HDHR Quatro Performance vs. legacy HDHR

[texneus]

I posted here a while back that I bought a HDHR Connect Quatro to replace what I thought was a failing legacy HDHR (the original off-white model), only to find the new HDHR suffered the same reception issues as the older model. After much troubleshooting I found the problem actually lied in the SageTV server and both HDHRs are functioning 100%. That said I decided to keep the Quatro for the increased tuner count (4 vs. 2) and will soon retire the legacy HDHR. Before I pulled the plug though, I thought it would be interesting to see how the two devices perform relative to one another to see if there is a performance advantage as well.

It should be noted this is a highly unscientific test based on a sample of one of each unit in a single location with the assumption that all hardware, cables, etc. are 100% functional. Therefore results are speculative, at best, and may not apply to all installations. It would be interesting to hear from anyone else who has tried this.

If you want the extra nerdy details, read below.

If you want the short version, read here: The new HDHR Connect Quatro (and presumably its dual tuner cousin) does seem to be better able to handle reception errors, particularly for (what is probably) multi-path, but does not appear to have better sensitivity. In other words, it is unlikely the Quatro will "see" additional stations vs. an older unit, but the likelihood of being able to lock consistently onto a problematic station appears to be much improved. If you have an intermittent station or two due to reception errors, the Quatro (and presumably Duo) might help. If you do not receive all your local stations due to low signal, you should look at improving antenna and signal distribution first.


Setup:

I live approximately 40 miles away from the majority of the TV transmitters. I have a fairly large antenna (I'm not sure of the make/model, I installed it quite some time ago, but it is similar to this one) installed in the attic. The antenna is connected via a short 300 ohm twin lead to a Channel Master Spartan 3 pre-amp, who's output connects via 75 ohm coax to a 4 way splitter. Three of the splitter taps directly feed TVs, one of the taps serves the HDHR after first passing through a Channel Master CM0747 power injector. To simultaneously test both HDHRs, a two way splitter was installed with one tap feeding tuner 0 of the legacy HDHR-US and the other tap feeding the HDHR5-4US Connect Quatro (here-in simply called the Quatro).

This ensures an identical feed to each HDHR device assuming identical losses from the split to each RF coax input. The Quatro on paper will have an immediate disadvantage in this setup due to the loss of the extra splitter in conjunction with its internal 4 way split. In reality though, if both tuners on an HDHR-US are used, a two way splitter must be used. The signal level presented to the HDHR-US is therefore representative of a real world installation. Since the entire Quatro receives an identical signal as one HDHR-US tuner, the performance of each device is directly comparable, although the Quatro would indeed likely perform slightly better in an ideal installation.

The firmware on the HDHR-US is dated 20170930, while the Quatro is 20171208. Honestly, it did not occur to me to ensure the same firmware was installed at the start. However, as the HDHR-US is no longer supported it is somewhat doubtful any improvements to the HDHR-US have been made in quite some time.

To run the tests the HDHR Config GUI was run on a Windows 7 laptop. Since heat can affect tuner performance, Tuner 0 on the HDHR-US and Tuner 1 on the Quatro was tuned to a strong station for 1 hour to ensure both devices were "warmed up" before proceeding. After the warmup, each tuner was set to RF 2 (an empty channel here) and the seek function was used on each device to advance to the next available channel. Once each device "saw" an RF channel, signal strength, signal quality, and symbol quality were observed for about 30 seconds. Since signal strength/quality tend to bounce a bit, I mentally averaged the readings before writing them down. Variation within 5% was considered normal.

A note on these metrics. Silicon Dust does not precisely define exactly what physical characteristics these parameters correspond to (i.e.: signal strength is a percentage of what?) Based on what I see in the data, I have to conclude signal strength is an arbitrary scale that differs between devices. I say this because, all things being equal, the signal seen by each Quatro tuner should be at least 6dB less than the HDHR-US due to it's internal 4 way split, but Quatro signal strength actually tends to read a few % higher than the HDHR-US. For this reason signal strength probably does not tell us much.

Signal quality and Symbol quality are somewhat defined by Silicon Dust, but again no relationship is drawn to an actual physical parameter. My assumption has always been (and this may be wrong!) that Signal Quality is a representation of the BER (Bit Error Rate) of the raw demodulated data stream. So a signal quality of 80% means that 20% of the bits as received are erroneous. I also assume that Symbol Quality represents how much of the data stream has been recovered after error correction has been applied. 100% means all received errors have been recovered (picture is perfect), anything less will result in glitches (pixelated and/or blocky picture), and 0% means that nothing was able to be recovered (picture freezes or goes black). These values seem to be consistent between between devices, or at least conform to my expectation of what these parameters are measuring relative to observed performance.


Results:

Results are attached as a text file. My interpretation of the results is as follows.


On the HDHR-US:

A total of 25 channels were "visible".

There are five stations with highly variable Signal Quality (RF 20, 29, 30, 43, and 46). Two of those stations (RF 20, 43) would not lock consistently presumably due to too weak of a signal. The remaining (RF 29, 30, 46) would lock without issue. My assumption is the highly variable Signal Quality is due to multi-path or possibly co- or adjacent- channel interference. Regardless of the cause, these stations will be more likely to occasionally "glitch" over a longer period of time or in response to atmospheric phenomena (RF 29 is a channel we watch somewhat regularly and it is occasionally problematic even on some TV tuners).


As compared to the Quatro:

A total of 25 channels were "visible" (same quantity and channel numbers as the HDHR-US).

There is one station with highly variable Signal Quality (RF 20), presumably due to too weak of a signal to reliably demodulate, and remained unwatchable. All others, even those that were problematic on the HDHR-US, were stable. In 2 out of 3 of the unstable channels, the average Signal Quality actually improved.

There is one station (RF 43) that would lock but only reach 100% Symbol Quality about 2/3'rds of the time. While not consistently watchable, this station might occasionally come in good enough to be usable on a good day. The improvement on reception of weak stations, whether by sensitivity or demodulation improvements, is enough to be measurable but appears to be unlikely to make them consistently usable.


Conclusion:

As compared to the HDHR-US, the Quatro does not "see" more channels despite that it routinely shows a few percentage points more Signal Strength than the HDHR-US (Note in my area there are several low power stations that on paper would become visible with a more sensitive tuner). Although reception of the two weakest channels did improve, they did not improve significantly enough to be usable. This suggests despite the increase in reported Signal Strength, the two devices are actually fairly similar in terms of tuner sensitivity. At best, sensitivity is improved but not sufficiently to make an already marginal channel functional.

As compared to the HDHR-US, the Quatro does seem to have improved reception of error prone signals as evidenced by more consistant and possibly improved Symbol Quality of stations that were problematic on the HDHR-US.

Hope somebody else found this useful/interesting...

[tvmaster2]

thanks. good info going forward...

[wayner]

Good analysis.

This may be a red herring, but have you tried different antennas? The antenna that you link to seems to be more of a combined antenna. My understanding was that generally the bowtie style CM 4221 or 4228 (see on this page ) were best for UHF TV reception. But that may depend on whether the channels in DFW or more on VHF or UHF. I have a 4221 in my attic and I have no problem receiving channels from Buffalo that are 80 miles away - but I have an unobstructed view across Lake Ontario. And these are a combination of VHF and UHF - the Chan number is what is relevant here and most of these are >13. So with the right antenna you should be able to get everything at 100%

Here is my list of channels:

Callsign	      Chan 	   Network	 Dist            NM
                                                 (mi)	Path	(dB)
 CFTO-DT 	 	9 	(9.1)		10.9 	2Edge 	48.2
 CBLT-DT 	-- 	20 	(5.1)	CBC	10.9 	2Edge 	47.8
 CBLFT-DT 	-- 	25 	(25.1)	SRC	10.9 	2Edge 	46.9
 CICA-DT 	 	19 	(19.1)	TVO	10.9 	2Edge 	46.9
 WNLO-DT 	 	32 	(23.1)	CW	50.9 	LOS 	45.8
 CIII-DT-41 	 	41 	(41.1)	GTN	10.9 	2Edge 	44.2
 CJMT-DT 	 	40 	(40.1)	OMN	10.9 	2Edge 	37.2
 CITY-DT 	 	44 	(57.1)	Ind	10.9 	2Edge 	36.9
 CFMT-DT 	 	47 	(47.1)	OMN	10.9 	2Edge 	36.7
 CIII-DT-27 	 	27 	(27.1)		58.2 	LOS 	29.6
 WIVB-DT 	 	39 	(4.1)	CBS	80.0 	LOS 	29.3
 WGRZ-DT 	 	33 	(2.1)	NBC	77.5 	LOS 	25.0
 WBBZ-TV 	 	7 	(67.1)		84.4 	1Edge 	18.

[texneus]

The antenna I have receives VHF-Low, FM, VHF-Hi, UHF. I need all but VHF-Low. It dates from 1990-something when VHF-Low was common. There is no universal one-size-fits-all "best" antenna. The Yagi styles such as mine are highly directional and good for when all channels are broadcast from the same location. Aim is critical since it's a bit like aiming a rifle. A little off to the side and it will miss the stations you want to recieve. Directionality also rejects RF noise leaking out from other markets since a Yagi effectively does not "see" it, which helps when receiving very faint signals. Directionality is also their downside if you need to recieve stations from multiple directions.

A bow-tie will be moderately directional, good for when the stations you want to receive are (just a guess) within about 45-90 degrees or so of one another, but will also recieve noise from anything else that inside this "cone". As such you will probably not be able to recieve weak stations as well, but may be the only option outside of multiple Yagi's or a rotor.

An omni-directional antenna doesn't care where the station comes from, it recieves equally from all directions. Predictably though it also receives all the noise from everywhere too, so these tend to not work well for anything but relatively strong stations.

You have some pretty cushy noise margins (my BEST stations are about as good as your WORST ones) and since you're apparently trying to recieve from multple markets I don't doubt a smaller bow-tie could be best for your situation. Getting all stations at 100% signal strength though will not happen unless you're way overdriving the HDHR. All things being equal your best station is 30dB stronger than your weakest one. Your 80 mile distant stations are Line of Sight which is probably the only reason they work at all.

[wayner]

Why is it that my best are as good as your worst? Do you have blockage from natural topography or buildings?

One good thing about the old HDHR is that you could connect separate antennas aimed in separate directions into the two different inputs and set up your channels in SageTV appropriately. Of course that may mean that you only get some channels on one tuner.

Apparently you can also combine antennas with a "splitter" - have you ever tried that? (It is recommended that you have the same antennas to be combined) Or you can get those "double" 4221 antennas that have 2x4 bowties that you aim in separate directions.

Actually my 80 mile stations (which are SSE) come up better than the 10 mile stations (which are WSW) as the antenna is oriented in that direction and there is some blockage by my house in the SW direction of the 10 mile stations that broadcast from the CN tower.

I can also get the Rochester channels if I turn my antenna more to the East, but I don't worry about picking them up since (1) they rarely have any content that the Buffalo stations don't already have, and (2) I have two HD-PVRs which give me the Buffalo stations on cable plus timeshifted west coast versions of the US networks (and Canadian networks)

Here is the map of my area - my house is approximately at the "o" in "Golden Horsehoe" that is in brown text a bit above Toronto.

[Tiki]

You do know there are 3 "o"s in Golden Horseshoe, right?

[wayner]

D’oh. The last one- right on the lake.

[texneus]

Q: Why is it that my best are as good as your worst?

A: Actually it's the other way around, and it's because I'm not 11 miles from the nearest transmitter and not one of my signals is LOS.


Q: Apparently you can also combine antennas with a "splitter" - have you ever tried that?

A: All the stations I want to receive are in one direction so I have no need to. A splitter is probably not what you want for this anyway, use something like a Jointenna which is probably a directional coupler so each antenna is isolated. No idea how well this works but I would suspect an HDHR per antenna would work best.

[Wirenut]

Hey Wayner,

I can physically see the WPXJ transmitter at night from my house. I'm not far from Darien Lake. I grab the same stations as you. I'm currently using my original HDHR ten years old, for Clear QAM on Spectrum. But your information is great. I'm thinking about going the cut the cable route this year.

Stay warm. It's -2 deg F here today!

Wirenut

[wayner]

Being on the Canada/US border is probably the best place for OTA as you can get stations from both countries. That map is from a site called remote central. They have very good info on the OTA options for the Southern Ontario - Western NY region.

[Polypro]

I just upgraded my whole OTA setup because I started losing channels (pixilated and choppy despite Sage Signal Meter looking good). It's like 0 degrees outside, so I didn't feel like troubleshooting all 3 systems (Antenna, Pre-Amp, HDHR's). Got the Quatro and a Televes DataBoss antenna. Better than before for me (Old: Clearstream 4V, Mast Pre-amp, and 2007'ish HDHRs). Can't say what improved it obviously as I changed everything.

Setup in Sage of the Quatro was easy-peazy, just like the older models.