- #Icom ic 756 pro ii dsp operation how to#
- #Icom ic 756 pro ii dsp operation pdf#
- #Icom ic 756 pro ii dsp operation mods#
- #Icom ic 756 pro ii dsp operation software#
When the indicator is off, the display is dark, the SSB shape factor is in use. It is my belief and claim that this indicator shows the IF filter shape factor state. It appears immediately to the right of the passband width indicator (page 10 of my manual). This indicator is not mentioned in the documentation (756PRO user's manual). The top line of the main display contains a yellow indicator labeled BPF.
#Icom ic 756 pro ii dsp operation how to#
This page describes how to select the two different shape factors (in the CW mode, it cannot be selected in SSB mode). Rob Peebles, W8LX, estimated the sharp CW shape factor to be 1.5, and the SSB shape factor to be 2.0. Calling one the CW shape factor and the other the SSB shape factor is my own terminology. One is the sharp CW filter, and the other appears to be the SSB shape factor, which is not as sharp.
It turns out that for filter widths of 500 Hz and less, it is possible to select one of two filter shape factors.
#Icom ic 756 pro ii dsp operation software#
Apparently a special DSP ROM (software) is available in Japan, but information on this modification has been difficult to obtain, and in any case, changing the DSP software is claimed to be a major project, in terms of taking apart the radio to access the relevant parts. Perhaps if the filter was not as sharp, the artifacts would not be as pronounced. One suggestion to improve performance has been to alter the CW filter shape. These various factors lead to CW receiver performance which some operators do not like. In other words, it hears the clicks better than other receivers. In addition, it has been claimed that the 756PRO receiver highlights flaws (key clicks) in the transmitted signal. Digital filters can have similar problems. In the analog domain, sharp filters can lead to ringing, and other artifacts.
That is, signals outside of the passband are substantially attenuated. On CW, the filter response created by the DSP is extremely sharp. The 756PRO receive audio, coming out of a digital signal processing (DSP) intermediate frequency (IF) stage, is much different in character than other purely analog receivers. I would like to thank Rob Peebles, W8LX, for bringing these capabilities of the radio to my attention. I will try to do a little better on this page. Situation with a brief mention of this topic in its Advanced Operation Guide for the 756PRO, but it does not clearly describe how to select the filter shape. The CW filter shape factor, and how it can be selected. The ICOM 756PRO documentation is silent when it comes to describing Icom IC-756 PRO (IC 756 PRO IC756PRO) technical specifications Icom IC-756 PRO (IC 756 PRO IC756PRO) technical specifications : Icom IC-756 PRO (IC 756 PRO IC756PRO) Expand tx-freqeuncy Icom IC-756 PRO (IC 756 PRO IC756PRO) CW Filter Shape Selection Icom IC-756 PRO (IC 756 PRO IC756PRO) Eliminate an adjacent channel noise problem (QST mod) Icom IC-756 PRO (IC 756 PRO IC756PRO) 6M oscillation problem
#Icom ic 756 pro ii dsp operation mods#
Mods for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Schematics for Icom IC-756 PRO (IC 756 PRO IC756PRO) :
#Icom ic 756 pro ii dsp operation pdf#
PDF Adjusments Procedures Manual with schematics for Icom IC-756 PRO (IC 756 PRO IC756PRO) : PDF User Manual for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Icom IC-756 PRO Instruction Manual Programming software for Icom IC-756 PRO (IC 756 PRO IC756PRO) : Programming interface schematics for Icom:
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