Home |
Search |
Today's Posts |
#9
![]() |
|||
|
|||
![]() Steve wrote: Steve wrote: I have a question about how the ANC-4 works. Specifically, it's about the antennas that you connect to the ANC-4 in order to cancel noise or make a 'phased array'. In some contexts, when noise is a problem, people will say that you want to keep the "noise antenna" that you use with the ANC-4 as small as possible. This is because you want the noise antenna to hear *only* the noise, which will be phased out, and not the target signal, which you don't want to be phased out. The suggestion here is clearly that, if your noise antenna *does* hear the target signal, you're going lose signal along with noise. However, when people use the ANC-4 to establish phased arrays of two or more antennas, this is usually with a couple of serious antennas, widely separated, *both* of which can hear the target signal. Hence my question: When the ANC-4 is connected to two largish antennas, both of which are capable of hearing the target signal, what prevents the desired signal from simply being phased out? Is determining what gets phased out just a matter of carefully adjusting the controls on the ANC-4? Thanks! Steve By this time I've used the ANC-4 enough to know that it's a big help. Where noise is concerned, it makes much more of a difference for me than running off batteries, ferrite cores, etc. I'm kicking myself for not getting one of these sooner. I find that my noise floor usually drops one or two S-units the instant I turn the ANC-4 on. Adjusting the controls then can make a huge difference; and at my location it almost always makes more of a difference than is necessary to compensate for the 6 dB insertion loss. It especially shines during the day on LSB and USB. I've tried it with a lot of different antennas, but I'll be experimenting with antennas for quite some time, I suspect. I did eventually get good results using the H-800 active whip. However, where noise reduction is concerned, I find that I get the best results using a wire antenna that snakes its way between my house and the neighbor's house and then back near some power lines. The nulls with the wire antenna are just as deep as they are with the H-800, but they're a lot easier to find. These conclusions are pretty tentative, though, as I am still experimenting and trying out different arrangements. On the whole, I think the ANC-4 is great and worth every penny if you have problems with noise. It works as advertised. Steve I have the ANC-4 (original JPS version), which was a great help with random wire antennas. It seems to be of no use with my welbrook. I tried to use the built-in noise antenna on the ANC-4 to make a null with my Wellbrook and never managed to get that to work. Of course, the Wellbrook is a very quiet antenna in the first place. |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
For Sale TimeWave DSP-59+ DSP unit | Scanner | |||
Stupid question G5RV | Antenna | |||
transmitter question - its a dousy | Homebrew | |||
transmitter question - its a dousy | Homebrew | |||
transmitter question - its a dousy | Equipment |