antenna advice for Marin County
 

Hello,

I'm on the floor of a valley with trees on ridge and nearby . The home owners association cable
system may be decommisioned in the coming months.

My tvfool report is

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

I'm interested in ABC,NBC,CBS,PBS,CW, FOX.
I'm experimenting with a flat roof mount 1980's Radio Shack 10 foot 10 elment yagi.
I don't have
the model as all labels gone, some rivets attaching elements rusting.
I guess 3 elements are UHF and 7 elements are VHF. The antenna is
pointed at 147 degrees magnetic using landmarks. I'm aiming just right of a 150 foot
redwood tree obstructing my line to Sutro tower. The antenna is tilted at the hill crest.
Using new 50 foot RG6 and new balum my Samsung TV scans 45 channels. After installing a
RCA preamp the Samsung scans 64 channels. Samsung reported signal strength varies.
( My model tv does not have signal quaility page)

7 ABC 2-8 bars
12 NBC 0-2 bars
29 CBS 5-10 bars
30 PBS 3-10 bars
41 ION 0-10 bars
44 FOX 0-10 bars
45 CW 0-10 bars

During bad weather I lose many channels due to wind and tree interference.
For improved reception I'm considering

Antennas Direct 91XG
Antennacraft Y10713
use RCA TVPRAMP1R preamp uhf/vhf inputs
100 ft RG6 run
non penetrating flat roof mount.

The nearby trees are on public property. I expect
my tree issues may increase going forward.

I'm using a saw horse to support the Radio Shack antenna. I plan to try other locations
on the roof.

I really want to avoid Comcast.

Trees are a problem. Look here at "Trees and UHF." http://www.hdtvprimer.com/antennas/siting.html

I don't think there's much you can do if the trees stay in the way. Unlikely you'll be able to go higher than a redwood tree. Redwoods are kinda narrow and tall - any chance you can move around on your roof to skirt the blockage of the big tree?

timgr,

Thank you for responding to my inquiry. Yes the problem redwood is tall and narrow. Too tall
to go over.
After I read the tree article, I'm going to moderate my expectations.

I'm going to search for better locations on the roof with my existing RS antenna.
If I find a better location, I guess the 91XG + Y10713 still the right tools for a poor location.

Here is an update

I deployed the Antennas Direct 91XG + AntennaCraft Y10713 at temporary locations
on the roof. Boresight 91XG at hill ridge towards Sutro Tower.
http://forum.tvfool.com/attachment.p...0&d=1425324822

Reception improved compared to the old RS yagi.
There are fewer intermittant dropouts. I can receive all of my must have channels when
conditions are good. KTVU (RF 44) remains a challenge. Most of the remaining dropsouts
on KTVU.

To make more progress, I need a better way to measure signal quality.
Accessing the Samsung TV Signal Strength screen is awkward.

I appreciate the wealth of information offered in this forum.

I am now using a SiliconDust HDTC-2US as a diagnostic tool.

91XG + 50ft RG6 + HDTC-2US

RF Strength Strength Signal Quality
29 80 90
43 73 78
44 75 67-78
45 81 85

91XG + RCA TVPRAMP1R + 100ft RG6 + HDTC-2US

29 100 98
43 100 85
44 100 73-81
45 100 90

I still experience intermittent reception
on KTVU (RF44). The stations on RF43, RF44 and RF45 come from Sutro Tower.
Could multipath interference still be an issue dispite deploying
the Antennas Direct 91XG? The RF44 flutuating signal quality looks suspious.
Signal quality on R29,RF43 and RF45 are stable.

Aiming between trees to hill crest limits my roof antenna placement.
Once I get a better mast, I will resume adjusting high. Right now using the
saw horse and pvc pole.

If it is multipath interference, I read stacking a 2nd 91XG may help.
I don't expect perfect reception. Just fewer intermittent events.

I agree using a chainsaw on the near trees would help :)

Have you tried tilting the front of the antenna up a bit? It sometimes helps, especially with 2 edge signals...

Tim,

Yes I'm using the tilt feature on the 91XG.

What is your proposed height with a new mast etc? That extra height might be worth it. As the 91XG and the VHF under it are really small antennas overall, I would be pushing the height for testing.

Flint Ridge,

I planning a 10 or 15 foot mast on the non penetrating roof mount. That will put the
antennas 25 AGL. I am going
to start low and see how that goes. This will be my first roof antenna :)
I'm not going to get above the redwood tree which is just left of my sight line to Sutro Tower.

My desired stations are still 2edge signals at 50 feet.
tvfool 50 ft prediction:
http://www.tvfool.com/?option=com_wr...f1f02b36a29948

I will miss the home owners community cable system. That system's head end
was on the ridge with LOS to all of the desired stations.

If you could mange that 50' height it would be a 1.2 db gain in theory. As db's double in strength every 3 db's, than that would (in theory) be 33% stronger signal. Pesky db's are funny little things we chase after, but that could be worth the additional effort/height.

Most of my channels are 2Edge and weaker than your Fox station, so maybe you can get the reliability up, not perfect, but better. Stacking properly 91XG's might get you 2+ db's as well. That is a really nice antenna.

My short term objective is improved signal quality. Signal gain will be a secondary goal.
I'm still experimenting with the HDTC-2US.

That would be my goal as well. Signal Quality is the single most important parameter reported by the HDHR metering. As you've observed, stable signal quality greater than '60' is a great predictor of reliable reception.

Multipath or active interference are at the the top of my list of theories... To prove or disprove a theory,I'd be experimenting with antenna location, height & aim. Also, don't rule out searching for equipment or devises in or near your home that may be producing interference.

GroundUrMast ,

Glad to know I'm going in the right direction.

It appears my sight line to Sutro Tower goes right through a Extenet Micro Cell tower along a public road. I have email to Extenet about my TV reception concerns.
The HDTC-2US reports unlabeled "auto" Signal Strength
of 70% on RF 58 , RF59, RF 60 and RF 61.

When I point the 91XG 15 degrees off line of Sutro
RF 44 Signal Quality improves.
But RF 29, RF 43 and RF 45 Signal Quality goes down :(

(left of redwood tree to ridge)
91XG + RCA TVPRAMP1R + 100ft RG6 + HRTC-2US

29 100 69-71
43 100 85
44 100 90
45 100 81

RF 44 channel specific interference? Even when coming from same tower it can happen :confused:

My best roof location can point left or right of the big redwood tree.
When I get a better mast I will try adjusting the antenna height. Will 6 inch increments
be a good starting place ? Maybe I will go back to pointing right of the redwood tree with height adjustment. I read the articles on stacking identical antennas to manage multipath
interference. That will be a last resort.

Once the above resolved, I need to deal with NBC RF 12 which is Signal Strength 87 and Signal Quality 60.
The Y10713 is really compact compared to my old 10 foot Radio Shack antenna.

Yes, interference can be, and often is, specific to a single channel. Spurious RF may be relatively stable in frequency and narrow in bandwidth, in which case it will only affect a TV channel if the interfering signal lands in the frequency range of that TV signal. Interference sources can be cell phones, or the towers that serve them, FM transmitters, computers or appliances in your home, energy saving light bulbs, etc. Tracking them down, especially if they are outside your home, can be difficult.

If you are seeing 'signal strength' reported by your HDHR tuner as "100", you may be approaching a signal level that could cause tuner overload. As long as the signal quality has not dropped or become unstable compared to the reported signal quality with no amplification, you don't have to be concerned. But there's certainly no need for anymore amplification when the HDHR signal strength is '90' or higher.

The UHF reception good enough for time being. I like the Antennas Direct 91XG.

Now I have VHF reception issues :confused:

I'm using an AntennaCraft Y10713 on a separate saw horse to receive KNTV (NBC) RF 12. During a sunset bad reception event Symbol Quailty drops to zero. Signal Quality 46.
Signal Strength 78.

`pwd`/hdhomerun_config 10519452 get /tuner1/debug

tun: ch=auto:12 lock=8vsb:207000000 ss=78 snq=46 seq=0 dbg=-5700/-8984
dev: bps=19885888 resync=0 overflow=0
ts: bps=19885888 te=1976751 miss=87041 crc=0
net: pps=0 err=0 stop=0


During the above event RF 7 comes in fine. I'm guessing RF 12 interference.

Here is RF 12 good daytime readings from SiliconDust HDTC-2US. The Y10713 aimed
towards San Bruno. During good reception Y10713 has good directivity. Best signal
strength pointing towards San Bruno Mountain (transmitter location).

Virtual Channel none
Frequency 207.000 MHz
Program Number 3
Modulation Lock 8vsb
Signal Strength 80%
Signal Quality 54%
Symbol Quality 100%


During the RF 12 bad reception event changing aim of Y10713 did not improve Signal/Symbol Quailty.

I will need a longer cable to try different roof locations for the Y10713.

I have a second Y10713 on order from Solid Signal :D
That way I have option to experiment with stacking to address possible multipath interference. I don't need additional gain.

Sounds like a plan. With added cable length you can experiment with combinations of height and location.


"Sunset ... event" reminds me of my telcom career. Our crew maintained a point to point microwave link that had problems during the time of the year when the setting sun would pass through the beam of the west facing antenna. There was simply no way to block the RF from the sun and we couldn't find a way to move the mountain that the antenna was located on. :(

An update

The homeowner association turning off the community basic cable service June 30th :<.


Currently using 2 Y10713 in vertical stacked phased array pointing to mount san bruno. Using 29 inch
spacing between the antennas.

On my SiliconDust HDTC-2US Signal Strength increased 2%. Signal Quality increased 6%?
During high wind event RF12 Signal Quality fluctuations went down.
With a single Y10713 on windy day Signal Quality fluctuation spread was 6% or greater.
The vertical stacked 2 Y10713 configuration tightened (reduced) Signal Quality fluctuation to 2%.
On rare occasions Symbol Quality is still lost with the stacked Y10713 configuration.
Still much improved over a single Y10713.

During the same high wind event RF44 Signal Quality fluctuation spread 8% or greater.
The Symbol Quality held up. So the picture looks ok. The 91XG also experiencing multipath interference.

Right now I'm the only house with an OTA array.

Thanks for the update...it is always nice to hear how things are working out.

An update

I'm the only residence with multiple big antennas.
I had to educate the home owners association about my right to deploy an antenna array. ;)

UHF channels still viewable.
Using latest SiliconDust firmware. The firmware update changed signal quality scale.

11.1 (RF 12) is still the challenging channel. Frequent reception failures compared
to 12 months ago. Stacked VHF antenna balun lead wires are breaking down.
Unplugging one VHF antenna drops signal quality by 10%.
I think stacking the VHF antennas is still a win.

RF 12 drops off reception cliff when signal quality drops below 50%

Conditions have changed for the worst of the last year.


Tuner Channel SS SNQ
0 7 ss=96 snq=90
1 7 ss=96 snq=90
0 12 ss=75 snq=58
1 12 ss=76 snq=59
0 49 ss=78 snq=80
1 49 ss=78 snq=81

My plan is to replace the VHF baluns.
I read in another posting that quality external baluns are hard to source :(

Trim some near branches.

If that does not improve situation, I may look for a new location for the VHF
antenna stack. Keep the UHF antenna at current location on roof.

I'm lucky to receive alternate KNTVHD 11.3 (RF 49).

Welcome back, ckwsp101_tv

I can't comment on your signals because I don't know your location and your tvfool signal report is no longer on the server.

I do, however, have a few comments on the balun replacement.

My favorite outdoor balun was the original Channel Master 94444 balun, which is now hard to find. I tried to order some on eBay, but the sellers kept sending me the new 94444 with the ring terminals, even though their photo showed the original balun.

It's really confusing when Channel Master changes the design but doesn't change the model number. They have done the same thing with the CM7777 preamp, which is now in its 3rd generation.

I finally found a few original baluns and was able to make a comparison between the old and the new 94444. This thread shows my test results:
http://forum.tvfool.com/showthread.php?t=16297

The other point, which you might already know, is that the two baluns must be in phase. If they are out of phase, the main lobe will split in two with a null between at the aim point. You have to reverse the leads on just one of the baluns to see which is the way that will produce one lobe and an increase in gain.

That's what happens with horizontal stacking; I've never tried it with vertical stacking.

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

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

Browser cut and paste issue :mad:

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

That seems to be true:

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

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?

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.

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.

Here is current antenna location on tripod.

https://forum.tvfool.com/attachment....9&d=1507238477

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

Thanks for the oblique satellite photo; it helps.

Here is the KNTV terrain profile:

http://forum.tvfool.com/attachment.p...1&d=1507254314

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

http://forum.tvfool.com/attachment.p...1&d=1507255080

or here:

http://forum.tvfool.com/attachment.p...1&d=1507255080

http://forum.tvfool.com/attachment.p...1&d=1507255080

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?

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.

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

Thanks for the details.
Looks like the signal path is between two trees.
Tree growth?
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.

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

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

Thank you for the new reports.
Considerable improvement with horizontal array, but you are still behind a hill.

https://forum.tvfool.com/attachment....5&d=1571790151

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

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.

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.

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
 

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

http://forum.tvfool.com/attachment.p...1&d=1589562436