Anyone measured power output of their bubble?

by **MightyGuru** » Sat Mar 08, 2008 11:30 pm

I am curious what others are getting for power output of the two stages?

850-960MhZ = 195mW
1930-1990MhZ = 110mW

by **inh** » Mon Mar 10, 2008 10:03 am

I'm getting about the same as you (23dBm from both, using 4089's and near Sirenza datasheet components). I keep blowing gates at higher levels, so it seems tough getting the full 500mW...(27dBm).

Also am trying different sawtooth fqs. Commercial units from HK scan at 60-110 Khz - and I read on a post that over 300KHz is good. I have removed some attenuation on the RF side, which probably helps...

by **MightyGuru** » Mon Mar 10, 2008 10:29 am

Thanks for the reply INH. I currently have a SXA-389 on the 850-960 and a SXB-4089 on the 1930-1990. I have removed all attenuation from the 1.9GhZ side.

I had to do some customized placing of passives when I installed the SXB-4089.

by **inh** » Mon Mar 10, 2008 10:38 am

one thing made a good bit of difference to the rf power - I substituted a 2.7pf cap instead of the 1.2pf that sirenza recommends for c40... (VCO output coupling).
I'd be interested in your custom passive placements, as I have been soldering and moving components while the unit is live, powered up and connected to my spectrum analyser...

things like solder junctions make a big difference...
the sirenza engineers I've been speaking to recommend excess solder only when necessary for mechanical reasons, like at the sma joints.

i have also found that measured output power does not always tell you jamming ability - ie scan fq is a different thing...

by **scoopin** » Mon Mar 10, 2008 2:11 pm

ive changed the oscillator in my jammer 380khz and got a solid carrier on the spectrum i noticed the jammer was not jamming most cell companys so i looked into my jammer noticed that triangle wave was not the answer my next idea is jamming the input side of the tower

by **scoopin** » Mon Mar 10, 2008 2:19 pm

but in spite of that post i still think 380 khz is better than any other freq it seems to have more range but still going to test the sweeping method....

by **inh** » Mon Mar 10, 2008 2:19 pm

i've been jamming input and output tower fqs with a broad sawtooth sweep - maybe not the right thing to do...

if you jam tower input/cellphone output, you become identifiable on the system by triangulation...

i also notice that in london where there are '000s of picocells, it is sometimes impossible to get line of sight from my jamming antenna to a cellphone jam target which can overpower what they are receiving already...

any thoughts?

i think tower output/cellphone input is the best target - agree? yes/no?

by **scoopin** » Mon Mar 10, 2008 2:27 pm

well put it this way im running 80w still i get sqwashed on the tower side since i have 80w my power should stomp on a phone easyer than the tower as far as them triangleing you i dont think they can since the system needs to talk to a phone to establish communication with the phone

by **inh** » Mon Mar 10, 2008 2:30 pm

good point (unless they really are after you!)

by **scoopin** » Mon Mar 10, 2008 2:35 pm

at this point when you sweep 380khz it makes a hi noise floor so that in mind you must increase power to make the differnce

by **inh** » Mon Mar 10, 2008 2:41 pm

at the moment I measure the actual sweep waveform at the vco input, while the unit is operating. are you saying that at higher sweep fq, watch out for sweep signal attenuation?

ie check that your vtune signal isn't drooping as sweep fq increases?

by **scoopin** » Mon Mar 10, 2008 2:50 pm

in some vco's thats critcal on the vt side

by **scoopin** » Mon Mar 10, 2008 3:01 pm

what i mean about the 380 khz is when you sweep the vco. the rf output will still be there but to the phone its a hi noise floor

by **MightyGuru** » Mon Mar 10, 2008 3:13 pm

scoopin wrote:...as far as them triangleing you i dont think they can since the system needs to talk to a phone to establish communication with the phone

You CAN be triangulated without any communication link to the cell site tower. Your 'jammer' is nothing more than a RF transmitter. As long as it is transmitting RF energy it CAN be located by triangulation. Trust me, HAM radio clubs make a sport of triangulation. And your 80W footprint makes for an easy target. The default wavebubble power output would be much more difficult to target. Ie. very small footprint. The key is not to leave the thing powered up for long periods.

by **scoopin** » Mon Mar 10, 2008 3:19 pm

thier is no dobt that you can be tracked ..just dont do it in the same place to long if you driving its ok.. if you are sitting for a while its not...

Anyone measured power output of their bubble?

Anyone measured power output of their bubble?

power

c40

scan fq

triangulation

noise floor?

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