137 MHZ NOAA satellite antenna ideas?

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marksroberson

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I want to get into "APT" viewing on the 136-137 MHz range due to my intrist in the HF weather satellite frequencies, however, many pictures I decode on HF are charts, or other non-satellite picture, but I did recieve a satellite picture at 8:00 PM 1/26/2015 on a frequency I have stored somewhere... But anyway, does anyone have any good antenna ideas for 136-137 MHz satellite reception?
For HF WeFAX right now I am using a Antennacraft ST-2 antenna and a Grundig Satellit 800 hooked up to my computer using multiPSK
 

Voyager

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My first thought would be something like this:
Antennacraft FMSS Turnstile Omni Directional FM Antenna Dipole 2 Element Outdoor | eBay

I don't know if you could shorten the elements from the FM band to aircraft/136, but even FM isn't too far out of band. The advantage with this style is that you won't have the null above you as you would with a vertical antenna. It is also good if the satellite antenna turns (and it likely does). You will notice any antennas used for transmitting to satellites have cross-polarization for this same reason.

A Scantenna might be a good second choice due to the angled elements.

A cross-polarized Yagi with a horizontal and vertical rotor including tracking would be better than either of these, but much more expensive.
 

rbm

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I normally use one of my ST-2 antennas for APT reception. With WXtoImg

That same antenna feeds a lot of other radios as well.

There's a low noise preamp mounted right at the base of the antenna.
(LNA-1000 from RF Bay Inc. You can see the specs on ebay)

Rich

If you click through to see the full size image here, you can see the list of frequencies.
I do have a few hills that shade the signal in one direction.




The resulting APT image:




I want to get into "APT" viewing on the 136-137 MHz range due to my intrist in the HF weather satellite frequencies, however, many pictures I decode on HF are charts, or other non-satellite picture, but I did recieve a satellite picture at 8:00 PM 1/26/2015 on a frequency I have stored somewhere... But anyway, does anyone have any good antenna ideas for 136-137 MHz satellite reception?
For HF WeFAX right now I am using a Antennacraft ST-2 antenna and a Grundig Satellit 800 hooked up to my computer using multiPSK
 

Voyager

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Forgot about the eggbeater antennas. Those would work well, too. They have them at the website listed in post 3.
 

ab5r

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I am using a helical type antenna and prefer it to the turnstile type that I previously used. Ideally, a Yagi tuned to 137 MHz range on rotator and elevation to TRACK is best, BUT that is costly. Good luck.
Jerry
 

cmeyer18

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My setup, using a homemade QFH and a LNA-100 (NOT the LNA 1000, this is a ~$30 tv signal booster that works great). Antenna setup
I did some digging into the LNA-100 and found that it does well enough for a general purpose LNA from 80-900 Mhz with very little noise. I don't see any increase in the noise floor until I turn up the gain on the rtl dongle, which I usually don't need to do. LNA-100 testing
Some of my decoded images: Decoded NOAA ATP

Antenna made using this guide: A QFH antenna for the weather satellite band
 

pinkfish457

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I'm thinking about building this QFH antenna, I have some questions. The designer states it's to be used indoors (in attic) are you using it outdoors? I can't seem to figure out the coax connections. His schematic is not very clear. How did you make the coax connections? Any pictures?

Thanks
 

cmeyer18

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I'm thinking about building this QFH antenna, I have some questions. The designer states it's to be used indoors (in attic) are you using it outdoors? I can't seem to figure out the coax connections. His schematic is not very clear. How did you make the coax connections? Any pictures?

Thanks
I used it outdoors for a while with no issues, as long as you seal up the connections it should be fine. Some hot glue and generous amounts of electrical tape seem to keep out the elements well enough. You can also put a trash bag over the top and completely seal it if you don't mind having that in your yard.

As for the connections I used this guide, and the rest of the construction and dimensions from the guide I posted previously.
 

prcguy

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The circular polarity has nothing to do with a spinning satellite and its because the satellite has a left hand circular polarity transmit antenna so you need a right hand circular pol antenna to receive it properly. All but the crudest satellites with spinning bodies (Hughes/Boeing) are spin stabilized where the RF package and antennas are fixed toward earth.
prcguy

Your best bet would be a turnstyle antenna tuned for the Noaa sat band just make sure that it is RHCP tuned that's because the weather sats are spinning right handed just google turnstyle ........
 
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prcguy

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My comment was for all satellites, geostationary, LEO, etc. Some satellites use circular polarity to make it easier on the receiving station so they don't have to worry about rotating polarity when installing an antenna or when tracking, just point AZ and EL and your done. Or in the case of polar or LEO sats, circular pol basically eliminates any polarity fading.

LEO or polar orbit weather sats have earth sensors to keep the cameras and antennas pointed toward earth and I'm not aware of any weather sats that have any spinning motion on the antennas. Usually antenna motion on a spacecraft is limited to small and cheap satellites with no station keeping like amateur, cube sats, Sputnik, etc.

Before I digress too far, my original point is if the satellite antenna was spinning it would not create circular polarity but that would be a good candidate for using a circular pol antenna to minimize any rotation effects.

As a side note, generally all satellites that have on board station keeping have a low gain omni directional antenna that's used for getting the spacecraft into orbit before the main antennas are deployed and especially if the spacecraft is tumbling and its also used in emergencies when the satellite screws up and the main antennas point away from earth.

Its interesting (to me) that the omni antenna used when the spacecraft is potentially tumbling is usually a linear pol Bicone, basically a fat dipole and that would be subject to rotational fading, but that seems to be the industry standard.
prcguy (and retired satelliteguy)


I'm not talking about the Geo sats but the Polar sats.......
 
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