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Old 8-Sep-2016, 8:17 PM   #21
rabbit73
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Which way is the antenna aimed in the photo?

Is it aimed at the solar panels?

Quote:
(This is something new AFTER I relocated the antenna from the ride corner of the roof to the left side. The reason I relocated it was because after my neighbor recently made an addition to his house, I noticed I got weaker TV signals. Maybe his new roof was reflecting the signals away from my antenna..?)
Does the photo show the new location?

Is the left side on the NW or SE? Maybe you could send me a satellite image of the antenna location in a PM, or I could send you an image with my guess marked.

Does the corner point to the east?
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File Type: jpg jerrymcTVFant.JPG (168.8 KB, 533 views)
File Type: jpg jerrymcTVFsolar.JPG (88.5 KB, 601 views)
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Last edited by rabbit73; 8-Sep-2016 at 9:30 PM.
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Old 9-Sep-2016, 5:40 PM   #22
rabbit73
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Thank you for the clarification by PM. I have a better understanding of your antenna location; not as close to the solar panels as I thought.
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Old 9-Sep-2016, 6:24 PM   #23
rabbit73
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If you are wondering about my concern with the 7777, here is the math:

your report for reference:
http://www.tvfool.com/?option=com_wr...e2cb74ea324603

KVCR Noise Margin is 61.2 dB + antenna gain of 13 dB = NM 74.2 dB, which is overload when the antenna is aimed at KVCR. When it is not aimed at KVCR, the strength of the signal depends upon the antenna pattern.



Interpreting Noise Margin in the TV Fool Report
http://www.aa6g.org/DTV/Reception/tvfool_nm.html

KVCR has a signal power of -29.6 dBm = 19.4 dBmV

Max input of the 7777 = 15 dBmV
http://www.channelmaster.com/TV_Ante..._p/cm-7777.htm
Quote:
This antenna amplifier is a high gain, low noise preamplifier used to allow weaker signals at the antenna to be amplified to a viewable strength, and is ideal for installations in which all broadcast towers are located at a distance of more than 80 miles......Due to the high gain output of this product, it can result in over amplification if not used in the appropriate scenario. Over amplification can cause issues with the television tuner’s ability to receive and display some or all channels.
Even without adding ANY antenna gain, KVCR will overload the input of the 7777.

KVCR signal power = -29.6 dBm

-29.6 dBm + ant gain 13 dB + preamp gain 30 dB = +13.4 dBm; tuner overload

even without adding antenna gain
-29.6 dBm + 30 dB preamp gain = +0.4 dBm; tuner overload

This calculation assumes that the tvfool report is accurate for your location, which isn't always true. But, it is necessary to be aware that a small amount of overload will affect the reception of weak signals even if the strong signals are not affected.


ATSC Recommended Practice:
Receiver Performance Guidelines

Document A/74:2010, 7 April 2010

RECEIVER PERFORMANCE GUIDELINES

5.1 Sensitivity


Quote:
A DTV receiver should achieve a bit error rate in the transport stream of no worse than 3x10E-6 (i.e., the FCC Advisory Committee on Advanced Television Service, ACATS, Threshold of Visibility, TOV) for input RF signal levels directly to the tuner from –83 dBm to –5 dBm for both the VHF and UHF bands.
5.2 Multi-Signal Overload

Quote:
The DTV receiver should accommodate more than one undesired, high-level, NSTC or DTV signal at its input, received from transmission facilities that are in close proximity to one another. For purposes of this guideline, it should be assumed that multiple signals, each approaching –8 dBm, will exist at the input of the receiver.
You should not need to use the 7777 AND the 3410 with your signals, which is why I asked about how your equipment is connected.

When the antenna is aimed at KCIO:
-57.7 dBm + ant gain 13 dB + 30 dB preamp + 15 dB 3410 = +0.3 dBm; tuner overload

Looking at your FM signals, KDEY-FM has a signal power of -23.6 dBm:
http://www.fmfool.com/modeling/tmp/b...7/Radar-FM.png

The 7777 says FM trap >15 dB

-23.6 dBm - 15 dB trap +30 dB preamp + 15 dB 3410 = +6.4 dBm at the tuner input

KDEY-FM is on 93.5 MHz; its 2nd harmonic is 187 MHz which falls on channel 9 (186 TO 192 MHz), which makes interference possible.

Testing for DTV Interference
http://www.tvtechnology.com/expertis...ference/202503
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Last edited by rabbit73; 9-Sep-2016 at 7:12 PM.
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Old 9-Sep-2016, 10:56 PM   #24
jerrymc
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Hi Rabbit:

A couple years ago I had the RCA ANT751 antenna with the RCA TVPRAMP1R pre-amp. I had decent signals from Mt. Wilson, albeit many upper UHF stations barely came in.

I decided to get the larger antenna and better/stronger pre-amp and I do get many more stations from Los Angeles.

KVCR is not a station we watch. If that's the issue with all the other stations, can I block KVCR's signals? (91.9Mhz) AND The FM signals in that range?
(I cannot tell you how many times I climbed that steep roof just to tweak the antenna!)

I just received my LTE filters from the UK but I do not think this is the correct range here in the US.
(Frequency range : VHF 5 - 300MHz (400Mhz trap)
Frequency range : UHF 470 - 790MHz)
LTE TV Filter

Many Youtube videos I see regarding LTE and OTA TV interference are from Australia and Europe. I read that US LTE will soon be utilizing the 600Mhz range which seems to cut into many stations here in the So. CA area.

I am going to remove the 3410 dist. amp and try out the LTE filter this weekend. I already grounded the coax, but still need to purchase and ground a new shorter 18 galvanized pole.

Does the 7777 pre-amp have a sufficient FM trap?

I will study the reports you sent this evening and once again, thank you very much for your help!
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar

Last edited by jerrymc; 10-Sep-2016 at 7:23 PM. Reason: too long
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Old 10-Sep-2016, 1:43 AM   #25
rabbit73
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Thank you for your reply with further background information.

It is not necessary for you to quote my whole post.

Your present antenna has much more gain than the RCA ANT751, and it is larger because it has more gain and it also covers real channels 2-6 VHF-Low, which may or may not be important to you.

Quote:
KVCR is not a station we watch. If that's the issue with all the other stations, can I block KVCR's signals? (91.9Mhz) AND The FM signals in that range?
The HLSJ will block everything below TV CH7 including the FM band and CH 2-6, but it will not block KVCR. That would require a custom band stop filter for real channel 26 from Tin Lee Electronics (expensive) or from Jan Jenca (less expensive) in eastern Europe who sells on ebay.

http://www.tinlee.com/index.php
http://www.tinlee.com/NotchTraps.php...ategory=offAir



If you want to experiment, you can try a notch filter that removes 24-29.
ChannelPlus ModelNF-471 Notch Filter
https://www.amazon.com/Linear-NF-471.../dp/B000J3AEYA

The Jan Jenca ch26 filter would probably be about the same price, but is a custom order from Slovakia.
http://www.antenne-komponenty.eu/eng...zlucovace.html
they also sell combiners
http://www.avsforum.com/forum/25-hdt...l#post37732809

Quote:
(I cannot tell you how many times I climbed that steep roof just to tweak the antenna!)
When the aim is that critical for the 277-281 degree LA channels, that might be an overload symptom.

It is balancing act, between the strongest and weakest desired channels, which is called the dynamic range. You went from a low gain antenna with a medium gain preamp to a high gain antenna with a high gain preamp. The best compromise might be a high gain antenna with a medium gain preamp, but it might require further experimentation by you. I suggested the HLSJ because it is an inexpensive and fairly easy first step.
Quote:
I just received my LTE filters from the UK but I do not think this is the correct range here in the US.
(Frequency range : VHF 5 - 300MHz (400Mhz trap)
Frequency range : UHF 470 - 790MHz)
Your thinking is correct, passing up to 790 is too high. TV channel 51, our present highest channel, is 692 to 698 MHz. The Channel Master LTE filter seems more like what is presently needed in the US, but only if there are cell transmitters just above CH51 in your area.

http://www.channelmaster.com/TV_Ante..._p/cm-3201.htm
https://www.google.com/?gws_rd=ssl#q...ter+lte+filter
Quote:
I read that US LTE will soon be utilizing the 600Mhz range which seems to cut into many stations here in the So. CA area.
Yes, the FCC will be selling off even more UHF TV channels to commercial interests, which will again squeeze the TV broadcasters even more. That bothers me a lot. I consider those frequencies a natural resource that belongs to all citizens, not for the enrichment of a private business.
Quote:
Does the 7777 pre-amp have a sufficient FM trap?
It does have an FM trap with an attenuation stated as at least 15 dB, but they don't give any further details, like an attenuation vs freq curve. I don't really know if it is sufficient, that is why I have suggested tests.
http://www.channelmaster.com/TV_Ante..._p/cm-7777.htm

The Antennas Direct Juice preamp has a 4G LTE filter built in, but no FM filter.
Attached Images
File Type: jpg Jan Jenca Notch Filter_1.jpg (31.4 KB, 1166 views)
__________________
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Last edited by rabbit73; 10-Sep-2016 at 1:46 PM.
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Old 10-Sep-2016, 7:26 PM   #26
jerrymc
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Hi again:

Is there a site that displays all stations' frequencies, in short of Googling every single station?

I've searched TVFool and other antenna sites, but not one shows the actual frequency channels these are using...

UPDATE:
Nevermind; I found this spreadsheet on RabbitEar.Info

http://www.rabbitears.info/ss/DTV-Channels.xls
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar

Last edited by jerrymc; 10-Sep-2016 at 9:42 PM. Reason: Update
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Old 10-Sep-2016, 11:48 PM   #27
RF Steve
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A frequency list of real broadcast channels is quite easy to find.
http://www.csgnetwork.com/tvfreqtable.html
Most of the current confusion is caused by the use of virtual channel numbers.
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Old 11-Sep-2016, 2:07 AM   #28
rabbit73
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https://en.wikipedia.org/wiki/North_...on_frequencies
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Old 11-Sep-2016, 4:02 PM   #29
jerrymc
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Thanks, but I was looking for something that had more of a channel list for an entire region with all frequencies in order from lowest to highest...

IE: KCBS 2 = UHF 43, Virt. 2.1, Freq. ?
KNBC 4 = UHF 36, Virt. 4.1, Freq. ?
KABC 7 = H-VHF 7, Virt. 7.1, Freq. ?

I suppose I could tune each and every station just to see what their analog broadcast signal really is...?
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar
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Old 11-Sep-2016, 5:52 PM   #30
rabbit73
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I don't think there is a list that gives real channel, virtual channel and frequency of real channel. If you know the real channel number, then you can look up the frequency of that channel in the link that I gave in post #28.

by zip code
http://www.rabbitears.info/search.ph...pe=dBm&height=



click on callsign to see subchannels



The display channel is the same as the virtual channel; the physical channel is the same as the real channel.

You can do it here:
http://www.rabbitears.info/search.php

If you enter just the zip code, the distance and direction will be off. If you add your street address, it will be more accurate. If you also check Strength Search (optional), it will generate a report similar to a tvfool report. I will not give a link to that result because it will show your street address.



Why do you need to know the actual frequency of the channel?

The only time I need it is to design an antenna for a certain channel, to calculate the specs for an interference filter, or to know if the second harmonic of an FM transmitter falls on a VHF-High channel.
Attached Images
File Type: jpg jerrymcTVFzip.JPG (32.1 KB, 1145 views)
File Type: jpg jerrymcTVFzip2.JPG (46.0 KB, 1153 views)
File Type: jpg jerrymcTVFzip4.jpg (111.9 KB, 1111 views)
__________________
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Last edited by rabbit73; 11-Sep-2016 at 7:21 PM.
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Old 11-Sep-2016, 6:41 PM   #31
jerrymc
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Thanks. I'm not sure how I missed post 28.

I'll add to my spreadsheet the real frequencies of local stations.

The reason I wanted the real frequencies is because my TV tuner has a "Partial channel scan" where it asks for the frequency to find more stations.
It's much quicker than doing a Full Scan and, more importantly, it doesn't delete the current channel list! 😁
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar
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Old 11-Sep-2016, 7:56 PM   #32
rabbit73
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Quote:
The reason I wanted the real frequencies is because my TV tuner has a "Partial channel scan" where it asks for the frequency to find more stations.
It's much quicker than doing a Full Scan and, more importantly, it doesn't delete the current channel list!
Excellent reason. Which tuner are you using to do that?

My Sony can also add a channel after scan, but I don't have to enter the freq.

the Diagnostics Screen shows the center-channel freq:

Attached Images
File Type: jpg SonyKDL22L5000ch40.jpg (129.3 KB, 1134 views)
__________________
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Last edited by rabbit73; 11-Sep-2016 at 8:05 PM.
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Old 15-Sep-2016, 4:36 PM   #33
jerrymc
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Solar Panels?

Hi again:

Well, I haven't been able to swap everything out yet because I'm waiting for WM and HD orders to arrive... (18 ga pole, dielectric jelly, more coax connectors, etc...)

On another reply you spoke of Solar Panels possibly interfering with the OTA signals.

It just so happens that my other neighbor, 2 doors down behind us, has panels and this is directly where I am pointing my antenna towards Mt. Wilson ( ~280 degrees west)
(see attached pic)

https://drive.google.com/open?id=0B6...VF0UXNROHlodUU

I notice that signals drop on many stations late afternoon, no matter how many times I tweak my antenna, and then great signal after about a couple hours....

How likely, in your opinion, would solar panels be the culprit?
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar

Last edited by jerrymc; 15-Sep-2016 at 4:39 PM. Reason: pic not showing...
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Old 16-Sep-2016, 1:05 AM   #34
rabbit73
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Ahh, yes. I see the green signal lines pass just to the right of his panels in the photo I sent to you by PM, but I didn't want to post it on the forum without your permission.

It is possible that you might be picking up EMI from his inverters. Some inverters produce more interference than others.

case history:
Would solar panels interfere with attic antenna?

http://www.avsforum.com/forum/25-hdt...c-antenna.html
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Last edited by rabbit73; 16-Sep-2016 at 1:19 AM.
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Old 16-Sep-2016, 2:54 AM   #35
Stereocraig
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I remember using Tripp Lite 12V inverters back in the 70s, before the car audio industry was producing anything larger than 24WPC.
The Crowns I was using, had ample filtering, but even being in the trunk, that noisy square wave, was still leaking into the system through the line level components.
The only point I'm even close to making, is that regardless of proper grounding, EMI may be entering through an unshielded wall wart, or other plastic component case.
Most filters may be capable of blocking 60HZ hum and ripple, but can't deal w/ the sharp transients of the higher frequency square waves. Or maybe at best, even not the newer modified sine waves.
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Old 16-Sep-2016, 5:31 AM   #36
jerrymc
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I was afraid that those panels being in the line of sight for Mt. Wilson would cause some sort of interference.

On another note, I was reading some Australian TV antenna forums and discovered that the loooong elements on VHF antennas are for stations 0-5 and could possibly cause more FM and other low-band interference. Many stations here are now H-VHF and UHF, and this HD-8200XL is more of a broad spectrum design. (FM, L-VHF, H-VHF, UHF)
I was thinking of folding in the longest elements to test that theory out.
Any input on this?
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar
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Old 16-Sep-2016, 9:58 AM   #37
Stereocraig
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Maybe a good start, but there's also the possibility of signal induction, when running them parallel to your phasing lines.
Not to mention, shorting out against the boom, or other elements.
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Old 16-Sep-2016, 2:12 PM   #38
jerrymc
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Quote:
Originally Posted by Stereocraig View Post
Maybe a good start, but there's also the possibility of signal induction, when running them parallel to your phasing lines.
Not to mention, shorting out against the boom, or other elements.
Forgive my ignorance, but I'm not very radio savvy.
When you mean "shorting out" are you saying the frequencies would go bonkers and no signal would be possible?
Or would it pick up more interference than before?
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar
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Old 16-Sep-2016, 2:28 PM   #39
Stereocraig
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By "shorting out", I mean that any signal present on the longest elements that seeped over from the elements that are being used , could be shorted directly to ground when you fold them, resulting in almost zero signal.
Similar to a garden hose that's kinked.
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Old 21-Sep-2016, 1:55 AM   #40
jerrymc
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Hey guys:

I did some experimenting this weekend:

I ran one coax directly from the large antenna (No splitters, pre-amps, or dist. amps) and all stations came in pretty well during the day.

I relocated the cable run from the opposite corner of eve to the closer corner of the roof eve. (Left side)
https://drive.google.com/file/d/0B6w...ew?usp=sharing

I tried bypassing the dist. amp, (Pre-amp only) but the picture was pixelating pretty bad. Without the pre-amp, the 5 TVs in the house got only a couple stations.

I re-installed the CM dist.amp and also closed/folded in the 3 longest elements and increased my KABC (177Mhz, the lowest frequency station) by about 6%. (see pic)

We also experimented by raising the antenna to the top of the pole, but it decreased the signal, so I lowered it as far as I could so it would clear the tile roof if I rotated it via the rotor motor.
I also replaced the pole with a Winegard 18 gauge steel one.

I need to remove the 2 splitters and try to combine them somehow, but the difficulty in this is that the 2 wired-in cables (Downstairs living room and master bed) are inside a TV box on the side of the house. (3 other TVs are connected to a splitter in the attic.)

Here's how it's all connected:

1. Antenna to CM pre-amp (exterior)
2. Pre-amp to CM dist. amp (attic)
3. Dist. amp to 4 port splitter (One goes to each of 3 other bedrooms.
The 4th goes to the TV box on side of house.
4. TV box connection has one 2-way splitter for both master bed and downstairs living room.
5. Coax is house grounded; pole is not grounded yet.

I'm pretty sure the coax is all dual-shielded RG6 only.
Would replacing the short coax between the antenna and pre-amp with quad shield have any significance in gain?

And do you think that a 5 port splitter would be best for our situation?

Thanks again for your expertise.
__________________
HD8200XL and HDB91X with RCA TVPRAMP1R pre-amp aimed at Mt. Wilson (Los Angeles) in Etiwanda area.
CM3410 dist. amp in attic for a 5 room hookup.

Located in foothills behind Mt. Baldy, and experiencing signal loss and pixelation depending on time of day.
Using RCA rotator motor now to tweak.

Location Radar
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