"J. B. Wood" wrote in message
...
That is very similar to what the Maxcom Antenna Matcher
did. It was reviewed (and panned) in November 1984 QST.
As you suspected, almost all the power would go into the
dummy load and very little would be radiated.

Honestly, it's not a very good idea. :-)

73,
Bob
K3PH

Hello, and generally not if maximizing operating efficiency (the portion
of available transmitter power that is being radiated by the antenna) is
of concern. However, placing a low-loss pad between the output of one
device and the input of another can be a simple, inexpensive broadband
matching technique if the power loss in the pad can be tolerated .
Sincerely, and 73s from N4GGO,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

I was wondering when we would hear from someone like you.

On Fri, 10 Oct 2008 11:27:09 -0400, (J. B. Wood)
wrote:

Now what ever happened to those
cute car-mount cell phone antennas? Guess they're in antenna heaven along
with the K40s. Sincerely,

Nope. The cell phone antenna on the vehicle roof has been replaced by
a GPS telematics antenna, GPS map antenna, wi-fi war driver antenna,
XM/Sirius DAB antenna, GPRS antenna, and possibly a mobile DTV
antenna. Aerodynamics and safety have dictated that today's vehicles
have curved roofs and air bags in the door columns, making most
permanent roof top antennas impossible. Besides, most of today's cell
phones do not include an external antenna connector or need a car kit
"docking station". Besides, modern cell phones have to handle a wide
variety of frequencies for world cellular coverage, GPS, wi-fi,
Bluegoof, mobile TV, WiMax, and whatever else can be crammed in. A
single external antenna just isn't going to work without a diplexer
and multiple connectors. At least the antennas are now all internal
or the typical smartphone will look like a porcupine antenna farm, or
if retractable, a Swiss army knife.

Incidentally, the K40 has been replaced by the Wilson 1000 and 5000 as
the mobild CB antenna of choice.
http://www.wilsonantenna.com/w1000.htm
http://www.wilsonantenna.com/W5000.htm
Good to 5,000 watts AM or 20,000 watts SSB. For mounting elsewhere on
the vehicle, there are antennas with oversized stainless base or
center loading coils that could probably survive a direct lightning
hit. Of course, you need two of them with a "co-phasing" harness.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

In article ,
Michael Coslo wrote:

JIMMIE wrote:

Once I joke about using a CB groundplane with a 10 db pad for an all
band antenna.
I thought about this for a while and decided to try it. I did nt have
to use 10 db maybe it was only 3db or 6db I cant remember now
to get an antenna that my soliddtate transceiver with no tuner was
happy with on allHF bands. I was fairly amazed at how well the
antenna worked or at least amazed that it did work at all.


What is more, you didn't have to spend 600 dollars for a bad antenna.


- 73 de Mike N3LI -

Years ago, I was working on a Marine HF Radio, on the bench, in Seattle
WA, connected to a Bird 1 Kw Dummy Load. As I was setting the -16 db
Pilot Carrier Level for the Public Coast Station KMI, at Point Rayes CA,
on 12 Mhz, I got a reply from the Operator, ON Duty, asking for Station
Call Sign. I had a nice chat with him for about 5 minutes. ANY antenna,
no matter how it is built, even a Dummy Load, will radiate, and
communicate IF the Band is open. If the Band is closed, it doesn't
matter how efficient the antenna is, you will not communicate.

--
Bruce in alaska
add path after fast to reply

"JB" wrote in message
...

"J. B. Wood" wrote in message
...
That is very similar to what the Maxcom Antenna Matcher
did. It was reviewed (and panned) in November 1984 QST.
As you suspected, almost all the power would go into the
dummy load and very little would be radiated.

Honestly, it's not a very good idea. :-)

73,
Bob
K3PH

Hello, and generally not if maximizing operating efficiency (the portion
of available transmitter power that is being radiated by the antenna) is
of concern. However, placing a low-loss pad between the output of one
device and the input of another can be a simple, inexpensive broadband
matching technique if the power loss in the pad can be tolerated .
Sincerely, and 73s from N4GGO,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

I was wondering when we would hear from someone like you.


---------

When using the radio with the padded antenna in a city environment and when
utilizing nearby repeaters, it is quite acceptable to design equipment this
way. It also reduces the sensitivity of the radio to unfortunate antenna
shorts against automobile interiors or body parts.

If you have enough power left over to be DFQ into the repeaters with the
power available, I see it as a viable compromise that can be most
beneficial.

Hams tend to think in terms of operating simplex out into the far reaches of
the aether, but there are many situations where padding is a useful feature.

Ed, NM2K

Doesn't B&W do exactly that?

They called it a "balancing network" or some such thing...a resistor. Army
published a paper on it in the 40's or 50's.

Problem is the loss it causes.


-GC
W2DB


wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

http://www.bwantennas.com/ama/fdipole.ama.htm

http://www.bwantennas.com/ama/veeant.ama.htm




"Howard Kowall" wrote in message
...
Has anyone ever tried putting a dipole antenna up with the center
insulator being a high power 50 ohm dummy load,then connecting the dipole
elements across the dummy load.This would always keep a suitable match
at 50 ohms and satisfy the transceiver.Would most of the power go to the
dummy load and not the elements and wouldn't radiate.In thinking about
this it all logically makes sense the load would really never change or
would it have some reactance with the dipole elements.
Thanx All
Howard
VE4ISP

From an offshore site:
http://www.radiohc.org/Distributions/Dxers/ttfd2.html


http://www.hard-core-dx.com/nordicdx...wire/t2fd.html

http://www.universal-radio.com/catalog/sw_ant/0562.html

http://www.johncon.com/john/T2fd/

http://www.wellbrook.uk.com/UMBT2FD.html


http://home.comcast.net/~smithab11/T2FD.htm


http://www.korpi.biz/t2fd.pdf

http://p1k.arrl.org/cgi-bin/topdf.cgi?id=29006&pub=qst (if you have a arrl
membership)







"George Csahanin" wrote in message
...
Doesn't B&W do exactly that?

They called it a "balancing network" or some such thing...a resistor. Army
published a paper on it in the 40's or 50's.

Problem is the loss it causes.


-GC
W2DB


wrote in message
...
Howard,
Yes. Been some years ago now, but there was even a commercial
version sold (did pretty well too). Wish I could remember the name of
that thingy.
- 'Doc

wrote:

...
I'm glad you called it a 'balun (rf transformer)' instead of a 'balun
(CM Choke)'. Did Cecil review this before you posted it?

That is very disappointing and does not speak well for you.

I certainly expected you to realize a 1:1 balun (1:1 rf transformer
constructed in transmission line mode) IS a common mode choke ... :-(

Hang in there ... you'll get it ... eventually.

Regards,
JS

Jeff Liebermann wrote:
On Wed, 08 Oct 2008 10:07:03 -0700, John Smith
wrote:

...
Then you would need a suitable name for it. Let me see, we are mating
up a "dummy load" with a "dipole." How about "Dummy-Pole?" grin

Been there, done that. About 30 years ago, I went on a field day
exercise where one of the HF stations was running a lightbulb on a
pole for an antenna. 100 watts RF, about 50ft of RG-8/u, voltage
stepped down with some kind of xfomer or balun, and a 150 watt
incandescent light bulb. I don't recall how well they did, but I
could see that the log was filling with contacts. Who needs an
antenna anyway?


Hmmm, sounds like that you mention might be the "Original DummyPole!"
Or, "DummyPole I."

This new design should probably be named "DummyPole II." grin

Regards,
JS

On Fri, 10 Oct 2008 18:03:39 -0700, John Smith
wrote:

Hmmm, sounds like that you mention might be the "Original DummyPole!"
Or, "DummyPole I."

This new design should probably be named "DummyPole II." grin

Nope. I vaguely recall it was called a "lamptenna".

Somewhat later, I helped build a dipole using four 4ft fluorescent
tubes (two in each leg of the dipole hung horizontally on bamboo
poles). The 96" length was about right for a 10 meter dipole. About
80 watts out got the bulbs to light up. Once lit, the tubes were
quite conductive and made a functional transmit antenna and impressive
light show. It was totally useless for CW, kinda marginal for SSB,
and just great for AM. We had RTTY but couldn't find anyone to help
test it. We never did figure out how to light up the bulbs so we
could try receive. Various gross violations of the electrical code
and of common sense were attempted with no useful results.

There are those that can see the light...
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS