Help! Seems OK but not doing the business!

The operation of transmitters designed to jam or block wireless communications is a violation of the Communications Act of 1934, as amended ("Act"). See 47 U.S.C. Sections 301, 302a, 333. The Act prohibits any person from willfully or maliciously interfering with the radio communications of any station licensed or authorized under the Act or operated by the U.S. government. 47 U.S.C. Section 333. The manufacture, importation, sale or offer for sale, including advertising, of devices designed to block or jam wireless transmissions is prohibited. 47 U.S.C. Section 302a(b). Parties in violation of these provisions may be subject to the penalties set out in 47 U.S.C. Sections 501-510. Fines for a first offense can range as high as $11,000 for each violation or imprisonment for up to one year, and the device used may also be seized and forfeited to the U.S. government.

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Mictronics
 
Posts: 63
Joined: Sat Feb 20, 2010 3:16 pm

Re: Help! Seems OK but not doing the business!

Post by Mictronics »

The only solution for more power is a third board with amplifier for each VCO. Requires an additional power supply as well.

Or another redesign of the WB with integrated preamplifier's.

TheFallen
 
Posts: 94
Joined: Mon Feb 08, 2010 1:28 pm

Re: Help! Seems OK but not doing the business!

Post by TheFallen »

The initial WB parts list calls for RP-SMA connectors, you're using SMA connectors on your antennas and aerials So unless you've destroyed your RP-SMA connectors that means you've got SMA connectors soldered onto your wavebubble.

soram
 
Posts: 22
Joined: Sat Jan 15, 2011 6:32 am

Re: Help! Seems OK but not doing the business!

Post by soram »

I have indeed. I had the RP-SMAs but got antennae that didn't fit so ordered SMAs for the board.
I looked it up at the time and it seemed that the only reason for RP-SMA was to stop cross use between some professional and commercial usage so I figured it wasn't a technical issue. Was I wrong? I can't imagine there to be too much (any) difference.
The finishing stage design lists both types of antenna. Rest assured I do have a a male and female antenna / connector combination though!

I have ordered the Penta antenna to try out but I don't expect it to double my output so I'm still looking for a solution to that in the 1800-2100MHz range. The original had a third board with nothing on it. Could that house extra power for those that want it? Even just for the high frequency VCO? The existing power switch could then be used to modulate the output to an acceptable duty cycle.

soram
 
Posts: 22
Joined: Sat Jan 15, 2011 6:32 am

Re: Help! Seems OK but not doing the business!

Post by soram »

Update....

Well I got the Penta antenna and it is a definite improvement in the 2100 MHz range. The bigger quad antenna however is no noticeable improvement over the stubby quad on the analyser.

The 1800 MHz band is way less powerful than the 800 Mhz so I'm going to play with the attenuator as it is in the higher band I need the power. I'm not sure I understand where the losses are as both VCOs are supposed to deliver between 7 and 8 dBm.

With an antenna on the input to the analyser for kicks I can see the iPhone sends out spikes way in excess of the power the jammer does when trying to connect to base.

I have used the resistor values for the T from the original design. Any comments on that? The low range VCO runs noticeably cooler than the high range one!

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lcstyle
 
Posts: 76
Joined: Sun Oct 26, 2008 10:55 am

Re: Help! Seems OK but not doing the business!

Post by lcstyle »

soram wrote:I've done a few tests with various frequencies. At very close range I can knock out the 3GS. Close being about 3 feet. Sometimes it gets knocked out but seems to find a signal somewhere else that seems more difficult to hit.

It would be great if I knew what channel the phone was working on so I could correlate that with the jammer. Anybody experience with IOS and where to read the frequency? I can do a basic app myself to display it if I knew where to grab the channel info. If indeed that was possible!

Secondly, I reckon power is a problem. I am only getting 10dBm in the high frequency range and have to open up it quite big to hit both the 1800 and the 2100 bands. I can get 20dBm from the lower VCO. Might it be possible to get some serious gain for short period bursts? I have no RF experience so wouldn't know what to do here but would it be possible to build an add on that would give some more power? As it is it is a nice toy but with the limited range it is not as useful as I would like it to be.

Have you verified that the vco input is a sweeping sawtooth wave ? Jamming is impossible without noise.

Also, you might want to read through the original thesis paper here and reflect on what may or may not be right with your build:
http://www.ladyada.net/media/pub/thesis.pdf

TheFallen
 
Posts: 94
Joined: Mon Feb 08, 2010 1:28 pm

Re: Help! Seems OK but not doing the business!

Post by TheFallen »

In fact without the sweeping sawtooth wave it would be impossible to get any output at all. However that is not the problem. He can jam, just not with to the desired distance. As for Lady Ada's thesis, it's definitely interesting reading, but doesn't focus on debugging a lack of range.

Excuse me being a bastard, but did you read this thread, or just the title, before commenting in it?

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lcstyle
 
Posts: 76
Joined: Sun Oct 26, 2008 10:55 am

Re: Help! Seems OK but not doing the business!

Post by lcstyle »

TheFallen wrote:In fact without the sweeping sawtooth wave it would be impossible to get any output at all. However that is not the problem. He can jam, just not with to the desired distance. As for Lady Ada's thesis, it's definitely interesting reading, but doesn't focus on debugging a lack of range.

Excuse me being a bastard, but did you read this thread, or just the title, before commenting in it?
You are right I obviously have no idea what I'm talking about.

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