Packet Radio ~ Proof of Concept

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Retro is now a thing of the future, if truth be told!

Look around you and you’ll see Polaroid Cameras being used once again, old ‘classic’ cars trundling past and many other ‘Retro‘ objects taken out from under the stairs or, perhaps, the loft? Indeed, there is currently a trend here in the UK for many older objects to be ‘re-invented’ and launched once again on to the unsuspecting shopper!

Amateur (‘Ham’) Radio is no exception to this new look at old things. Packet Radio is making such a resurgence within the hobby.

Picture above: Navico AMR 1000S Radio to the left & a PacComm TNC Tiny-2 Mk2 to the right. Both are from the 1980s and are still working fine!

What is Packet Radio?

Packet radio is a particular digital mode of Amateur Radio (“Ham” Radio) communications which corresponds to computer telecommunications. The telephone modem is replaced by a “magic” box called a terminal node controller (TNC); the telephone is replaced by an amateur radio transceiver, and the phone system is replaced by the “free” amateur radio waves. Packet radio takes any data stream sent from a computer and sends that via radio to another amateur radio station similarly equipped. Packet radio is so named because it sends the data in small bursts, or packets.

What is the history of packet radio ?
Data packet technology was developed in the mid-1960’s and was put into practical application in the ARPANET which was established in 1969. Initiated in 1970, the ALOHANET, based at the University of Hawaii, was the first large-scale packet radio project. Amateur packet radio began in Montreal, Canada in 1978, the first transmission occurring on May 31st. This was followed by the Vancouver Amateur Digital Communication Group (VADCG) development of a Terminal Node Controller (TNC) in 1980.

The current TNC standard grew from a discussion in October of 1981 at a meeting of the Tucson Chapter of the IEEE Computer Society. A week later, six of the attendees gathered and discussed the feasibility of developing a TNC that would be available to amateurs at a modest cost. The Tucson Amateur Packet Radio Corporation (TAPR) formed from this project. On June 26th 1982, Lyle Johnson, WA7GXD, and Den Connors, KD2S, initiated a packet contact with the first TAPR unit. The project progressed from these first prototype units to the TNC-1 and then finally to the TNC-2 which is now the basis for most packet operations worldwide.

Why packet over other modes?
Packet has three great advantages over other digital modes: transparency, error correction, and automatic control.

The operation of a packet station is transparent to the end user; connect to the other station, type in your message, and it is sent automatically. The terminal Node Controller (TNC) automatically divides the message into packets, keys the transmitter, and then sends the packets. While receiving packets, the TNC automatically decodes, checks for errors, and displays the received messages. Packet radio provides error free communications because of built-in error detection schemes. If a packet is received, it is checked for errors and will be displayed only if it is correct. In addition, any packet TNC can be used as a packet relay station, sometimes called a digipeater. This allows for greater range by stringing several packet stations together.

Users can connect to their friends’ TNCs at any time they wish, to see if they are at home. Some TNCs even have Personal BBSs (sometimes called mailboxes) so other amateurs can leave messages for them when they are not at home. Another advantage of packet over other modes is the ability for many users to be able to use the same frequency channel simultaneously.”   [Ref: https://www.tapr.org/pr_intro.html]

 

So what is the fascination with Packet Radio for 2017?

Well, as I said, retro is all the thing …………. but, in this case, in a world of digital communications, it is fun to go back to where it all started.

Transmitting data at 1200 Baud means that it is slower than sending a text message on a mobile phone, but then again ~ Packet Radio is free to use, has many uses (see below) and, at the very least, is a straightforward ‘answerphone‘ that is not reliant on the telephone system.

For those who gained their Ofcom Amateur Radio licence after the widespread introduction of the internet during the 1990s, when packet radio began to wane, the fascination of learning the basic commands and getting old kit to work again can be both fun and rewarding.

Secondhand TNCs are going up in price as the hobby reacts to the relaunch of Packet Radio. Of course, not all areas are very active ~ but the County of Kent (UK) is making a good crack at it, with many new licensees jumping on board.

I am also resurrecting the Bulletin Board System (BBS), callsign GB7RMS, in the very near future ~ and that will be the subject of another post.

What can you use Packet Radio for?

There are many uses of Packet Radio, even today, both for normal ‘everyday‘ operation and for ‘Emergency Communications‘ in times of need, or to support other agencies:

  • Mail exchange (via store-and-forward mailboxes)
  • File uploads and downloads
  • Callsign lookups
  • Bulletins about local, regional and national ham activities
  • Bulletins about propagation predictions
  • Bulletins about satellite Keplerian data
  • One-to-One chat
  • Network links that allow regional conversations
  • Internet links that allow inter-continental conversations
  • Satellite communications
  • ISS communications
  • Meteor Scatter
  • TCP/IP linking
  • Automatic Packet Reporting System ~ APRS ~ mapping in real time, message handling, etc.

My experience of using Packet Radio

I started off using the cassette port from the back of a BBC-B computer into a secondhand Trio (Kenwood) 520S valve radio in 1984. There were just a  few of us on at the time ~ I recall 4 from the UK and myself [operating as DA1JU in (West) Germany]. We had to use what is known as ‘CONverse Mode’, which effectively meant you did not link to anyone in particular but, rather, ‘threw out a signal‘ for others to receive and decipher, pretty much instantly, on their computer screen. [HF communications use the slower 300 Baud speed]

Soon after that I imported, from Tampa Florida (USA), a TNC kit which I built over one weekend. Fortunately it worked first time!

On returning to the UK at the end of 1989, I set-up a Packet Radio BBS & forwarding Node (callsign GB7SEA) in Seasalter, Whitstable, Kent. I ran two 70cm Band radio nodes: 1 for forwarding/receiving from other BBS/Node stations & the other for user access. I also ran 2 @ 2m Band radio nodes in the same way. Additionally, I had a 6m Band radio link from Seasalter to Hastings, and return, for BBS linking,

You have to remember that this was before there was widespread domestic internet available, so the use of Packet Radio was ‘revolutionary’ and gave us access to a wealth of information, support and fun from all around the world!

After Packet Radio, in its original form, died out, due to the eventual success of the internet, my equipment was packed away. Most still exists!

After about 10 years, APRS became popular ~ so some of my equipment was pressed into service. I still put out regular beacons when I am driving around.

The future?

Who knows? For now, and for increasing numbers of operators, it is fun to go back to the older technology, blow the dust off and give it a go!

I will post other developments as they happen, so please watch this space.

Maybe follow this blog?

Best 73 de John G0GCQ

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The Packet Radio antenna ~ Diamond X50.

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