Cell phone jammer detector
Conundrum, Sun Mar 19 2017, 09:15PMHi, as I now suspect someone nearby is using a banned videosender circa 2002 and mucking up my 4G service, is there a way to locate this?
Having a keyring sized detector with direction and signal/band meter would be handy as the ones built into phones only say when they are in LTE mode/etc but do not show much more.
The problem is that folks bring stuff back from Eastern Europe and probably don't appreciate that what is acceptable there is a real problem here such as quad band phones that are only legal in their country of origin.
Thanks, -A
Re: Cell phone jammer detector
Carbon_Rod, Mon Mar 20 2017, 05:19PM
In general, some MIMO setups want one antenna vertically polarized, and the other mounted at about 30' (note some places use +45' and -45 rotations). These style of UWB PCB antenna are quite directional, and the pair must match your carrier's bands supported by your modem's chip-set.
Note, the antenna gain must not exceed your existing transceiver power rating, and a telecom can blacklist or throttle malfunctioning hardware. Hint, 4 antenna set-ups usually allow one to optimize the RX antennas with higher gain rigs, and with better SNR increase data throughput.
For checking the spectrum, it is now cheap to listen with SDR:
During peak use hours, bad weather, and solar-flares one can expect service degradation.
Carbon_Rod, Mon Mar 20 2017, 05:19PM
In general, some MIMO setups want one antenna vertically polarized, and the other mounted at about 30' (note some places use +45' and -45 rotations). These style of UWB PCB antenna are quite directional, and the pair must match your carrier's bands supported by your modem's chip-set.
Note, the antenna gain must not exceed your existing transceiver power rating, and a telecom can blacklist or throttle malfunctioning hardware. Hint, 4 antenna set-ups usually allow one to optimize the RX antennas with higher gain rigs, and with better SNR increase data throughput.
For checking the spectrum, it is now cheap to listen with SDR:
During peak use hours, bad weather, and solar-flares one can expect service degradation.
Re: Cell phone jammer detector
Conundrum, Mon Mar 20 2017, 07:43PM
Adds "solar flare detector" to his list of uses for this device.
Conundrum, Mon Mar 20 2017, 07:43PM
Adds "solar flare detector" to his list of uses for this device.
Re: Cell phone jammer detector
Hazmatt_(The Underdog), Tue Mar 21 2017, 01:14AM
I'd just use a small soup can with a 1/4 wave stub inside and feed that to an AD8307 log amplifier, and to whatever display driver you like.
Even a small soup can would probably give you at least 6dB gain.
Granted the 8307 is only useful to about 500 MHz, you get the idea. There are more in the same family that cover higher frequency too.
Hazmatt_(The Underdog), Tue Mar 21 2017, 01:14AM
I'd just use a small soup can with a 1/4 wave stub inside and feed that to an AD8307 log amplifier, and to whatever display driver you like.
Even a small soup can would probably give you at least 6dB gain.
Granted the 8307 is only useful to about 500 MHz, you get the idea. There are more in the same family that cover higher frequency too.
Re: Cell phone jammer detector
Conundrum, Wed Mar 22 2017, 04:24AM
Good idea, thanks.
Trying not to thread hijack here but has anyone here messed with SDR?
I have a module here which has the well known RTL2832 chip but lack a working remote, the one found is either faulty or for a different unit as it does not turn on!
EDIT: It does work, remote does not. I found a workaround for now which is to use SDRSharp.
Apparently its also possible to filter the 5V line and other hacks to increase performance, not so much of an issue on my fairly RF-quiet quad AMD Toshiba C650d but can be a problem on older dinosauroids.
Has anyone else hacked these before, if so what did you do to resolve the chip heating problems?
EDIT: Recalibrated both internal oscillator and frequency counter, had no idea how "noisy" these were.
I can incidentally pick up what I can only assume to be microwave oven interference, see the other two pictures posted on the relevant thread:
Thanks.
Conundrum, Wed Mar 22 2017, 04:24AM
Good idea, thanks.
Trying not to thread hijack here but has anyone here messed with SDR?
I have a module here which has the well known RTL2832 chip but lack a working remote, the one found is either faulty or for a different unit as it does not turn on!
EDIT: It does work, remote does not. I found a workaround for now which is to use SDRSharp.
Apparently its also possible to filter the 5V line and other hacks to increase performance, not so much of an issue on my fairly RF-quiet quad AMD Toshiba C650d but can be a problem on older dinosauroids.
Has anyone else hacked these before, if so what did you do to resolve the chip heating problems?
EDIT: Recalibrated both internal oscillator and frequency counter, had no idea how "noisy" these were.
I can incidentally pick up what I can only assume to be microwave oven interference, see the other two pictures posted on the relevant thread:
Thanks.
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