Jamming says it uses the Electronic Warfare skill, but it never says what you roll or what it does. ECCM adds to the device rating. So if you have a good rating 6 ECCM program on your Signal 4 comlink they'd need a rating 10 jammer to affect you right?

IMHO, the EW skill should add hits to the jammer, but it never says to roll anything, just that it uses the skill and that it's a complex action.

I agree. Jammers seem to be all or nothing. They are good against those that do not load ECCM but only until they load it. A base 3 signal and 3 eccm will defeat the best jammer on the market. that's just silly.

One thing you guys need to remember is that certain technologies even mated ones outpace each other. Read the old SR2 book Fields of Fire in regards to armor vs. armor piercing tech. Coming from a real-world spec ops communications background I can honestly say that attempting to jam wave-based communications is extremely difficult, even harder if you add in encryption. A far more reliable means than jamming is direction-finding (DF) which locks onto radio transmissions and give you a direction to the source, instead of jamming the signal you trace it back to it's origin and take it out there. In SR where you have access to a lot of wizzer gear you use a DF module (likely already built into a TRS station), and relay the bearing of the generating signal (via your own signals or other ways) to a drone, AVM, or heavy fire support to take out your oppositions comms.

I recall using a similair method for tracking someone, using their limo's transponder signal plugged into a signal locator.

A good way to track a particular object (like said limo) would be to hack into the vehicles Lo-Jack (or whatever the 2070's version is) and have it relay directly to a deck as opposed to the service provider's computer system. Or better yet, attach a GPS unit linked to a radio transmitter that's conveniently linked to your cyber-commlink frequencies, which is then routed to your optical display link, so you track your target's location in relatively close to real-time.