ATIS Transmitter - Power Ouput

[ridgescan]

10 watts.

Thanks man!

 

[kma371]

ok (what's "SUU")

AirNav: KSUU - Travis Air Force Base

 

[kma371]

Whats the farthest an ATIS has ever been heard from its source?How far have you heard one?

Currently copying these on my discone.

46 miles
52 miles
47 miles

 

[ridgescan]

Thanks kma371
Far as k2rty's question that 49 mile trip from the Travis ATIS would be my furthest catch.

 

[ATCTech]

530/840/1700 kHz ATIS broadcasts, in the AM commercial broadcast band? Really? You're not confusing the ATIS with an airport information radio station are you?

I don't even see an ATIS listed for San Rafael CA for example. There are a couple of AWOS VHF air band frequencies listed, but no ATIS.

 

[ridgescan]

530/840/1700 kHz ATIS broadcasts, in the AM commercial broadcast band? Really? You're not confusing the ATIS with an airport information radio station are you?

I don't even see an ATIS listed for San Rafael CA for example. There are a couple of AWOS VHF air band frequencies listed, but no ATIS.

Yeah I was using the ATIS loosely in describing those. 530 and 840 are automated city info stations and 1700 is airport info for Oakland. Hope I didn't bump this off topic. Just wanted to show how far 10 watts on am can go.

 

[ATCTech]

Ahh, I see, ok. Of course comparing 10W reception ranges at LF and MW bands to VHF is total apples and oranges too.

 

[ridgescan]

Ahh, I see, ok. Of course comparing 10W reception ranges at LF and MW bands to VHF is total apples and oranges too.

Apples and oranges? Please explain.

 

[ATCTech]

Sorry, just commenting on the likelihood of a 10W signal propagating considerably further at 530kHz versus 133MHz on any given day, just like AM broadcast band reception at hundreds of miles versus FM broadcasts being essentially line of sight unless conditions are just right.

Anyway, back to ATIS-es....

 

[ridgescan]

Sorry, just commenting on the likelihood of a 10W signal propagating considerably further at 530kHz versus 133MHz on any given day, just like AM broadcast band reception at hundreds of miles versus FM broadcasts being essentially line of sight unless conditions are just right.

Anyway, back to ATIS-es....

That's all true if I were talking about hundreds of miles but these MW auto-information stations are only at 17 miles, 15 miles, and 8 miles and I get them in the daytime. San Mateo's runs 24-7 though so I get them all night too.
Like Majoco commented earlier, these guys just run off a vertical stick so no huge antenna-I guess they're kinda like CBs on a lower band
Travis, which is the one that pertains to the OP's thread here being a true ATIS, I can only get when nightfall hits and early in the morning, although right as I type this, I have that frequency on and it's fading in and out very weakly.
To me, getting this at 49 miles now (1:33pm pst) even as weak as it is, aint bad for an omni discone.
BTW I looked up 840 and it's actually Belvedere, Ca-near San Rafael-had a senior moment there.

 

[majoco]

Ridgy said:

Like Majoco commented earlier, these guys just run off a vertical stick so no huge antenna-I guess they're kinda like CBs on a lower band

...but I was only talking about VHF air band ATIS! There aren't many terminal NDB's left in NZ now, and only a few of them had the ATIS audio on them.

....or did you mean the UHF CB (?) band?

 

[ridgescan]

Ridgy said:


...but I was only talking about VHF air band ATIS! There aren't many terminal NDB's left in NZ now, and only a few of them had the ATIS audio on them.

....or did you mean the UHF CB (?) band?

Oh sorry bout that Marty-I meant the MW recorded info stations at 10 watts-I'm pretty sure they use a vertical antenna for these too-someone please correct me if wrong.

 

[navaidstech]

Oh sorry bout that Marty-I meant the MW recorded info stations at 10 watts-I'm pretty sure they use a vertical antenna for these too-someone please correct me if wrong.

Yes....vertical antenna for two reasons: 1. omni coverage and 2. you cannot use horizontally polarized antennas at LF or MW due to ground attenuation.

 

[ridgescan]

Yes....vertical antenna for two reasons: 1. omni coverage and 2. you cannot use horizontally polarized antennas at LF or MW due to ground attenuation.

Good info thanks

 

[poltergeisty]

25 miles is terrible coverage. Jet and turboprops usually want to have this information before they enter the terminal area. 80 to 120 miles out has been my experience. At altitude, 5 to 10 watts will do it. Aircraft radios are generally 5 to 25 watts.

I wish ATIS had that kind of coverage in Flight Simulator! :lol:

 

[navaidstech]

What is the power output of an ATIS transmitter? Is it fixed or dependent on location?

Thanks

Just looked up in our maintenance document. It states that the power output of an ATIS transmitter shall not be more than 50% of its rated full power output. Since our transmitters are capable of 50W power out, then you're looking at 25 watts.
The nominal power of our transmitters here in Toronto is 20W and I would imagine Dorval would be the same as would the rest of the country (with the exception of high power PALs and areas of poor RF coverage).
Our ATIS transmitters are putting out 5 watts hence I have a feeling YUL would be the same or even bumped to no more than 10 watts.

 

[Rt169Radio]

I was wondering about something, do the ATIS antennas transmit upwards or 360 all around?

 

[ATCTech]

In Canada they're the same VHF omni-directional antennas used by all the ATC & FSS transmitters, nothing special about them at all.

 

[poltergeisty]

At the airport over here KFNL the ATIS comes in better in FM. I don't know why. I have to hold my Pro-26 horizontally towards the airport to pick it up.

 

[ind224]

I'll help confuse the issue. What about military ATIS power / antennas in the 200-400 range?
This morning I'm getting Grissom on 270.8 in Indianapolis. Never heard it here before.