Kenwood TS-870S instruction manual Appendix a Learning about DSP, Appendices

		APPENDICES ●
APPENDIX A: LEARNING ABOUT DSP	that different signal and band conditions can produce
	different results. Try not to come to any conclusions
	about which settings are best at this early stage. Keep
First-time users of a DSP transceiver may feel	an open mind until youÕve done a lot more
	experimenting on various bands with different
bewildered by the quantity of functions that they have
	propagation conditions.
never encountered on previous transceivers. When
	Widen the receive pass band by turning the LO/WIDTH
combined with the collection of new terminology that
accompanies DSP, even an experienced operator may	control counterclockwise and the HI/SHIFT control
become frustrated. The purpose of this section is to	clockwise. Try to find a QSO in progress between two
offer a few examples that help you to begin learning	stations who are experiencing interference from a third
about the effects and benefits of DSP. ItÕs best to read	station that may be tuning slightly off frequency but
this section after you are comfortable with using the	within your pass band. Press [BEAT CANCEL]. You
Menu system, and after you are fully familiar with the	may think the tuning station stopped transmitting. Press
controls and buttons on the TS-870S. This manual will	[BEAT CANCEL] again to switch OFF the function.
not make you an expert on using the DSP functions;	The station is still tuning and you can hear it again!
that knowledge will come as a result of hands-on	Beat Cancel can be so effective at automatically finding
experience with the TS-870S.	and canceling tones that are audible in the pass band
Regardless what style of operating you prefer, DSP can	that you may not be aware of the ÒinterferingÓ stations at
	all. With Beat Cancel ON, experiment by changing the
help you. What operator doesnÕt want the quiet,
	Beat Cancel response time via Menu No. 16. The
low-noise pass band offered by DSP operating in the IF
	response time of the function decreases as the setting
stages? Who doesnÕt want to effortlessly eliminate
	number increases (selection 0 has the fastest response
interfering tones caused by others tuning up near their
	time).
operating frequency? Why wouldnÕt anybody want to
	Press [AUTO NOTCH]. Since Auto Notch functions in
narrow their CW bandwidth to a razor-thin slice of
spectrum if they can still listen to a pleasing CW note	the IF stages, it may work better or worse than Beat
without analog filter ÒringingÓ? These are only a few	Cancel for a given situation. Compare the effect of Auto
examples where DSP shines.	Notch versus Beat Cancel with the same interfering
To begin with, the default Menu values chosen for the	tone or tones. Change Menu No. 17 to try different
	response times for Auto Notch while that function is
DSP functions on the TS-870S Menu have been
	activated. Experiment and listen.
carefully considered by the design engineers. They are
	If you are a CW operator, switch to the CW section of a
good starting points. If you have already changed many
Menu items as youÕve experimented with your new	band and search for a crowded portion. With the CW
transceiver, do a Temporary Menu Reset {page 24} or a	mode selected and the LO/WIDTH control turned
Full Reset {page 63} so that you know you are starting	clockwise to select a 1 kHz bandwidth, tune to a
with the default Menu values.	frequency where two or more stations are audible. Now
Switch over to an Amateur band with lots of activity.	turn the LO/WIDTH control counterclockwise to reduce
	the bandwidth. Forget old ideas associated with analog
Tune in an SSB station with reasonable signal strength.
	filters for how narrow you like the bandwidth when
Press [N.R.] to activate Noise Reduction. You will hear
	operating CW. With the minimum bandwidth, you may
a drop in the background noise that makes listening to
	need to tune a little to center the desired signal in the
the signal much more pleasant. If your station is
	pass band. Press [FINE] to reduce the tuning step to
located in an electrically noisy city, this function alone
	make tuning easier. Listen to the quality of the chosen
may make you a DSP believer. Assuming the default
	signal. Can you believe the bandwidth displayed on the
Menu values are selected (due to the reset above), you
	Front Panel? There are other functions to help you fight
are now using the Line Enhance function (Menu No. 13
	CW interference (such as IF Shift) but this example is to
is ON). This function is ÒtrackingÓ (Menu No. 18 is ON)
	illustrate the benefits that DSP offers when using
the signal as the unwanted noise is removed.
	extremely narrow bandwidths.
Try changing Menu No. 14 to reduce and increase the
	After reading this manual, you should be equipped with
response time of the Line Enhance function. What do
	the basic knowledge to begin learning how to use DSP
you notice? Maybe little change can be heard with this
	to your advantage. The DSP benefits that you enjoy will
signal or maybe you hear an important change. The
	be related to the amount of time that you spend
longer you allow DSP to monitor the signal, the better
	experimenting with DSP while operating.
the adaptive filters can determine how to fight the noise
that is present. But there are tradeoffs. Monitoring a
particular signal for too long will mean that the
transceiver responds too slowly. Experiment and listen.
Switch OFF Menu No. 13. You are now using the SPAC
filter. Listen for a change in audio quality as you switch
Menu No. 13 OFF and ON. While Menu No. 13 is OFF,
change the setting for Menu No. 15 to select a different
correlation time for the SPAC mode. If you canÕt hear a
significant difference for the current receiving situation,
then select a longer SPAC time for better audio quality.
Although you may prefer the audio produced when, for
example, the Line Enhance function is ON, remember

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