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 The cell phone antenna on the vehicle roof has been replaced by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Incidentally, the K40 has been replaced by the Wilson 1000 and 5000 as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

"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.

"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

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