Hi all, i am installing a mobile radio into my car soon. I need an antenna
that will cover 2 metres, 70cm and uhfcb as the rig only has one antenna
socket. I would appreciate any information on how to make one antenna to
suite these 3 bands or maybe there is one available. I would prefer to build
one. Yes, i know I'm not supposed to be using a ham radio on UHFCB so don't
bother mentioning it.

Thanks.

Gary
VK3LCD

Gary,
I'm not familiar with UHFCB at all, what frequency range is it in?
- 'Doc

UHF Cb in Australia is in the range of 476.425 - 477.400 MHz.
Sorry, i was thinking i was posting in an Australin ng.

So i need an antenna to cover 144-148, 430-440 and 476.425-477.400MHz

Thanks.

Gary

wrote in message
...
Gary,
I'm not familiar with UHFCB at all, what frequency range is it in?
- 'Doc

Gary,
For what it's worth, take a look at some of the "Comet" mobile 'dual
band' antennas. They advertise as being broadbanded and are to some
extent (how much, I don't know). I've had no reason to try the
'UHFCB' frequencies, but I do know that at least one of 'Comet's dual-
band antennas is fairly broadbanded on 2 meters/150 Mhz. Can't
measure on the UHF portions so can't say one way or the other.
- 'Doc

And also keep in mind that "FWIW" thingy! As in, don't take my word
for it.

Gary Smith wrote:
UHF Cb in Australia is in the range of 476.425 - 477.400 MHz.
Sorry, i was thinking i was posting in an Australin ng.

So i need an antenna to cover 144-148, 430-440 and 476.425-477.400MHz

Thanks.

Gary

=======================================
UHFcb in Oz-land is highly likely similar to PMR446 in Europe and FRS
in the USA.

PMR446 are 8 RF channels with 12.5 kHz spacing starting at 446.0025
MHz . That means using a Ham radio it must have the capability to be
set at 2.5 kHz channel spacing and few if any ham transceivers have
that. Also, the deviation is set at a low 1.5 KHz.

So I wonder how UHFcb is operated in Australia ........would a Ham radio
with extended range be usable ?

Frank GM0CSZ / KN6WH

They certainly are, i'm using a couple at the moment. Our 2 Mtr and 70cm and
UHF CB are all 25KHz spacings.
There is talk of changing the UHFcb to 12.5 Kc to get 80 channels instead of
40 but i don't see how this will work as there will still be thousands of 40
channel radios out there with standard deviation splattering all over the
newer narrower radios.

As for the pmr446 band, you need a radio that will do 12.5kHz not 2.5 which
are available here and i would guess many other countries. From what i read
the band starts at 446.0 and goes to 446.1, thus 446.012.5 - ch1, 446.025 -
ch2, 446.037.5 - ch3 446.050 - ch4 etc. The deviation for that would be
around 8kHz and for 25KHz would be around 12. i think, not 100% but i'm sure
it's something like that over here.

Anyhow, i still need an antenna lol.

Gary


"Highland Ham" wrote in message
...
Gary Smith wrote:
UHF Cb in Australia is in the range of 476.425 - 477.400 MHz.
Sorry, i was thinking i was posting in an Australin ng.

So i need an antenna to cover 144-148, 430-440 and 476.425-477.400MHz

Thanks.

Gary

=======================================
UHFcb in Oz-land is highly likely similar to PMR446 in Europe and FRS in
the USA.

PMR446 are 8 RF channels with 12.5 kHz spacing starting at 446.0025
MHz . That means using a Ham radio it must have the capability to be set
at 2.5 kHz channel spacing and few if any ham transceivers have that.
Also, the deviation is set at a low 1.5 KHz.

So I wonder how UHFcb is operated in Australia ........would a Ham radio
with extended range be usable ?

Frank GM0CSZ / KN6WH

On Wed, 28 May 2008 12:58:03 +0100, Highland Ham
wrote:

Gary Smith wrote:
UHF Cb in Australia is in the range of 476.425 - 477.400 MHz.
Sorry, i was thinking i was posting in an Australin ng.

So i need an antenna to cover 144-148, 430-440 and 476.425-477.400MHz

Thanks.

Gary

=======================================
UHFcb in Oz-land is highly likely similar to PMR446 in Europe and FRS
in the USA.

PMR446 are 8 RF channels with 12.5 kHz spacing starting at 446.0025
MHz . That means using a Ham radio it must have the capability to be
set at 2.5 kHz channel spacing and few if any ham transceivers have
that. Also, the deviation is set at a low 1.5 KHz.

So I wonder how UHFcb is operated in Australia ........would a Ham radio
with extended range be usable ?

Frank GM0CSZ / KN6WH
That depends on the laws of your country. In the US it would have to
be type accepted by the FCC and ham radio would not qualify.


--
73 for now
Buck, N4PGW

www.lumpuckeroo.com

"Small - broadband - efficient: pick any two."

On Tue, 27 May 2008 12:34:53 +1000, "Gary Smith"
wrotF:

Hi all, i am installing a mobile radio into my car soon. I need an antenna
that will cover 2 metres, 70cm and uhfcb as the rig only has one antenna
socket. I would appreciate any information on how to make one antenna to
suite these 3 bands or maybe there is one available. I would prefer to build
one. Yes, i know I'm not supposed to be using a ham radio on UHFCB so don't
bother mentioning it.

Thanks.

Gary
VK3LCD

Hi Gary,

The Comet CA-2x4SR almost makes it with 140-160/435-465 MHz @ less
than 1.5:1.
http://www.cometantenna.com/products.php?CatID=1&famID=4&childID=4

You could play around with a conical monopole, sort of like an upside
down discone. Nil-Jon used to sell one.
http://www.eham.net/reviews/detail/1326

Mike kc9doa

Gary Smith wrote:

Hi all, i am installing a mobile radio into my car soon. I need an antenna
that will cover 2 metres, 70cm and uhfcb as the rig only has one antenna
socket. I would appreciate any information on how to make one antenna to
suite these 3 bands or maybe there is one available. I would prefer to
build one. Yes, i know I'm not supposed to be using a ham radio on UHFCB
so don't bother mentioning it.

Thanks.

Gary
VK3LCD

Two options come to mind, Gary. The first is to find a commercial diplexer
that covers your frequency ranges, which is not likely, second is to build
a three port diplexer. Google for diplexer, and you find a fair number of
designs, many of which could be modified quite easily, I think.

Third, a 1/4 wave antenna at VHF is a 3/4 wave antenna at UHF. Can you make
one broadbanded enough to cover? Don't know, but it might be worth trying.

--
Bob Smits, VE7HS, Ladysmith, BC

"What a wonder is USENET; such wholesale production of conjecture from such
a trifling investment in fact." -- Carl S. Gutekunst