug 2010 18:21:08 -0300, Alejandro Lieber
wrote:

the link to the results is:

http://lieber.com.ar/enfeed.png

Not Found
The requested URL /enfeed.png was not found on this server.

Likewise I get: " Sorry, the page you were looking for could not be
found"

And when I click it in Roger's quote of the original post, it works for me.
Why would that be?

Owen