signal jammers

[9C1Driver]

Years ago I talked to a local basement tech that described to me a way he delt with a trouble maker on the channel years ago. He took a dinky cheap cb, modded it up so it would send out a low powered signal across several channels. It was activated and powered by a 9 volt battery, then wrapped in duct tape. Then at night he tossed it in the guys gutter or front shrubs. For several days when the problem child turned on his radio he had constant interference in his receive. It had no effect on the rest of the people on the channel. Pretty cool. I will have to try and get more details.

 

[Moleculo]

Why not tell people how you use an oscilliscope to verify an amplifier is splattering all over the RF spectrum?

This.

I made a comment almost just like this to a certain radio tech on 1 Stop years ago and it got me banned, LOL.

I had almost forgotten about that until this post!

 

[-=PEAKABOO=-]

Yes indeed, that forum was very political just like its sister forum that is up now.

This.

I made a comment almost just like this to a certain radio tech on 1 Stop years ago and it got me banned, LOL.

I had almost forgotten about that until this post!

 

[Moleculo]

Back on topic, here is a channel specific device that won't really "jam" the channel, but will create a very annoying carrier when hooked up to an antenna. It doesn't take hardly any power to work and can render nearby receivers fairly useless.

Let's see how long it takes for someone to recognize this.

 

[linearone]

Back on topic, here is a channel specific device that won't really "jam" the channel, but will create a very annoying carrier when hooked up to an antenna. It doesn't take hardly any power to work and can render nearby receivers fairly useless.

Let's see how long it takes for someone to recognize this.

that sure looks like the osc. board from a texas star.

 

[linearone]

I've got a schematic and .pcb files I made up last year, it does wide-band TX, most of 26, and the majority of 27 all at the same time, while staying out of adjacent ham bands.

And for anally challenged we'll just call it wide spectrum 11 meter tuning aid which runs on a single 9 volt battery for about a month, more batteries can be paralleled for extended operation.

Warning Tossing this device in a tree may cause such interference that it could render CB radios completely useless within a few hundred yards, and may be considered malicious interference! As such I suggest only using with an appropriate 50 Ohm Good-Buddy Load!

Its been about a year, so I'll have to dig up the DVD I have the files archived on.


Oh, and the nice thing is it just uses a hand full of parts, of which the most expensive is a 2N2222, If I recall correctly 2 or 3 bucks worth if you have an under stocked junk box and have to buy them all....

Ever find this? Id love to see its schematic/pcb files.

 

[Moleculo]

that sure looks like the osc. board from a texas star.

That didn't take long

 

[linearone]

That didn't take long

two questions, where did you find freq. specific crystals in our band? What did you exactly have to modify?

I see it like this:
b+ to the collectors via a trace near c8

b- to the big wide trace they show as ground

the key is obvious but there is a discrepancy on the cb tricks site. the pic shows 220pf out to antenna but the schematic shows 2200pf. which?
is it even necessary or is it acting as some sort of resonant filter like to trap a frequency? I saw something done similar to a palomar once on the output/

 

[jazzsinger]

Ever find this? Id love to see its schematic/pcb files.

This wouldn't be it would it? I would imagine a few circuit changes around the coil/var capacitor would change the output frequency.if i'm not mistaken an antenna could be added at the collector/coil/6pf cap junction.


http://www.next.gr/inside-circuits/TV-and-FM-jammer-schematic-l4106.html

 

[Robb]

Tried to find the schematic for the Texas Star oscillator board on CB Tricks - but couldn't find it.

Imagine you can power it with two 9v batteries in parallel for a a long 'jam session'.

I see that Mole had set his for ch 28.
Having some problems down south with a local?

 

[linearone]

This wouldn't be it would it? I would imagine a few circuit changes around the coil/var capacitor would change the output frequency.if i'm not mistaken an antenna could be added at the collector/coil/6pf cap junction.


TV and FM jammer schematic « Inside Circuits « Free Electronic Circuits/Schematics Directory :: Next.gr

I'll fiddle around with this on the weekend. On the link they kinda say its pretty much for 100mhz like broadcast band but I will fiddle with the coil.

 

[linearone]

Tried to find the schematic for the Texas Star oscillator board on CB Tricks - but couldn't find it.

Imagine you can power it with two 9v batteries in parallel for a a long 'jam session'.

I see that Mole had set his for ch 28.
Having some problems down south with a local?

http://www.cbtricks.com/Amp/txstar/dx400v_dx500v/graphics/ts_osc_pcb_layout.gif

 

[DTB Radio]

An idea for a short-range wideband transmitter would be to take a PLL-controlled CB, unhook the VCO from the PLL chip, and use an oscillating voltage (sin wave, triangle wave, or sawtooth) to drive the VCO. To keep the CB within a certain band, just set the peak voltage of the oscillator output and adjust the VCO coil. Using a sawtooth generator of about 1khz would sound almost like a constant roger beep tone across the entire transmitter band, because you'd essentially be sending a quick pulse of RF on every frequency at a rate of 1000 times per second. VERY effective jammer in theory.

Another idea is to just overmodulate the heck out of a CB or export that uses pure solid state AM regulator modulation (NOT a 148 or similar that uses a transformer driving a regulator). Use a resistor in the driver's collector circuit or base circuit to control the output level. Modulate the radio with about a 1khz tone, and completely disable the AMC. The extreme audio harmonics, combined with normal Intermodulation Distortion, will modulate the carrier over a VERY wide range, making a reasonably effective jammer which can be limited in range with careful driver control. This would be extremely effective on the specific channel to which its tuned, and gradually less effective the further away from that channel you went.

 

[Lil'Yeshua]

An idea for a short-range wideband transmitter would be to take a PLL-controlled CB, unhook the VCO from the PLL chip, and use an oscillating voltage (sin wave, triangle wave, or sawtooth) to drive the VCO. To keep the CB within a certain band, just set the peak voltage of the oscillator output and adjust the VCO coil. Using a sawtooth generator of about 1khz would sound almost like a constant roger beep tone across the entire transmitter band, because you'd essentially be sending a quick pulse of RF on every frequency at a rate of 1000 times per second. VERY effective jammer in theory.

Another idea is to just overmodulate the heck out of a CB or export that uses pure solid state AM regulator modulation (NOT a 148 or similar that uses a transformer driving a regulator). Use a resistor in the driver's collector circuit or base circuit to control the output level. Modulate the radio with about a 1khz tone, and completely disable the AMC. The extreme audio harmonics, combined with normal Intermodulation Distortion, will modulate the carrier over a VERY wide range, making a reasonably effective jammer which can be limited in range with careful driver control. This would be extremely effective on the specific channel to which its tuned, and gradually less effective the further away from that channel you went.

Cool!
Just make it mobile and drive around near all the loud mouths.

 

[Mudfoot]

Wideband arcing is all that's needed. Cheap, simple and devastingly effective.