First, of the two you list, I prefer the R8500, and yes I do own a couple of them. For a wideband receiver it is pretty good on HF, something that is rare. I see you have ordered an R-75, and for HF work it is better in most ways than the R8500. So the following is a "general info" post for people asking the same question in the future.
Lets think about the application for a second. You specifically are looking at Utility, and those tend to be short duration transient signals in modes other than AM or FM. Setting on known or published frequencies is one approach. Scanning known freqs does not work well as to scan you must use squelch, and that typically does not work well with SSB signals unless the signals are significantly above the noise floor...and many of the interesting ones are often more in the noise.
To find transient signals simply nothing works better than a panadapter like or panadapter equipped receiver, like an SDR.
The SDR-IQ is probably the best bang-for-the-buck SDR on the market, being inexpensive and performing quite well. But the 192 kHz max display width is slightly limiting. The SDR-14 (now discontinued) could display more bandwidth, but not record more or show more while demodulating.
The Perseus has a much wider instantaneous bandwidth than the SDR-IQ, but at almost 2.5 times the cost, of course it also has a better front end.
Right now the top of the heap in my opinion, for utility station applications, is the WinRadio Excalibur G31DDC. It falls in cost between the SDR-IQ and the Perseus and techncally probably is better than the SDR-IQ, but not quiet up the Perseus front-end. However it has features the Perseus does not. The fact that it displays the entire 0 - 30 MHz (or 50 MHz, if you have that selected) spectrum in a waterfall all the time is very useful. And the fact that you can see backwards in time up to 6 minutes on the wideband waterfall is outstanding. You might be listening to, and watching in an expanded scale, a station on 6 MHz, but you can still watch a frequency up on 10 MHz for activity. If a signal pops up on the 10 MHz freq just click on it on the display and you are tuned to it. Of course, you will not hear the signal that keyed you, but you will hear the next transmission. Or, you can listen to three frequencies in any given 2 MHz wide piece of spectrum simultaneously, each on a completely independent demodulator, like having three radios in that 2 MHz chunk.
Yes, I use all of the rigs above, plus several more in the shack here. But to be honest since I got the Excalibur it has become my main utility receiver, it remains to be seen what kind of third party and plug-in software will show up for it. If you can deal with the fact that you must use a computer with the SDR then the SDR is significantly superior to a none-SDR for utility listening and transient signal detection.
T!
Mohave Desert, California, USA
Anyway good luck and look forward to your posts.
