I have used a Radio Shack DSP40 for the last 5 years.
It is usefull under bad band conditions and can really
clean up hetrodyne. In the CW mode it allows one
CW singal to be "extracted".
The downside is it "muffles" decent audio, in fact I get
a headache if I use it too much. Maybe 15 to 30 minutes
max.
I have just traded for a PCR1000 that has the added
internal DSP. It works but not as completly as the DSP40.
But it mangles the audio less and does a fairly good job.
I haven't used the PCR1000 on HF that much, it overloads
very easily. The DSP module does mak eth PCR1000 run
about 20C hotter. Hot enough so I added aslowpeed 12V
muffin fan to cool the case. The fan is congtroled by the
DCT or CTS, whichever RS232C line the PCR100 asserts
when active. Would I buy a PCR1000 new, or pay the
addtional ~100+$ for the DSP, no way. It was part of a trade
and I plan to use it for local "emergencies", like the winter storm
that is supposed to hit us this evening. I plan on buildng different
frequency list to dump in and use it more as a VHF scanner then
anything else. Even for this use the PCR1000 is awkward
requiring a PC or palm pilot. I also got a Pro2067 that may be
better suited to my plans.
Terry