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# Sacramento, CA - OTA - Page 334

Quote:
Originally Posted by Calaveras

You are in a favorable location on the west side of the valley having a little elevation over most of the valley.

My elevation is only at 89 ft.

Quote:
Originally Posted by Calaveras

You're also within the service contour of Sacramento. I don't think the FCC Service Contours for full power stations extend much past 60 miles.

The service contour would have to extend past 70 mile to reach my location (how far I am from the broadcast towers). So are you saying I am in the service contours of the stations, but not the FCC Service Contours?

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Quote:
Originally Posted by Theducksfan2010

My elevation is only at 89 ft.
The service contour would have to extend past 70 mile to reach my location (how far I am from the broadcast towers). So are you saying I am in the service contours of the stations, but not the FCC Service Contours?

Okay. I see you are about 10 miles past the service contours of both Fresno and Sacramento but your situation makes up for it. You pretty much overlook the valley. Is the elevation of your antenna 89' or is that the ground elevation?

What determines LOS is the height of the transmitters and the height of your antenna. Here's a simple formula to determine distance to the horizon over flat earth:

Distance = SQR(H x 7912)

H= Antenna Height in Miles

Distance = SQR(0.38 x 7912) = 54.7 miles.

If you antenna is 40' then your distance to the horizon is 7.7 miles. I could be a lot more if you're aimed over downsloping terrain.

54.7 + 7.7 = 62.4 miles is the maximum distance you could be from KOVR to get LOS over flat ground. I think your distance is farther since you're aiming over downsloping terrain which makes your antenna effectively higher.

KSEE is so high that their horizon is nearly 84 miles.

Chuck

@Calaveras So I am 2 edge from the Sacramento stations at 70 miles and LOS to 15KW KBID (1,912ft) at 90 miles, because of the additional height for their tower, same location (Meadow Lakes) as KSEE (1,972ft).

Ground elevation is 89', and my antenna is 40' above the ground.

I'm not sure how TVFool is coming up with 1 or 2 edges for Walnut Grove. KMAX is listed as LOS while KCRA and KQCA are listed as 2 edge. Those stations share the SAME antenna. I suspect that everything from Walnut Grove is pretty close to LOS from your antenna.

Where did 1912' for KBID come from? It is 4572' above sea level.

The horizon for your antenna then is 14 miles if the ground slopes down to near sea level towards Walnut Grove. That makes Walnut Grove very close to the limit for LOS. LOS or close to it is more important for reception than FCC service contours which just specify a field strength based on calculations with certain assumptions.

TVFool is a good guide to what you may be able receive and the service contours are a good guide to what the FCC thinks the station coverage is but neither are the final word as to what can be received in any situation.

Chuck
Quote:
Originally Posted by Calaveras

Where did 1912' for KBID come from? It is 4572' above sea level.

Chuck

31‑1

24

KBID‑LP

88.92

100°

0.15 kW

 Display Channel Physical Channel Video Audio Call Sign Network/Programming Nickname Notes Print 31-1 24.1 480i DD2.0 Sports "My Combat Channel" 31-2 24.2 480i DD2.0 Euronews 31-3 24.3 480i DD2.0 News (Arabic) "Al Mayadeen" 31-4 24.4 480i DD2.0 Independent "Care World TV USA" 31-5 24.5 480i DD2.0 Armenian "AMGA" 31-6 24.6 480i DD2.0 Armenian "Horizon"
Technical Data and Screencaps
FAC-ID: 23276   FCC Query   CDBS List   Correspondence   RabbitEars TV Query  REC Query

TSID: 8575 (0x217F)

 LD-PL: Channel 24  FRESNO, CA (SCM) (Est. Pop. 1,129,354) BDISDTL-20091230ABZ (1350651) - App BLDTL‑20140403ABF (1632866) - App 1912' 15 kW CA (  ) (37.4 mile contour / 4401.3 sq. mi. area) (0.9 kW TPO + 12.22 dB gain = 15 kW ERP) 91' AGL; 4573' ASL (1223835);  Stringent Filter Unknown or 0° Elec Beam Tilt; Kathrein K723147 ARRAY NAD27: N 37° 4' 25" (37.074), W 119° 25' 52" (-119.431) (S) (F) Meadow Lakes (CA) NAD83: N 37° 4' 25" (37.074), W 119° 25' 55" (-119.432)

Bitrate Allocation: Unknown

http://www.rabbitears.info/dxlocation.php?id=327

KMUM (Rf 31) CH 15, Telemundo from Sacramento is now running Ion on both 15.1 (1080i) and 15.2 (480i). PSIP is still showing TLMD. Anyone else notice this? Why would Sac need another ION station, especially a LP with KSPX being a full power affiliate??

Edited by Theducksfan2010 - 4/13/14 at 5:34pm
Quote:
Originally Posted by Theducksfan2010

That's probably Height Above Average Terrain (HAAT). That's applicable for a large part of the country but not so much for California where most of the population lives near sea level and the transmitters are on mountains. It's better to use Above Mean Seal Level (AMSL) in that case. See the FCC Query for AMSL:

http://transition.fcc.gov/fcc-bin/tvq?state=CA&call=KBID&arn=&city=&chan=&cha2=69&serv=&type=0&facid=&asrn=&list=0&dist=&dlat2=&mlat2=&slat2=&dlon2=&mlon2=&slon2=&size=9

If the KBID antenna is at 4572' and you're at 89' then KBID at 1912' HAAT doesn't make much sense.

Chuck
Height Above Average Terrain (HAAT) is one of those FCC ideas from the 50's which made a lot of sense at the time, when computers couldn't really do the kinds of analysis we can do today. Now, I'm not so sure.

To explain, in case you're interested, imagine that instead of a mountain range, it was a mesa. (Easier to picture an example this way.) So what is now the ridge line, and behind it, is perfectly flat, but elevated by 4,000 feet. The valley, we'll assume, is at sea level (0 feet). So for each of the eight cardinal directions, you sample every kilometer from 3.2 to 16.1 km away. On the mesa, this gives you 4,000 feet. In the valley, this is 0 feet. Since half of your points are at 4,000 feet, and half are at 0 feet, when you take the average, you get 2,000 feet. Then, if the transmitting antenna is 100 feet high (on top of the 4,000 foot mesa), you add 100 feet to the total. So, your station is now 2,100 feet above "average terrain."

I chose that example because it shows the flaw in the method. In the direction of the mountains, the tower is only 100 feet high, so its coverage is really small in that direction. By contrast, toward the valley, it has a 4,100 foot advantage, good for probably 100 miles or more of coverage. Over relatively flat terrain, this method works very well. It works significantly less well over rough terrain. If you know your own elevation, taking the difference between the height above sea level value of the station's antenna and your antenna, as Calaveras suggests, is the best way to do that calculation. That height (for the station) is available on RabbitEars, directly to the left of the words "Stringent Filter" in your copy+pasted section. AMSL is "Above Mean Sea Level." (AGL is "Above Ground Level.")

- Trip
Edited by Trip in VA - 4/10/14 at 5:01am
inversions (or leaves/multipath) are back! not much coming in tonight reliably at my place; time to raise the antenna to it's summer height
Bob C

@Trip in VA so AMSL would be good for the Fresno stations, but HAAT would be good for the Sacramento stations, since they are mainly on the valley floor in Walnut Grove?

Quote:
Originally Posted by Theducksfan2010

@Trip in VA
so AMSL would be good for the Fresno stations, but HAAT would be good for the Sacramento stations, since they are mainly on the valley floor in Walnut Grove?

For Walnut Grove HAAT and AMSL are almost identical.

Chuck
Quote:
Originally Posted by bobbyc

inversions (or leaves/multipath) are back! not much coming in tonight reliably at my place; time to raise the antenna to it's summer height
Bob C

Even though I've been gone for a few days I noticed we had some inversion issues. A couple recordings on Friday night are a bit short of an hour on KOVR. This afternoon, the time with the least ducting, Salinas stations were pounding in here. KQET was overriding KOVR. KMUV analog was full quieting. Anything on Sutro that is co-channel with Salinas was wiped out.

Chuck

@Calaveras, what is (or is there any) correlation between ducting on TV and on FM? I have been noticing some crazy ducting on the radio since I hooked it up to a rooftop antenna. Is there any part of the dial where ducting on FM would be indicitive of ducting on TV?

Edited by Theducksfan2010 - 4/13/14 at 10:05pm
Quote:
Originally Posted by Theducksfan2010

@Calaveras
, what is (or is there any) correlation between ducting on TV and on FM? I have been noticing some crazy ducting on the radio since I hooked it up to a rooftop antenna. Is there any part of the dial where ducting on FM would be indicitive of ducting on TV?

Yes, FM has ducting too. You'll find something going on everywhere at the same time.

Chuck
Quote:
Originally Posted by Calaveras

Yes, FM has ducting too. You'll find something going on everywhere at the same time.

Chuck

I know last year there was ducting the was bringing 102.7 The Wolf out of Fresno in perfect stereo 24 hours a day for over 2 weeks straight (normal conditions leave nothing but static on 102.7). @Larry Kenney is this the same type of ducting you are talking about for DXing during the summer?

Does the UHF band get the same type ducting? As strong and long lasting? I am definitely looking forward to seeing what happens....

I never see anything here that lasts 24 hours a day for 2 weeks but conditions can vary widely from location to location. There's no special ducting for one frequency band only. It usually affects all frequencies to some degree but what you receive is highly dependent on the location of the transmitter so it might appear to affect some signals/frequencies more than others.

At my location all signals from Fremont Peak and Mt. Toro seem to go up and down in unison. But signals can vary widely between Sutro Tower and Mt. San Bruno. Good conditions to Sutro rarely occur at the same time as good conditions to San Bruno.

There's a famous summertime duct that forms between Hawaii and the west coast. The duct has entry and exit elevations. On the Hawaii end you need to be far up a mountain. On the west coast end you can be low. Two way contacts have been made by amateurs on 145 MHz, 432 MHz and even 1296 MHz at the same time.

Chuck
Quote:
Originally Posted by Calaveras

It usually affects all frequencies to some degree but what you receive is highly dependent on the location of the transmitter so it might appear to affect some signals/frequencies more than others.

Chuck

I learn so much from you in here on a routine basis. That explains why there are times ducting only comes from the Bakersfield area, other times Bakersfield and Fresno, others Sacramento only, and still others all at the same time including Chico. As well as why I can get ducting here when its raining but sunny and warm in Bakersfield.

Quote:
Originally Posted by Theducksfan2010

I know last year there was ducting the was bringing 102.7 The Wolf out of Fresno in perfect stereo 24 hours a day for over 2 weeks straight (normal conditions leave nothing but static on 102.7). @Larry Kenney
is this the same type of ducting you are talking about for DXing during the summer?

Does the UHF band get the same type ducting? As strong and long lasting? I am definitely looking forward to seeing what happens....
The DXing I was talking about is E-Skip where signals reflect off the E layer of the ionosphere. We very, very seldom see any of that here on the west coast. It all seems to occur east of the Rockies to the Atlantic coast.

Ducting is different and while I've heard of it, I'm not sure how it works. Seems like signals go from a specific area A to another specific area B.

Around here most of the changes in signal strength are due to inversion layers. They can build up big time in the summer months when there are no storms to wipe them out.

Larry
SF
KMUM-CD 15 Telemundo (rf 31) is still broadcasting Ion HD/SD.

How does this bode for Ion 29 KSPX (rf 48)?
Quote:
Originally Posted by Theducksfan2010

KMUM-CD 15 Telemundo (rf 31) is still broadcasting Ion HD/SD.

How does this bode for Ion 29 KSPX (rf 48)?

I have no idea why KMUM is broadcasting ION but I doubt that it means anything from KSPX.

Chuck
Josh,

With your low VHF antenna you'll probably want to look for stations coming in via sporadic E from mid May through early August. That's the "E" season. Look on channels 2 - 6. It was much easier when there were many analog stations but it may be possible to receive some LP stations. Signals vary rapidly and there is often multipath which would make decoding the DTV signals difficult. Skip is very common on channel 2 but rare above channel 6 into the FM band. I've seen it a couple of times on 144 MHz in the ham band but never on channel 7. It's true that the east gets more of it than we do in the west.

Use this real time map of contacts made on the 50 MHz ham band as a guide to when to look on channel 2.

http://www.dxmaps.com/spots/map.php?Lan=E&Frec=50&ML=M&Map=NA&DXC=N&HF=N

Right now is is likely to be blank but that will change dramatically in about 6 weeks. Look for lots of red lines extending to northern California.

You should look for analog stations also. I received XEPM Ciudad Juarez several times a few years ago when I had a low VHF antenna up. There was a channel 5 much weaker from the same place. XEPM has a UHF DTV transmitter now so I don't know if they're on analog 2.

Chuck

Does anyone know anything about this station, KEFM-LP (analog 6)? The id on the screen says Sacramento, but everything I can find online lists KEFM-LP analog 6 as a Chico repeater of KNNN-LP.
It transmits from Sutter Butte near Yuba City. It's one of many "Franken-FMs" which are analog LPTV operations on channel 6 which pretend to be radio stations due to the channel 6 audio being at 87.7 FM.

- Trip
Quote:
Originally Posted by Trip in VA

It transmits from Sutter Butte near Yuba City. It's one of many "Franken-FMs" which are analog LPTV operations on channel 6 which pretend to be radio stations due to the channel 6 audio being at 87.7 FM.

- Trip

It's not in your database, don't track the Franken-FM's? Apparently it used to actually be a tv station a long time ago. All of these type of stations will disappear when analog goes away next year? Or will they actually flush cut to digital (apparently they have the permit).
Edited by Theducksfan2010 - 4/15/14 at 12:29pm
I do not track analog stations, only digital stations, so it's not on RabbitEars. It's still licensed as a TV station, but is just operating like a radio station.

Yes, they will disappear when the LPTV transition to digital comes. Some will probably go off the air; the rest will convert to digital and thus become unavailable on FM.

- Trip
Quote:
Originally Posted by Calaveras

Josh,

You should look for analog stations also. I received XEPM Ciudad Juarez several times a few years ago when I had a low VHF antenna up. There was a channel 5 much weaker from the same place. XEPM has a UHF DTV transmitter now so I don't know if they're on analog 2.

Chuck

Both analog channel 2 and 5 are still on in Juarez.
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