questions about building CB antenna...
 

Hi, I am looking to build an antenna for CB band... It will be going up
in my attic with about a 19 foot ceiling. I would like to have it free
standing as I have no way to get to the top to hang a wire type
antenna...

here is what I was thinking of doing:

I was going to biuld a 1/2 dipole but out of 1/2" copper pipe using PVC
pipe as insulators for the center and bottom and building some kind of
wood base for it.

will this work the same as a 12g wire dipole? do I still make each
side 8' 5" long or will this change? Does it matter what side is up?
any tips or ideas?

thanks
Jim

questions about building CB antenna...
 

On 22 Dec 2005 18:45:44 -0800, wrote:

Hi, I am looking to build an antenna for CB band... It will be going up
in my attic with about a 19 foot ceiling. I would like to have it free
standing as I have no way to get to the top to hang a wire type
antenna...

here is what I was thinking of doing:

I was going to biuld a 1/2 dipole but out of 1/2" copper pipe using PVC
pipe as insulators for the center and bottom and building some kind of
wood base for it.

will this work the same as a 12g wire dipole? do I still make each
side 8' 5" long or will this change? Does it matter what side is up?
any tips or ideas?

thanks
Jim


Don't waste your money on copper pipe. 12 or 14 gauge wire will work just fine.

You can also build a 1/4 ground plane, and stick it on a 9 or 10 foot mast.

Vinnie S.

questions about building CB antenna...
 

On 22 Dec 2005 18:45:44 -0800, wrote:

Hi, I am looking to build an antenna for CB band... It will be going up
in my attic with about a 19 foot ceiling. I would like to have it free
standing as I have no way to get to the top to hang a wire type
antenna...

here is what I was thinking of doing:

I was going to biuld a 1/2 dipole but out of 1/2" copper pipe using PVC
pipe as insulators for the center and bottom and building some kind of
wood base for it.

will this work the same as a 12g wire dipole? do I still make each
side 8' 5" long or will this change? Does it matter what side is up?
any tips or ideas?

thanks
Jim


Jim,

Here is the site for the homemade 1/4 ground plane. The pipe would work better
here. So would rigid solid copper wire. I think this is a better option for
local talking. The dipole would work better for DX.

Whatever you do, keep it the hell away from any kind of romex or AC wiring. It
will induce some noise. I had a similar problem because of that. But you are
better off with a 19 foot attic. Get the antenna tip to the top of the roof.

Vinnie S.

questions about building CB antenna...
 

Vinnie S. wrote:
On 22 Dec 2005 18:45:44 -0800, wrote:


Hi, I am looking to build an antenna for CB band... It will be going up
in my attic with about a 19 foot ceiling. I would like to have it free
standing as I have no way to get to the top to hang a wire type
antenna...

here is what I was thinking of doing:

I was going to biuld a 1/2 dipole but out of 1/2" copper pipe using PVC
pipe as insulators for the center and bottom and building some kind of
wood base for it.

will this work the same as a 12g wire dipole? do I still make each
side 8' 5" long or will this change? Does it matter what side is up?
any tips or ideas?

thanks
Jim



Jim,

Here is the site for the homemade 1/4 ground plane. The pipe would work better
here. So would rigid solid copper wire. I think this is a better option for
local talking. The dipole would work better for DX.

Whatever you do, keep it the hell away from any kind of romex or AC wiring. It
will induce some noise. I had a similar problem because of that. But you are
better off with a 19 foot attic. Get the antenna tip to the top of the roof.

Vinnie S.

The unbalanced 1/4 wave GP will match to the CB better then a balanced dipole.

Coax is unbalanced. It's a hot and a shield. Dipoles need equal and opposite feed.

You need about 8.6 feet per element.

http://www.monsterfm.com/engineering/antcalc.htm

I built the yagi at arrl.org, 7db for 7 bucks.
Works damn good for being made of coat hangers and a 1x2!

I tried to build CB antennas. They are BIG. 2 meter antennas are much smaller.
VHF-FM has much better local range then 11 meters. I use part 95 and 97 all the time.

I may have to try one of these for 2 meters and another for 430 MHz ATV.
http://www.softcom.net/users/kd6dks/quad.html

Yagis are simpler to build, but I'm told quads have better gain.
Quagis have quad feeds and yagi elements. I need to bug Jay for
some good matches for coax to balanced feed units.

Another ham mentioned that the shorter director is capacitive
and the longer reflector is inductive. The lead/lag of the
elements causes the waves to constructively add in one direction
more then others.

questions about building CB antenna...
 

On Fri, 23 Dec 2005 01:15:07 -0500, Scott in Baltimore
wrote:

The unbalanced 1/4 wave GP will match to the CB better then a balanced dipole.

Coax is unbalanced. It's a hot and a shield. Dipoles need equal and opposite feed.

You need about 8.6 feet per element.


We need to find out what he is going to use it for. I would probably go with the
1/4 GP mounted on a PVC mast. That would be about 8 feet off his attic floor.
Might work pretty well.

I has a Starduster in the attic in 1983, and did OK. This will work better that
the Starduster.


Vinnie S.

questions about building CB antenna...
 

I am really looking for mainly local talking...

vinnie I don't think you included the web address for the 1/4 GP
antenna...

questions about building CB antenna...
 

On 23 Dec 2005 13:30:15 -0800, wrote:

I am really looking for mainly local talking...

vinnie I don't think you included the web address for the 1/4 GP
antenna...


Crap. Sorry about that. Usethe 1/4 ground plain.

http://home.att.net/~wizardoz/cbmw/a...i.html#groundp


Remember to cut the center radial long, and trim shorter to adjust SWR. Mount it
on a plastic mast like PVC or ABS. It does not have to be metal since it's
indoors, and there is no wind ot weather. Get the tip as high as possible.

Also, use a 1:1 balun so the coax doesn't radiate. Basically, that is a fancy
term for coiled coax, which should be place just before the feedpoint.

Here is a site to help:

http://www.hamuniverse.com/balun.html

When I built mine, I used two PVC 4 inch couplers glued together. And I wrapped
the coax around it, tying it down with ty-raps. If you need pictures, I can send
them. The purpose of this coil is to choke RF so the coax does not act as a
ground radial or part of the antenna. That is also why it's place as close to
the feed as possible.



Vinnie S.

questions about building CB antenna...
 

pics would help I am a visual person... does the ground plane have to
be put at a 45d angle?

questions about building CB antenna...
 

also if I could get a 1/2 wave dipole up would it work as well as the
1/4GP

questions about building CB antenna...
 

On 23 Dec 2005 14:15:11 -0800, wrote:

pics would help I am a visual person... does the ground plane have to
be put at a 45d angle?

I don't think so, only because I have seen flat ground planes. My Starduster
were at a sharp angle. Maybe Scott can knows better. I would think the flat or
GP at 90 degrees to the center conductor is fine.

BTW, since you are running it indoors, use Belden 9913 coax. It is more flexible
than LMR400 or such.


Vinnie S.

questions about building CB antenna...
 

On Sun, 25 Dec 2005 21:55:26 GMT, james wrote:

On Sun, 25 Dec 2005 15:55:38 -0500, Scott in Baltimore
wrote:

+At least we can discuss things rationally, without resorting
+to name calling and finger poking! Happy Holidaze!
*****

Not my style to insult, it does not get any where.

james
is damned internet newbie an insult?

questions about building CB antenna...
 

I don't think so, only because I have seen flat ground planes. My Starduster
were at a sharp angle. Maybe Scott can knows better. I would think the flat or
GP at 90 degrees to the center conductor is fine.

Straight radials would create a 30 ohm antenna.
45 degree droops create about 50 ohms.

There shouldn't be any current flowing down the outside of the
shield with a groundplane, so you won't need a balun,
unlike a dipole that requires equal and opposite phases.
If you try to feed a dipole with coax, the outer shield
becomes part of the antenna system, causing high SWR readings,
(even if the SWR is low), RF interference and degraded performance.

questions about building CB antenna...
 

On Fri, 23 Dec 2005 19:30:25 -0500, Scott in Baltimore
wrote:

I don't think so, only because I have seen flat ground planes. My Starduster
were at a sharp angle. Maybe Scott can knows better. I would think the flat or
GP at 90 degrees to the center conductor is fine.

Straight radials would create a 30 ohm antenna.
45 degree droops create about 50 ohms.

How come I use to see both during the CB era? Radio Shack made a ground plane
with straight radials.



There shouldn't be any current flowing down the outside of the
shield with a groundplane, so you won't need a balun,

There you go. That is one less step !

unlike a dipole that requires equal and opposite phases.
If you try to feed a dipole with coax, the outer shield
becomes part of the antenna system, causing high SWR readings,
(even if the SWR is low), RF interference and degraded performance.


Thanks, for the info.

Vinnie S.

questions about building CB antenna...
 

The radio shack GP w/ horizontal radial worked but had higher SWR than the
starduster with it's drooping radials. Have you considered using an old
102" SS whip mounted on drooping radials that you would construct? The
drooping radials would allow for an almost perfect 1:1 SWR match but include
the spring since the vertical element needs to be 108" long. This antenna
would essentialy be a starduster.
wrote in message
ups.com...
also if I could get a 1/2 wave dipole up would it work as well as the
1/4GP

questions about building CB antenna...
 

On 23 Dec 2005 14:15:11 -0800, wrote:

+pics would help I am a visual person... does the ground plane have to
+be put at a 45d angle?
******

Lowering the ground radials from 90 degrees to the main radiator to 45
degrees helps to rasie feed impendance.

Feed impendance and antenna tuning are interactive with each other. If
you have to keep them at 90 degrees,then you will have to adjust the
length of the radiator.

james

questions about building CB antenna...
 

On Fri, 23 Dec 2005 19:30:25 -0500, Scott in Baltimore
wrote:

+ I don't think so, only because I have seen flat ground planes. My Starduster
+ were at a sharp angle. Maybe Scott can knows better. I would think the flat or
+ GP at 90 degrees to the center conductor is fine.
+
+Straight radials would create a 30 ohm antenna.
+45 degree droops create about 50 ohms.
+
+There shouldn't be any current flowing down the outside of the
+shield with a groundplane, so you won't need a balun,
+unlike a dipole that requires equal and opposite phases.
+If you try to feed a dipole with coax, the outer shield
+becomes part of the antenna system, causing high SWR readings,
+(even if the SWR is low), RF interference and degraded performance.
******

At 30 Ohms you will need some matching network to cancel the reactive
portion out and rasie the radiation resistance of the antenna up to
that of 50 Ohms. I would not reccomend direct coax attachment even to
a 1/4 lambda ground plane antenna.

james

questions about building CB antenna...
 

On 23 Dec 2005 14:55:34 -0800, wrote:

+also if I could get a 1/2 wave dipole up would it work as well as the
+1/4GP
*****

As for efficiency somewhat similar. The two will have entirely
different radiation patterns. It will be these two differning patterns
that will make one better or worse for a particular propogation path.

james

questions about building CB antenna...
 

On Sat, 24 Dec 2005 16:27:10 GMT, "GHB" wrote:

The radio shack GP w/ horizontal radial worked but had higher SWR than the
starduster with it's drooping radials. Have you considered using an old
102" SS whip mounted on drooping radials that you would construct? The
drooping radials would allow for an almost perfect 1:1 SWR match but include
the spring since the vertical element needs to be 108" long. This antenna
would essentialy be a starduster.


Can he make a longer radiating element and put the radials at 90 degrees? That
woulb be easier than drooping the radials.

Vinnie S.

questions about building CB antenna...
 

On Sat, 24 Dec 2005 18:26:15 GMT, james wrote:

On Fri, 23 Dec 2005 19:30:25 -0500, Scott in Baltimore
wrote:

+ I don't think so, only because I have seen flat ground planes. My Starduster
+ were at a sharp angle. Maybe Scott can knows better. I would think the flat or
+ GP at 90 degrees to the center conductor is fine.
+
+Straight radials would create a 30 ohm antenna.
+45 degree droops create about 50 ohms.
+
+There shouldn't be any current flowing down the outside of the
+shield with a groundplane, so you won't need a balun,
+unlike a dipole that requires equal and opposite phases.
+If you try to feed a dipole with coax, the outer shield
+becomes part of the antenna system, causing high SWR readings,
+(even if the SWR is low), RF interference and degraded performance.
******

At 30 Ohms you will need some matching network to cancel the reactive
portion out and rasie the radiation resistance of the antenna up to
that of 50 Ohms. I would not reccomend direct coax attachment even to
a 1/4 lambda ground plane antenna.

james

So what reactive component does a 1/4 wave monopole have? How much
loss do I have on my 40 meter 1/4 wave vertical fed directly with RG-8
coax? Should I put a coil or capacitor at the feedpoint of my
vertical?

questions about building CB antenna...
 

On Sat, 24 Dec 2005 18:28:50 GMT, james wrote:

On 23 Dec 2005 14:55:34 -0800, wrote:

+also if I could get a 1/2 wave dipole up would it work as well as the
+1/4GP
*****

As for efficiency somewhat similar. The two will have entirely
different radiation patterns. It will be these two differning patterns
that will make one better or worse for a particular propogation path.

james

He's talking about mounting his dipole vertical. How different is the
radation pattern of vertical dipole than a 1/4 GP?

questions about building CB antenna...
 

On Sat, 24 Dec 2005 18:26:15 GMT, james wrote:

On Fri, 23 Dec 2005 19:30:25 -0500, Scott in Baltimore
wrote:

+ I don't think so, only because I have seen flat ground planes. My Starduster
+ were at a sharp angle. Maybe Scott can knows better. I would think the flat or
+ GP at 90 degrees to the center conductor is fine.
+
+Straight radials would create a 30 ohm antenna.
+45 degree droops create about 50 ohms.
+
+There shouldn't be any current flowing down the outside of the
+shield with a groundplane, so you won't need a balun,
+unlike a dipole that requires equal and opposite phases.
+If you try to feed a dipole with coax, the outer shield
+becomes part of the antenna system, causing high SWR readings,
+(even if the SWR is low), RF interference and degraded performance.
******

At 30 Ohms you will need some matching network to cancel the reactive
portion out and rasie the radiation resistance of the antenna up to
that of 50 Ohms. I would not reccomend direct coax attachment even to
a 1/4 lambda ground plane antenna.

james

Ok, I just ran my 40 meter vertical on a simulator...

R=35.87 jX=.354

SWR=1.39.. now why do I need a matchbax?

But of course a matchbox wont raise the radiation resistance of my
antenna... will it?

questions about building CB antenna...
 

"GHB" wrote in message
. net...
The radio shack GP w/ horizontal radial worked but had higher SWR than the
starduster with it's drooping radials. Have you considered using an old
102" SS whip mounted on drooping radials that you would construct? The
drooping radials would allow for an almost perfect 1:1 SWR match but
include
the spring since the vertical element needs to be 108" long. This antenna
would essentialy be a starduster.
wrote in message

Or if you work the upper channels leave the spring off.

questions about building CB antenna...
 

yeah, give it to cranus the anus and let him stuff it in his ass

questions about building CB antenna...
 

At 30 Ohms you will need some matching network to cancel the reactive
portion out and rasie the radiation resistance of the antenna up to
that of 50 Ohms. I would not reccomend direct coax attachment even to
a 1/4 lambda ground plane antenna.

james


LMAO!


Ok, I just ran my 40 meter vertical on a simulator...

R=35.87 jX=.354

SWR=1.39.. now why do I need a matchbax?

But of course a matchbox wont raise the radiation resistance of my
antenna... will it?

Nor will it fix the basic mismatch.

30 ohms. Oh ****! I better put a 20 ohm resistor is series
with my radio of it's gonna' burn up!

1.5:1 SWR can be 25 or 100 ohms.
25 ohms will draw more current and drop more voltage. (more current X less voltage)
100 ohms will draw less current and drop the voltage less. (less current X more voltage)
50 ohms will draw the most amount of POWER from the source. (equal voltage X equal current = MAX
POWER TRANSFER)

James, you need to learn the power transfer theorum and how
little is actually lost by a 1.5:1 or less SWR. You gain
more with a resonant antenna, then a bit of impedance mismatch.

questions about building CB antenna...
 

Vinnie S. wrote:
On Sat, 24 Dec 2005 16:27:10 GMT, "GHB" wrote:


The radio shack GP w/ horizontal radial worked but had higher SWR than the
starduster with it's drooping radials. Have you considered using an old
102" SS whip mounted on drooping radials that you would construct? The
drooping radials would allow for an almost perfect 1:1 SWR match but include
the spring since the vertical element needs to be 108" long. This antenna
would essentialy be a starduster.



Can he make a longer radiating element and put the radials at 90 degrees? That
woulb be easier than drooping the radials.

Vinnie S.

Resonance occurs due to the physical lenght of the radiator plus any
coils minus any capacitance. The electrical match is due to the feedpoint
impedance. An odd quarterwave has a low impedance. Anything else has a
higher impedance. To match 50 ohm unbalanced coax to various types of
antennas, baluns and beta/delta/gamma matches were created.

Some antenna designs have the radials at 90 degrees because that is
where the designer put them to work properly with their design.

questions about building CB antenna...
 

On Sat, 24 Dec 2005 20:11:18 GMT, Lancer wrote:

+Ok, I just ran my 40 meter vertical on a simulator...
+
+R=35.87 jX=.354
+
+SWR=1.39.. now why do I need a matchbax?
+
+But of course a matchbox wont raise the radiation resistance of my
+antenna... will it?
****

Okay. Take the matchbox and put it on the shelf. FIrst off I never
said a matchbox but an matching network. Unless you put the matchbox
at the feed point, a matchbox is not a matching network. A matchbox
inserted in the trransmission line acts far different than that of a
matching network at the feed. Then with any basic knowledge of
electronic circuits should reveal that.

A gamma match, beta match, and even simple load elements like a
capcitor or an inductor will facillitate matching. Yes a matching
network can be used to cancel out the reactive portion and transform
the load resistive component to an appropriate level in which maximum
power can be transfered.

Basic electronics. A simple circuits problem that does not need any
fancy smancy computer model to figure out the solutions.

james

questions about building CB antenna...
 

On Sun, 25 Dec 2005 06:25:08 -0500, Scott in Baltimore
wrote:

+James, you need to learn the power transfer theorum and how
+little is actually lost by a 1.5:1 or less SWR. You gain
+more with a resonant antenna, then a bit of impedance mismatch.


Scott.

A 1.5:1 SWR means that about 4% of the source power is reflected back
from the load. This is entirely different from antenna efficiency and
how much delivered power is actually radiated. Again your
understanding of antenna efficeincy and radiated power density is
quite lacking.

A resonant antenna is just that, a resonant antenna. It will often
give the widest possible bandwidth for SWR and radiation efficiency.
That is all. Physically short or exceptionaly long antenna can be made
to operate over a small frequency bandwidth with equal or better
radiation efficiency. For example consider electrically short loop
antenna can be as efficient as 98% in radiation. Due to their low
radiation resistance the antenna is quite high in Q. Thus a relatively
small bandwidth for efficient radiation.

SWR is the measure of power delivered to the load and what is
reflected back from the load to the source. Nothing more, nothing
less. It is a measure of what is happening inside the transmission
line. Not necessarily the performance of the antenna. Just because you
have a 1:1 SWR does not mean that all the power is being radiated. In
fact in some installations as little a 10% is actually being radiated.
The rest is heat.

james

questions about building CB antenna...
 

On Sat, 24 Dec 2005 19:21:36 GMT, Lancer wrote:

+On Sat, 24 Dec 2005 18:26:15 GMT, james wrote:
+
+On Fri, 23 Dec 2005 19:30:25 -0500, Scott in Baltimore
wrote:
+
++ I don't think so, only because I have seen flat ground planes. My Starduster
++ were at a sharp angle. Maybe Scott can knows better. I would think the flat or
++ GP at 90 degrees to the center conductor is fine.
++
++Straight radials would create a 30 ohm antenna.
++45 degree droops create about 50 ohms.
++
++There shouldn't be any current flowing down the outside of the
++shield with a groundplane, so you won't need a balun,
++unlike a dipole that requires equal and opposite phases.
++If you try to feed a dipole with coax, the outer shield
++becomes part of the antenna system, causing high SWR readings,
++(even if the SWR is low), RF interference and degraded performance.
+******
+
+At 30 Ohms you will need some matching network to cancel the reactive
+portion out and rasie the radiation resistance of the antenna up to
+that of 50 Ohms. I would not reccomend direct coax attachment even to
+a 1/4 lambda ground plane antenna.
+
+james
+
+So what reactive component does a 1/4 wave monopole have? How much
+loss do I have on my 40 meter 1/4 wave vertical fed directly with RG-8
+coax? Should I put a coil or capacitor at the feedpoint of my
+vertical?
****

Lancer there is only one real solution for an antenna that will match
a 50 Ohm feedline. That is when the antenna is 50 + j0 Ohms. Or 50
Ohms resistive. There are an infinite number of complex solutions
that will yield a magnitude of 50 Ohms impedance. What solution yours
is will be totally unique to your location and installation. No way
for me to predict that. Therefore there is no way that I can predict y
our losses. Either from load reflections as well as radiation
efficiency of your antenna. Then again if the magnitude of the
imedance of your antenna is 30 Ohms then you may choose to live with
the reflections in the transmission line as well as any looses due to
inefficiency do to the actual radiation resistance what ever it is for
your installation.

Loss in an antenna, that is radiation efficiency, is dependant on the
radiation resistance of the antenna. This also sets the Q or quality
factor of the antenna. That is the bandwidth in which there is
reasonably efficiency of the antenna (70.7%).

Actually a coil or capacitor is best inserted in the radiator. Choice
of base load or loads at other locations are for another discussion.
The reactive component value will mainly depend on the physical length
of the radiator and its reference to lambda.

james

questions about building CB antenna...
 

On Sat, 24 Dec 2005 19:26:15 GMT, Lancer wrote:

+On Sat, 24 Dec 2005 18:28:50 GMT, james wrote:
+
+On 23 Dec 2005 14:55:34 -0800, wrote:
+
++also if I could get a 1/2 wave dipole up would it work as well as the
++1/4GP
+*****
+
+As for efficiency somewhat similar. The two will have entirely
+different radiation patterns. It will be these two differning patterns
+that will make one better or worse for a particular propogation path.
+
+james
+
+He's talking about mounting his dipole vertical. How different is the
+radation pattern of vertical dipole than a 1/4 GP?
*******

Gee I seem to have lost that in the translation.

Even still the two will have different radiation patterns depending on
how high the vertical mounting of the 1/2 lambda antenna is about
virtual ground.

james

questions about building CB antenna...
 

On Sun, 25 Dec 2005 06:32:53 -0500, Scott in Baltimore
wrote:

+Vinnie S. wrote:
+ On Sat, 24 Dec 2005 16:27:10 GMT, "GHB" wrote:
+
+
+The radio shack GP w/ horizontal radial worked but had higher SWR than the
+starduster with it's drooping radials. Have you considered using an old
+102" SS whip mounted on drooping radials that you would construct? The
+drooping radials would allow for an almost perfect 1:1 SWR match but include
+the spring since the vertical element needs to be 108" long. This antenna
+would essentialy be a starduster.
+
+
+
+ Can he make a longer radiating element and put the radials at 90 degrees? That
+ woulb be easier than drooping the radials.
+
+ Vinnie S.
+
+Resonance occurs due to the physical lenght of the radiator plus any
+coils minus any capacitance. The electrical match is due to the feedpoint
+impedance. An odd quarterwave has a low impedance. Anything else has a
+higher impedance. To match 50 ohm unbalanced coax to various types of
+antennas, baluns and beta/delta/gamma matches were created.
+
+Some antenna designs have the radials at 90 degrees because that is
+where the designer put them to work properly with their design.
*******

The only time an antenna is resonant is when the feed impendance is
real. That is when the imaginary portion of the antenna is zero.
Therefore the feed point impendance is R + j0. Resonance does not have
to occur at 50 + j0 Ohms.

There are an infinite solution to where the magnitude of the impedance
is equal to a magnitude of 50 Ohms.


james

questions about building CB antenna...
 

At least we can discuss things rationally, without resorting
to name calling and finger poking! Happy Holidaze!

questions about building CB antenna...
 

On Sun, 25 Dec 2005 15:55:38 -0500, Scott in Baltimore
wrote:

+At least we can discuss things rationally, without resorting
+to name calling and finger poking! Happy Holidaze!
*****

Not my style to insult, it does not get any where.

james

questions about building CB antenna...
 

Hi, I am just checking in...

I set the 1/4GP up for my brother in his attic and it works good... the
only problem is it is messing up one TV in the house. You can slightly
hear him talking over the TV and this is with CABLE. I think the tv has
a problem. but other than that it works great thanks for all the help
guys.

Now I just got to stop being lazy and put uf the used A99 I bought for
my house...

Jim

questions about building CB antenna...
 

On 31 Dec 2005 10:59:18 -0800, wrote:

Hi, I am just checking in...

I set the 1/4GP up for my brother in his attic and it works good... the
only problem is it is messing up one TV in the house. You can slightly
hear him talking over the TV and this is with CABLE. I think the tv has
a problem. but other than that it works great thanks for all the help
guys.


Jim,

Try a TVI filter. Also, make sure the radio is ground to a ground rod outside
the house.

The problem might be that it's too close to the wires inside his house.

Now I just got to stop being lazy and put uf the used A99 I bought for
my house...


Vinnie S.

questions about building CB antenna...
 

I will have to try that I will let you know how it goes...

If I flip the ground plane kit upside down on the A99 will it still
work right and SWR ok... So they would be pointing up at 45d not down?

questions about building CB antenna...
 

On 1 Jan 2006 07:57:27 -0800, wrote:

I will have to try that I will let you know how it goes...

If I flip the ground plane kit upside down on the A99 will it still
work right and SWR ok... So they would be pointing up at 45d not down?


No. I do not think so. I would leave it off.

Vinnie S.

questions about building CB antenna...
 

On Sat, 31 Dec 2005 17:13:09 -0500, Vinnie S.
wrote:

+On 31 Dec 2005 10:59:18 -0800, wrote:
+
+Hi, I am just checking in...
+
+I set the 1/4GP up for my brother in his attic and it works good... the
+only problem is it is messing up one TV in the house. You can slightly
+hear him talking over the TV and this is with CABLE. I think the tv has
+a problem. but other than that it works great thanks for all the help
+guys.
+
+
+Jim,
+
+Try a TVI filter. Also, make sure the radio is ground to a ground rod outside
+the house.
+
+The problem might be that it's too close to the wires inside his house.
+
+Now I just got to stop being lazy and put uf the used A99 I bought for
+my house...
+
+
+Vinnie S.
*****

A TVI filter may not be sufficient. Close proximity to the inside
house wiring may also be a problem. He may have to place brute force
filter in line with the affected TV power cord.

james

questions about building CB antenna...
 

On Sun, 01 Jan 2006 23:50:29 GMT, james wrote:


A TVI filter may not be sufficient. Close proximity to the inside
house wiring may also be a problem. He may have to place brute force
filter in line with the affected TV power cord.

james


I was afraid someone would say that. Would the 1:1 choke balun help? Scott said
it's not needed in a GP.

Vinnie S.

questions about building CB antenna...
 

On Sun, 01 Jan 2006 20:49:01 -0500, Vinnie S.
wrote:

+On Sun, 01 Jan 2006 23:50:29 GMT, james wrote:
+
+
+A TVI filter may not be sufficient. Close proximity to the inside
+house wiring may also be a problem. He may have to place brute force
+filter in line with the affected TV power cord.
+
+james
+
+
+I was afraid someone would say that. Would the 1:1 choke balun help? Scott said
+it's not needed in a GP.
+
+Vinnie S.
*****
A choke balun would only help if the feed line is radiating. I doubt
that is happening. What more likely is happening is that the house
wiring is acting as a receiving antenna. This is so due to close
proximaty to the RF near fields of the antenna. The power lines then
could conduct sufficient energy into the TV where anything might
happen.

Also the TV sets RF front end maybe overloaded due to the TV set's
receiving antenna is to close to the CB antenna.

Either of these cases a choke balun would not be helpful.

james