Question: TV fool: your weakest RELIABLE signal?

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#1
A question for everyone using an antenna, on the fringe. On your TV fool chart, what's your lowest RELIABLE signal?

Please give the REAL channel, and-
1: NM (dB)
2: Power (dBm)
3: Path (LOS, 1Edge, 2Edge)
4: Your antenna and height.

Maybe this can help us all figure out what's possible, and when there's no use even trying!
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#2
Mr. Pogi,

I realize I'm not quite following the rules in your post, but these links should explain my situation best. Please click the REC Networks links below and then click VIEW MAP.

K26IC-D (real 26) is a translator for my CBS affiliate KIRO-7 (real 39) in Seattle. It is 16+ miles away, LOS. Currently, its ERP is 900 watts but early last summer it had 40 watts ERP. Now, it is rock-solid on any antenna I aim toward it and I am currently using a Channel Master 4221 under the peak of my roof in my backyard. At 40 watts ERP, I used a Channel Master 4228 (old style) to capture it.

REC Broadcast Query | REC Networks
------------------------------------------------------------------------
KIRO-7 has another translator that is within range, K47LG-D (real 47) and it qualifies as my weakest dependable station (although I don't need to use it because I use K26IC-D).

It is 14+ miles distant, 1-edge, 1.1 kW ERP and to receive it I use my home-brew 11-bar 'cut-to-48' Yagi, 22 feet (minimum) above my roof. The TVFOOL map below is extremely optimistic regarding its signal to the NNE.

REC Broadcast Query | REC Networks

K47LG-D POINT PULLEY, ETC., WA <--(thanks, Trip!)

Jim
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#4
Pogi,

Here you go! By the way, thanks for sending me back to TVFOOL: it has been significantly updated regarding Canadian channels since the last time I plugged my own address into it.

Jim
----------------------------
TV Fool <---at 10 feet for channels 13, 14-(20) and 26.

TV Fool <--- at 30 feet, for the others.

*Note: The report is absolutely wrong regarding real channels 38, 39, 48, 31 which are 1-edge, 3/4 miles from me (same 'farm'). None of the numbers aside from the channel numbers have any significance here.

Now that 39 has raised its antenna to the top of its tower I can receive it.

I receive 48 via a reflection off of a downtown skyscraper with my Yagi pointed SE!

Ch. 38 also raised its antenna but I don't have a useable signal ... yet.

Channel 35 is my most distant station, just over 75 miles away.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#5
Oh, Canada! you get any of those stations? We used to pull in a few Canadian stations when I lived in upstate NY - a good 60 to 70 miles across lake Ontario. Keep an eye on them, they're going digital soon.
K26IC-D must have been really weak at 40 watts...
 

Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#6
Pogi,

I used to receive analog Channel 10 but now I can barely 'see' their carrier on two UHF antennas: my 'Project-9' antenna is still not in the air (I need to change my 30' telescopic mast to a 40' version, first). I haven't 'looked' for any other Canadian stations as they have yet to change to digital. Ironically, K26IC-D at 40 watts ERP was the second digital station I captured, the first being KVOS-12 (35) after I built my Project-35 antenna for it.

Jim

Edit/PS: I built, bought and tested a bunch of antennas last summer on my test-mast and depending on the particular antenna, I captured 33 local channels or translators (including subchannels) plus 3 analog carriers from distant stations or translators awaiting their change to digital.
 
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n2rj

Moderator
Staff member
#7
As I've said before, TVFool doesn't reflect much of reality for me.

TV Fool

I'm going to hook up the analyzer and run a scan and post it so you can compare.
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#8
n2jr,
TVFool doesn't reflect much of reality for me.
Exactly why I asked! Sort of a "reality check".
Not to knock TVfool, its the best tool out there, along with rabbitears.info - I just want to see how much "your mileage may vary"

Seriously, though... Only 5 stations LOS on a 70 ft tower, wow!
 
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n2rj

Moderator
Staff member
#9
Here is my scan:



Some notes:

WNYW - multipath issues but it decodes just fine. It does do have an occasional dropout here and there which varies by day of week and time of day. However they are very much watchable.

WWOR is solid, but a bit weak these days. Still solid, no dropouts. I guess the meter is a bit conservative.

WRNN- solid but antenna is 90 degrees away, hence weak signal. They are SD with mostly infomercials anyway.

KYW - reliable at night. Remarkable considering the antenna is not aimed in that direction.

WTNH - comes in occasionally but not enough for a lock. Some PSIP data does come in and hence it does ID. Antenna not in that direction either.

WXTV - borderline but solid. No dropouts at all.

WFME - Antenna not in that direction. I couldn't care less. 100% end of the world, religious cult programming.

Seriously, though... Only 5 stations LOS on a 70 ft tower, wow!
Yep, most stations are 50-90 miles away and it's hilly here.

And I agree about TVFool - VERY helpful site, but it is only a ballpark estimate.
 
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BCF68

DTVUSA Member
#13
As I've said before, TVFool doesn't reflect much of reality for me.

TV Fool

I'm going to hook up the analyzer and run a scan and post it so you can compare.
Yep TVfool is a nice guide but it has it's issues. For my area 1 foot off the ground is supposedly the best height until you get about 175 feet off the ground. There is no way that is correct. I would bet cash money that a 50 foot tower would produce better results than ground level no matter what TVfool says. At my friend's house it says one station is supposedly at about -8 NM dB yet he gets it in INSIDE his house with a 2-Bay at 70% 24/7. For his location the FCC's website is actually closer to the truth.
 

dkreichen1968

Moderator
Staff member
#14
My TVfool is here: TV Fool

Looking at the Northern (Denver) stations using a homemade UHF/VHF antenna of my own design and a RCA DTA800B1 the signal levels are as below:

2.1 (RF34) 27%
4.1 (RF35) 17%
6.1 (RF18) 23%
7.1 (RF7) 50%
9.1 (RF9) 46%
12.1 (RF13) No Signal
14.1 (RF15) 28%
20.1 (RF19) 45%
31.1 (RF32) 45%
53.1 (RF46) 13%

The Southern/Colorado Springs signals are LOS and strong, with my highest being 72% (RF10). If I use my AntennaCraft Y-5-7-13 in the attic and point it the right direction, I can barely get RF 13 (12.1) but get it from the Colorado Springs translator, so it doesn't matter. But, based on TVfool it should be one of my strongest VHF signals from the north. Guess TVfool isn't always right.
 
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Fringe Reception

Super Moderator, Chief Content Editor
Staff member
#15
BCF,

As you have probably read from me in the past, I have determined receiving digital OTA television in some cases is a black art. You can park your antenna at a given height and it gets almost everything you want to receive ... move it up or down 6" to 24" and the missing channels come in perfectly ... but other channels disappear!

I'm currently working with a friend north of Seattle who has this problem: my next try is to vertically stack two 4-bay CM-4221's to try to capture both 'regions' (heights) at the same time. Wish me luck!

Jim
 

re_nelson

DTVUSA Member
#16
A question for everyone using an antenna, on the fringe. On your TV fool chart, what's your lowest RELIABLE signal?
Here's the TV Fool chart:

TV Fool

The weakest facility I get with total reliability is KXII/12 on RF-12.

1). NM 16.6 dB
2). Power -74.3 dBm
3). Path 2Edge
4). The antenna for this station is a Clearstream C5 mounted in an attic, 12' AGL. Remarkably the C5 picks up KXII on the back side since the antenna is aimed toward the SSW (Cedar Hill). The reading I get on it is IF-AGC 86 and SNR 27 on a Sony Bravia. Even during thunderstorms, I don't get a dropout.
 

M4ny

DTVUSA Member
#18
Here's some TEST RESULTS I did last year with some antennas but it shows how accurate or not the TVFool plot is. You can see from the data that I was able to get stations into the -nm on the TVFool chart even with a stock cm4221 and a cm0064 amp. I ran some more tests this spring here are those TEST RESULTS. As others have stated the TVFool chart is a nice guide but is not perfect. I could never receive some stations that the chart showed as being stronger than many I was able to receive on a regular basis.

I set up an antenna for the land owners where I do my testing and they get one particular station WQPX ch32 TVFool -27.9 nm all the time with a simple 4 bay antenna and a cm0064amp and they set about 50ft lower than where I do the testing. Keep in mind this is a very rural area and man made noise is very low, that can make a huge difference with fringe signals.
 

FOX TV

Contributor
#19
Very Nice Data charts M4ny. I have a ton of spectrum screen shots doing the very same thing you have done here. Comparing different antennas on the same signal has been my focus, in regards to aiming, using them indoors, and many other aspects trying to show forum users how important aiming and other aspects of DTV antennas are. I just don't really have a good place to post them. Nice work !!!
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#20
M4ny,

As Monty Burns would say :)

Excellent...

I hearby bestow upon you the Montgomery Burns Award for Outstanding Achievement in the Field of Excellence

You've also given me enough info to help with my 2 bay clone.
 
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