International Space Station FM Repeater Now On The Air!

Ham radio operators have viewed the International Space Station as the holy grail of QSL cards - and I’m one of them. We’ve had the ability to chat FM simplex with astronauts or use the ISS digipeater on APRS. Now they’ve installed a customized Kenwood D710G and a new high-gain antenna with an FM repeater on the ISS making contacts easier than ever! You can likely use your HT and a rubber duck to hear the repeater with ease. Obviously, a directional antenna makes a huge difference in making contacts with ease.
Have you tried using your radio on then new ISS FM repeater? Tell me how it went in the comments below.
Special thanks to KB0TDW for helping make this video possible!
Check out my blog: www.k0lwc.com
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[@coachcannonstm]

Great video. Me and my 9 year old listened one night last week in the front yard. It was hopping with folks trying to make contacts. Thanks for sharing.

[@leeharrell67]

LOL. When you're standing in front of your car, talking to the camera, it looks like you're on a boat in high seas. Great information! Thanks!

[@K0LWC]

Holding my phone between two fingers is difficult. ☺️

[@tomcatGB]

hahahaha I was wondering why he was moving... great video by the way (apart from the swaying about) :-)

[@Camman010]

One of the best things to tell everyone is "BUY A TRIPOD", also never do "talking head" videos and never shoot video with a phone. A cellphone is hard to balance they don't have the steady-cam functions of even a basic Sony camcorder. I haven't worked the ISS in about 15 years but the antenna I used was a 10 element broomstick and cloths-hanger antenna mounted on a cheep tripod and an Alinco DJ-580 handheld. I still have the QSL card around someplace.

[@TheWatcher469]

I was getting sea sick :)

[@WKMG365]

Had good reception on the pass this morning. I didn't try to make any contacts this time, just getting the radio set-up. Thanks for the info.

[@K0LWC]

Nice! Can’t wait to hear if you’re successful in making a contact! It’s super busy right now - but keep trying and you’ll make it in!

[@ve1xop]

Thank you for the video. I managed to work the repeater using 2 handhelds. And made contact + heard myself via one of the handhelds. Impressive!

[@K0LWC]

That’s awesome! Congrats man! 73

[@Larrymarx]

Thank you for taking the time to make and post this video... Will be listening to 437.800.. Glad I found this video.. 73"s

[@K0LWC]

That’s awesome!

[@WJ6FRadio]

Great video! Will be breaking out the Elk Antenna for this! Nice mobile set up!

[@K0LWC]

Yesssssss! Best of luck! 73

[@kevinwasilauskis8943]

I still have to try this. Nice video. I'm going to program my TM-V71A tonight. Thanks. KC1JWE

[@okhamradio]

Great video! Thanks for this information!

[@digitalanalogueham]

Wow well done this has gone viral.

[@BatColonyEvictor]

What a cool video! We'll be listening

[@applejacks971]

Your buddy is in Omaha, I'm in Norfolk, 100 miles north, wohoo!!! :)

[@K0LWC]

Not too far away!

[@dalerobinsuk]

On that radio you can move the "CTRL" (Without moving the PTT) across to VFO B and adjust the receive frequency while still transmitting on VFO A.

[@peterkunka2694]

Pretty cool, I'm going to start monitoring 437.800 while mobile in the Jeep, and now that Phoenix is cooling off and I'll be outdoors in the evenings more often, I'll check the ISS orbit schedule and see if I can hit their repeater from home. 73. Pete - KI7LIL

[@jwheldon]

great video and nice to see people in the aria of the new hyvee are into the hobby 2, seen the parking lot and was like " yup thats my beer store." i myself am pretty new to the hobby ,started with 2 trunking sdr's then a hackrf1 and my mobile is a uhf/vhf kenwood . pretty sure i have seen ya around town,sic tesla btw, my mobile is in a white wrx with blacked out tail lights and green headlights, hard to miss :)

[@Bernard-John]

Hi,good video, well explained, thanks from Rotterdam

[@camp5150]

It was fun Matt thanks

[@K0LWC]

Thanks for being there and recording!

[@melangiehayden4167]

Thanks for a good video. If you opened the rear hatch would that tilt the antenna to almost to a horizontal position relative to the sky? If so maybe that would have allowed for a better contact. Might be interesting to try. Enjoyed the video.

[@Rob2]

The frequency selection of the ISS repeater is very unfortunate! The 3rd harmonic of the 145.990 uplink (437.970) is so close to the downlink (437.800) that it is difficult for people operating dualband radios to hear their own downlink. That again makes it more difficult to be considerate to others making calls at the same time (because you don't hear them). You see this effect in this video as well: while he is talking, the receive S-meter is wobbling and not indicating the same value as when others are talking. They should have selected a downlink at a much lower frequency in the 435-438 sat band!

[@twentyone3811]

Interesting

[@spesunica6147]

For dowlink (437 800mhz) a CTSS frequency of 67hz is also needed?

[@jesselannigan2300]

What you are experiencing is called desensitization or de-sense. A couple ways to remedy that: Use separate radios with separate antennas with at least 1/2 wavelength of the lower band distance between them. Use directional antennas like a 5 element yagi on 2m and a 7-10 element on 70cm. Use a diplexer (aka band pass filter) on the coax to isolate stray rf. In my home station I use two sets of satellite arrays to work the ISS crossband repeater. A large set of horizontally polarized yagis stacked vertically to hit low angle passes with longer distance. The second set is vertically polarized and set on a horizontal cross boom with 1m separation. On an azimuth rotator and tilted at 45 degree elevation. Coax feeds go to two switches and VHF fed to one mobile radio, the UHF to another. I've made hundreds of contacts on the ISS with this setup. When the repeater is active, I am one of the stations you will most likely hear. (K7AXA)

[@Rob2]

@@jesselannigan2300 I am very aware what the problem is, even though I did not explain that in my message, but the issue mainly occurs because the 3rd harmonic of the tx signal (with all its noise etc) is so close to the receive frequency. With a downlink at 435.800 instead of 437.800 it would likely work without any special filtering and on a shared antenna. That is why I consider the frequency selection unfortunate.

[@uniquewilson5237]

Checking in from Omaha Nebraska ❤️🤍

[@NexxuSix]

A handheld Arrow antenna will help with obtaining a better signal, and yes, you will need to adjust for Doppler shift on-the-fly. 73!

[@K0LWC]

An Arrow is on my wish list! 😊

[@DrDiff952]

Going to try tomorrow and Monday

[@K0LWC]

Totally worth it, no matter the radio. So fun!

[@alvarogaitan2529]

hi Matthew nice and terrific video thanks 73 from kb2uew

[@K0LWC]

Thanks for watching, Alvaro.

[@XPFTP]

hahhah watched this video few weeks ago or so.. then i just spoke with you on 20m with your audio checking.. hahahha KB2WVO....

[@K0LWC]

Ha! KZbin works in mysterious ways.

[@ChrisHirner]

I had forgotton how fun ham could be. KI0JF.

[@alexosow]

I have no idea what you're talking about like 75% of the time but now I wanna buy a ham radio and contact the space station myself lol, do I need a license to do so? I wanna do this as part of my high school's tech club competition and this sounds perfect

[@airgliderz]

Man, gotta try this.

[@K0LWC]

Yesssssss!

[@scotthill6807]

Thank you for the video and information. I've got to try this. 73 de KI5HII

[@SteelWolf13]

When you rock back and forth more then your grandma's rocking chair.

[@ALSmith-zz4yy]

Will try listening on my Uniden BC355N scanner tonight. Unfortunately the frequency steps on the 400 MHz band are 12.5 KHz which will make adjusting for doppler difficult. There will be one pass with an elevation of 85 deg so there should be a reasonably long period of very little shift.

[@K0LWC]

Indeed. That would be a good one to try!

[@larryk1978]

I haven’t had much luck... I been using my old Kenwood Tm-731 dual bander with a J-pole and haven’t done so well... The radio does 50 Watts and I thought that should be plenty with a base setup... I will keep trying , 73 fellas W5LWK

[@K0LWC]

When you have a vertical the better passes tend to be elevations between 25-50 or so degrees.

[@Larrymarx]

Update: Got to hear ISS Repeater this morning at 6:41am here in New Jersey (Trenton area).. Using this tracking site to follow ISS: spotthestation.nasa.gov/tracking_map.cfm ..Thank again K0LWC

[@tylerhottes6760]

Great video!

[@leeramblezton5659]

Cool

[@Aussat]

Great video and good luck, had a play this morning and managed a contact with my vertical.

[@K0LWC]

Awesome! That gives me a hope! 73

[@HarishKottayam]

Always waiting to make this contact.. Hope will be accomplished soon... 73's, VU3FXE

[@dave1m2003]

I'm not a radio guy and only happened upon this by accident, but it caught my attention. Correct me if I'm wrong, but Isn't FM pretty much line-of-sight? If so, wouldn't the ISS need to be in view of both the transmitting station and the receiving station for it to work? That makes for a pretty short time of use doesn't it? What about antennas? Would one need a directional antenna aimed at ISS (which would move across the sky quickly) or not? Or, do I have it all wrong?

[@K0LWC]

Correct, this is line-of-sight communication. Given the height of the ISS, the footprint where it has LOS is massive - and yes, both stations needs to be in the LOS footprint. That footprint can encompass 30%-40% of the U.S. on an average pass. The time depends on how close it passes overhead. On a really good near 90-degree pass overhead you can get 10-13 minutes of usable time. The best antenna for this is a directional antenna where you can point it towards where the ISS is located in the sky, there are augmented reality phone apps to help in this regard. However, you can easily hear it and even access that repeater using a simple vertical (as seen in the video). The one thing you’re missing is Doppler shift. It’s moving at 17,000 mph. Just like a train horn changes pitch as it comes towards and moves away, the frequency you hear the ISS changes as it comes towards you and moves away (as seen on the video).

[@bradlow3786]

Definitely going to try this. K5BDL

[@grigorirasputin5020]

Now, if we could just get a geostationary satellite repeater over the middle of CONUS, preferably on DMR (two voice paths at once) UHF, that would be the stuff!

[@evanbv8793]

Why DMR? FM is better

[@evanbv8793]

They should do both

[@grigorirasputin5020]

@@evanbv8793 I generally prefer FM analog for simplicity and clarity. That said and as I noted, DMR would provide two voice paths which would allow for more use and enjoyment of the system.

[@davidmohr4606]

a turnstile antenna would work well also.

[@locoparentis244]

You don't need directional antenna, you just need this antenna tilted to radiate to the sky. Your antenna radiation pattern (horizontal) was all wrong once the ISS increased elevation beyond some initial point.

[@Grandassets]

the mount he has looks adjustable, all he has to do is swing it down 90 deg and depending on the pattern park facing north may give a little extra edge :)

[@OperatorTony]

K0FAN also in your area, have not tried this new repeater yet tho

[@K0LWC]

Give it a shot! It’s crazy busy, but fun!

[@SuAmigoElilegal]

I have 3 pairs of motorolla cp200 UHF and also 3 VHF cp200. Witch will give me a better a coverage and quality in urban area by using a repeater ?

[@Xpurple]

That's pretty awesome!

[@PhillipRhodes]

Awesome. Just fired up CHIRP and plugged the frequencies into my trusty Baofeng FP-8HP. Unfortunately the ISS is nowhere near me right now. I'll be really curious to see if you can really work this repeater with an HT.

[@K0LWC]

It’s busy with people trying, so be patient and know it could take multiple tries.

[@jonlynch9089]

The amount of time to connect would still be the same,right? Example; when I watch the ISS go over head and I try for contact,I have approximately 5 minutes before it's to far away.

[@K0LWC]

Depends where it’s flying over relative to you. Straight overhead passes give you more time. Generally, you get 2-12 minutes where you can make contact with the ISS repeater.

[@anthonygallo3576]

I did this a few times and I believe you need a dual band radio to do this if I'm making a mistake please let me know what it is this is not the first repeater I have programmed in manually

[@K0LWC]

Yes, it needs to be a dual-band radio.

[@daleneurauter2810]

Or a VHF transmitter and a UHF scanner / receiver.

[@tegrqbruh4158]

Im gonna try to receive some activity with my rtl-sdr dongle some time soon

[@K0LWC]

Let me know how it goes for you!

[@glenecollins]

The little SDR worked well for me, I am in outback Australia so no exotic accents but you can see the blue shift and red shift of the incoming signal.

[@aaronlewis5613]

Should I hear the carrier ACK if I'm able to reach the repeater?

[@danielgiraud2192]

I picked up the ISS on 437.800 this morning

[@K0LWC]

Awesome. I was trying again this morning too!

[@ericpadilla3430]

What radio you are using Sir? Dual band ?

[@dont1265]

Stand still.... I think I'm going to puuuuke.....

[@juanjocp]

You need to compensate for receiving Doppler frequency shift.

[@K0LWC]

Yes, you see me adjust the downlink in the video.

[@grigorirasputin5020]

@@K0LWC I have listened to satellite repeaters before and could get satisfactory reception by setting my receiver to scan the center frequency and up 5 KHz and down 5 KHz. This allowed me to hear the true frequency and doppler shifts. I have a dumb question I have never seen addressed. I have never transmitted to a satellite repeater. When doing so, do I need to match the frequency I am receiving it on, just transmit on the true frequency, or something else? Thanks for an answer.

[@2e1paw]

Anyone else getting sea sick lol . Stand still 😁

[@solarflare1008]

Now I believe in anything.......

[@FirePhotog]

Great Demo video KB1SDQ Rhode Island

[@K0LWC]

Thanks for watching, Fred!

[@spesunica6147]

For dowlink (437 800mhz) a CTSS frequency of 67hz is also needed?

[@K0LWC]

No.

[@Grandassets]

its about 250 miles away so thats not actually to bad, just swing your Ant. down it looks adjustable? up like that your talking off the Null Point

[@K0LWC]

People indeed say to swing the antenna more at an angle would likely improve the signal.

[@N8TheSnake]

Does anyone have a CHIRP sequence to account for the doppler effect as the ISS passes over? I think I heard somewhere that this is possible.

[@w2gdj1]

I use 2.5 KHZ steps in the uplink and downlink frequencies. This keeps you in the passband pretty well. I program 3 different sets. One as the ISS is approaching, one when the ISS is at its closest approach to you and one as the ISS is going away from you. I did this when I worked 2 way voice contacts with the cosmonauts on MIR and astronauts on our Space Shuttle. GL.

[@DrDiff952]

So was this delivered by the SpaceX capsule

[@K0LWC]

Yes! They are delivering HF equipment on another SpaceX flight later this year.

[@Olderbird]

It was off loaded in March. Took them awhile to set everything up. I’m sure it’s quite a process to get everything installed and safe from potential disasters.

[@kennethn5vho602]

@@K0LWC Really? What sort of HF gear and what bands?

[@Leo_Davis_]

I cant find any information, is this narrow band? Im assuming it is. I have picked recieved the downlink, but i cant get the uplink to connect. I have the PL tone set.

[@K0LWC]

It’s 25 kHz.

[@ericpadilla3430]

Is that vhf and uhf type radio?

[@ericpadilla3430]

What's that 25 khz ?

[@jfrphoto01]

@@ericpadilla3430 ... 25 kHz = wide bandwith and 12.5 kHz = narrow bandwidth.

[@flexicanhomie]

The N95 mask on your car passenger side floor is all anyone in the future needs to guesstimate what year this video was made

[@Casonplayz]

2020-2022 time frame? This comment was made on mon Jan 30 2023

[@kevingoshe4371]

The only ISS trackers i can find only show nighttime passes for viewing purposes. How did you find the info for daytime passes?

[@K0LWC]

ISS Detector app for iPhone/Android

[@kevingoshe4371]

@@K0LWC thank you. Catch you on the bands. 73.

[@ALSmith-zz4yy]

On heavens-above.com you can select visible only or all passes.

[@kevingoshe4371]

@@ALSmith-zz4yy thank you for the tip! 73.

[@sukiiish]

Hi, how you folow iss position. Do you have some app ? Regards

[@K0LWC]

ISS Detector is a fantastic iOS/Android app.

[@sukiiish]

K0LWC Thank you.

[@drdoom8633]

Sky Guide works great too.

[@sukiiish]

DRDoom Thank you, i will try it :)

[@kb5fhk]

Heavens Above is a great app for Android users.

[@digitalanalogueham]

Brilliant and a very good 1st try.

[@K0LWC]

I’ll get it! I think a lower angle pass would do better given the vertical.

[@digitalanalogueham]

@@K0LWC yes good luck. I have got a rubbish Aerial. And I heard when it was going France. It seems quite powerful.

[@digitalanalogueham]

@@K0LWC just got my first contact with the space station repeater. Managed to record a tiny tiny snippet yipee

[@K0LWC]

Digital Analogue Ham On a vertical? What power?

[@digitalanalogueham]

@@K0LWC on a ground plane quarter-wave vertical. Homemade. In the loft.50w. 29 degrees. And about 150m away over land.

[@taztaz728]

Have you tried the quantum field time phase generator?

[@wingmannj]

dafug?

[@anthonygallo3576]

I tried it on my yesu ft 7900. With the repeater shift enabled and the pl tone set when I keyed up on the transmit frequency it did automatically not shift to the receive frequency.

[@K0LWC]

It’s not programmed like a normal repeater. It’s two independent frequencies in VFO mode, one on each band.

[@remingtonkevin65]

Are these frequencies still the ones I put in my yaesu 3D? Or has it changed?

[@K0LWC]

Still the same.

[@remingtonkevin65]

@@K0LWC great! Now, what frequencies do I put in to talk to the astronauts?

[@Davidjb37721]

can you do more videos thanks

[@K0LWC]

Working on it!

[@juanchemencedji1911]

hoy intente contactarla...pero no pudo ser ... sera la proxima...cx3et

[@jaymeleon2245]

I think the Doppler effect has affected his brain

[@handlebullshit]

I would not even key up when i can't even hear the downlink. No chance for a proper contact that way.

[@SteveWrightNZ]

Remember to chase the uplink doppler as well, and shut the squelch ffs.

[@K0LWC]

Squelch open!!!!

[@SteveWrightNZ]

@@K0LWC Everyone does that, but why. It's noisy and doesnt do anything useful.

[@SteveWrightNZ]

@@Idahoser11 The FM squelch will open a long time before a signal is readable.

[@morlanius]

I expected him to say "hullo youtubes"

[@K0LWC]

HeLlO YoUTUbeSsSsSsSSSSSSSSS.

[@nathanpetrovski7525]

Didn't they have one before? How would I set this up on a Baofeng UV5R?

[@K0LWC]

They had a radio where you could talk to astronauts on simplex, but not a repeater. The video covers the frequencies you would need in your radio.

[@nathanpetrovski7525]

@@K0LWC I meant how would I set it up on that radio?

[@kennethn5vho602]

Yes, there used to be one on the D700 using 437.800 uplink and 145.800 downlink. It was active around 2008.

[@MirlitronOne]

@@nathanpetrovski7525 Google is your friend. Start with AMSAT.

[@Vicpet959]

The space station travels at 17,500 miles an hour

[@ku4uv]

The ISS isn't moving at quite 21,000 MPH. More like 17,500.

[@K0LWC]

Good catch, that was my flub!

[@ku4uv]

No worries, nice video!

[@user-mt2qn4yp8w]

Nice video. So you didn't say how you knew when the station was going to be overhead and what time. You must be using some sort of software and if so what is it. Thank you for the video. 73 Clark KG7LOI

[@K0LWC]

Yes! ISS detector app for iOS and Android is the best for knowing when it will be overhead.

[@duanewhite3184]

Put an antenna up in top of a big fir tree that's what I did I get out on my radio just fine

[@tx2sturgis]

I guess you dont know this is not new....I used to work the crossband repeater on ISS around 15-20 years ago. Made dozens of contacts.

[@K0LWC]

It’s new for people who weren’t around back in the day, and a new radio to do it on.

[@alvaropineiro5171]

Lu3fca creo haber escuchado a Patricia desde Argentina 😃 59

[@bobbal455]

Do you have detail on you mobile install?

[@bobbal455]

@TFo Where did you pull power and where did you run antenna. Any issues with interference?

[@longrider42]

What is the "Tone Mode" and is there a PL tone for the downlink?

[@K0LWC]

No tone for the downlink, just 67hz PL on the uplink.

[@groutdoctor]

Argentina

[@Ei2iP]

5w and HT antenna in Europe, not a hope.... Yagi and 50w minimum...

[@Josh-of-all-Trades]

hitting a repeater in space... with an omnidirectional antenna... I see you like to do it the hard way.

[@K0LWC]

💪🏻

[@JoseRivera-lk4cz]

Thanx. Don’t like the static

[@user-tj3ms5jl9h]

The ISS isn't stationary ether, that is another thing you have to look at. It's not like any stationary satellite where you can just shoot and point. the ISS is constantly moving.

[@Thunderbyrd.]

17,000 mph

[@tylerhottes6760]

If the ISS had a digital repeater for all modes, that would be cool...

[@K0LWC]

I’d love a digital repeater!

[@tylerhottes6760]

K0LWC, I like to see an all mode repeater, also. there is also some single side band digital mode, called freedv, that would be nice if they put that in for their repeater

[@MrTurnermason]

Tyler Hottes it would be pretty hard/expensive to design an all mode digital repeater, however freedv/codec2 will work on anything analog. You can use it on your local 2m repeater or even on the ISS cross repeater. That would be a great video for K0LWC to make!

[@tylerhottes6760]

mason turner exactly! Good idea

[@luish19779]

21,000 Ml 😏 G-Force 🤔

[@LadyNicola]

They'll just say that NASA can CGI frequency signals now. 🤣🤣🎥🎥🌎🌎🌎🌎😂😂

[@ve3bwp56]

Twin Cities? Which twin cities? Where where located?

[@K0LWC]

The Twin Cities metro.

[@brianpietrzyk8945]

Minneapolis-Saint Paul according to Google.

[@K0LWC]

Correct.

[@brianpietrzyk8945]

I live in the GTA so i would have never known that.

[@USAFJUNKIE]

I've literally never heard of anyone referring to any other cities when using the term "the Twin Cities."

[@tremendousfaws]

The iss is only going 17500 mph, or 28168 kph. :)

[@K0LWC]

Yep, that was my flub!

[@anthonystephenson4180]

Time frame is limited

[@bbeen40]

Only..... Lol

[@petemitchell6788]

Eyes are like slits.

[@ObamaoZedong]

Even for the people who do make contact, how can you understand a single word they're saying? It all sounds like mush.

[@wmcg.1091]

Yo dude your “Doppler shift” aka dancing in your driveway is killing my eyes........STOP!!! Other than that great video!!!!!!

[@K0LWC]

Just pretend you’re on a boat. 😂

[@wmcg.1091]

K0LWC 🤣🤣🤣🤣🤣

[@wmcg.1091]

ISS almost does a direct fly over Monday morning at 0657 MTN time. Going to try with the truck radio!!!

[@K0LWC]

What antenna?

[@wmcg.1091]

K0LWC Well since you asked the brand I cant recall, pretty much the same you have on your car. I have an arrow antenna but my tripod broke and the Yaesu I have doesn’t dual band simultaneously. Haven’t ordered the new Yaesu yet.

[@seanvandiijk2889]

So this video proves iss is real? No aquariums staged scenes? I suppose it only work when passing over the city..m

[@K0LWC]

😂...Yes, it’s real.

[@UpvoteSoup]

FBI, open up!

[@K0LWC]

Sorry, I’m busy!

[@richardgraymusic6853]

The iss does not move at 21,000 mph Its 17,500mph

[@K0LWC]

Yep, that’s my flub.

[@Elfnetdesigns]

The problem with working this stuff is that some people are inconsiderate and will walk all over you or take up as much time as they can making contacts and you never get a call in before the bird is gone out of range. That's ok I have a 100 watt Motorola Astro Spectra and a pretty big VHF Hi band Yagi antenna, pretty sure that will make a dent in the QSO collectors feefees. If not I have bigger more powerful amps.

[@K0LWC]

True, it seems to be chaotic. Then again, all satellites to a degree seem that way.

[@MirlitronOne]

Yes, shouting will always help.

[@pechimex934]

Braker, braker good buddy, come in !!!!!!

[@K0LWC]

Copy that, rubber duck!

[@KJPage]

That Tesla deserves a nice radio like a Yaesu or an Icom. ;) .-.-.

[@K0LWC]

Ha. Kenwood or bust!