I was hoping for something better. The tuner in the HR20 is mediocre at best. The one in my Samsung LCD TV is far better.
Here is my initial evaluation of the two units. I'm about 30 miles from the tower complex.
The first set of numbers after the channel number is the HR20-700 signal level on tuner1/tuner2. The next set is the HR21-200/AM21 on tuner1/tuner2. Following that is a comment on "bounce" which is an indirect measure of multi-path.
Channel HR20-700 HR21-200/AM21
5-1 85/85 93/93 (less bounce on AM21 as well)
8-1 100/100 100/100 (no bounce on either receiver)
8-2 100/100 100/100 (ditto)
11-1 ditto ditto
11-2 ditto ditto
13-1 ditto ditto
17-1 80/80 83/83 (less bounce on AM21 as well)
23-1 54-71/56-84 69-77/67-83 (lots of bounce on both, AM21 better)
Both receivers fed by the same antenna, balanced signal levels, fine tuned OTA setup (gain distribution, preamps, attenuators etc)
The AM21 tuner is better in both domains:
a. Bit-Error-Rate (as shown by the higher percentage on all non-full strength stations)
b. Maintaining BER in the face of multi-path (bounce). The bounce range in the AM21 is considerably less on those signals where bounce/multi-path is a problem.
Both the HR20-700 and the HR21-200/AM21 produce a perfect OTA signal at first glance. Lots more looking to do at the PQ of the HR21-200/AM21.
The AM21 tuner is every bit the equal of the tuner in my Sammy HL-R5667W, which has been outstanding from day one.
GREAT START D*! Congrats on a job well done.