The ISS now has a cross band repeater

Project4

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I am new to the sport of amatuer radio and I need help. Is the CTCSS frequency for the uplink 145.990 frequency + or - 67 hz. Thanks for any guidance.
Offset, (+) or (-) is not a CTCSS parameter. Your channel transmit setting will be 145.990 MHz with the 67 Hz encode tone. Your channel receive setting will be 437.800 MHz. Talk into the space station repeater on a 2 Meter band frequency, listen on a 70 centimeter band frequency. It is a "Cross-Band" repeater aboard the Space Station.

It may be necessary to adjust your transmit frequency slightly above and below 145.990 MHz due to the Doppler shift of the fast moving repeater. The article didn't detail that concept so it might not apply. Hopefully someone else will chime in here to advise.
I have only "worked" a few amateur "birds" over the years but it is always amazing what the community has launched and what hams on Earth can use with very simple radios.
 

n0nhp

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The advantage of a wider FM signal on the crossband is that doppler should not affect the signal much. On SSB linear transponders where most of the other amateur satellites operate doppler will cause the signal to drift in the passband to the point it is unintelligible.
In other words, don't sweat the doppler until you get the bug to try the other amateur sats.
 

Project4

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Thank you. I have my radio programmed and I will attempt this little scientific experiment on the next fly over.
Your profile photo features the Kenwood TM-D710. That should be an ideal transceiver for working an FM cross-band repeater.
My few contacts through FM amateur satellites were all made with the Kenwood TH-D7 portable in duplex mode so I could hear my own signal through headphones. I used a three element homebrew yagi, cut for two meters and hand-aimed in the direction of the satellite.

Some links I have found useful:
The current ISS location: AMSAT - Satellite Tracking
Operating technique: https://www.amsat.org/wordpress/wp-content/uploads/2017/12/FM-Satellites-Best-Practices.pdf

Please update us on your progress with this project and welcome to the "amateur" part of spectrum activity.
 

ka3jjz

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According to the article you can sign up for alerts when the Station is going to be in range...


Mike
 

krokus

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I am new to the sport of amatuer radio and I need help. Is the CTCSS frequency for the uplink 145.990 frequency + or - 67 hz. Thanks for any guidance.
The + or - is for terrestrial (single band) repeaters. It controls if your radio transmits above or below your receive frequency, as the input to the repeater.

The crossband setup means you do not use the + or - on either band. (Unless someone is using an unusual setup, and they specify to do so.)
 

RockyBennett

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The + or - is for terrestrial (single band) repeaters. It controls if your radio transmits above or below your receive frequency, as the input to the repeater.

The crossband setup means you do not use the + or - on either band. (Unless someone is using an unusual setup, and they specify to do so.)

Thank you, I am new to the hobby of amateur radio. I guess that I am a real amateur.
 

ind224

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https://www.n2yo.com/?s=25544 and Heavens Above is what I use. Heavens Above lets you see predictions for all passes or you can filter to just those that would be visible to your zip code. ISS passes are about 90 min apart. Several years back NASA had a program called J-Track J-Track 3D Satellite Tracking | Science Mission Directorate that was a 3D view of Earth and you could click and zoom on a sat to see its position. I loved it but they stopped supporting it. You could zoom out and see all the different orbit paths.
 

N4DJC

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Use Narrow FM, works much better. Doppler on the uplink is not really necessary. The downlink isn’t sounding very good.

It requires a full duplex radio, so far it’s taking 25 watts to capture the repeater. If you don’t hear yourself on the downlink you are probably not getting in.
 

vagrant

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It requires a full duplex radio, so far it’s taking 25 watts to capture the repeater. If you don’t hear yourself on the downlink you are probably not getting in.
Exactly what antenna setup are you using that requires 25 watts to capture the repeater? Are you using an omni on your roof and or were there others pushing to get in at the same time?

Also, it does not require a full duplex radio unless you want to hear yourself to confirm you are reaching the repeater...which is wise, but not necessary.
 

KK2DOG

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I've worked them 4-5 times over the years on simplex with a 706MKIIG and Diamond V-2000 vertical.
The easiest way is to simply put the downlink frequency into a memory channel and wait until you hear them.
 

N4DJC

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Exactly what antenna setup are you using that requires 25 watts to capture the repeater? Are you using an omni on your roof and or were there others pushing to get in at the same time?

Also, it does not require a full duplex radio unless you want to hear yourself to confirm you are reaching the repeater...which is wise, but not necessary.
It was extremely busy in the early going. I use an Elk.

While full duplex isn't a requirement you have no way of monitoring your transmission on the downlink without it, on a very busy ISS repeater it creates a lot of QRM. Keep in mind it's still in the testing phase and will be better and probably more crowded when it's fully operational.

Since it's running 5 watts, it should be much easier to hear when they get everything worked out. The CW identifier was running last week according to some reports.
 

marlin39a

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I was watching a pass coming down the California coast at 0515 this day. When the ISS came by LA, at a distance of 550 miles from me, I started picking up activity on the downlink. Lasted until it went by San Diego. I have a good pass coming over my area in a couple of days. I’ll try hitting it with a HT.
 
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