want circuit/schematic for CB "jammer"
 

Golly -- FYI:
Jamming is illegal -- subject to an FCC fine

--
73 From The Signal In The Noise
Caveat Lector Ya All
"Limitedselection" wrote in message
...
Help!

I want to effectively "jam" CB reception on my property.
The "jammer" would need to be low power and cover an area about as large
as a
'small' city block.

I have searched google, but I have only found references to schematics
that
were either posted to usenet as a picture (thus not saved in google
archives),
or located on web servers in domains that no longer exist.

Any information would be appreciated!

Golly -- FYI:
Jamming is illegal -- subject to an FCC fine

--
73 From The Signal In The Noise
Caveat Lector Ya All
"Limitedselection" wrote in message
...
Help!

I want to effectively "jam" CB reception on my property.
The "jammer" would need to be low power and cover an area about as large
as a
'small' city block.

I have searched google, but I have only found references to schematics
that
were either posted to usenet as a picture (thus not saved in google
archives),
or located on web servers in domains that no longer exist.

Any information would be appreciated!

"Limitedselection" wrote in message
...

[snip]

Since the signal would not leave my property

[snip]

Cool! How do you do that? And if you can keep your jammer signal limited
to your own property, why can't you use the same trick to keep the CB
signals off your property?

Frank Dresser

"Limitedselection" wrote in message
...

[snip]

Since the signal would not leave my property

[snip]

Cool! How do you do that? And if you can keep your jammer signal limited
to your own property, why can't you use the same trick to keep the CB
signals off your property?

Frank Dresser

I won't offer legal advice, but I can offer technical advice.

There's no way to make a signal stop at your property line, short of
putting a perfect shield around your property. And if you did that, you
wouldn't be bothered by your neighbor's CB anyway.

It also looks like you might misunderstand what "jamming" does and how
it works. There's no practical way to make interference go away by
"jamming". "Jamming" is a masking technique. For example, the communist
bloc nations used to jam Western broadcasts, with high-power
transmitters placed close to the intended audience, and producing
powerful noise-like signals. So all the intended audience could hear is
the noise, and not the Western broadcasts. If you build a local jammer,
you'll simply hear it instead of the CBer. That is, you'll just be
replacing the interference he causes with interference you cause. You
can accomplish the same thing by running the jamming signal modulation
into some earphones, putting them on, and turning off the radio the CBer
is interfering with.

Roy Lewallen, W7EL

Limitedselection wrote:
To "Caveat Lector":

Thanks for your 'help'!

Apparently you are a lawyer (or play one on usenet)?

Somehow I don't think the FCC would fine me for jamming CB reception on my own
property.
I specifically asked for a low power circuit that would only cover the area
around my house - not powerful enough to reach the neighbors.
Since I would be jamming myself I would not complain.
Since it's my property the FCC would not know I was doing it - if they drove up
to my gate it specifically says "No Trespassing - violaters will be
prosecuted".

Since the signal would not leave my property, and there would be no complaints,
and it would not interfere with anyone other than me, and to detect the jamming
signal you would have to trespass on my land (at your peril) - I assume that I
could 'get away' with it.

Again, any help (other than legal advice) would be greatly appreciated!

I won't offer legal advice, but I can offer technical advice.

There's no way to make a signal stop at your property line, short of
putting a perfect shield around your property. And if you did that, you
wouldn't be bothered by your neighbor's CB anyway.

It also looks like you might misunderstand what "jamming" does and how
it works. There's no practical way to make interference go away by
"jamming". "Jamming" is a masking technique. For example, the communist
bloc nations used to jam Western broadcasts, with high-power
transmitters placed close to the intended audience, and producing
powerful noise-like signals. So all the intended audience could hear is
the noise, and not the Western broadcasts. If you build a local jammer,
you'll simply hear it instead of the CBer. That is, you'll just be
replacing the interference he causes with interference you cause. You
can accomplish the same thing by running the jamming signal modulation
into some earphones, putting them on, and turning off the radio the CBer
is interfering with.

Roy Lewallen, W7EL

Limitedselection wrote:
To "Caveat Lector":

Thanks for your 'help'!

Apparently you are a lawyer (or play one on usenet)?

Somehow I don't think the FCC would fine me for jamming CB reception on my own
property.
I specifically asked for a low power circuit that would only cover the area
around my house - not powerful enough to reach the neighbors.
Since I would be jamming myself I would not complain.
Since it's my property the FCC would not know I was doing it - if they drove up
to my gate it specifically says "No Trespassing - violaters will be
prosecuted".

Since the signal would not leave my property, and there would be no complaints,
and it would not interfere with anyone other than me, and to detect the jamming
signal you would have to trespass on my land (at your peril) - I assume that I
could 'get away' with it.

Again, any help (other than legal advice) would be greatly appreciated!

From: (Mike W)
You are talking about the groundwave, think about the skywave.
I can assure you that even a low power jammer will be receivable over
most of the world at some stage or other, depending on propagation
conditions.

Ah, I had not thought of that. Is there any way to ensure that did not happen?
Locating the jammer inside the house?
The angle of the antenna?
Sheilding the jamming device?
Only operating at certain times?

I do NOT want to interfere with any reception (other than my own).

From: (Mike W)
You are talking about the groundwave, think about the skywave.
I can assure you that even a low power jammer will be receivable over
most of the world at some stage or other, depending on propagation
conditions.

Ah, I had not thought of that. Is there any way to ensure that did not happen?
Locating the jammer inside the house?
The angle of the antenna?
Sheilding the jamming device?
Only operating at certain times?

I do NOT want to interfere with any reception (other than my own).

Roy,
Thanks - Mike posted about sky waves (I was unaware of), so even a very low
power device centrally located in my property would apparently be heard
world-wide - which is NOT what I want.

Actually, I did want to jam the reception of the existing CB signals on my
property (at least in and around the house).

One of my neighbors uses rather 'salty' language and the local kids use some
walkie talkies around the house - I fugured that jamming the outside signals
would still allow the kids to talk due to their close proximity.

Thanks again.

From: Roy Lewallen

There's no way to make a signal stop at your property line, short of
putting a perfect shield around your property. And if you did that, you
wouldn't be bothered by your neighbor's CB anyway.

Roy,
Thanks - Mike posted about sky waves (I was unaware of), so even a very low
power device centrally located in my property would apparently be heard
world-wide - which is NOT what I want.

Actually, I did want to jam the reception of the existing CB signals on my
property (at least in and around the house).

One of my neighbors uses rather 'salty' language and the local kids use some
walkie talkies around the house - I fugured that jamming the outside signals
would still allow the kids to talk due to their close proximity.

Thanks again.

From: Roy Lewallen

There's no way to make a signal stop at your property line, short of
putting a perfect shield around your property. And if you did that, you
wouldn't be bothered by your neighbor's CB anyway.