Fox 11 symbol quality dipping every 15-20 sec - dave01

Reception, channel detection, network issues, CableCARD setup, etc.
dave01
Posts: 15
Joined: Tue Mar 17, 2020 7:01 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Wed Mar 18, 2020 9:24 pm

The preamp I'm using (AD Clearstream Juice) has an LTE filter built in. I was thinking of adding an FM filter as well, but knowing that WVNY will be moving to channel 7, I know it'll weaken its signal if I add one.

Here you go --> https://www.rabbitears.info/searchmap.p ... y_id=71080

The thing is that I'm not having the same signal dropouts issues on this same channel/antenna/setup when plugged to my Haier TV or Hauppauge PCIe tuner.

As for UHF, I'm using an 8-bay "bowtie" style antenna (DipoleHD HD-1028) located in my attic, with another Clearstream Juice preamp and hooked to the Hauppauge QuadHD. Off of this antenna, I'm receiving all channels in green and yellow from my rabbitears listing above, 29 channels including their subs.

Going to the HDHR4, it's the stellar labs 30-2476 antenna that I'm dedicating to ABC (WVNY), a 3dB attenuator and a stub tuned for channel 12, plugged at the antenna and right before another Clearstream Juice.

If I don't put the preamp, the signal is not strong enough and I'm having issues with adjacent channel 12 which is 15 miles away. I had to attenuate it somehow and I did not want to pay another 4-700$ in specialized filters to get rid of it, so I tried the stub plus attenuator which seems to do it.

The weak signals you saw were probably when I was playing with the antenna this afternoon. Anything after 6:30PM is coming from the stream where I did not touch a cable or changed a thing. There has been glitches here and there, but that's the best and most stable I can get it at.

I have read other posts suggesting that some VHF stations had or have cabling issues and this seems to be describing my issue here as well. However, the HDHR4 is by far more stable for me than the HDHR5 was, probably because of the tuner's sensitivity I assume.

As a side note, I had a Cessna that flew over my house this evening and I had a good 15-20 seconds signal drop while it was on the path between my house and the emitter... Man that VHF band is a fussy lady!! LOL ;)

shoman94
Posts: 46
Joined: Sun Jan 29, 2017 7:48 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by shoman94 » Wed Mar 18, 2020 9:47 pm

dave01 wrote:
Wed Mar 18, 2020 9:24 pm
The preamp I'm using (AD Clearstream Juice) has an LTE filter built in. I was thinking of adding an FM filter as well, but knowing that WVNY will be moving to channel 7, I know it'll weaken its signal if I add one.

Here you go --> https://www.rabbitears.info/searchmap.p ... y_id=71080

The thing is that I'm not having the same signal dropouts issues on this same channel/antenna/setup when plugged to my Haier TV or Hauppauge PCIe tuner.

As for UHF, I'm using an 8-bay "bowtie" style antenna (DipoleHD HD-1028) located in my attic, with another Clearstream Juice preamp and hooked to the Hauppauge QuadHD. Off of this antenna, I'm receiving all channels in green and yellow from my rabbitears listing above, 29 channels including their subs.

Going to the HDHR4, it's the stellar labs 30-2476 antenna that I'm dedicating to ABC (WVNY), a 3dB attenuator and a stub tuned for channel 12, plugged at the antenna and right before another Clearstream Juice.

If I don't put the preamp, the signal is not strong enough and I'm having issues with adjacent channel 12 which is 15 miles away. I had to attenuate it somehow and I did not want to pay another 4-700$ in specialized filters to get rid of it, so I tried the stub plus attenuator which seems to do it.

The weak signals you saw were probably when I was playing with the antenna this afternoon. Anything after 6:30PM is coming from the stream where I did not touch a cable or changed a thing. There has been glitches here and there, but that's the best and most stable I can get it at.

I have read other posts suggesting that some VHF stations had or have cabling issues and this seems to be describing my issue here as well. However, the HDHR4 is by far more stable for me than the HDHR5 was, probably because of the tuner's sensitivity I assume.

As a side note, I had a Cessna that flew over my house this evening and I had a good 15-20 seconds signal drop while it was on the path between my house and the emitter... Man that VHF band is a fussy lady!! LOL ;)
Just so you know the Juice does not have an LTE filter in it.

Maybe look at an adjustable preamp. You could try an FM Filter and also a Channel master LTE filter. I have one coming in to try.

dave01
Posts: 15
Joined: Tue Mar 17, 2020 7:01 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Wed Mar 18, 2020 9:56 pm

Ahem! Yes it does, read on ;) --> https://www.antennasdirect.com/juice.html

It's the FM filter that they dropped on the Juice.. Its predecessor had both filter types but was not offering the same overload protection from nearby stations and low noise insertion figures, that's why I chose this one.

shoman94
Posts: 46
Joined: Sun Jan 29, 2017 7:48 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by shoman94 » Wed Mar 18, 2020 10:21 pm

dave01 wrote:
Wed Mar 18, 2020 9:56 pm
Ahem! Yes it does, read on ;) --> https://www.antennasdirect.com/juice.html

It's the FM filter that they dropped on the Juice.. Its predecessor had both filter types but was not offering the same overload protection from nearby stations and low noise insertion figures, that's why I chose this one.
That link has a dead shop now button so I'm not sure that's accurate. This link doesn't mention anything about it nor does the packaging. https://store.antennasdirect.com/JUICE.html
ADTECH never told me it had it and I believe it since I was getting very strong LTE signals with the Pre-amp on. I found this Q&A: The filter in the Clearstream Juice preamp begins to decrease the gain of the incoming signal at 770 MHz, and hits 0 dB gain at 800 MHz....... Lots of LTE below 770 mhz and they say just no gain so its like not having the filter..... IDK I could be wrong.

The US has 600mhz LTE and LOW 700MHZ LTE we need to deal with now. This is the filter I have coming.

Image

Image

I did find this so maybe it has some suppression but I'm not sure if that mean just no gain.
Yes, the Juice is pretty much a re-done CPA19. We had to change manufacturers so we redid the name, the physical packaging (we kept the metal injection mold), the power supply and, internally, the filtering. The CPA19 had a filter that suppressed between 250 and 400+ MHZ, the Juice deleted that filter and replaced it with one that rolls in just above 700 MHz for 4G/cellular suppression. There was only enough circuit board real estate available for that one filter, so it's the only one in the Juice. FM filtering, if needed, can be done with one of our external full band filters.

Gain averages about +18 dB +/- ~1 dB across design band of 54-698 MHz.

Noise figure averages around 2.5 dB in low-VHF, ~1.75 in high VHF, and averages sub 3 dB on UHF. The gradual roll-in of the 4G filter slightly affects the top end of the UHF band. TANSTAAFL, as they say.

As far as IMD performance, it tests out to between +35 and +38 dBm TOI (Third Order Intercept), depending on the frequency at which it is tested. My personal observation is that this model is the most overload resistant amp that's come across my workbench so far.

For those who hate TOI results, I've tested a few other protocols. Frankly, testing this thing for overload is a PITA because my test gear doesn't readily produce hot enough signals and the dynamic range of the Rigol isn't all that wide. It is necessary to use attenuation on its input to keep the mixer input below -10 dBm so it doesn't introduce any IMD of its own which affects the ability to display weak and strong signals at the same. Depending on the RBW and attenuation settings, it's hard to achieve 70 dB of dynamic range. But, hey, it's a $2K piece of gear, several 10s of thousands of dollars.

A sampling of test results:
505 MHz with IP3 @ -46 dBc --- +61.9 dBmV (+13.1 dBm) fundamental output
505 MHz with IP3 @ -60 dBc --- + 7.7 dBm (TOI=37-38 dBm) fundamental output
DIN45004B 3-tone @~500 MHz --- 119.35 dBuV

Several notes: Samples from the same batch of amps will vary, sometimes by several dB. Also note that the Rigol's accuracy is somewhat limited in its precision (+/- 1 or 1.5dB IIRC). Far more accurate lab gear would reduce the results range for greater accuracy but that is outside my assigned charter. In general, the readings taken with the Rigol are very close to those obtained by our test lab engineer in his facility with his HP/Agilent gear.

P1dB test results usually ranged between +21 to just over +23 dBm depending on the individual sample and the test frequency.

I will be happy to try to answer any performance related questions that you might have.
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dave01
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Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Thu Mar 19, 2020 6:06 am

I knew it wasn’t filtering sub 700MHz frequencies, however, they are not an issue in Canada as of yet. However, yes, ordering a CM LTE filter will be a necessity eventually. For me personally, the AD preamp’s internal filter greatly improved my situation, as I have a Videotron antenna right in front of me, approx 400ft away, emitting in the 2000MHz band. I had tons of issues on my UHF antenna and the minute I hooked it up, they all went away and I had no more pixelation.

What I think my issue remains is still having channel 13 being slightly overloaded from adjacent channel 12. Do we have any ways to confirm that without specialized equipment?

I’m thinking of ordering one of those cheap SDR’s to be able to have a view at the radio spectrum, but that won’t help in solving my issue. I will also need to figure out how to use and understand it...

nickk
Silicondust
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Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by nickk » Thu Mar 19, 2020 7:43 am

What is the reported signal strength on 12 and 13?

dave01
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Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Thu Mar 19, 2020 9:59 am

nickk wrote:
Thu Mar 19, 2020 7:43 am
What is the reported signal strength on 12 and 13?
Hi Nickk,

Right now from the HDHomeRun Android app:

Channel 12: SS 100 / SNR 98 / SQ 100

Channel 13: SS 100 / SNR 69 / SQ 100

Wow, not sure what’s happening, as the signal strength was attenuated to around 85 yesterday... But I’m not seeing SQ glitches, so far, so good...

dave01
Posts: 15
Joined: Tue Mar 17, 2020 7:01 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Thu Mar 19, 2020 10:12 am

One thing I’m noticing in the RF broadcast band allocation, right next to channel 13 at 213MHz, is the radar frequency from 216-225MHz. On my path from my house almost straight to Mt. Mansfield emitter, I’ve got Trudeau Airport, maybe 10 miles away.. I wonder if it has to do with the SQ glitches I was seeing and that now that almost all flights are grounded, SQ is real stable... I guess we’ll find out when air travel activity resume...

As for signal strength, it’s now showing at 82 on both channels, which makes more sense and is in line with my results from yesterday.

Let me know if you need any additional information.

shoman94
Posts: 46
Joined: Sun Jan 29, 2017 7:48 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by shoman94 » Thu Mar 19, 2020 12:19 pm

dave01 wrote:
Thu Mar 19, 2020 6:06 am
I knew it wasn’t filtering sub 700MHz frequencies, however, they are not an issue in Canada as of yet. However, yes, ordering a CM LTE filter will be a necessity eventually. For me personally, the AD preamp’s internal filter greatly improved my situation, as I have a Videotron antenna right in front of me, approx 400ft away, emitting in the 2000MHz band. I had tons of issues on my UHF antenna and the minute I hooked it up, they all went away and I had no more pixelation.

What I think my issue remains is still having channel 13 being slightly overloaded from adjacent channel 12. Do we have any ways to confirm that without specialized equipment?

I’m thinking of ordering one of those cheap SDR’s to be able to have a view at the radio spectrum, but that won’t help in solving my issue. I will also need to figure out how to use and understand it...
What my thought was to use the CM LTE filter and remove the preamp so its not overloaded by the close tower. All it takes is one overloaded signal to cause problems across the board.

dave01
Posts: 15
Joined: Tue Mar 17, 2020 7:01 pm

Re: Fox 11 symbol quality dipping every 15-20 sec - dave01

Post by dave01 » Fri Mar 20, 2020 9:12 am

The CM-3201 is rated to filter out 600-2000 frequencies. Issue is that I've got a Videotron cell tower 400ft in front of my house emitting at 2100MHz, not sure it'll get filtered out.

Other thing is that in Canada, LTE is still operating above 700MHz, so we still have channels operating up to theoretically channel # 53, highest channel # I currently get is 49. However, on my stellar labs antenna, that wouldn't be an issue since I am dedicating it to VHF as much as possible.

Best for me would be to build myself a notch filter to pass that one single channel and filter out everything else, period.

I looked at Chebyshev filters, but their response curves are not sharp enough.

From what I can see, there's also butterworth filters, where a 6th order one would seem to have a sharp enough response and be suitable for my application?

Now I have to find values, plans, etc...

Anybody has made one already? Or a better suggestion, other than spending $100's on already made commercial solutions?

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