(Continued from Part 1. This concludes the article.)
A $20 SDR-UTL dongle can cover 1.8MHz to 1.2 GHz, and see and hear the entire 220MHz Ham band, or the entire spectrum with the right software. Yet who would use precious power to monitor a band with no traffic on it anyway? The more expensive Dongle covers most everything else including frequencies that drones would use… With the $20 dongle, a poor man’s frequency analyzer, one can see weak transmissions even though they cannot hear them. And one can spot spurious transmissions, secondary harmonics, that can lead to the identification of those using the notorious Baofeng UV-5R. Having a Baofeng or two, I’ve tested this. If the user is using something besides a Baofeng, I would consider them the more serious threat. So even you-guys with a Yaesu, Kenwood, or whatever fine radios, can be identified by their lack of spurious RF!
Detection, DF-ing, and Intrusion
To better detect threats using low power radio, rip the television antenna off the chimney that is actually this often dual band UHF/VHF antenna horizontally polarized receiving antenna, but mount to pole so that is vertical (that is up and down orientation), and point it in the direction of the most likely avenue of approach. Using the old cable that is on the old television antenna, strip and push one of the bare wires into the scanners antenna plug, and attached the other wire to the body of radio or ground of that antenna base of the scanner. This is the tricky part, but the correct connector and a 50 ohm, or even 75 ohm cable TV cable without the proper connector can be run from the antenna to the scanner. It is of course best to plan ahead, and do it the correct and reliable way. Program the scanner with only GMRS/FRS, MURS, and even CB frequencies, and others if you can. Use a second scanner on the same cable to sweep the entire 2 meter Ham band.
The common as dirt radio out there. is the ubiquitous GMRS/FRS radios and represents the most likely radio that Bubba and his gang might use if knocking off preppers. CB radio will be their second choice, and possibly even 2 meter. GMRS/FRS radios have a very short range, so we use a direction antenna that will pick up the weakest signal. and exclude signals that are not as much of a threat. We would want to hear all traffic in the area as well, but our focus should first be at the front door, and primary avenue of approach. If any traffic is heard they are very close by, and so is the threat. It would be best to put a patrol out to confirm and gauge the threat, or at least put eyes out on the approach, and ready the defense.Continue reading“Signals Intelligence for Regular Folk – Part 2, by Tunnel Rabbit”