Hmmm…I was going to stay out of this thread…but I guess not.
I own both radios in question, the DE1103 and the R8500. And I have done side-by-side comparisons of the DE1103 (and other portables) to several of my desktops, including the R8500 (the R8500 is not, by the way, an exceptionally good HF radio, but it is one of the better ones made that includes the HF ability with the VHF/UHF ability). The basic answer I have found is that on a small to moderate sized external antenna the good portables will hear almost every signal the desktops will on the same antenna as long as those signals are in the clear and there is little interference. However, if you have the room for a large or full sized HF antenna, or the signal is in a crowded or high noise environment, the desktop will pull out signals the DE1103 turns to mush.
What it comes down to, in my opinion and from my first hand experience, is if you are listening to AM mode broadcast stations with mid to high power output and have a mid sized to small external antenna the better portables are going to do just about as well as the desktops. But, if you have a large or a very efficient antenna that provides higher received signal levels the desktop will handle the situation better (less likely to overload/image), resulting in hearing very weak stations the portable will never hear on the smaller antennas or be able to handle because of their response to the larger antennas. Additionally, if your reception targets are lower power broadcast stations, non-broadcast stations in other than AM mode, or in very crowded portions of the spectrum, (i.e. for everything but arm chair copy broadcast) the desktop generally performs better than the portable regardless of antenna (down to a very small antenna size, like say a whip).
To reiterate, if your only measurement of success is raw sensitivity and you ignore all of the other important receiver performance factors (like dynamic range, image rejection, close signal rejection, filter performance, etc, etc) then the portables like the Degen DE1103 are not that bad. Their raw sensitivity is typically on the order of many desktops, possibly exceeding some desktops in some regions. But, raw sensitivity is never the only answer, so everything else HAS to be considered.
I have measured the sensitivity of the DE1103 and also of the R8500. At 10 MHz using the SSB filter width achieving a 10 dB SINAD I got about 0.32 microVolt (-117 dBm) for the DE1103 and about 0.12 microVolt (-125 dBm) for the R8500 (most unbiased 3rd party measurements result in better numbers than the Icom published 0.2 microVolt from 2-28 MHz). AM mode at the same freq I got about 1.1 microVolt (-106 dBm) for the DE1103 and about 1.4 microVolt (-104 dBm) for the R8500.
As for MDS and audio receivers (by the way, I have measured the R8500 at about -133-135 dBm MDS). Yes, this is a number that is good to know (and quick and easy to measure) but has relatively little to do with overall performance, mostly because of what it does not tell you. For example, if I have an RX with an excellent MDS of -147 dBm but the filters and product detector are cut rate I could end up with a sensitivity for a usable signal (decent signal to noise ratio) that was very bad. Or if the dynamic range is poor I could end up clipping/saturating on mid level signals.
Bottom line, try the two radios side by side and on the same good, efficient, HF antenna, go for reception of things other than the big broadcasters or weaker signals completely in the clear. And you will see that the R8500 regularly outperforms the DE1103, or pretty much any recently made portable I personally have tried. In other words, yes, the DE1103 does miss a lot of signals when compared to the big rig. But, the comparison is unfair. Now try the R8500 with a short (say 36”
whip antenna and a 12 VDC battery all in your backpack as you climb to the top of a hill. Not only will the DE1103 be more fun to use and carry, but I bet it will even work every bit as well as the R8500, if not better. Errr…unless you want to listen to UHF Mil Air, or public service VHF/UHF, or VHF civ air, or hams on 6 meter, 2 meter, 70 cm, etc, etc, etc…then I guess you are out of luck with the DE1103.
The two are not even apples and oranges…it is more like apples and lizards, and each has its niche to fill.
T!
