[PCR-1000] CWGet

[Harry Flaxman]

And as I mentioned in my previous post, I don't get perfect signals on the
CW side of things.  I think this is why I am having a few problems getting
the program to work right for me.  It could be my reception, as I've
mentioned previously, but I have to keep retuning the squelch to keep the
signal coming in at all.  Otherwise, the signal drifts and I either get a
continuous noise, or nothing at all.

Will continue to shop around and look and try other programs.

Thanks.

Harry


On 30-May-2002,  wrote:

> CWGet, like most such programs, requires almost perfect signals in order
> for the decoding to be accurate. That means a minimum of noise and
> absolutely correct tuning and timing of the signal. Most amateur radio CW
> is marginal in timing such that most programs give fairly poor results.
> That is not true of all stations since many use keyboards and
> computer-generated code with perfect timing.
>
> A further stringent requirement for machine decoding of CW is the need for
> correct signal level management. If the signal to be copied is of too high
> amplitude or of too low amplitude, the decoding logic is prevented from
> operating correctly. Since it is common for amateur CW signals to vary in
> amplitude with time due to band conditions, interference, etc. a receiver
> with very effective AGC is required to maintain a fairly constant signal
> level to the decoding program.
>
> In view of these requirements and based upon a great deal of listening, I
> have to conclude that the PCR1000 is uniquely *unsuited* for CW reception
> for any purpose. It is literally, as the old saying goes, "as broad as a
> barn door" on CW and the SSB modes and suffers from a lack of
> "single-signal" reception on CW as well. That means that you can tune in a
> CW station on "both sides of zero beat." While this does not prevent most
> humans from reading such code, the effect of the wide bandwidth is to
> contaminate the desired received signal with all manner of noise and
> interference from other stations.
>
> My 1000 does not have the DSP module, and it may be that the additional
> audio filtering it provides might make the signal more decodeable. In the
> absence of the internal DSP, one could add an external audio digital
> processor and improve upon the selectivity shortcoming.
>
> The second area of substantial shortcoming for the 1000 is the lack of
> capability of the front-end circuitry to deal with strong signals. The
> result of the lack of adequate selectivity both in the IF and the front
> end
> is that strong signals tend to take over the AGC and dominate the receiver
> function. Multiple strong signals cross-modulate and inter-modulate to
> such
> an extent that they become just a jumble of "noise." The use of either
> internal or external DSP filtering cannot overcome the deterioration of
> signals produced by an inadequate front end.
>
> The bottom line is that these two shortcomings of the 1000 play a major
> role in restricting the uses of the radio. I hate to rain on anyone's
> parade, but for CW monitoring the PCR-1000 is just not a suitable radio to
> use.
>
> I might add that the Icom R-10 scanner-sized "comunications receiver" has
> about the same shortcomings with a serious lack of selectivity. I called
> the Icom technical support people shortly after getting my R-10 and they
> explained that the operational problems that I noticed were normal for the
> radio since it was just too small to contain effective filters.
>
> I have found that of all the digital programs with CW capability, MixW is
> the only one that can provide consistently accurate copy of marginal
> signals. It provides over 20 signal modes, including most of the digital
> modes and CW, SSB, SSTV, etc. But even MixW requires clean signals and
> narrow bandwidths to remove as much interference and noise as possible.
>
> These are interesting little receivers for casual monitoring, but their
> shortcomings in the areas of selectivity and front-end robustness rule out
> any serious use for communications and limit their applications for
> monitoring. I bought the first PCR-1000 sold at Texas Towers when they
> first came out and one of the first R-10 receivers. Many hours of
> listening
> to these little receivers have demonstrated the deficiencies described
> above.
>
> 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