Thanks Ethan. Yes , I did not know that you are from IPVM and that you are the testing person.
Secondly, English is not my mother tongue as you probably noticed, but at any rate I never intended to insult anybody. Pls read again what I wrote and note that I did NOT imply what you might have understood about the Chinese scientists. I just wrote that the Chinese scientists ( Dahua engineers are most probably Chinese, aren't they ? I just wrote Chinese because as far as I know ALL analog HD solutions come from China ) who designed the new technologies we are discussing here are NOT NECESSARILY RF interference experts. I still stand behind this assumption. If analog HD technologies would have originated in the US, I would have written US or American Engineers, again without any disrespect.
Let me explain : I must humbly "confess" that just because of a very unique profesional CV I became a seasoned CCTV and RF expert, and that these two expertises are rarely found in the same person or even electronics Engineer. Its just two different disciplines - Baseband, and RF, or carrier if you wish. What these engineers designed is ingenious to anybody that understands how difficult it is to send high bandwidth signals over long distances with no negative effect of the cable frequency slope, attenuation etc. Even SD or old NTSC video is sometimes challenging for 1000 Ft cables, with apparent color loss, wrong colors, bad contours, shadows, noise etc. So HD that needs 6 times more bandwidth and flatness is really really hard over long distances. Almost magic !!!!
I was trying to unravel the mystery or the "magic" since nobody is officially giving the technological concept, or namely this RF modulation technique. I then registered to IPVM several days ago with hope that your reviews will help me to find out. It eventully did because it was the only place that confirmed that this 1080P analog CCTV systems really work at 1000 ft, and even work good, to my surprise. You might take it for granted as another market product, but I was amazed. I then got even more motivated and went and found out that 58Mhz story written by somebody not from Dahua. Assuming what he explained is correct, and it makes sense that he is correct, then there might be a crosstalk problem because its a single carrier frequency going in all cables, unless each camera has a DIFFERENT carrier freq, but this in turn might create a configuration issue and compatibility problems.
You mentioned that you did not see any crosstalk problems in any of your testings, but as far as I saw, your tests were mainly using SINGLE analog HD camera connected to a monitor or DVR through a long cable on a spool. If I am wrong, and you have a test where two camera were working in tandem with two cables running parralel and very close to each other, then pls direct me to the relevant test or article.
The ultimate and most challenging crosstalk test for this new technology would be a strong signal interfering a weak signal, with real world coax cables T-wrapped together over several hundred feet, and this can be done in several ways.
I am willing to bet that two Cat5 cables with baloons running in parralel would show a very strong crosstalk effect. Coax is better of course because of the shielding, but still I anticipate an issue.
And again, if anybody was disturbed from the Chinese Scientists remark, although no offense meant, I do appologize.