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The PHASE NORM-REV switch will turn a NULL point into a PEAK point. Adjust for a null as
above, and then reverse the PHASE switch.
Unwanted signals or noise can only be nulled if present on both A and B
antennas.
Desired signals can only be peaked if the have about the same S/N ratio on both
antennas and when spacing is correct.
Different fading rates and times between dissimilar or wide spaced antenna can
make control adjustment tedious.
The most stable and reliable nulls occur when antennas are moderately close
together (between 1/10 and 1/4-wavelength apart), oriented in the same
direction, and sharing the same polarization.
The PHASE control changes the phase relationship between
A
INPUT and
B
INPUT, effectively
changing the direction of a peak or null. When the phase control is fully counterclockwise, INPUT
A
has minimum phase shift and INPUT
B
has maximum phase shift. As the PHASE control is
rotated clockwise phase shift in INPUT
A
increases while phase shift in INPUT
B
decreases.
The PHASE NORM-REV switch inserts zero (REV) or 180-degree (NORM) phase inversion in
INPUT
B
. This switch has the effect of changing a peak to a null, or a null to a peak. If a signal is
nulled with the NORM-REV switch in one position, changing the position will result in a peak.
If you have a general coverage receiver, select a strong steady signal between 1.5 and 30 MHz. The
ideal signal would be ground wave, although the time and frequency standards on 5, 7.335, and 10
MHz are good alternatives. Try to use a signal that does not have excessive or rapid fading.
Note:
Any signal being nulled or peaked
must
be adjusted to the same level as seen at the
receiver from both channels or the
NCC-1
Phase Control will not work as expected.
Manual Updates
Every effort is made to supply the latest manual revision with each product. Occasionally a manual
will be updated between the time your DX Engineering product is shipped and when you receive it.
Please check the DX Engineering web site (www.dxengineering.com) for the latest revision manual.
