NORCAL NC2030 Manual page 107

The SCAF is also useful when listening to a very weak signal. Using the RIT to tune the weak signal to
a lower tone (such as 400 or 500 Hz) will place the signal near the bottom of the receiver pass band.
Then the SCAF can be adjusted until it just starts to attenuate the weak signal. Back the SCAF off just a
bit, and you will have narrowed the receiver bandwidth significantly. Reducing the bandwidth reduces
the total noise, thus enhancing the weak signal.
The frequency readout of the receiver is in cw. You have already used the frequency counter to set the
PTO frequency. The default mode when the receiver is turned on is the "E" mode, which simply reports
the frequency in the "xxRx" format, which is 10s KHz, 1s KHz, "R" (cw decimal point), 100s Hz.
Given the limited tuning range of the receiver, this is good enough. The frequency counter is normally
not running, but when it is activated, there are points in the band when you will be able to hear it. You
probably do not need to know more about the frequency counter than that, but there are further operating
instructions at the end of this manual.
There can be a few operating anomalies when using this transceiver. With only two screws holding the
top and the bottom of the case together, the case is not very RF tight. Because of this, the DC receiver
LO leaking from the case can be picked up by the antenna if the antenna is very close to the receiver.
This can cause a feedback "howl" in the receiver. You could modify the case to make it more RF tight,
but the easiest thing is to locate the antenna feed point at least five feet from the transceiver. This is
more of an issue with an end feed antenna or a small portable vertical than an elevated antenna such as a
dipole. It is probably not a good idea to place an auto tuner inside the transceiver and connecting a
random wire antenna right to the back of the radio.
The other anomaly is detection of high power shortwave broadcast transmissions. It takes only very
slight non-linear anomalies in the front end of a DC receiver to cause it to pick up AM broadcast signals
that are off frequencies. I have only heard this twice when using my NC2030, but the effect does exist.
When this happens, what you will hear is a voice or music broadcast that is the same no matter where in
the band the receiver is tuned to. The NC2030 is much better is this regard than past DC receivers, but
the problem can still exist.
Other than that, enjoy using the receiver. It can be fun to make up a switch to move the antenna from
the NC2030 to a second test receiver to hear the difference between the two. Simply make sure the
second receiver is set to LSB as that is how the NC2030 is configured. You should notice immediately
the difference in the roll off as a signal goes out of the pass band. The NC2030 pass band is very sharp.
You will find that the upper frequency and lower frequency roll off is much steeper than you are
probably used to on other rigs using only crystal filters. The steep roll off makes signals, even very
strong ones, seem to pop up then disappear as your tune across the band.
Secondly, search for very strong signals that cause the test receiver problems. For very close in signals
the NC2030 reacts much better to strong signals just outside the receiver pass band than other very good
receivers. In the case of a very strong signal very close in, the key clicks are often the artifact that is
heard as it is extremely rare to have a signal that causes the receiver to overload. Using a 500 ft loop
during field day this year, no such signal was ever encountered.
Norcal NC2030 v5 12-18-05
Page 107 of 128