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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 | ||
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 | [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 | Beat Cancel can be so effective at automatically finding | ||
experience with the | 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 | |||
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 | |||
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 | |||
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 | |||
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that is present. But there are tradeoffs. Monitoring a |
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particular signal for too long will mean that the |
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transceiver responds too slowly. Experiment and listen. |
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Switch OFF Menu No. 13. You are now using the SPAC |
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filter. Listen for a change in audio quality as you switch |
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Menu No. 13 OFF and ON. While Menu No. 13 is OFF, |
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change the setting for Menu No. 15 to select a different |
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correlation time for the SPAC mode. If you canÕt hear a |
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significant difference for the current receiving situation, |
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then select a longer SPAC time for better audio quality. |
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Although you may prefer the audio produced when, for |
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example, the Line Enhance function is ON, remember |
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