Showing posts with label HVDN Satellite Channel. Show all posts
Showing posts with label HVDN Satellite Channel. Show all posts

Sunday, February 28, 2021

UPCOMING 3/15/2021 HVDN:LIVE - VHF/UHF is NOT just FM Repeaters: The IC-9700 & IC-705 Punch-Out



On the 8:00PM EST March 15th 2021 episode of HVDN:LIVE, we will take the Icom IC-9700 and IC-705 for a in depth conversational review thanks to Neil W2NDG as moderator with Jim WA2UMP and Steve K2GOG trying to defend reasons why to or not acquire either of these radios.

VHF/UHF is NOT just FM repeaters

This review is not going to be a product endorsement in any way, but it just so happens that both of these radios do not have any direct current production competition, so that is why we are stuck with making this an Icom focused discussion. 

The goal will be to highlight all the interesting things you can do on VHF/UHF aside from only talk on repeaters.

Both the Icom IC-9700 and IC-705 will be in full view during the discussion to ensure we provide fact rather than fiction for both radios. It will be really fun! 

Basic flow is going to be:

  • Introductions 
  • Reasons why did Jim acquire the Icom IC-9700  
  • Reasons why did Steve acquire the Icom IC-705 
  • Discussion on if they would do it again
  • Discussing "Was it easy to do...…" 
  • Focus on hardware tips & tricks
  • Focus on software tips & tricks
  • Remote operation comments 
  • Live Q&A

How to join HVDN:LIVE?

We are going to experiment and see how many people can join the live meeting and we will be using  Jitsi instead of Zoom since HVDN supports and encourages open source projects.

If interested in attending on March 15th at 8:00 PM Eastern Time , please join using http://meet.jit.si/hvdn/livemarch15th2021 and use the password "hvdnlive"

This event will be recorded for later playback, but anything live is always better than a recording, so be sure to check it out and get your questions ready for Neil, Steve & Jim! 

Feel free to drop some questions below in advance!

Thursday, February 25, 2021

Getting high with Xyla Foxlin?


Xyla Foxlin

Really tried hard on a catchy title for this amazing spin on putting something unique into high altitude exposures.   

Credit for this goes to RTL-SDR.com  for sharing this first though. Check this out and more of Xyla's amazing adventures below. 



Tuesday, October 20, 2020

Use it or lose it: Death of 3.4GHz










Wireless spectrum is what makes amateur radio valuable. Without the ability to experiment at different frequencies, "ham" radio will stagnate into being known only for what was up until today 0.0163% of its total available spectrum. This is totally NOT fair! 

What else beyond HF?


The high frequency HF or "shortwave" bands which are used for long range communications is what much of the public know amateur radio for. In times of emergencies or most any regular day or night, very low speed data or narrow band voice communications can be heard across a variety of sub-bands that are only to be used for amateur radio mostly between 1.8 MHz and 30 MHz.  Moving higher up the spectrum chart, much higher speed data and digital voice communication has been gaining in popularity globally.

As noted in a past presentation on satellite communications given at the Trenton Computer Festival when humans were able to gather in social settings with no fear of global pandemic,  Steve K2GOG shared an overview of how much discontinuous spectrum is available to all three classes of amateur radio operators in the United States.























Amateur radio satellite communications


While ham radio is known for its long history surrounding the so called "short waves", once you get beyond 30 MHz, the actual wavelengths get much, much, much shorter and commercial users have long used spectrum just above or below where amateur radio operations live in the VHF, UHF and SHF spectrum. Within these higher bands, there are specific portions set aside for satellite communications.























While there are some tiny portions of amateur radio spectrum that are dedicated for only satellite communications, they add up to over 300 MHz in what could be considered the more easily accessed spectrum between 7 MHz and 47 GHz.

While there is no commercial users likely looking to take back spectrum under 30 MHz, there are a few HF satellite frequencies in use, with examples being the very old AO-7 satellite and a few new Chinese satellites that will start using the 21 MHz band. 

Most amateur radio operators have been exposed to educational school contacts or narrow band picture sharing known as "slow scan television" by way of the International Space Station which mostly uses the 145 MHz spectrum.   

More specific satellites that act as "bent pipes" or repeaters often use 435 MHz as an uplink frequency and 145 MHz for a downlink.  To date, there is limited use of other frequencies above the 435-438 MHz satellite band, with satellites such as AO-91, AO-92, SO-50, FO-29 and RS-44 as a few of the more popular satellite destinations for amateur radio experimenters today that use these frequencies.

The AO-92 satellite also uses a 1.2 GHz uplink during specific times to help show use by the amateur radio community in an otherwise less frequented portion of spectrum, which much like the 3.4 GHz band, has been under attack from commercial users who could benefit from valuable amateur radio spectrum.  

The QO-100 satellite relies upon a 10 GHz downlink and 2.4 GHz uplink and this makes it the most advanced satellite that is accessible to amateur radio operators today, but just not in the United States due to its stationary position covering all of Europe, Asia, Africa and parts of South America.

The neighbors have better stuff


Over the past two years, European regulators such as CEPT and OFCOM tried to to make a case to take away parts of the 145 MHz, 1.2 GHz, 2.3 GHz and 3.4 GHz allocations to help expand different commercial services such as long range aircraft positioning and different "Internet of Things" applications along with different applications that can be considered as part of the 5th generation of mobile communication, often shortened to 5G. 

While fending off the recent attacks on the important bottom part of the L-Band from 1240-1300 MHz was successful as well the somewhat distracting 145 MHz allocation battle,  the spectrum just below the common 2.4 GHz Wi-Fi band was lost to commercial users in Europe. 

Within the United States, the Federal Communications Commission has decided to "delete" the ability for amateur radio operators to use its allocation in the 3.4 GHz band due to the needs of 5G, especially that of CBRS which will drastically change the way spectrum is licensed moving forward.






















We need to change

There is nothing wrong if HF focused operation is what is of most interest to you or anyone looking to get involved in amateur radio today. Those that decide to just spend a casual weekend enjoying the already well understood and no longer innovative 3.7 MHz, 7 MHz and 14 MHz bands are akin to being a bunch of "home bodies" and those that are easily pleased and that is ok.

While it is possible to take HF equipment out in the field and operate from battery power and make contacts with others using voice, Morse code or digital data modes such as  PSK31, FT4 or JS8CALL, this does not advance the hobby if we are trying to defend our spectrum. This use case demonstrates a level of converged activity.

In the next few decades, the novelty of HF based communication will be much harder to entice a next generation of amateur radio operators to unless they first are shown all the amazing things that can be done across other frequencies and applications such as satellite based communications.

We owe it to the next generation of prospective amateur radio enthusiasts to find differentiated applications for the 144 MHz, 435 MHz, 1200 MHz and all the way up to 60 GHz if we wish to remain relevant  rather than as a forgotten hobby deep rooted in the evolution of electronic innovations we have seen over the last 100 years.




Friday, January 25, 2019

How To Guide: Satellite Based APRS iGate

There is so much amazing activity these days surrounding satellite and software defined radio (SDR), but there are not many clear and current guides for those interested in creating receive only gateways to send satellite born APRS signals over the internet. Let's change that.



APRS & Satellites (and balloons, drones, etc)

Currently there are three active satellite based digipeaters in low earth orbit. The International Space Station (ISS), PCsat NO-44, and SAT NO-84 all operate on 145.825 MHz.

There is also a fourth APRS satellite named FalconSat-3 that was turned over from the United States Air Force in 2017 for amateur radio use, but is operated on 145.840 MHz and requires a little more work to use. There are other amateur digital mode satellites in the planning stages.


othernet amateur radio aprs
Image Courtesy of  http://aprs.org/outnet.html


What is an iGateway?

An iGateway is nothing more than a radio receiver that is connected to the internet. Signals received by the antenna are passed from the radio over the internet.  The iGateway is designed for digital or data signals and not voice however. Websites such as findu.com and aprs.fi are two examples are where the benefit of igateways can be shown and show APRS data.

There is also the Othernet (Formerly known as Outernet) project that sends information from its ground station back up towards different satellites that "datacast" to special receivers such as the Dreamcatcher. Properly addressed APRS messages are in turn broadcast over this separate satellite network. This is not the same as an iGateway, but does add some other unique potential.  For an amateur to route a message with APRS through one of the mentioned satellites earlier, one must use the path of "OUTNET" instead of "ARISS".

General users of APRS for ground based modes typically leave the path as WIDE1-1 or WIDE2-1, but those interested in satellite communications must use the alternatives listed since a satellite works differently from a propagation perspective to ground based or even low altitude aircraft or balloons.

How To:  SDR & Raspberry Pi iGateway

To create an iGateway you will require:

  • An inexpensive USB SDR
  • Raspberry Pi Computer or other similar device
  • Antenna capable of overhead reception
  • Various cables and stuff for your installation

There are way too many variables on antennas and cabling specific to every installation so we will keep this brief and skip that part. The shortest run of coaxial cable from antenna to radio is needed. The highest and clearest view towards the horizon in as many directions as possible is required for optimal reception when considering setting up a iGateway.

The satellites we will be monitoring pass over most locations about 3-5 times every day for just a few moments, so it's possible a APRS capable satellite will pass over once every 60-90 minutes.

Lets setup the software bits and bobs....

The main goal of this article is to only share the steps for configuring software to get a SDR dongle working with a Raspberry Pi.  These steps can also work for those looking for alternate uses for SDR based hardware such as the now out of date L-band focused Dreamcatcher v 2.03 boards that were replaced with the newer Ku-band Dreamcatcher v3 and likely could be used too.

The real magic here is the software and how it will all work together.

First step, is get a working operating system on your device of choice such as the Raspberry Pi or Dreamcatcher v2.03. Most of these instructions will work for other linux based computers but is not the focus of this article.

Please run sudo apt-get update and sudo apt-get upgrade first to ensure your operating system is current and has most all of the popular packages installed for general use before continuing.

Second step, involves setup of Dire Wolf which translates sound to packet decoding. Run the following on your device to install it.
sudo apt-get install libasound2-dev
git clone https://github.com/wb2osz/direwolf
cd direwolf
make
sudo make install
make install-conf
Next, you need to configure the operating system to take virtual audio from an inexpensive SDR dongle and pass it to direwolf.  Go ahead and plug in your SDR dongle to your raspberry pi. If you are using a Dreamcatcher, there is no need since the SDR is part of the board already!
sudo apt-get install cmake build-essential libusb-1.0-0-dev
cd
git clone git://git.osmocom.org/rtl-sdr-git
cd rtl-sdr
mkdir build
cd build
cmake ../ -DINSTALL-UDEV_RULES=ON -DDETACH+KERNAL_DRIVER=ON
make
sudo make install
sudo ldconfig
sudo reboot

Let's pause for a moment and test the SDR to make sure its recognized.

run "rtl_test"  and ensure you get a status update like this before continuing. This shows that the SDR is being recognized by your Raspberry Pi, Dreamcatcher 2.03 or other single board linux computer.


Now we need to configure Dire Wolf and the best way to do that is copy some of the great work that Keith G6NHU has compiled. Head on over to his interesting site here:

http://qso365.co.uk/2017/02/a-guide-to-setting-up-an-aprs-receive-only-igate-using-a-raspberry-pi-and-an-rtl-sdr-dongle/ 

The only basic change you need to make is to select the correct frequency. In the United States much of the APRS activity is on 144.390 MHz, but since we are interested in satellite based APRS, change it to 145.825 MHz instead.

What did you say about balloons?

Perhaps you may tire of the same general activity on APRS terrestrial activity or even what may be bouncing off a satellite.  The next logical thing to look into would be tracking a balloon of some sort.

Taner DB1NTO has a new product out to cater to people looking to track something that can only carry a very light weight device.  He calls it PicoAPRS Lite and should open up lots of possibilities to experiment with alongside perhaps with a portable version of an iGateway connected via cellular hotspot.



If anyone in the Hudson Valley is interested in experimenting with tracking objects other than a house which does not move much, or a car, lets start talking.

The STEM (31630) DMR talk group seems a logical spot as well as the AMSAT (98006) talk group, so lets make something happen here when spring time arrives!










Sunday, October 28, 2018

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.

SSTV space station file
Play MP3 Recording:  10:28AM 10/28/2018 ISS SSTV


slow scan television amateur radio space station
Play MP3 Recording:  10:31 AM 10/28/2018 ISS SSTV

space station contact amsat SSTV ISS
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.

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



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!