Topband: noise canceller comparison
tod at k0to.us
Sat Dec 22 20:20:49 EST 2007
I occurred to me that I should have posted this to the reflector rather than
only to Jon
> Anyone compared the DX Engineering *NCC-1 with the MFJ-1026,
> 1025 or others? How much difference?
The NCC-1 costs about 2 times the price of the MFJ-1026.
Both units will cancel noise quite well.
The NCC-1 is much 'smoother' to use since it has switch selectable reversal
of inputs and 180 degree phase change as well as better control over the
signal amplitude of the inputs. The phase control seems to operate more
'linearly' than the phase control of the 1026. By that I mean the phase
control of the 1026 [ using the MAIN and AUX antennas I had available]
seemed to be skewed to one end of the control and the adjustment to achieve
a null sometimes was extremely 'tight'. Switching the phase did not always
seem to produce optimum addition of the signals that had been nulled. The
NCC-1 seems to be easier to use to find nulls which are then changed to
'adds' by switching the phasing by 180 degrees.
My experience is sufficiently limited [it took a six month wait to get my
NCC-1 which arrived just before the first of November 2007] that I cannot
state will absolute conviction that the NCC-1 has twice the "performance' of
the 1026 in my circumstances.
I feel that the success one has with these nulling/enhancing devices is
strongly dependent on the noise source locations relative to the RX and
Noise Sense antennas and not necessarily with the choice of nulling unit.
The same devices located in two different geographies may give good results
in one geography and marginal results in the other. The problem is probably
not with the NCC-1 or the 1026 but rather with the location of the antennas
relative to each other and to the noise.
If at all possible one should 'borrow' or 'rent' such a nulling device and
see how it performs in your geography. You can also experiment with RX and
Noise Sense antenna location if that is possible. Either device will give
you a strong indication of how well nulling can perform in your situation.
After that you can decide how much you want to spend to get somewhat easier
finding of nulls and enhancements.
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