[TenTec] Carl, Pmni, 756 etc

[George, W5YR]

Carl, just one question:

Does the 340 have a DSP dynamic range of only 40 db? Or is that a typo?

The PRO uses 24-bit AD/DA data which yields a theoretical 6*24 = 144 db
overall range. Toss out the LSB in dither and noise and you are left with
138 db of digital dynamic range.

Is this the figure you intended instead of "40 db?"

A 40 db range corresponds to an effective data sample length of about six
bits . . .

73/72/oo, George W5YR - the Yellow Rose of Texas         
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe   
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
Icom IC-756PRO #02121  Kachina 505 DSP  #91900556  Icom IC-765 #02437

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Carl Moreschi wrote:

> That said, if your are inside the roofing filter, you are obviously
> limited to the dynamic range of the DSP chip.  This is 40 db.  So
> for signals that are closer than 10 khz to the desired signal, 40 db
> is all the dynamic range you have.  When an undesired signal is
> within 10 khz of the desired signal and stronger than 40 db above
> the desired signal, the analog AGC will come up some to keep the
> DSP processor from overloading.