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-   -   Antenna Whine? (https://www.radiobanter.com/cb/31892-antenna-whine.html)

Randy May 17th 04 05:04 PM


"Chris" wrote in message
nk.net...
You should be able to remove the plastic inserts where the antennas are
mounted. You may also have a problem with the splitter that allows the
stereo and TV to use the same antennas. Maybe you can use one antenna for
the CB and the other for everything else. As for the whine, I agree with
everyone else. Once the antennas are working properly, it may go away.

Chris


If I remove the plastic inserts from the antenna mount, will that create a
direct short when I am transmitting?

I believe the splitter could be the problem also, like I said earlier if
this my truck I would rip it all out and start from scratch. I did a little
work ... swr @ 2.1. I just transmitted 9 miles. Whine still there ...
might be louder.

I am still wondering what is actually causing the whine i.e. alternator,
fuel pump ....... maybe I need to look at the source of the whine rather
than the ability to filter it out?



Chris May 17th 04 09:36 PM

The mounting bracket should be grounded to the truck and attached to the
coax sheild. There SHOULD be an insulator between the antenna and the
bracket so leave it there.

Chris
"Randy" wrote in message
...

"Chris" wrote in message
nk.net...
You should be able to remove the plastic inserts where the antennas are
mounted. You may also have a problem with the splitter that allows the
stereo and TV to use the same antennas. Maybe you can use one antenna

for
the CB and the other for everything else. As for the whine, I agree with
everyone else. Once the antennas are working properly, it may go away.

Chris


If I remove the plastic inserts from the antenna mount, will that create

a
direct short when I am transmitting?

I believe the splitter could be the problem also, like I said earlier if
this my truck I would rip it all out and start from scratch. I did a

little
work ... swr @ 2.1. I just transmitted 9 miles. Whine still there ...
might be louder.

I am still wondering what is actually causing the whine i.e. alternator,
fuel pump ....... maybe I need to look at the source of the whine rather
than the ability to filter it out?





Frank Gilliland May 17th 04 11:03 PM

In , "Randy" wrote:

snip

Just so I am clear about one thing .... In all of these articles that I
have been reading, when they talk about grounding the antenna, they are
referring to a RF ground (ground plane) and not a physical ground? If for
some reason the shield is not grounded would this be my problem?



Close. Whine is RF interference from the engine electrical system (and sometimes
other electrical devices like the fuel pump) and occurs on almost all vehicles.
The difference is that an engine compartment which is fully enclosed by metal
will shield the radio and coax from this noise (the noise can also pass through
the electrical system, but that doesn't seem to be your problem). If you have a
fiberglass hood, or if your coax passes through the engine compartment, the coax
must be grounded at the radio end or it will pick up this noise just like an
antenna.

An RF ground is both an electrical ground -and- a physical ground. It is a
low-impedance path for RF and is very dependent on the physical properties of
the connection. Usually, a good RF ground is any point where electricity can
easily take many different directions -- kinda like ****ing into a lake. Just
about any point on the chassis will be a good RF ground. A single wire to the
chassis is a better antenna than an RF ground. For example, if your radio is
grounded with a wire longer than just a few inches it will allow RF voltage to
develop on the radio chassis, and the radio effectively becomes part of your
antenna system. That makes it very suseptible to engine noise and other types of
RF interference that may be picked up by the coax shield (which is connected
directly to your radio chassis) or passed through the electrical system to your
power leads. So by RF grounding the radio (and therefore your coax) you are
shunting all that RF interference to ground so the radio doesn't have to deal
with it.

Not having a good RF ground at the antenna can screw up your SWR, but that's
about all. It's much more important to ground that radio!


My boss will not care that this unit has a whine. I am not sure he would
care whether it has a CB or not. I had to take the truck down to the shop
last week to get the steer tires balanced, I had to pay for everything. He
is not a bad guy ... just cheap!



If it's a business expense it should be paid for by the business.


The unit might not be grounded very good. It sits in an upper header
console, just strapped in not bolted. I will ground the unit and purchase a
noise filter then adjust my antennas.



The upper header console is a terrible ground if your roof is fiberglass. I
would recommend mounting it on the dash or the hump, close to the chassis. That
will require rerouting the coax, but at this point that seems unavoidable.


I tried reading as many articles as I could but they all were saying the
same things and some of that I could not understand. I thank you for your
time. I will let you know if the problem persist after these changes.

Thanks again






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Frank Gilliland May 18th 04 12:20 AM

In , Professor Bob wrote:

"Randy" wrote in
:


"Chris" wrote in message
nk.net...
You should be able to remove the plastic inserts where the antennas
are mounted. You may also have a problem with the splitter that
allows the stereo and TV to use the same antennas. Maybe you can use
one antenna for the CB and the other for everything else. As for the
whine, I agree with everyone else. Once the antennas are working
properly, it may go away.

Chris


If I remove the plastic inserts from the antenna mount, will that
create a
direct short when I am transmitting?

I believe the splitter could be the problem also, like I said
earlier if
this my truck I would rip it all out and start from scratch. I did a
little work ... swr @ 2.1. I just transmitted 9 miles. Whine still
there ... might be louder.




I am still wondering what is actually causing the whine i.e.
alternator, fuel pump ....... maybe I need to look at the source of
the whine rather than the ability to filter it out?



That would be your best bet, if your fuel pump comes on like most when
you turn the key to on position without starting the truck, then you can
tell if it is fuel pump or if vehicle started and the noise increases
with engine rpm then it may be alternator or even the electronic
ignition. Once you find out what it is then you can try and correct the
problem otherwise you are shooting in the dark. Alternator whine and fuel
pump noise can usually be correct by a capacitor and or choke, the
igniton may need to be shielded to stop that.



I believe he said that the whine follows the engine RPMs, so it's probably the
alternator. Regardless, if you reduce or eliminate the source of the noise you
are not fixing the problem, because the radio will still be suseptible to other
sources of RFI such as the whine from other vehicles, power lines, industrial
equipment, etc. It's as annoying as those pop-ups in your internet browser.
Properly grounding your radio works like a good pop-up blocker.





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-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Randy May 18th 04 12:36 AM


"Frank Gilliland" wrote in message
...
In , "Randy" wrote:

snip

Just so I am clear about one thing .... In all of these articles that I
have been reading, when they talk about grounding the antenna, they are
referring to a RF ground (ground plane) and not a physical ground? If for
some reason the shield is not grounded would this be my problem?



Close. Whine is RF interference from the engine electrical system (and

sometimes
other electrical devices like the fuel pump) and occurs on almost all

vehicles.
The difference is that an engine compartment which is fully enclosed by

metal
will shield the radio and coax from this noise (the noise can also pass

through
the electrical system, but that doesn't seem to be your problem). If you

have a
fiberglass hood, or if your coax passes through the engine compartment,

the coax
must be grounded at the radio end or it will pick up this noise just like

an
antenna.

An RF ground is both an electrical ground -and- a physical ground. It is a
low-impedance path for RF and is very dependent on the physical properties

of
the connection. Usually, a good RF ground is any point where electricity

can
easily take many different directions -- kinda like ****ing into a lake.

Just
about any point on the chassis will be a good RF ground. A single wire to

the
chassis is a better antenna than an RF ground. For example, if your radio

is
grounded with a wire longer than just a few inches it will allow RF

voltage to
develop on the radio chassis, and the radio effectively becomes part of

your
antenna system. That makes it very suseptible to engine noise and other

types of
RF interference that may be picked up by the coax shield (which is

connected
directly to your radio chassis) or passed through the electrical system to

your
power leads. So by RF grounding the radio (and therefore your coax) you

are
shunting all that RF interference to ground so the radio doesn't have to

deal
with it.

Not having a good RF ground at the antenna can screw up your SWR, but

that's
about all. It's much more important to ground that radio!


My boss will not care that this unit has a whine. I am not sure he would
care whether it has a CB or not. I had to take the truck down to the shop
last week to get the steer tires balanced, I had to pay for everything.

He
is not a bad guy ... just cheap!



If it's a business expense it should be paid for by the business.


The unit might not be grounded very good. It sits in an upper header
console, just strapped in not bolted. I will ground the unit and purchase

a
noise filter then adjust my antennas.



The upper header console is a terrible ground if your roof is fiberglass.

I
would recommend mounting it on the dash or the hump, close to the chassis.

That
will require rerouting the coax, but at this point that seems unavoidable.


I tried reading as many articles as I could but they all were saying

the
same things and some of that I could not understand. I thank you for your
time. I will let you know if the problem persist after these changes.

Thanks again






-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----


Actually the header is aluminum and part of the cab, not bolted or riveted.
After working with it today I feel the alternator is the primary problem.
Since I have no ignition and no whine with the key in the ON position (Fuel
Pump), the alternator seems to be the culprit. I have been reading about
installing a micro_farad capacitor between the alternator and ground in
order to steady the voltage thus reducing the whine. I understand the theory
but could use some feedback about the practical application.

I feel this might be my least time consuming and least expensive solution.



Steveo May 18th 04 12:43 AM

Frank Gilliland wrote:
It's as annoying
as those pop-ups in your internet browser. Properly grounding your radio
works like a good pop-up blocker.

cool analogy.

--
http://www.allpar.com/mopar.html

Frank Gilliland May 18th 04 01:07 AM

In , "Randy" wrote:

snip
Actually the header is aluminum and part of the cab, not bolted or riveted.



Then you might get a fairly good ground right there. Bolt the bracket right to
the aluminum and run the black power lead to one of the bracket bolts, cutting
the wire as short as possible (no longer than six inches should be fine).


After working with it today I feel the alternator is the primary problem.
Since I have no ignition and no whine with the key in the ON position (Fuel
Pump), the alternator seems to be the culprit. I have been reading about
installing a micro_farad capacitor between the alternator and ground in
order to steady the voltage thus reducing the whine. I understand the theory
but could use some feedback about the practical application.

I feel this might be my least time consuming and least expensive solution.



You could try that, too. Find yourself a 'motor run' (NOT a 'motor start')
capacitor of around 1 to 5 uF. They usually have tabs for terminals so you can
use crimp connectors, and they can be mounted just about anywhere with a cable
clamp. Mount it as close as possible to the alternator, or even right on the
alternator if possible. Run one wire to the output and the other to ground,
again keeping the wires as short as possible. The capacitor is not polarized so
it doesn't matter which terminal goes to ground.

But know that some regulators are messed up by putting a cap across the
alternator. If you screw up your engine, don't blame me.





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-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Landshark May 18th 04 01:58 AM


"Steveo" wrote in message
...
Frank Gilliland wrote:
It's as annoying
as those pop-ups in your internet browser. Properly grounding your radio
works like a good pop-up blocker.

cool analogy.


He's fairly right on that analogy.

Landshark


--
The world is good-natured to people
who are good natured.



Keith Hosman May 18th 04 10:31 PM


"Keith KC8TCQ" callsign @ qrz dot com wrote in message
I've installed a few roof-mounts, but GM seems to be stingy when it comes

to
steel. If you don't reinforce the roof with some 0.064 or better it goes

'pong'
whenever you go above 20 mph.


My 75 Dodge I had a 102" whip with 4 inch spring mounted dead center
of the the front rail of the bed right behind the cab, and to keep it
from slapping into the back of the cab I put a tennis ball on the whip
just below the roof of the cab. Worked like a charm with my old 148
GTL.

A friend of mine tried using a mag mount antenna on the roof of his
S-10, only problem is, he used a fiberglass whip which was a bit too
heavy and not flexible enough, combined with a weak mag mount. End
result, a Semi passed him, blew the antenna off the roof, it (the
magnet) came smashing through the rear window and gave him a
concussion.

I too have used stud mounts and reinforced the body with washers and
sheet steel. worked great.



Dumbest installation I have ever seen, a guy bought an older S-10 4x4, it
needed some body work but not much, he went out and bought a roll bar, had
lights mounted on it, and mounted his antennas on it. It looked really
sharp, Only one problem, he never got around to actually mounting the roll
bars to his truck, one day he took off from a stop light in Toledo trying to
act like Mr Bada$$ leaving Franklin Park Mall, his roll bars flew right out
of the bed taking the lights and antenna with them.



Randy May 19th 04 03:16 AM


"Frank Gilliland" wrote in message
...
In , "Randy" wrote:

snip
Actually the header is aluminum and part of the cab, not bolted or

riveted.


Then you might get a fairly good ground right there. Bolt the bracket

right to
the aluminum and run the black power lead to one of the bracket bolts,

cutting
the wire as short as possible (no longer than six inches should be fine).


After working with it today I feel the alternator is the primary problem.
Since I have no ignition and no whine with the key in the ON position

(Fuel
Pump), the alternator seems to be the culprit. I have been reading about
installing a micro_farad capacitor between the alternator and ground in
order to steady the voltage thus reducing the whine. I understand the

theory
but could use some feedback about the practical application.

I feel this might be my least time consuming and least expensive

solution.


You could try that, too. Find yourself a 'motor run' (NOT a 'motor start')
capacitor of around 1 to 5 uF. They usually have tabs for terminals so you

can
use crimp connectors, and they can be mounted just about anywhere with a

cable
clamp. Mount it as close as possible to the alternator, or even right on

the
alternator if possible. Run one wire to the output and the other to

ground,
again keeping the wires as short as possible. The capacitor is not

polarized so
it doesn't matter which terminal goes to ground.

But know that some regulators are messed up by putting a cap across the
alternator. If you screw up your engine, don't blame me.





-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----



Well I have learned a tremendous amount about whine in a CB in the last
week. I stopped by a shop today to purchase a capacitor that I was going to
place on the alternator and the tech said he could fix the problem for
twenty dollars. I watched him open the unit, desolder a capacitor and
resolder a larger one in its place, he then shorted a couple of connections,
probably tweaking the unit. I figure he was doing the same thing I was going
to do but he did it inside the unit. I can just barely hear the whine ...
well worth twenty dollars.

I want to thank everyone for taking time to help me ... I did learn a lot
and I might put it to use when I have more time.

P.S. You all leave poor old George alone. If you would quit fueling the
fire the fire would burn itself out. I do not know what started it but it is
very detrimental to this group.




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