Thank you very much Edmscan for your extensive testing. I've been listening to receivers (HF to UHF) since 1970 (earlier really since my dad was a ham starting in the late 60’s), and ever since I can remember, people have been having the discussion of wanting better performing radios (especially regarding selectivity). I've still got a Pro-2004/5/6 somewhere (with a dead backlight) that probably performs better than today's radios in terms of receiver performance. I know you don’t have a BCD536HP Edmscan, but do you have any insight into its RF circuitry compared to an HP-2?
I too would love a purpose-built base/mobile scanner with all the best low noise-figure parts. But for every extra dollar spent, multiply that by 3-5 times to determine how much more it will cost you, the guy who buys from a storefront. Maybe it's worse now, I don't know. From manufacturer to distributor, there's markup. From distributor to store there's a markup. Then of course the store has to add markup to sell to us the public. Now I don't know about scanners, but the bump at the store is often 100% and more for some items. So if the store paid $100, you and I pay $200. (I know the markup is a lot less for some items; or I've heard that anyway; TV's used to be less, but diamonds and jewelry in general, maybe 2 to 3 times more than the 100% figure).
And I'm not suggesting anyone's greedy here. That last stop-off, the storefront, probably has the most overhead of the supply chain (not sure of that, but I doubt the distributor has a much overhead). So if Uniden or Whistler puts in just $20 worth of better parts, our end cost is probably pretty close to $100.
Many of us say we'd pay the extra cost. Has anyone ever tried this and built the better-performing base/car (vs handheld where battery life is at stake) scanner that supports all the modulation types? We've had software defined radios for a decade (more maybe?) and I'm still waiting for the combination of the benefits and cost reductions of an SDR and the scanning features of a Uniden or Whistler. (I thought maybe the AOR DV1 was going to be that radio, but it isn't). Is Uniden's and Whistler's trunking software patented such that this is a big roadblock? I am aware of at least one open source effort to provide a software package for an SDR to make it imitate a scanner, but my sense is it's still a long way away from having everything the best of Uniden and Whistler (or GRE before them) offers.
To that end, why do you suppose a scanner manufacturer hasn’t employed an SDR as the radio part of a modern-day trunking digital scanner? Or maybe someone has? Is there an inherent weakness that I don’t understand yet (I’m a wannabe RF engineer who is a software engineer)? Maybe this has been discussed ad-nausea already? Maybe the cheapest approach (based on reading your selectivity thread) is to buy an FM notch filter and be happy.