Channel Master FM Filter Question

[jasonl]

I think you're likely to see a noticeable improvement on WJBK with a dedicated high VHF antenna. The elements being more appropriately sized for that frequency alone would help, and then adding directors will increase the gain and directionality, helping to minimize any multipath you might be encountering. There are still always environmental factors that can mess up anything on VHF (LED/CFL lights, car ignitions, any kind of fan/motor/pump/compressor, etc.), but the better the signal you start with, the better you're likely to end up.

[JDazell]

OP, Your Televes antenna has the same ability to receive VHF-Hi as the Stellar Labs Antenna, if not better. The Televes also has a way higher Gain with the built in amplifier powered on. And it has a narrower Beam Width, which will optimize the signal for Ch 7, if the antenna is oriented correctly.

VHF can be troublesome not just due to multipathing and reflected signals , which affect VHF more so than UHF. But as Jason mentioned there are so many things that can interfere with VHF signals. LED Lighting, noisy or failing power transformers, etc. You have already eliminated the FM harmonic interference issue, but you might want to test adding one of the SiliconDust LTE filters, it has a wider frequency rating than the one built into the Televes antennas.

To get the best signal, it may be that you need to aim the antenna a few degrees off center from the Channel 7 Transmitter, if there is an unseen obstruction between you and the tower.
If you are getting intermittent interference, then you will need to document when this happens, to try and see if there is a pattern.

I professionally install Antennas and HDHR in N/W Ohio and S/E Michigan, so I can attest that Channel 7 out of Detroit can be a problem Child. Additionally the Broadcast lobes inherent to the Channel 7 transmitter could also affect your received signal. Go and check out the Channel 7 Technical data at Rabbitears; https://www.rabbitears.info/contour.php ... a72&site=1. The % of signal being broadcast towards Grand Rapids is the lowest. https://imgur.com/a/ApdMXb9

[jasonl]

The Televes isn't anywhere close to any dedicated high VHF yagi in performance, and that 30° beamwidth claim on their spec sheet for high VHF is like they meant to put a – to omit it and someone decided to copy the UHF number over instead. The actual beamwidth on that is likely to be somewhere in the mid 70s or higher on channel 7. The 90° listed for the 30-2475 is wrong too, more like 60° at channel 7 and dropping as the frequency rises. 48° on the 30-2476 does seem accurate for at least some point in 7-13.

[JDazell]

Good to know. Manufacturers need to step up and enter the correct specs. Thanks for the correction.

[KeithAbbott]

If you have room for the 7' boom, the Stellar Labs 30-2476 would be my pick because of having more director elements and a better reflector, and costing less than the Televes.
https://www.newark.com/stellar-labs/30- ... dp/71Y5462

Jason, I just wanted to thank you for the antenna recommendation. I installed the smaller version of the above antenna, using a Televes SmartKom antenna amplifier/combiner. Not only did it solve my high-VHF signal quality issue, but I find that it receives some (not all) of the UHF stations better than my Televes antenna. I'm still fine-tuning some of the settings, but here's my experience with my local Fox station (channel 7):

Prior to installing the Stellar Labs antenna, signal quality for Fox was fluctuating between 50% to 80% signal quality, averaging 65%-70%.

After installing the Stellar Labs antenna, signal quality for Fox has stayed at 100% for the past two weeks.

Now I can turn my attention to ABC (channel 25), which is fluctuating between 75% to 99% signal quality, with occasional symbol quality dropouts to zero. Any recommendations for a better UHF antenna than the Televes DAT BOSS MIX (149483)? The antenna(s) are installed in the attic above my garage, with around 15 feet separating the two antennas.

[jasonl]

Can you turn on the Send diagnostic information option on the System Menu page on the HDHomeRun's web page, run a channel scan, and reply back with the device ID? I'd like to see what the signals look like currently.

[KeithAbbott]

Can you turn on the Send diagnostic information option on the System Menu page on the HDHomeRun's web page, run a channel scan, and reply back with the device ID? I'd like to see what the signals look like currently.

Device ID: 1080E1F3

When you say run a channel scan, I assume you wanted me to click the "Detect Channels" button on the Channel Lineup page.

Channel 25 (ABC) is currently connected to the Stellar Labs antenna. Let me know if you want me to change it to the Televes antenna and rescan.

[jasonl]

Can you switch back to the Televes and then watch or record something on ABC for a while? The signal does look pretty good from the Stellar Labs, but there were some reception issues earlier. I'm not sure that you're going to do significantly better than the Televes. There are a few options that are somewhat better, but nothing that is going to give you the bang for the buck that the Stellar Labs did. Have you tried moving the Televes around to see if there is a better spot for it? You might be getting some multipath that a different location or orientation might help. Keep in mind that not pointing directly at the towers can sometimes be better if it puts a source of multipath into a null in the antenna. You might end up with a stable 90 vs. fluctuating 75-100.

[KeithAbbott]

Can you switch back to the Televes and then watch or record something on ABC for a while? The signal does look pretty good from the Stellar Labs, but there were some reception issues earlier. I'm not sure that you're going to do significantly better than the Televes. There are a few options that are somewhat better, but nothing that is going to give you the bang for the buck that the Stellar Labs did. Have you tried moving the Televes around to see if there is a better spot for it? You might be getting some multipath that a different location or orientation might help. Keep in mind that not pointing directly at the towers can sometimes be better if it puts a source of multipath into a null in the antenna. You might end up with a stable 90 vs. fluctuating 75-100.

I switched over to the Televes antenna, and began watching ABC. At the moment, the signal quality looks fantastic, but we'll see if that changes over time. The Televes SmartKom can adjust each channel from -3 to +3 dBmV (from a baseline of 9 dBmV), right now I have it set to 0. I'll keep watching for another 30 minutes or so. I do have recordings scheduled for later tonight, tomorrow morning, and lunchtime tomorrow.

As far as moving the antenna, that would be difficult (especially for trial and error), since it is located in an unfinished attic. I could, however, change the horizontal angle of the antenna without too much trouble. Right now, I have it set to 113 degrees true north, the broadcast tower for channel 25 is also at 113 degrees true north.

[jasonl]

Not a single issue with ABC in the logs since the antenna swap last night..

[KeithAbbott]

This morning, the signal quality did dip down to 67% briefly. Other than that, it has been running at 88% or better. I might try to adjust the +/-3 dBmV setting, to see if I can further optimize it.

When I connected the Stellar Labs antenna, I initially had channel 25 set to use the Televes antenna. I was having some signal quality issues, which is what prompted me to move it to the Stellar Labs antenna. I'll give it some time, and see how things go.