Red indicates an unwatchable or undecodable station. Yellow indicates a signal that is mostly usable but with dropouts.
| Ch | Callsign | HDHR2 (SS/SQ) | HDHR4 (SS/SQ) | Notes |
| 7 | WJLA | 97 / 0-64 | 100 / 61-68 | |
| 8 | WMDO-LD | 76 / 45 | 92 / 49 | |
| 9 | WUSA | 100 / 82-92 | 100 / 98 | |
| 11 | WBAL | 97 / 75-97 | 100 / 90 | |
| 12 | WWPX-LD | 71 / 0 | 83 / 42 | |
| 13 | WJZ | 95 / 75-83 | 100 / 81 | |
| 14 | WWTD-LD | 82 / 73-86 | 95 / 90 | |
| 15 | WFDC | 100 / 100 | 100 / 98 | |
| 23 | WDDN-LD | 80 / 0 | 85 / 0 | |
| 24 | WNVC | 100 / 100 | 100 / 98 | |
| 25 | WZDC-CD | 81 / 79 | 82 / 77 | |
| 27 | WETA | 87 / 77 | 89 / 85 | |
| 29 | WMPB | 51 / 0 | 54 / 42 | |
| 30 | WNVT | 95 / 75-95 | 95 / 90 | |
| 33 | WHUT | 92 / 100 | 100 / 100 | |
| 34 | WPXW | 100 / 100 | 100 / 98 | |
| 35 | WDCA | 100 / 73-96 | 100 / 98 | |
| 36 | WTTG | 100 / 79-100 | 100 / 98 | |
| 38 | WMAR | 83 / 0-65 | 83 / 67 | |
| 40 | WNUV | 91 / 86-100 | 94 / 90 | |
| 41 | WUTB | 53 / 42 | 57 / 43 | |
| 42 | WMPT | 92 / 100 | 94 / 85 | |
| 44 | WIAV-LD | 83 / 76 | 85 / 72 | |
| 46 | WBFF | 95 / 100 | 100 / 98 | |
| 48 | WRC | 98 / 83-96 | 100 / 90 | |
| 50 | WDCW | 96 / 84-100 | 100 / 98 |
Please note, I took these measurements this morning, having played with the tuner before-hand a bit.
Now, a few things jump out at me:
First of all, the obvious one, is that a lot of the "bouncy" signal levels, indicated by a range of signal quality numbers, are now stable. This suggests to me significantly improved multipath handling.
Second, I believe the signal strength calculation has been changed. This is most evident on VHF, but it looks different on UHF as well, as many signals have clearly gone up. I haven't ruled out a better quality cable from the splitter on the newer tuner, but they're identical cables, so I can't imagine there being that much difference. Considering some of the multipathed signals seem to be relatively consistent, it doesn't look to me like they necessarily changed the 0 dBmV threshold that is 100%, but rather, made some change to how that is being measured. I will investigate with my spectrum analyzer at a later date.
Third, I believe the signal quality calculation has also been changed. I used to have many signals that maxed out at a solid 100%. Those signals, except for WHUT, now max out at 98%. The old tuners had 100% at about 32 dB MER, but modern transmitters regularly put out 36 dB or more. It also appears to me that the new tuner has a lower threshold to showing signal quality. Note how WWPX-LD and WMPB both show quality (albeit without decoding) on the new tuner but not the old one. I would also point out that WUTB showed broken PSIP on the old one, but not on the new one, despite the signal quality being one point higher on the new one. The threshold for clean decoding seems to be very similar, however; on either tuner, WMDO-LD breaks up significantly at 48, but is pretty solid at 52.
More analysis is needed, but I feel very confident that the HDHR4 clearly outperforms the HDHR2. Please let me know if you have any questions or comments.
1 From Brian in CT -
Uh, Trip, you're table is in black & white. There are black bars where there should be red & yellow ones.
2 From Tripelo -
Trip, thanks for the info.
I would like to know what demodulator chip is used in the HDHR4.
As you probably know, the ability to handle multipath mostly resides in the demodulator.
The last generation of set-top converter boxes used 6th generation demodulators, but there were some versions that were better (for multipath), than others.
It appears that many of the 6th gen demodulators have continued in newer tuners, probably for cost reasons.
There has been at least one 7th gen demodulator produced (LGDT3305), maybe others. This device has been used in some computer-based tuners.
Without purchasing a television, it seems very difficult to determine what demodulators are used in televisions.
If the HDHR4 were using a 7th gen demodulator, it might indicate a wider usage of those devices.
3 From Trip Ericson -
Brian,
Not sure what browser you're using, but it's definitely yellow and red here. Tested in Firefox, Chrome, and Konqueror.
Tripelo,
I own the WinTV Aero-M which has the 7th generation chip. I should do a side-by-side with the HDHR4 and see how the two compare.
4 From Bob Nelson -
Are you now feeding the data to the signal charts with the HDHR4?
5 From Trip Ericson -
Not yet. Still using my HDHR2 for that.
6 From Bob Nelson -
Quick followup, Trip. Let's say the HDHR4 is an improvement and I opt to get it. Since I use it for both recording shows and for feeding the signal charts, how's the cabling done with just one input? Does the HDHR4 split it internally between the two onboard tuners?
7 From nRd -
The chart shows black-bars only in IE for me. MS must be in mourning. All the others browsers seem red-yellow.
As for generation, many think anything termed beyond 6th generation is mere marketing hype. It is these low-power/cost hybrids that are gaining much wider usage. 8th & 9th-gen hype has been replaced by terms like 'SuperRadio." They're "next-gen," heh.
I'm looking forward to Trip's side-by-side comparison,
There is an internal split on the device to supply both tuners.
8 From Trip Ericson -
Bob,
What I've been told is that there is an internal splitter, and that internal splitter is active rather than passive, to try to minimize loss.
9 From Bob Nelson -
Thanks all for the info about the internal splitter in the HDHR4.
As for MSIE's display problem, it's the odd man out. I've tested this page on Opera, Midori, Epiphany, Mozilla 1.7.8 (Mozilla was Firefox's predecessor) and, get this, Netscape. All of those render the colors correctly. MSIE 11 on Windows 8.1 just shows the black area.
As Trip knows, I primarily write in C++, some C along with tons of Perl and shell. Some of my frontends are web-based so that means PHP and Javascript. MSIE is my nemesis. Because it's so widely used, I have to make it work but my code is littered with special case conditions just for MSIE. They've gotten a lot better since the horror of MSIE 6 and before but it still is the oddball...yet is the 800 pound gorilla.
10 From nRd -
quite honestly, I love all your code that I've seen... the msie strife might be the best part ;0
11 From Bob Nelson -
Trip --
There's an easy fix to satisfy the color rendering on MSIE and still be portable to every known broswer, including Mosaic which I probably have tucked away somewhere on a virtual machine.
Just use standard 6-digit HTML colors. Instead of the shortcut of #FF0 for yellow, make it #FFFF00.
12 From Trip Ericson -
Bob,
Thanks for the note, I've updated accordingly. Should be better now!
nRd,
The LG 7th generation chip in the Aero-M is definitely superior, in my experience, to the 6th generation LG chip that was in the DTT900 converter box. Using only the built-in stick antenna on the Aero-M, I successfully decoded four different UHF signals from 53 to 79 miles away at my parents' house--indoors! I challenge any older receiver to do that.
13 From nRd -
Trip,
I'm with ya. I was just saying the concept of "generation" had dried up at that point and "7th" was more for marketing, though a better chip indeed. The newer combos from ML purport a lot of individual goodies, but have never mentioned a generation other than within their own line. (i.e. this is 2nd)
The new HDHR4s seem to have better off-air tuners than any of the network tuners I've tried, but I'd love to see your shootout between the two.
14 From Brian in CT -
Thanks Trip. Using Google Chrome fixed it.