On 2 Dec 2008 06:15:20 GMT, Top wrote:

(Dave Platt) wrote in
:

In article
, Douglas
W. \"Popeye\" Frederick
wrote:
I suspect you'd get more bang for your buck by simply
mounting a single antenna in a better location (e.g. roof
mount) and paying attention to making the antenna's
grounding to the chassis/groundplane as direct and solid as
possible.


Cophase being omindirectional? You need to do some more
reading before you try to correct anything.



IF the cophased antennas are less than 1/4 wave apart, there is
virtually no change.

On Mon, 1 Dec 2008 23:55:02 -0800, (Dave Platt)
wrote:

In article ,
Top wrote:

Cophase being omindirectional? You need to do some more
reading before you try to correct anything.

The directionality of a broadside array (with the two radiators fed
exactly in phase) depends very strongly on the separation between the
two antennas. For separations of 1/4 wavelength or less, there's very
little directionality - the pattern is very close to omnidirectional.

Every dual-antenna truck setup I've seen has been a side-by-side
mounting (e.g. one on the left mirror and one on the right), and the
harness feeds them both in-phase. I've been assuming that this was
what was being meant by "co-phase".

If so, I stand by my statement that two CB antennas, fed in phase
through a co-phase harness (i.e. no phase difference between the two),
and separated by only 54 inches, produces a nearly-omnidirectional
signal. The two antennas need to be further apart, before the pattern
becomes significantly directional.

Take a look at the NEC plots at http://www.cosjwt.com/index.php?a=20
to see... the 4.5-foot separation model produces a pattern which is
almost circular. There is little gain towards the front and back, and
very little loss off to the sides. These plots seem to jibe well with
other references I've read (Terman, Kraus, and the graphs in the ARRL
Antenna Book).

The other alternative is an end-fire array, with the antennas fed
signals of opposite phase - with these then there can be significant
directionality even with close spacing of the antennas. In a
truck-antenna system, this would require placing the antennas one in
front of the other, separating them by several feet, and inverting the
phase of the signal sent to one of the two antennas (perhaps by having
the feed coax to one antenna be 1/2-wavelength longer than the other).
You could get several dB of gain this way... but the close spacing
will cause the antenna feedpoint impedance to drop a lot, and some
form of matching network will certainly be required to keep the radio
happy and develop maximum power from the transmitter.

The two bottom plots on the site I mentioned above, show the effect of
feeding the antennas with signals of different phase. In these
examples, the pattern is being skewed off to one side - the difference
in feedline length is converting the antenna from a broadside array to
an end-fire array. With the right amount of phase shift, you end up
with a cardioid pattern, with a broad lobe in one direction and a very
deep null in the other.

Ya gots to understand with whom you are trying to communicate.
"Top" is the master know it all who has absolutely no background in
electronics. He just drives a truck and thinks that gives him the
knowledge. You've heard of "Billy Big Rigger"? You just met the dude.
Top just goes along with what other truckers have said over the years.

I have the actual working experience to back me up with.
The only thing Top knows about CB is how to yack on it.

On Tue, 2 Dec 2008 03:17:22 -0500, "Douglas W. \"Popeye\" Frederick"
wrote:

"Dave Platt" wrote in message
...
In article ,
Douglas W. \"Popeye\" Frederick wrote:

You still didn't give any useful information. No surpise since
you have none. For an average of the cb band running 1/4 wave
the antennas should be spaced 54 inches apart. Use a
commercially produced cophase harness if you can find it. Make
sure you match the SWR and you will out do any other mobile
off the front or rear.

Top

Thanks Top!

I think that Top's calculations (and recommendations) are a bit off?

I'm a "single antenna" guy myself.

I think, in a truck, at least, that "big radio" is synonymous with "big
wris****ch". :-)

We can't mount the antennae high or center, because the 13', 6" height of
the truck is where the low bridges start.

Also, most tractors have this horrific system that intergrates AM/FM with
the CB coax.

A CB stick on the left mirror and an AM/FM on the right, and a splitter in
the coax, so I always run my own coax seperately.

And I have a cellular antenna on one side, any way, for dual plane signal
boost, and it has to be 8" (I think) away from other sticks.

But hhhhhere's a question for the braintrust:

I'm after a (mobile) VHF radio that's common to northern (i.e., the Yukon,
and Northwest Territories) Canadian truckers- who don't monitor CB bands.

(info http://forums.qrz.com/showthread.php?t=171741

I'm sure, as a sine wave challenged layman, that I can't use the same
antenna and coax as my CB?


No dumb****.
As I have tried to explain to you once before, DO NOT buy one of those
radios. If you get caught with it in the USA alone, and are
transmitting on it, no license? Bye bye. Pay the $10,000 fine lose the
radio.

Every trucking company in Canada that uses them has a Canadian license
to operate them with. They are not like CB's. They are commercial
business radios.

I trust maybe now you'll listen to one of the radio experts for a
change.

Would one of you in the radio groups who knows Canadian radios please
explain this to the jerk?
He thinks that because he's a trucker, he can have any damn radio he
wants in his truck.

In article ,
Douglas W. \"Popeye\" Frederick wrote:

But hhhhhere's a question for the braintrust:

I'm after a (mobile) VHF radio that's common to northern (i.e., the Yukon,
and Northwest Territories) Canadian truckers- who don't monitor CB bands.

(info http://forums.qrz.com/showthread.php?t=171741

I'm sure, as a sine wave challenged layman, that I can't use the same
antenna and coax as my CB?

In principle, you could combine the CB output (27 MHz) with the VHF
radio output (up above the 2-meter band) using a diplexer, and feed
the result down a single coax.

At the antenna end, you'd have a couple of choices. You can use
another diplexer to split out the HF and VHF signals, and feed them to
two separate antennas. Or, you might be able to find a single CB-type
antenna which is also capable of matching up well enough on these VHF
frequencies to work tolerably well.

The chances are very poor that a randomly-selected CB antenna would
give you a tolerable SWR on the 160-or-so-MHz VHF band... and if it
did, there's no telling what its vertical radiation pattern would look
like. An antenna intended for these two bands would probably have to
be custom designed - I can think of a couple of possible ways to do
it. Such a dualband antenna would almost certainly be a compromise
antenna on both bands - it wouldn't work as well as separate antennas
designed for best operation on a single band each.

Commercial HF/VHF diplexers run somewhere around $80, last time I
looked. You'd probably find it less expensive in the end to just run
a second coax and put up a second (VHF-only) whip antenna.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

What if you ran a wire between those two truck antennas? Only
saying,,,,,
cuhulin

uuuuhhhh..... you're wrong as usual Bulli****.

Top was Military and got his commo expertise there. IIRC he's not a truck
driver at all.

"Zeke" wrote in message ...
uuuuhhhh..... you're wrong as usual Bulli****.

Top was career Military and got his commo expertise there. IIRC he's
not a truck driver at all.


Exactly, a matter of public record here that Richard has seen several
times previously, and just forgot.

Here's Richard's esteemed military career (and how he was caught lying
about it): http://bolo_bullis.tripod.com/

What's amazing is that Richard and I were just discussing what a total,
absolute and complete asshole he makes himself look like every time he tries
to make himself look tough or smart at anyone's expense.

Of course he can't hear a word of that, and immediately starts this.

Richard, who is also a career pedophile and damn proud of it, has had, and
will always have, the same problem, and that's that he just can't keep his
festering gob shut.

What amazes me is that he's skunked a dozen usenet groups over the years,
is internationally know as a scumbag, but still sees the world through his
own rose colored glasses, like we might have forgotten his previous and
extensive bombast and flummery.

Funny, or sad?

--
Popeye
"Best thing for him, really. His therapy
was going nowhere," -Hannibal Lector.

www.finalprotectivefire.com
http://picasaweb.google.com/Popeye8762

"richard" wrote in message
...
On Tue, 2 Dec 2008 03:17:22 -0500, "Douglas W. \"Popeye\" Frederick"
wrote:

"Dave Platt" wrote in message
...
In article ,
Douglas W. \"Popeye\" Frederick wrote:

You still didn't give any useful information. No surpise since
you have none. For an average of the cb band running 1/4 wave
the antennas should be spaced 54 inches apart. Use a
commercially produced cophase harness if you can find it. Make
sure you match the SWR and you will out do any other mobile
off the front or rear.

Top

Thanks Top!

I think that Top's calculations (and recommendations) are a bit off?

I'm a "single antenna" guy myself.

I think, in a truck, at least, that "big radio" is synonymous with "big
wris****ch". :-)

We can't mount the antennae high or center, because the 13', 6" height
of
the truck is where the low bridges start.

Also, most tractors have this horrific system that intergrates AM/FM
with
the CB coax.

A CB stick on the left mirror and an AM/FM on the right, and a splitter
in
the coax, so I always run my own coax seperately.

And I have a cellular antenna on one side, any way, for dual plane
signal
boost, and it has to be 8" (I think) away from other sticks.

But hhhhhere's a question for the braintrust:

I'm after a (mobile) VHF radio that's common to northern (i.e., the
Yukon,
and Northwest Territories) Canadian truckers- who don't monitor CB bands.

(info http://forums.qrz.com/showthread.php?t=171741

I'm sure, as a sine wave challenged layman, that I can't use the same
antenna and coax as my CB?


No dumb****.
As I have tried to explain to you once before, DO NOT buy one of those
radios.

**** you, dickhead.

If you get caught with it in the USA alone, and are
transmitting on it, no license? Bye bye. Pay the $10,000 fine lose the
radio.

Sure.

What's the fine for my 250 watt kicker?

Don't forget to add that in.

Every trucking company in Canada that uses them has a Canadian license
to operate them with. They are not like CB's. They are commercial
business radios.

I trust maybe now you'll listen to one of the radio experts for a
change.

I am.

They said the radios were available, the private frequencies, not the
radios, are licensed, and the freqs I'm interested are available to the
public.

And the license, if you want one, is easy and cheap.

Were your mother and father related -before- the wedding?

Inquiring minds want to know.

Because you have an uncanny resemblence to the Deliverance banjo boy.

Would one of you in the radio groups who knows Canadian radios please
explain this to the jerk?
He thinks that because he's a trucker, he can have any damn radio he
wants in his truck.

Jesus, are you stupid.

Try reading the thread that I cited, that flatly proves you wrong.

And as I already stated, and you apparently forgot, the radio would be for
emergencies only, and that I would have no reason to use it in the states.

Your memory is just shot, ****head, have you ever met a guy named John
Francis?

Or been to Australia?

I find it amazing that you'd be afraid of an FCC fine, that I have a
one-in-ten-million chance of -ever- receiving, while you publically brag
about being in possession of 45,000 child pornography pictures.

Amazing. Simply amazing.

--
Popeye
"Best thing for him, really. His therapy
was going nowhere," -Hannibal Lector.

www.finalprotectivefire.com
http://picasaweb.google.com/Popeye8762

"Dave Platt" wrote in message
...
In article ,
Douglas W. \"Popeye\" Frederick wrote:

But hhhhhere's a question for the braintrust:

I'm after a (mobile) VHF radio that's common to northern (i.e., the
Yukon,
and Northwest Territories) Canadian truckers- who don't monitor CB bands.

(info http://forums.qrz.com/showthread.php?t=171741

I'm sure, as a sine wave challenged layman, that I can't use the same
antenna and coax as my CB?

In principle, you could combine the CB output (27 MHz) with the VHF
radio output (up above the 2-meter band) using a diplexer, and feed
the result down a single coax.

At the antenna end, you'd have a couple of choices. You can use
another diplexer to split out the HF and VHF signals, and feed them to
two separate antennas. Or, you might be able to find a single CB-type
antenna which is also capable of matching up well enough on these VHF
frequencies to work tolerably well.

The chances are very poor that a randomly-selected CB antenna would
give you a tolerable SWR on the 160-or-so-MHz VHF band... and if it
did, there's no telling what its vertical radiation pattern would look
like. An antenna intended for these two bands would probably have to
be custom designed - I can think of a couple of possible ways to do
it. Such a dualband antenna would almost certainly be a compromise
antenna on both bands - it wouldn't work as well as separate antennas
designed for best operation on a single band each.

Commercial HF/VHF diplexers run somewhere around $80, last time I
looked. You'd probably find it less expensive in the end to just run
a second coax and put up a second (VHF-only) whip antenna.

Thanks!

That's the kind of helpful and intelligent response I was looking for.

The radio would be for emergency communications anyway, to trucks in
the -immediate- vicinity.

The 4 "LADD" frequencies are used by the scale houses up there, as well.


--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!



--
Popeye
"Best thing for him, really. His therapy
was going nowhere," -Hannibal Lector.

www.finalprotectivefire.com
http://picasaweb.google.com/Popeye8762

"Dave Platt" wrote in message
...
In article ,
Douglas W. \"Popeye\" Frederick wrote:

The radio would be for emergency communications anyway, to trucks in
the -immediate- vicinity.

The 4 "LADD" frequencies are used by the scale houses up there, as well.

I'd offer a "metoo" for some advice you got from another poster... do
NOT operate unlicensed. Don't even install a radio for which you
don't have whatever license is required by the law in the areas in
which you will be driving.

Thanks, but don't put too much stock in the idiot.

I don't chat on the radio, regardless of how he tries to project his own
activities on others, and from what I can discern so far, no license is
required.

I notice Richard the expert hasn't provided any such information, either.

Possibly you're not aware of this, but unlicensed 10 meter radios with
in-line amps are quite common in our trucks, and openly sold (although one
major truckstop chain was, I believe, fined after several warnings)
everywhere.

I'll be happy to get a Canadian license if I can, but, I don't need or
intend to use the licensed business frequencies.

So, if as I understand, -that's- what I need a license for, I have no need
for one.

From the cite: "The Canadian equivalent of the FCC has a site in which it
post Northwind Trucking as 165.840 MHZ.. Now in Canada they do not partition
the VHF High band into commercial 151-162 and Government 162-174 like we
do.. they are all over the place. Also They provide unlicensed LADD channels
which are used alot by trucks Ladd 1 -154.1 Ladd 2 -158.94 Ladd 3- 154.325
and Ladd 4 173.370.. Again they are all over the place with stuff up there.
Most of the action on Inuvik is on VHF. Nothing appears to be on 30-50 MHZ
and the Hospital and Airport are using UHF."

"They provide unlicensed LADD channels which are used alot by trucks"

"They provide unlicensed LADD channels which are used alot by trucks"

"They provide unlicensed LADD channels which are used alot by trucks"

"They provide unlicensed LADD channels which are used alot by trucks"

Where I drive is not where you live.

http://picasaweb.google.com/Popeye87...43959490865794

That radio may mean the difference between freezing to death or not, or,
literally, being eaten alive.

"Officer, it's only for emergency use" is certainly preferable to that,
and, grossly unlikely anyway.

I've been through a score of vehicle inspections, with an illegal kicker
in -plain sight-, and nobody gives a damn.

They're a whole lot more concerned if we have brakes, and are sober.

Contrary to Stupid Richard's rantings, I've never seen an FCC roadblock in
35 years of driving.

Planning to use the "Officer, it's only for emergency use" response,
when challenged, could be a very expensive tactic. You might find
out, the hard way, that the local regulatory body takes a "possession
is considered proof of intent to use" approach... even if you don't
get hit with criminal charges or a civil forfeiture order, you could
find that your radios are considered de facto "contraband" and are
subject to being seized without warning.

Here in the US, unlicensed operation could get you hit with equipment
confiscation and a fine of many thousands of dollars.

I'm sure that's true.

If you want to operate VHF, you should either get a proper license
(e.g. for business-band frequencies) or stick to radios which have no
legal requirement for a license. For example, here in the U.S., the
MURS (multi-use radio service) is a collection of a few VHF
frequencies (formerly licensed-business-band) which have been
reassigned, and which can be used without a license as long as the
radio you use is properly certificated for this purpose.

I don't know if Canada has a MURS-equivalent, or if any of the
truckers up there use it. Check the regulations before you buy.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!



--
Popeye
"Best thing for him, really. His therapy
was going nowhere," -Hannibal Lector.

www.finalprotectivefire.com
http://picasaweb.google.com/Popeye8762