Survey Results: U.S. 2018 70cm Band Spectrum

A poll concerning the use of 420 to 450 MHz spectrum in the United States was posted on the popular QRZ.com website on August 29th 2018.  Participation was open through end of 2018.

There were actually a total of 83 votes, but 6 respondents indicated they do not use 70cm or only listen from time to time. This would have represented 7.22% of the total results. All details below do not include those 6 responses since they do not actively use 70cm spectrum in the United States.

Maybe 2019 will be different for those and others not currently using 70cm for many different activities.  Here are the results of the 2018 survey.

Methodology & Goals

The reason to run a survey was to quantify the current and major use cases of the 420-450 MHz amateur spectrum in the United States. There is currently a huge disruption taking place thanks to digital voice communications through modes such as DMR, Fusion, D-Star and others and a survey helps to add fact to this statement.

The survey included 10 questions focused on use cases or common applications of the spectrum in question. These questions were than able to be aggregated into 5 general categories of:

• Analog FM Voice - Repeater based communication, Point to Point Simplex and short range hot spot use for things like Echolink were the three questions asked. The survey indicated 44.17% of active 70cm users use analog FM communication methods.

• Wide Band Modes - There was only one question asked in the 2018 survey about wide band modes and focused on amateur television or ATV. This type of activity requires channels four or more times wider than the widest audio only modes.  Only 2.41% of the survey respondents use wide band modes in 70cm spectrum based on the 2018 survey.

• Digital Voice Modes - Repeater, simplex and hot spot use cases were the three digital voice mode use questions within 70cm spectrum. For relatively new technology, an impressive 23.38% of survey takers reported to use digital voice as a primary activity on 70cm in the United States.

• Weak Signal Modes - Two weak signal questions were asked that covered single side band voice (SSB) and all other terrestrial or natural objects often associated with weak signal work such as beacons, EME bounce, Morse code and other things such as FT8, PSK31 and WSPR.  11.69% or survey takers enjoy the challenges of weak signal mode operation on 70cm with 7 of 9 category votes captured by SSB, likely during UHF contest periods.

• Satellite Modes - Only one question was asked since most all satellite operation takes place in a protected portion of the 70cm spectrum from 435 to 438 MHz. Uplink and downlink use of any mode used to make contact through man made objects like a space station or satellite were easy to ask in one question in the 2018 survey. With 18.18% of the survey results coming from satellite based use cases, it is clear that amateurs who use 70cm for this reason are active and create a strong reason to have dedicated spectrum for this sort of application. Most any mode is permitted and 2019 will start to see a rise in digital voice satellite use thanks to the recently launched and operational D-Star ONE.

Additional Survey Insights

The below table lists out all questions 9 of 10 questions and the category they contributed towards.

Some Additional Thoughts

Considering at of the end of 2018 there are 755,416 licensed radio amateurs in the US according to official FCC records, this survey sample size is microscopic. However, the total number of active annual radio operators is probably closer to 20% (1 in 5) This would equal 151,083 of  active amateurs in the last year somewhere across all amateur spectrum and not just on 70cm.

The QRZ.com website is pretty popular and seemed to be the best place to field a survey since its fairly agnostic and does not favor those for or against the direction of the ARRL which may have clouded the survey results, but likely would have increased the total number of respondents.

QRZ.com may attract more forward thinking amateur radio operators who are open to learning about new and advanced things to do within this hobby where they can be openly discussed. Many members of the ARRL are on QRZ.com, but only the ARRL can report on things from its membership which is only 170,000 as of 2016 or 22.5% of all amateurs in the US.

While ARRL membership totals are pretty close to the number of estimated active amateur radio operators, the ARRL also includes some non-US members, clubs and supporters so may not accurately represent those most active in the amateur community.  Its total membership may only represent a smaller number of active amateur radio operators than it may care to admit but may be changing due to new leadership in 2019.

If we were to consider that possibly 3 of every 10 active licensed hams (151,083) also frequent QRZ.com, the total pool of likely respondents would have been about 45,325 and potentially 1 of every 7 QRZ.com visitors who may have even found the survey area and logged in to take it would mean roughly a total pool of 6,346.

Ergo, 83 responses from a pool of 6,346 is 1.3% which is right on the border for statistically significant survey results considering that a professional firm touts results over 2% as very successful.  A 2019 survey hopefully will do much better.

If a 2019 survey for 70cm use cases can be organized by the ARRL and other organizations on neutral grounds, it would likely be more accurate based on total responses and prove beneficial towards leadership in emerging aspects of the hobby to create better experiences for all amateur radio operators in the United States looking at digital voice operation, best practices and equipment purchasing decisions.

Questions?  Comments?

If you wish to contact the team responsible for this article, please send a detailed email to 4info@hvdn.org  but remove the "4" or your message will not go through.

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SSTV: Images from the ISS

Zipping around planet Earth at 220 miles above on October 27th to 29th 2018 was the International Space Station and its special series of image transmissions using amateur radio slow scan television (SSTV)

What is SSTV?

Slow Scan Television or SSTV for short is a method of sending images over very narrow wireless bandwidth with fairly good color resolution in a short amount of time.

There are many different types of SSTV signals or modes and the one currently in use by the International Space Station is known as Robot36 or PD120

145.800 MHz is the "down-link" frequency for amateur radio operation from the ISS.  Sometimes it is used for voice communication and other times it is used for experiments such as SSTV.   On 145.825 MHz is data "packet" APRS operation for two way "text message" like contact with or through the ISS>

How To Receive SSTV Images?

There are two inexpensive ways to receive and decode an ISS SSTV transmission that can be done with less than $50 of equipment, not including the cost of your computer or smartphone.

Method #1:  USB SDR Dongle & Computer Setup 

Wide band software defined radio (SDR) receivers such as the RTL-SDR v3 can be used for many things, including the reception of signals orbiting above you and around you.  

Other things you can use this 24 MHz to 1.7 GHz  "SDR" receiver for include finding your lost car key remote, monitoring smart home devices, listening to weather, music and so much more.

With free software such as SDR#, its possible to record a "visualization" of the signal for later playback and decoding of SSTV signals. The same signal can also be sent from SDR# to MMSSTV software in real time for decoding of the SSTV transmission.

Method #2:  Inexpensive VHF/UHF Hand Held Radio & Smartphone Setup 

A basic dual band hand held radio can be purchased for about the same price or less as the receive only SDR but will also offer the ability to transmit on a narrow range of amateur frequencies also used by the ISS as well as by over 2,500,000 amateur radio operators globally. 

A very simple way of decoding a SSTV transmission is to simply hold the radio next to your smartphone while running the Robot36 application found on in your favorite mobile app store. By turning the radio volume up, the microphone on your smartphone will hear the SSTV signal and decode it. Sample signals to listen to are found later in this article.

The application will decode the received audio with no physical connection to the radio which makes this very easy to demonstrate for those not very computer savvy.  

Antenna Stuff:   Very important!

While any combination of radio receiver and computing device can be used beyond the examples provided, antennas are just as critical if not more so for receiving the best signal possible.

Having what is called a good "Signal To Noise Ratio" or SNR is needed to help differentiate white noise and static from the actual SSTV signal.  Any interference to the SSTV signal will just look like static like on a television screen, so a good antenna helps increase the SNR and produce a better picture

The good new is that the ISS SSTV signal is often very strong and easy to pick up with basic antennas, but a high power directive antenna is a good idea for optimal reception since it will focus the maximum signal strength from the ISS into your radio.

The reverse polarity SMA-J connector is common on Chinese origin radios such
as those for sale by Baofeng, Wouxon and a few others. 

While good reception results will often be had with the including telescoping dipole antenna with the RTL-SDR V3 or the longer "whip" antenna included with many of the inexpensive hand held analog radios such as the UV-8, a directional antenna is a good idea to consider.

Some options that can be purchased separately made by companies such as Nagoya, Comet and Diamond are easily sourced for VHF only of VHF/UHF operation.

It is best to pay close attention to what type of connector on an antenna like this can be used with your radio as they are not all the same.

The SMA antenna connector version of this same antenna is more common for radios
\made by Alinco, Kenwood, Icom, Yaesu, TYT and Retevis.

An alternate and higher gain antenna called the tape measure yagi beam can be constructed with simple hand tools and materials for less than $20.

There is also a ready made antenna available for purchase from the Arrow Antenna Company as well as the Elk Periodic from vendors such as Ham Radio Outlet.

The beam antenna is a great club project or one for a few like minded hobbyists. Many can be constructed quickly at one time if people work together in cutting and preparing different parts of the antenna for final construction..

What does a SSTV signal sound like and how do I find it? 

In order to know what to listen for, below are three very good signals and the resultant decoded image.

Feel free to try decoding these files with the MMSSTV or Robot36 applications to get familiar with the software since you do not want to miss the fast traveling ISS the next time they are transmitting SSTV images.

The "ISS Detector" app for Android is a great way to find out when the ISS will pass over your location next.
You an also track other satellites and even planets too with this program

To find out when the ISS will be over your location next, please visit AMSAT.org for more information about tracking the ISS, satellites and other interesting space related amateur radio topics.

Play MP3 Recording:  10:28AM 10/28/2018 ISS SSTV

Play MP3 Recording:  10:31 AM 10/28/2018 ISS SSTV

Play MP3 Recording: 12:00 PM 10/28/2018 ISS SSTV

How about SSTV with an SDR?

A nice feature with the SDR# software is you can play back a recording of spectrum at any point in time.

This is also called a base-band IQ file and was discussed in prior articles about receiving voice transmissions from the International Space Station.

• Happy Monday Again!; Ashford School and ISS Make Contact

• SDR: Let's Walk To The Space Station?

This file is a base-band IQ file for the "Atlantis and Mir" SSTV image to help with your own testing.

• Download 1200 PM ET SDR IQ SSTV 10/28/2018  (Caution: 225 MB File)

Select the  IQ file option  in SDR#
and play back the 225 MB recording 

Share your success stories, questions and comments below.  Thanks for reading!

Local to Hudson Valley?  Consider Joining HVDN

Happy Monday Again!; Ashford School and ISS Make Contact

The front gate to Burger Hill at Drayton Grant Park in Rhinebeck, New York was closed (and locked) at 8:45 AM this morning, so a quick decision to either quickly go home or find an alternate location to record the 9:05AM rescheduled ISS contact with a school in Ashford, CT was needed.

One of the many student questions that Serena Auñón-Chancellor answered included important ion propulsion technology that may one day take Earthlings to Mars. More below including recordings!

Ion propulsion will be important in getting to Mars - Serena KG5TMT

Tracking the ISS

Orbitron software was used to track the International Space Station. Combined with the software defined radio program, SDR#, its possible to keep the frequency locked on to accommodate for slight drift called the "Doppler Effect".  At VHF ((145.800MHz), the Doppler effect is not as pronounced compared to higher frequency, such as at 445 MHz. 

\

Recording location was far from optimal for best line of site on the grounds of CO. in Rhinebeck on such short notice.

The Ashford Band YouTube channel has shared a video of the setup and ultimate discussion with Astronaut Serena Auñón-Chancellor M.D, KG5TMT.

Reception site of K2GOG in NY and KM1Z down-link site for ISS in Connecticut

YouTube link jumps to 41:50 into the 56:00 video where the actual contact between KZ1M and NA1ISS, operated by Serena.

To both see and hear the down-link signal from the International Space Station, HVDN has two files:

• MP3 Audio File - 10/22/2018 - NA1SS & KM1Z (Ashford, CT)

• IQ Baseband Recording - 10/22/2018 - 145.000 MHz to 146.000 MHz (Caution 2 GB!!)

The HVDN files are only “one way” because line of sight from the ISS to where the recording took place was too far away from where KZ1M was located.

Here are some past articles for additional reading:

• SDR: Let's Walk To The Space Station?

• Happy Monday!: ISS & STEM Academy Make Contact

• Amateur Satellite Basics: Where, When & What to listen for

Register for updates for the latest from the HVDN Notebook

SDR: Let's Walk To The Space Station?

I had high aspirations on Wednesday to do a base-band SDR recording of a scheduled International Space Station (ISS) contact with a school in Ashford,  Connecticut. 

Burger Hill at Drayton Grant Park Rhinebeck, NY 12572

The weather was nice, so I decided to trudge up the measly 550 feet of Burger Hill for amazing views and to maybe cross paths with a passersby or two interested in what I was up to with my collection of equipment. 

What is a base-band recording?  Think of it like recording a television show with a DVR or VCR.  The only difference is a base-band recording lets you record a wide block of spectrum say from 162 to 163 MHz and be able to point and click on any activity received for later playback. This would be like recording multiple movies, news and sitcoms on different channels all at the same time.

Bummer: Well, no activity from the ISS on 145.800 MHz at 14:39 PM ET (1839 UTC). 

As it turns out, the ISS contact was cancelled at the last minute due to an experiment in the Columbus module that would have prevented the use of the functional radio in that part of the space station. 

The radio to be used was actually considered the spare radio as the main radio after years of service no longer is functional.  A replacement is supposed to be sent up before the end of 2018.

I only found out about this change of schedule on a Facebook Group that I joined once I got home which is more up to date than all my usual sources such as the official ARISS Project website, AMSAT mailing lists and various NASA pages.

Serena Auñón-Chancellor, KG5TMT preparing the
NanoRacks Cubesat Deployer-14

This just goes to show that social media is still the best spot for breaking news!

Looking on the bright side...

All was not lost though. Not many minutes later at 15:02 ET was a pass of the elderly SO-50 satellite and I quickly made a contact with Tom, K8TL in grid EM89, 500+ miles away from me in FN31 thanks to this "repeater in the sky".

All that was needed was 1 watt of transmit power & a directional antenna! 

However, the down-link for the SO-50 satellite is centered on 436.795 MHz and there was someone using digital voice on that frequency which made it hard to make more contacts as SO-50 reached its apex and started to move out of range.

I did not have a DMR capable radio with me, but I am pretty sure that is what mode it was and it was local versus coming from the satellite. 

Listen:  Do you hear a "digital sound" on 436.795 MHz?

Trespasser!!

No hot spot or repeater stations appeared listed on Brandmeister on that frequency in the satellite band, so it could be some joker or ill informed amateur about the suggested ARRL and ITU band plan just intentionally interfering. Rhinebeck is pretty much far away from any "majorly" strong out of band signals that could have interfered, so it had to be an amateur radio operator.

I knew the signal was also local because if it was somehow coming in from SO-50 by someone transmitting DMR on the VHF up-link of 145.850 MHz, it would have come from the direction of the satellite and not from another direction to my south west at a "terrestrial" elevation.

This sort of interference makes me sad because 436.795 MHz is well known for over 16 years that this is where SO-50 transmits back to earth on.

There are plenty of other frequencies that can be used for digital voice that would not interfere with those interested in satellite communications.

Lets change the subject back to base-band

While I was at the great location of Burger Hill, I decided to do a 30 second base band recording of the weather band from 162-163 though should anyone wish to test it out since every NWS channel is in use from that location.

A "Normal" Recording:

A center frequency of 162.475999 MHz with a bandwidth of 15 kHz can easily be recorded and played back using pretty much any audio player, but only just that one frequency can be heard. The file size is 1.9 MB. Play: Standard AF Recording (1.9 MB)

Play: Standard AF Recording (1.9 MB)

A "Base-band" Recording: 

Compared to the "Standard AF Recording", the base-band recording for the same 30 seconds is 60.9 MB or 3105% larger. However, you can listen to any signal of any bandwidth in any mode across the entire 162 to 163 MHz captured for 30 seconds.

SDR# will help you visualize the entire 1 MHz wide
recording without needing a radio

In order to play the base-band file, you can not use a regular audio application or otherwise the sound might sound like an Imperial Probe Droid from Star Wars.

Play/Download:  IQ Base Band File (60.9 MB)

If you are a Star Wars fan, you know the
audio I reference from Echo Base on the ice planet Hoth

Ham Solo: Return of the SDR#

Download and install the popular SDR# program and select the "IQ File" option as shown. 

Then navigate to where the "IQ Base-band File" was saved and press play in SDR#

From the Burger Hill location and its good line of site, multiple weather stations were received as well as a few other signals not related to the weather.

Hudson Valley National Weather Service (NWS) stations
broadcasting 24/7 on the 162 MHz spectrum

Hopefully this article gave you a taste of a few interesting things you can do with amateur radio or use equipment for a dual purpose unrelated just to ham radio.

Next time there is a planned live ISS contact receivable from the Hudson Valley, we will definitely try to get that recording, just as long as the astronauts do not get busy at the last minute! 

Check Out The HVDN STEM Project Here

Search for more satellite and space related content on HVDN 

Happy Monday!: ISS & STEM Academy Make Contact

On July 2nd 2018 at just past 11:30 AM was a scheduled contact between the International Space Station and the Pearl technology STEM Academy in Peoria, Illinois. Students submitted questions in advance that astronaut Serena Aunon was going to answer by using the space stations amateur radio equipment.

“Nothing beats waking up on a technological marvel and then starting the day off with an antique method of navigating. Sextant Operations from @Space_Station! Still considered a potential backup method of navigation for future vehicles…” said NASA astronaut Serena M. Auñón-Chancellor on her Twitter

Since New York where HVDN is located was in the general foot print of the space station orbiting overhead at 200+ miles high on its way over Peoria, here is a brief recording of some of the questions asked before the space station got out of range.

Recording:  NA1SS operated by Serena Aunon answering questions facilitated by W9DWJ

The reason only one side of the conversation was heard was because the ground station in Illinois is too far to hear directly on VHF spectrum in New York directly.  

The ground station setup at the STEM academy was transmitting on an up-link frequency to the ISS of 144.49 MHz and the ISS was transmitting back down on the 145.80 MHz down link. 

Start and end positions on where the ISS was first heard and when it was out of range.

It is fantastic for students to be able to leverage technology to have real time contact with the space station and to instill an interest in science, technology, engineering and mathematics at an early age.  Serena is a great role model for younger generations to see what they can be when they grow up.

Amateur radio allows anyone to experiment with this hobby, be they young, old, male, female, technical, non-technical, English speaking or otherwise.  There is much that can be learned with each other and HVDN plays an active part in the Hudson Valley area of New York in fostering interest in emerging and exciting parts of amateur radio.

Here is the radio used to record the ISS contact.

HVDN has recently launched the STEM Talk Group available on the Brandmeister DMR network which uses DMR technology to create easy and clear communications globally. 

More information can be found at the below link and perhaps this great resource can be used to connect explorers, astronauts, engineers, or anyone else who can share unique insight about amateur radio, what its capable of and how it can influence future generations to better communicate. 

• More about STEM Talk Group 31630

• More about Astronaut Serena Aunon

ANNOUNCEMENT: On Saturday July 6th, Steve K2GOG will be taking a ride in a hot air balloon as part of the Balloon Festival at the Dutchess County Fairgrounds in New York. Anyone interested in arranging contact via TG 31630 with him, can listen on TG 31630 between 6:00 AM and 8:00 AM New York time. He will be routed on to the network via the N2MCI repeater located in Kingston, NY.  Steve's location will also be found on the aprs.fi website under the N2HVD-11 call sign. He will also be making direct contact on suggested analog or digital frequencies too on 2m, 1.25m, and 70cm below

• 146.52 MHz Analog FM
• 223.500 MHz Analog FM
• 446.00 MHz Analog FM
• 446.075 MHz Digital DMR (TG 99, CC1, TS1)
• 145.790 MHz Digital DMR (TG 99, CC1, TS1)

Your Next Antenna Project: Upgraded Space Station Communications

This came up on the weekly North American astronomy net and now I know what my next antenna project will be. Not sure if NASA will be willing to share the plans with me or not though. 😉

Here is a nice article from April 27th 2018 with more detail.

NASA Upgrades Space Station Emergency Communications Ground Stations

Since the launch of the International Space Station’s first component in 1998, communications infrastructure has been critical to the station’s success and crew safety. NASA is currently implementing upgrades to very high frequency (VHF) communications ground stations that backup the station’s primary communications system, the Space Network, and communicate with Soyuz spacecraft when out of Russia’s range.

NASA’s VHF ground stations provide two-way, audio-only communications and transmit over two frequencies, VHF1 and VHF2. VHF1 is used for emergency communications with the International Space Station. VHF2 communicates with Soyuz spacecraft.

Russia also operates a VHF network independently from NASA's. The combination of the two networks ensures VHF communications are available on every orbit of the space station and Soyuz.

The space station hosts two VHF1 antennas, 180 degrees apart. They flank the Zvezda Service Module, an early Russian contribution to the station that served as an early cornerstone for its habitation. Astronauts and cosmonauts can communicate with mission control from any module of the station via VHF1.

“Maintaining the availability of utility-like communications between the crew and the ground is paramount to enabling mission success and ensuring crew safety,” said Mark Severance, Human Spaceflight Communications and Tracking Network director. “The NASA VHF network, in combination with the VHF network operated by our Russian partners, does just that.”

Under normal circumstances, the station relies on NASA’s Space Network, a series of Tracking and Data Relay Satellites in geosynchronous orbit. The network provides near-continuous communications coverage between the station and mission controlcenters around the world who make sure the station’s systems function properly. The Space Network also enables the transmission of high-resolution science data, ultra-high definition video and special downlinks like student contacts with astronauts. VHF1 would only be used in the unlikely event that the space station was unable to communicate via the Space Network.

Russian Soyuz spacecraft sport a single VHF2 antenna towards their tail. Russia uses VHF2 as their primary system for voice communications from launch at the Baikonur Cosmodrome in Kazakhstan to docking with the space station and upon undocking and returning to Earth.

On most Soyuz missions, the spacecraft docks with the space station prior to exiting Russia’s VHF network coverage. The same is true on return to Earth. However, on Soyuz missions that require a longer, 34-orbit rendezvous, the NASA VHF network stands by to provide emergency communications while the Soyuz is outside of Russia’s range, orbiting over the continental United States. NASA’s VHF network could also provide emergency communications in the event a problem required the Soyuz to stay in orbit for an extended period of time.

NASA’s upgrades to VHF network ground antennas, currently underway, involve improvements to numerous electronic components and installation of new software for tracking the space station and Soyuz. Additionally, new antennas at the ground stations, able to operate at VHF1 and VHF2 simultaneously, will add redundancy to the network so that if one system fails, the other system will be able to take over immediately.

“The purpose of these upgrades is to ensure the VHF ground stations remain a robust capability for backup and emergency communications,” said Severance. “The addition of redundancy, the ‘belt and suspenders’ approach, is particularly important given that these systems would only be employed due to failure of the primary space station communications system or an emergency onboard the Soyuz.”

NASA maintains VHF ground stations in two locations: Wallops Flight Facility in Wallops Island, Virginia, and NASA’s Armstrong Flight Research Center in Edwards, California. These ground stations are strategically placed to maximize contact with the station and Soyuz as they orbit above North America. The Russian VHF ground stations are located throughout Russia, providing contact as the space station and Soyuz orbit above Asia and Europe.

NASA’s VHF system is managed by NASA’s Goddard Space Flight Center’s Exploration and Space Communications projects division. NASA’s Space Communications and Navigation program office provides programmatic oversight to the network.

Banner image: The International Space Station. Credit: NASA

---

By Danny Baird
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Last Updated: April 26, 2018

Editor: Rob Garner

https://www.nasa.gov/feature/goddard/2018/nasa-upgrades-space-station-emergency-communications-ground-stations 

Amateur Satellite Basics: Where, When & What to listen for

Interested in trying something new using your handheld VHF or UHF radio?  How about putting that old scanner to use or using one of those other bands not used in your "all mode/all band" HF radio?  What about using that $20 software defined radio dongle you may have gotten for Christmas?

Diana Eng photo with home made antenna in a 2009 Make magazine article.  Look here for more info

Consider satellite listening as your next adventure!

This article will only focus on when, where and what to listen for. Later articles will cover transmitting and other related best practices in using the amateur radio satellite constellation for your enjoyment.

What is out there to listen to?

The below chart from the radio amateur satellite corporation or AMSAT for short shows the name of current satellites and general usage patterns. As you can see, there is a lot floating and spinning around Earth that are amateur focused satellites.

Where to listen for these satellites?

There are sub-bands set aside for satellites and to ensure there is minimal interference from other users in different parts of the world or for those with other interests not related to satellite operations.

In the United States, the ARRL and FCC have negotiated a general band plan along with the ITU and other regulatory bodies such as OFCOM, JARL and many others. Here is a summary taken from the ARRL website for where these special allocations of frequencies exist for satellite only activity.

• 10m band  satellite down-link from 29.3 to 29.510 MHz
• 2m band new OSCAR sub band from 144.3 to 144.5 MHz
• 2m band linear translator inputs from 144.5 to 144.6 MHz
• 2m band linear translator outputs from 145.1 to 145.2 MHz
• 2m band OSCAR sub band from 145.8 to 146.0 MHz
• 70cm International satellite sub band from 435.0 to 438.0 MHz
• 23cm band satellite up-link sub band from 1260 to 1270 MHz
• 13cm band satellite sub band from 2400 to 2410 MHz

The above adds up to almost 24 MHz of total band width available for two way satellite communications.  Not included above are other frequencies available for "Earth-Moon-Earth" communications where you can bounce your signal off the moon as a passive repeater to communicate to other stations elsewhere on Earth. Also not included are frequencies at the 3.3 GHz, 5.6 GHz and 10 GHz frequency bands also used for satellite communication.

Have a look for more detail here on the ARRL website: http://www.arrl.org/band-plan 

Making it more simple

The below frequencies would be a good starting point for just listening, so save them into a radio that you have plenty of left over empty channels in or some other radio you do not use too often.

FM based satellites (down link frequencies)

• SO-50 on 436.795 MHz
• AO-85 on 145.980 MHz
• AO-91 on 145.960 MHz
• AO-92 on 145.880 MHz
• ISS on 145.800 MHz ( Over North America only)

There are a few others that can be looked up on the AMSAT website and the above are the most easy to listen for currently.  https://www.amsat.org/fm-satellite-frequency-summary/ 

SSB based satellites (down link frequencies)

• FO-29 on 435.8 to 435.9 MHz 
• AO-73 on 145.950 to 145.970 MHz

These will be in side band mode and may either be USB or LSB depending on what is sent up via up link and is then inverted on the way down. Other SSB or "transponder" satellites can be found here: https://www.amsat.org/two-way-satellites/

Data focused satellites (down link frequencies)

• APRS via the ISS on 145.825 MHz
• APRS via NO-44/PCsat on 145.825 MHz

There is a lot more not even touched on in this article such as FalconSat, LilacSat, XW-2 Series and others, but all the above should be easy to hear with even modest antennas such as a 3 element tape measure beam or a simple gain "rubber duck"

How to find when to listen?

There are many applications such as Orbitron, Gpredict and others for PC or MAC based computers, but are not very portable.  For an Android based smart phone, look for "ISS Detector" in the Google Play store. It does much more than just predict when the space station is overhead.

AMSAT has a prediction tool on its website here:  http://www.amsat.org/track/index.php

Also, NY2O has a great website as well for finding when to listen: http://www.n2yo.com/passes/amateur-radio.php 

Next steps?

K6KLS has a great website for getting started called http://www.work-sat.com and is worth having a look for more info.

There are also a number of dedicated discussions taking place on Echolink, D-Star and DMR where satellite enthusiasts gather to talk about best practices, so have a look at the HVDN activity calendar to learn more. 

Space Station Contact with Syracuse, NY

This morning, astronaut Mark Vande Hei KG5GNP was able to make a prearranged contact with the Museum of Science & Technology and students from the Danforth Middle School, Syracuse, NY, 

(Astronaut, Mark Vande Hei KG5GNP on the ISS. Courtesy of www.nasa.gov)

Children were able to ask a few questions before the Space Station moved out of range. 

The frequency the International Space Station was heard to be transmitting on was 145.800 MHz.  The K2MST in Syracuse  ground station received Mark loud and clear for a few minutes starting at about 9:08 AM New York time.  In order to communicate with the ISS, the K2MST team were receiving on 145.800 MHz, but transmitting on 144.490 MHz. Mark's radio at 220 miles above Earth was set up opposite as those back on Earth. He was receiving on 144.490 MHz and transmitting on 145.800 MHz.

This split frequency operation is used to minimize interference since different parts of the world have a slightly different VHF "2m band" allocation. In Europe for example, they can still listen for down-link signals on 145.800 MHz, but typically use 145.200 MHz for up-link. 

Here is a video documenting the event:

The ARISS project has coordinated 1,000+ contacts with schools around the world with the International Space Station since it has been in orbit.

HVDN is proud to work with local schools in the Hudson Valley to help coordinate an event like this in the future in our area.

Please contact Steve K2GOG  at K2GOG@amsat.org if your school is interested in learning about how to get on the ISS schedule if you are located in Dutchess County NY or one of the adjoining counties.