antenna advice for Marin County

[ckwsp101_tv]

I refreshed the link

http://www.tvfool.com/?option=com_wr...e6a44ae36c6631

There is a chance that after the repack
KNTV 11.1 (RF12) on Mt. San Bruno will move to
RF 13.

http://www.avsforum.com/forum/45-loc...a-ota-499.html

[rabbit73]

Thanks for refreshing the link, but that doesn't work. It has been deleted from the tvfool server because it is out of date. It will be necessary to do a new report.

post 1, last part of link:
3de6a44ae36c6631
post 21, last part of link:
3de6a44ae36c6631

It's the same report.

This is the 50 ft report in post 9 that says "The requested report ID is no longer on our server. To start a new analysis, click here."
http://www.tvfool.com/?option=com_wr...f1f02b36a29948

[ckwsp101_tv]

Browser cut and paste issue

http://www.tvfool.com/?option=com_wr...e6a4535ed606db

[rabbit73]

There is a chance that after the repack
KNTV 11.1 (RF12) on Mt. San Bruno will move to
RF 13.

That seems to be true:

http://www.rabbitears.info/market.ph...&callsign=kntv

[rabbit73]

Thank you for the new report link; it works fine.

I will study your report, but I'm not sure that I can add anything useful other than it's the terrain and the tree.

Have you asked for help on the AVS SF local reception thread that you linked?

[ckwsp101_tv]

Thank you for responding.

I think vertical stacked VHF balun polarity was correct.
The SiliconDust tuner diagnostic reports 10% quality improvement
over single VHF antenna
I can view KNTV (RF 12) when signal quality is above 55%. There is more
variation in recent months. Symbol quality sometimes goes to zero. Multipath
issues continue.

I agree it is likely the terrain and tree.

I will first try replacing baluns.


Will check out the AVS forum.

[ADTech]

There is a chance that after the repack
KNTV 11.1 (RF12) on Mt. San Bruno will move to
RF 13.

A chance? No, a certainty.

KNTV has been assigned RF13, KGO will be moved to RF 12, and KRON wll be moved to RF 7 as part of the repack process. All moves are scheduled for the spring of '20 for the Bay area.

[ckwsp101_tv]

Here is current antenna location on tripod.



I guess growing trees degrading VHF reception.
Will try to trim tree limbs on my property.

[rabbit73]

Thanks for the oblique satellite photo; it helps.

Here is the KNTV terrain profile:



Is the antenna here (I used the vertical instead of the oblique):



or here:





Is the antenna at the teardrop or at A.

Are B and C solar panels? Thermal or PV?

Do you have an inverter? They can cause interference on VHF.

What is D?

[ckwsp101_tv]

Antennas placed at the tear drop.
At this position UHF channel reception is fine.
VHF RF 12 gradually degraded over the last 6 months.
I can view alternate KNTV NBC 11.3 on RF 49 from Mt Allison San Jose.


B and C are open areas.
D is over the roof copper water pipe repair done 10 years ago.


Nearby houses do have roof solar systems. I would expect panel interference
to be greater during the day and less during the night. I will take more measurements
using the SiliconDust diagnostic program.

I'm suppose it could be other interference.
The residential development has underground power distribution from the 60s.
The county is slowly converting to LED intersection lights.That was done 2 years ago
Could I use AM radio as a interference detector?

My SiliconDust tuner is 2 years old. Maybe the power supply is failing and weak station
reception is first symptom of pending failure.


To do list:

Replace baluns and check connections before rainy season.
Replace SiliconDust tuner wall wart power supply.

If simple measures do not improve situation I may just bail on RF 12. Depend
on RF 49 for NBC network content.

[ckwsp101_tv]

An old SiliconDust forum posting suggests noise in pre-amp or powered splitters
could lower signal quality. I'm going to assume the RCA pre-amp is working ok.
If all other measures fail then re exam issue raised in the SiliconDust posting.
If RCA premap really needs replacment maybe upgrade to the AD Juice pre-amp.

https://forum.silicondust.com/forum/...&t=4474#p25503

Splitters and amplifiers can introduce noise which will lower the Signal Quality, even if the Signal Strength increases.

[rabbit73]

Thanks for the details.

Antennas placed at the tear drop.
At this position UHF channel reception is fine.

Looks like the signal path is between two trees.

VHF RF 12 gradually degraded over the last 6 months.

Tree growth?

Could I use AM radio as a interference detector?

Yes, interference that is heard on the AM broadcast band is often strong enough to affect VHF-High TV reception. A battery operated portable can be used as a direction finder; its built-in loop antenna is directional. Tune to a clear spot at the low 550 end and then at the high 1600 end.

The last case I helped with was detected on an AM radio in a car as it drove in a road with the power line along side. The source of the interference was a battery charger affecting VHF-High. Other cases involved LED lights, and switchmode AC to DC power adapters for laptops.

Some of the sources of interference are constant; others time related.

[ckwsp101_tv]

Long time no post.

https://www.rabbitears.info/searchma...study_id=16913

http://www.tvfool.com/?option=com_wr...9038b74b56328c

Attempted to trim tree branches on my property.
No improvement on RF 12 reception.

I was able to get KNTV content from alternative RF 49 transmitter.
So I did not do much until this summer.

RF 7 and RF 12 signal quality continued to degrade.

Replaced baluns twice on the 2 stacked y10-7-13s resulted in improvement on RF 7.
Still no lock on RF 12.
Silicondust needs signal quality of 50% or better to lock.

HDhomeRun Config
RF 12
ss 75%
sq 43%

As experiment I converted my vertically stacked Y10-7-13 to a horizontal layout using saw horse next to
antenna mount.
Trial and error horizontal distance between the antennas.


11.1 (RF 12) finally locks with horizontal layout.
Silicon Dust
ss 81%
sq 60%

RF 7
ss 98%
sq 85%

RF 12 right at digital cliff.
Over time the best spot on roof for RF 12 changed. I may need a separate location and mount for RF 12 longer term :<

Quality of retail baluns not very good. Maybe I need to make home made versions for y10-7-13 array.
So far RCA pre-amp still working. If I need to replace I will consider combining UHF and VHF feeds and use Antennas Direct Juice pre-amp.

Found on Silicondust forum

SS%  dBmV
0%   -60 dBmV
5%   -57 dBmV
10%  -54 dBmV
15%  -51 dBmV
20%  -48 dBmV
25%  -45 dBmV
30%  -42 dBmV
35%  -39 dBmV
40%  -36 dBmV
45%  -33 dBmV
50%  -30 dBmV
55%  -27 dBmV
60%  -24 dBmV
65%  -21 dBmV
70%  -18 dBmV
75%  -15 dBmV
80%  -12 dBmV
85%   -9 dBmV
90%   -6 dBmV
95%   -3 dBmV
100%   0 dBmV

[ckwsp101_tv]

KGO RF 7 switching to auxiliary antenna lower down on tower 24/7 until repack completes 5/1/2020.

Both hi VHF RF 7 and 12 marginal.

Too bad KGO RF 7 was my ABC station.

https://www.avsforum.com/forum/45-lo...l#post58670562

[rabbit73]

Originally Posted by ckwsp101_tv

Long time no post.

https://www.rabbitears.info/searchma...study_id=16913

http://www.tvfool.com/?option=com_wr...9038b74b56328c

Thank you for the new reports.

Attempted to trim tree branches on my property.
No improvement on RF 12 reception.

Replaced baluns twice on the 2 stacked y10-7-13s resulted in improvement on RF 7.
Still no lock on RF 12.
Silicondust needs signal quality of 50% or better to lock.

HDhomeRun Config
RF 12
ss 75%
sq 43%

As experiment I converted my vertically stacked Y10-7-13 to a horizontal layout using saw horse next to
antenna mount.
Trial and error horizontal distance between the antennas.

11.1 (RF 12) finally locks with horizontal layout.
Silicon Dust
ss 81%
sq 60%

RF 12 right at digital cliff.
Over time the best spot on roof for RF 12 changed. I may need a separate location and mount for RF 12 longer term :<

Considerable improvement with horizontal array, but you are still behind a hill.

Found on Silicondust forum

SS%  dBmV
0%   -60 dBmV
5%   -57 dBmV
10%  -54 dBmV
15%  -51 dBmV
20%  -48 dBmV
25%  -45 dBmV
30%  -42 dBmV
35%  -39 dBmV
40%  -36 dBmV
45%  -33 dBmV
50%  -30 dBmV
55%  -27 dBmV
60%  -24 dBmV
65%  -21 dBmV
70%  -18 dBmV
75%  -15 dBmV
80%  -12 dBmV
85%   -9 dBmV
90%   -6 dBmV
95%   -3 dBmV
100%   0 dBmV

Thank you for the useful conversion chart. Just for fun, I have added dBm values in a Sandbox post.
https://forum.tvfool.com/showthread....2341#post62341

[ckwsp101_tv]

Originally Posted by rabbit73

Considerable improvement with horizontal array, but you are still behind a hill.

Very true.

I did not realize magnitude of RF 12 multi-path interference at my location.
The horizontal array is a big win.

Reception fine most of the time.
Signal Quality stable. Fewer jumps/jitters

Likely reception will change again after 5/1/2020 repack completes.

[jrgagne99]

Just curious, what value did you end up with for horizontal spacing? What was the value you were did vertical stacking?

Do you think the values would be good for stacking Stellar Labs 30-2476, which I believe has a similar configuration as the Y-10-7-13's ?

[ckwsp101_tv]

Originally Posted by jrgagne99

Just curious, what value did you end up with for horizontal spacing? What was the value you were did vertical stacking?

Do you think the values would be good for stacking Stellar Labs 30-2476, which I believe has a similar configuration as the Y-10-7-13's ?

My current horizontal distance is 100 inches.
I need longer feed lines to increase distance.

I did not find a best vertical stacking distance as i had limited space on mast.
i used 30 inches.

I used Silicondust signal quality measurement to confirm distances doing right thing.

My situation atypical. Likely I will need another mount and location to place 2nd y10-7-13 longer term. Right now using saw house mount.

[ckwsp101_tv]

Bay Area Phase 9 repack done.

https://www.rabbitears.info/searchma...study_id=16913

Rescan and now KNTV on RF 13.
Better viewing experience.
Transmitting antenna higher on tower and higher power.


SiliconDust
RF 13
Signal Strength 92%
Signal Quality 83-90%

Signal Quality still bouncy.

I need to investigate UHF channel reception.
After repack some UHF stations now have issues.

KBCW 44 was on RF 45 after repack on RF 28.

SiliconDust tuner reports lower Signal Quality for KBCW 44 RF 28.

RF 28
Signal Strength 90%
Signal Quality 67-76%
Symbol Quality 0-100%

RF 27
Signal Strength 92%
Signal Quality 85%
Symbol Quality 100%

RF 33
Signal Strength 99%
Signal Quality 90%
Symbol Quality 100%


Guess I am at digital cliff for reliable reception of KBCW 44 RF 28.
Signal Quality bouncy.
Now multi-path issues?
Impairments specific to RF28 as RF27 reception better.
KKPX-TV RF 33 also better.
Antennas Direct 91XG gain on RF 28 lower than RF 45.

Most of time recorded shows on KBCW RF28 viewable with some breakup.
Maybe take further action after exiting lockdown.

[bobsgarage]

Originally Posted by ckwsp101_tv

Bay Area Phase 9 repack done.

https://www.rabbitears.info/searchma...study_id=16913

Rescan and now KNTV on RF 13.
Better viewing experience.
Transmitting antenna higher on tower and higher power.


SiliconDust
RF 13
Signal Strength 92%
Signal Quality 83-90%

Signal Quality still bouncy.

I need to investigate UHF channel reception.
After repack some UHF stations now have issues.

KBCW 44 was on RF 45 after repack on RF 28.

SiliconDust tuner reports lower Signal Quality for KBCW 44 RF 28.

RF 28
Signal Strength 90%
Signal Quality 67-76%
Symbol Quality 0-100%

RF 27
Signal Strength 92%
Signal Quality 85%
Symbol Quality 100%

RF 33
Signal Strength 99%
Signal Quality 90%
Symbol Quality 100%


Guess I am at digital cliff for reliable reception of KBCW 44 RF 28.
Signal Quality bouncy.
Now multi-path issues?
Impairments specific to RF28 as RF27 reception better.
KKPX-TV RF 33 also better.
Antennas Direct 91XG gain on RF 28 lower than RF 45.

Most of time recorded shows on KBCW RF28 viewable with some breakup.
Maybe take further action after exiting lockdown.

Thanks for the follow up! Sounds like you benefitted from the re-pack, I'm worried about multi path here as it seems the Chicago market has all the stations packed together