Skysho
Member
Just wanting to see if there are some folks in the group that use any of the devices mentioned in the title. Looking for someone with the first version KN2C Doppler.
Thanks
Thanks
ARDF, Dopplers, Sniffers, and Body Fading
- Thread starter Skysho
- Start date
I have the first version of the KN2C DDF2020 that uses 5 antennas.
Skysho
Member
Can I bother you to take a look at the control cable? Looking at the Rj-11 connector I'm trying to find out if it has four or five wires in it? The other question is if it's a straight through regular connector or reversed. Some of the data transfer connectors are reversed. Thanks in advance if you are able to do that.
Ubbe
Member
There are four antennas it controls, prcguy says he has a 5 antenna version, so it will need one signal wire for each antenna and one common ground wire, 5 in total, so will need a 6 pin RJ11 cable. It should be pin 1 going to pin1 standard cable, anything else would be highly unlikely. It's RJ45 8 pin network cables that use twisted pairs but still has pin 1 going to pin 1, except special patch cables that are crossed.
/Ubbe
/Ubbe
I scanned the control cable, it has 6 wires and 1:1 no crossover.
Skysho
Member
Thank you very much. I recently acquired one and the cable was missing. The seller is sending what he found and I'm hoping it's correct. The other unit I have is the newer model, so nothing to compare. Unfortunately, he said he thought one was four and the other five. :-( I've reached out to Gyo An too.
Ubbe
Member
If you have four or five antennas it needs to be RJ11 with 6 wires, that makes it a RJ12. You can buy whatever length you will need from Amazon or probably any electronic store that sells data cables and phone cables.
/Ubbe
/Ubbe
I'll be curious how the newer model works vs the older. I find my 5 antenna version to be very numb on reception but when the signal strength is good it works very well.
Skysho
Member
Yeah, me too! I have been very happy with the one I have. I rarely use it with the laptop, too much of a pain. The doppler sits on top of the dash and my wife has a Mk4 sniffer with a 2m Arrow loop attached to a piece of PVC that extends out her side window and above the cab. I drive toward the doppler signal and she measures how close we are to the target. When the sniffer hits 8 we are on top of it.
I plan on this one staying home and in my shack. I should be able to track movement (we've had a mobile jammer for a few years) and determine signal strength with my sniffer attached to an Elk Yagi on a rotator in my attic. I can track him (hopefully) before jumping in the rig and wasting gas. We know he's a trucker and quite a bit of information on him and his delivery route. It's been a challenge.
I plan on this one staying home and in my shack. I should be able to track movement (we've had a mobile jammer for a few years) and determine signal strength with my sniffer attached to an Elk Yagi on a rotator in my attic. I can track him (hopefully) before jumping in the rig and wasting gas. We know he's a trucker and quite a bit of information on him and his delivery route. It's been a challenge.
Ubbe
Member
There isn't much that can be done to improve performance of a doppler DF besides using an as sensitive receiver as possible, bandpass filters will always help a scanner in a mobile environment. The simulated rotating of one antenna creates a doppler tone that gets polluted from background noise when a signal are weak in RF strength. The detector that uses that tone will probably have difficulties to use some sort of noise eliminator. You usually have some kind of slew control that adds integration time to make the indication go slower or you can watch the LED's and see which ones that lights up more than the others.
I've used the Ramsey kit, I believe it was $150, with an Icom portable scanner, that have great sensitivity, and the kit came with magnetic telescope antennas that can be tuned to the frequency of interest. It worked great but you always have to consider reflections from buildings and terrain when trying to get a direction of a signal. It helps if you can calibrate to a signal from a known direction before doing a DF.
/Ubbe
I've used the Ramsey kit, I believe it was $150, with an Icom portable scanner, that have great sensitivity, and the kit came with magnetic telescope antennas that can be tuned to the frequency of interest. It worked great but you always have to consider reflections from buildings and terrain when trying to get a direction of a signal. It helps if you can calibrate to a signal from a known direction before doing a DF.
/Ubbe
Skysho
Member
I wonder if a preamp would make a difference? I use preamps on two balloon trackers that use Raspberry Pi's and RTL-SDR's. My newer model DF2020T is coupled with a Yaesu FT-90, I actually mounted it to the top of the case and removed the mic. This one, if I get it working, will use an Icom R-3 scanner which will allow a pretty wide range of frequencies.
I also purchased a Kerberos, which is now upgraded to a Kraken but still using the four-antenna array. The local hams that were paying attention to this jammer figured that was the unit that would successfully track the culprit. I can tell you it was pretty much useless in the attempts. Way too many competing signals from every direction and you had no idea which was the jammer. The jammer always plays his games during a scheduled net that coincides with his travels. Seeing the LED light up on the DF2020 when he transmits has worked and you can see the direction change as he passes on the highway. The Kraken creates the vectors and heat map on the Android tablet of all the signals and there is no way to filter that specific signal out. I've talked at length with the folks that make them, and they agree tracking him would be next to impossible without a filter or fingerprinting his signal. They have been talking about the fingerprint idea, I have my doubts that will come to fruition. Plus, the Kraken is rather a PIA to setup for a short hunt.
For the easiest and fastest chase, I use a two-element cubicle quad out the wife's window and the MK4 Sniffer. The sniffer has both visual and audio for the signal strength and with the directional attributes of the quad you can get to the target. Of course, reflections, creek beds, and terrain contours can send you off chasing your tail. Dale Hunt (WB6BYU) and I host many of the transmitter hunts in this area. On occasion, since we are both retired, we'll each hide a transmitter and the only clue is it being within a 25-mile radius around our QTH, we live about 40 miles from each other. The goal is to make it very difficult to find to give us practice. Since he is way more skilled, I use much more fuel for the hunt. He has a website www.practicalantennas.com it has a DFing section.
Bryant
W7BDB
I also purchased a Kerberos, which is now upgraded to a Kraken but still using the four-antenna array. The local hams that were paying attention to this jammer figured that was the unit that would successfully track the culprit. I can tell you it was pretty much useless in the attempts. Way too many competing signals from every direction and you had no idea which was the jammer. The jammer always plays his games during a scheduled net that coincides with his travels. Seeing the LED light up on the DF2020 when he transmits has worked and you can see the direction change as he passes on the highway. The Kraken creates the vectors and heat map on the Android tablet of all the signals and there is no way to filter that specific signal out. I've talked at length with the folks that make them, and they agree tracking him would be next to impossible without a filter or fingerprinting his signal. They have been talking about the fingerprint idea, I have my doubts that will come to fruition. Plus, the Kraken is rather a PIA to setup for a short hunt.
For the easiest and fastest chase, I use a two-element cubicle quad out the wife's window and the MK4 Sniffer. The sniffer has both visual and audio for the signal strength and with the directional attributes of the quad you can get to the target. Of course, reflections, creek beds, and terrain contours can send you off chasing your tail. Dale Hunt (WB6BYU) and I host many of the transmitter hunts in this area. On occasion, since we are both retired, we'll each hide a transmitter and the only clue is it being within a 25-mile radius around our QTH, we live about 40 miles from each other. The goal is to make it very difficult to find to give us practice. Since he is way more skilled, I use much more fuel for the hunt. He has a website www.practicalantennas.com it has a DFing section.
Bryant
W7BDB
