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Old 23-Oct-2020, 10:55 AM   #1
awright11877
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Tuning distant stations

New to the forum but a long-time user of this site. I'm hoping to get some advice or clarity into whether I can pull in distant channels at my remote camp in Vermont, namely those from Sherbrooke or perhaps Montreal. Even though I can pull Montreal's FMs in from my location, I think their TV signals are a long shot given the distance and terrain in between.

I've put an Antennas Direct ClearStream 4MAX on my roof about 20 feet off the ground, facing NNW toward Canada, and I have a Winegard Boost XT Outdoor Digital TV Antenna Preamplifier about 10 feet from the antenna, sheltered under my deck to keep it out of the elements. Camp elevation is about 2200 feet, with waterfront exposure to from NW to SW.

My co-ordinates:
44.50644165269277
-72.21341907978059

RabbitEars.Info signal map query:
https://www.rabbitears.info/searchma...tudy_id=167084

TVFool TV Signal Analysis Results:
http://www.tvfool.com/?option=com_wr...9038b5adb100a4

For reference, I can receive WCAX, WPTZ, WVNY, WFFF, WETK, WNNE (now on Mt. Mansfield with the other Burlington/Plattsburgh stations) and the WLED-TV NHPTV repeater out of Littleton, NH on ch 11.
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Old 23-Oct-2020, 2:28 PM   #2
jrgagne99
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Unfortunately, I think even the Sherbrooke stations are took weak to pull in reliably, and Montreal looks even further down in the weeds. A Stellar Labs 30-2476 is your best bet to try for the Sherbrooke stations, since 3 out of 4 are VHF-hi. But I'd say your odds of reliable reception of those are close to zero, and even less for Montreal with their noise margins around -40 dB.
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Old 23-Oct-2020, 3:59 PM   #3
rabbit73
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Quote:
Originally Posted by awright11877 View Post
I'm hoping to get some advice or clarity into whether I can pull in distant channels at my remote camp in Vermont, namely those from Sherbrooke or perhaps Montreal.

I've put an Antennas Direct ClearStream 4MAX on my roof about 20 feet off the ground, facing NNW toward Canada, and I have a Winegard Boost XT Preamplifier

My co-ordinates:
44.50644165269277
-72.21341907978059

RabbitEars.Info signal map query:
https://www.rabbitears.info/searchma...tudy_id=167084

TVFool TV Signal Analysis Results:
http://www.tvfool.com/?option=com_wr...9038b5adb100a4
Hello, awright11877; welcome to the forum.

Thank you for the reports and details.



I agree with jrgagne99; Sherbrooke will be very difficult and Montreal would be not likely.

Although Sherbrooke is only 56 miles away, there is a mountain in the signal path that is close to your location.



using different profile software:



the coverage map shows no color in your area:



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Last edited by rabbit73; 23-Oct-2020 at 4:32 PM.
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Old 23-Oct-2020, 4:12 PM   #4
jrgagne99
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You need to put a repeater at the top of the ridge at the northern end of the pond. :-)

J/K, but seriously, does anyone have any experience with repeater setups, i.e. the following 3-antenna setup:

TV transmitter ~~~> Ant1 ---> amplifier ---> Ant2 ~~~> Ant3 ---> TV

Seems like it would be a fun middle school science project.
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Old 23-Oct-2020, 8:00 PM   #5
Tower Guy
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Quote:
Originally Posted by jrgagne99 View Post

J/K, but seriously, does anyone have any experience with repeater setups, i.e. the following 3-antenna setup:

TV transmitter ~~~> Ant1 ---> amplifier ---> Ant2 ~~~> Ant3 ---> TV

Seems like it would be a fun middle school science project.
I have built such a repeater. You also need a channel filter. The signals available on top of the mountain look like this.

https://www.rabbitears.info/searchma...tudy_id=167161
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Old 23-Oct-2020, 8:24 PM   #6
jrgagne99
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Tower Guy,
Why is the channel filter needed, i.e. why can't you just re-broadcast everything?
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Old 23-Oct-2020, 9:34 PM   #7
Tower Guy
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Quote:
Originally Posted by jrgagne99 View Post
Tower Guy,
Why is the channel filter needed, i.e. why can't you just re-broadcast everything?
Because you will also retransmit unintended things such as airplane navigation signals.
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Old 23-Oct-2020, 9:37 PM   #8
jrgagne99
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Ok, so some combination a UVSJ, HSJ or similar should be used to make sure you're just transmitting the relevant TV frequencies? Would this approach be starting to skate pretty close to FCC rules about transmitting licenses, etc?
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Old 23-Oct-2020, 9:45 PM   #9
Tower Guy
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The FCC rules do not currently allow such boosters.

The booster I built was on 2 GHz. 4’ dish on receive, 8’ dish on transmit, 70 dB isolation between antennas, 50 dB amplifier.

Without a filter, the NEXRAD radar from 35 miles away overloaded the amplifier.
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Old 23-Oct-2020, 11:36 PM   #10
awright11877
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Thank you all, I had a sneaking suspicion that Stannard Mountain was in the way of grabbing any signal from Sherbrooke, despite the fact that I'm not all that far away.
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Old 24-Oct-2020, 1:18 AM   #11
Tower Guy
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Quote:
Originally Posted by jrgagne99 View Post
You need to put a repeater at the top of the ridge at the northern end of the pond.
Another approach is a Tablo tuner and a point to point WiFi link
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Old 26-Oct-2020, 1:57 PM   #12
jrgagne99
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That's a neat idea--- a repeater station with a Tablo and Wifi link powered by solar PV and batteries.
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Old 29-Oct-2020, 10:34 AM   #13
awright11877
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One more?

One more scenario from my home:

RabbitEars signal map query:
https://www.rabbitears.info/searchma...tudy_id=169375

TV Fool Signal Analysis Results:
http://www.tvfool.com/?option=com_wr...903826a4b857c2

Co-ordinates:
44.4942313
-73.0866617

I'm aware that boosting my antenna to pull in distant stations would probably blow out Burlington's stations 15 miles away on Mount Mansfield, which are close enough for me to get even with the most rudimentary of antennas.

I'm looking into whether I can grab CBFT, CBMT, CFTM or CFCF with an antenna 20-25 feet up on the NW corner of my home. I may be up against the same problem I encounter at my camp (at the top of the thread), where I have a few hills here blocking my path, or the fact that MTL's towers are so far away that this is a fool's errand.

Any guidance or advice is appreciated. Thanks.
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Old 29-Oct-2020, 1:46 PM   #14
JoeAZ
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A whole lot of work and expense for not much return. In Canada,
subchannels are rare, if they exist at all.
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Old 29-Oct-2020, 2:21 PM   #15
jrgagne99
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Based on the RabbitEars report, I think that CBFT and CBMT are certainly possible if you are up for a challenge. The are sitting at -5 dB noise margin. For comparison, I reliably (99%+ of time) pull in WFFF on RF-16, which is -5 dB at my location. The trick is to find a sweet spot and use a high gain UHF antenna. I have a dB8e, but a cheaper alternative HDBX8 is also comparable, and HDB91X yagi is equally up to the task. If you go down this path, use a single 50' length or less of good (preferably new) RG-6, going to exactly one TV to start. Solve the reception problem on one TV before adding amplification and distribution equipment. And choose vendors with good return policies in case it doesn't work. When finding the sweet spot, keep in mind that moving the antenna a foot or two in any direction X, Y, and Z, can make a big difference for UHF. Also tweaking azimuth and adding a slight upward tilt can sometimes help. It helps to have two people: one on the roof tweaking the aim and one reporting signal quality. Use a TV with a decent signal quality metric. Sony Bravia has a good one. There are others. Good luck.
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Old 29-Oct-2020, 6:15 PM   #16
Tower Guy
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I think that CBFT and CBMT will be harder than you realize. They are on channels 19 and 21. WCAX is on channel 20 and 70 dB stronger. That suggests that you need an antenna with an extreme side lobe rejection. The 91 XG and DB-8e are both in the 20 dB range by themselves, and that’s not enough. A potential solution is a pair of either of those antennas, one stacked 5.8” to the left of the mast and the other above it stacked 5.8” to the right. Add them together with a two way splitter with identical lengths of RG-6.

If the antenna works as exactly predicted The reception will probably be marginal. If it works better than predicted, the reception will be fine.
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Old 30-Oct-2020, 2:01 PM   #17
jrgagne99
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Quote:
Originally Posted by Tower Guy View Post
I think that CBFT and CBMT will be harder than you realize. They are on channels 19 and 21. WCAX is on channel 20 and 70 dB stronger.
Good point. I missed that detail. It certainly does make it a lot harder. Seems worth a shot for a single antenna with good return policy though.
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Old 30-Oct-2020, 8:05 PM   #18
Tower Guy
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I would not bother trying a single antenna. The ATSC spec says that reception must work when the undesired adjacent channel is 30 dB stronger than the desired channel. In this case WCAX is 70 dB stronger. The azimuth difference between WCAX and the two Canadian stations is 85 degrees. Therefore, awright would need an antenna with a 40 dB front to side ratio. The patterns on the Antennas Direct web site show 20 dB front to side ratios on their 91XG and DB-8e on channel 20.

The solution is two antennas stacked one above the other but offset by 1/2 a wavelength, creating a deep null 90 degrees off axis. When installing the antenna, the trick is to null WCAX, not maximize CBC.

Where I grew up we always watched Hockey Night in Canada. I hope awright can too.

Last edited by Tower Guy; 30-Oct-2020 at 8:12 PM.
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Old 30-Oct-2020, 8:14 PM   #19
jrgagne99
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Wow, that's some high-level analysis Tower Guy. It's neat that the recommended horizontal spacing is tailored to the precise channel, not just the band. Do you have a recommendation on the vertical spacing?
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Old 30-Oct-2020, 9:09 PM   #20
Tower Guy
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The vertical spacing for the offset pair would be the same as if they were not offset.

I taught myself these tricks in 1982 when I was attempting to pick up channel 13 from Albany, NY at a location in Utica that received Channel 13 from Rochester at almost the same signal strength as Albany.
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