pa0r

PSK-mail is a mail delivery system for shortwave radio. You may see it as a POP3 and SMTP client for use over shortwave links (of course it could also be used at UHF/VHF, but that is covered by Packet Radio and Paket/Internet gateways). The difficult bit is the rf link, which is low quality most of the time.

Of course there is a system in existence based on Pactor, called WINLINK 2000. This is a semi-professional system with gateway stations in most parts of the world and propriatory client software only available for Window$. All but a few gateway stations nowadays use Pactor 2 or Pactor 3 mode, which is patented by SCS, so you have to pay rediculous royalties (in the form of a PTC constroller and a special license for Pactor3). All this makes the system uninteresting for ham use.
I have tried using the system with a MFJ1278B Pactor1 controller, but the results were unacceptable. On most days the 30 minute-per-day limit did not even allow to download the list of headers in the database! Of course it makes you think twice before you set up the antenna at the back of the camper, hook up the rig and the computer, just for the fun of zero data transfer!!

I also tried GPRS via the mobile telephone, but when it is available (tried using it in Spain and France?) it is expensive.

As I am on the road (or at sea) most of the time, I want to be able to access my mail via wireless. So the only way (again) was DIY.

I have written a simple POP/SMTP client (in PERL) so I can use the mail database of my internet provider. The functions are LIST, READ and DELETE. The radio interface is a slightly hacked version of gMFSK (a phantastic program written by Tomi Manninen), which covers all popular digital modes. As I want to use the system to upload patches for the programs I write when on the road (sometimes the trips are as long as 2 months) I need some kind of checksumming or ARQ. Not all digital modes are suitable for ARQ. I have tried MT63, MFSK16, PSK31 and PSK63.
The FEC-based systems have rather long turn-around times (MT63 and MFSK), but are very robust (few data errors on a mediocre channel). PSK31 has very stringent requirements with respect to frequency stability of the rig, So I settled for PSK63.

I now have a test system running at PI4TUE in Eindhoven. It allows me to download the mail, but not to upload it. That is because gMFSK at the server end is running without AFC. If I switch AFC on, the center frequency of the PSK detector runs away... so i cannot find the right frequency to raise a connection.
Also the checksum is calculated over a complete message, so in case of error (1 bit is enough) the whole message, sometimes 4 k, has to be repeated. Fortunately, Paul Schmidt, K9PS has written a specification for a block oriented link layer protocol for use at rf digital modes which I can use, so back to the keyboard....

This leaves 2 sub projects on the todo list:

* Hack gMFSK such that it goes back to it's home frequency at regular intervals
* Implement the block oriented link layer protocol in PERL.

This will be fun....

> I thought I had read in one TLF posting about possibly having a TLF
> Live CD where TLF can just be operated while the ham cd is inside the
> laptop. Â Is this going to happen or has
> it happened already?

actually it happened about a year ago, I have made an update to the first pilot system on January 17th 2005, just in time before my winter holiday trip. Since then I have not had any comment or bug report about it, so there are 2 possibilities.... either nobody is using it, or it works so well nobody is complaining.

The dxpedition disk project was started after my experience with the TS7N dxpedition,where I was responsible for the networking of several Window$ laptops. I have written an article about it in the german Funkamateur" magazine, an english translation of the story is available in http://www.iae.nl/users/reinc/Chaos.html.

There had been quite some discussion on the Linux ham forums about a linux distribution on 1 or 2 floppy disks, but nobody did something about it. At that time (around Feb. 2001), still a rookie at Linux, I had started tlf as a programming exercise. It turned out that tlf was a candidate for the contest distribution together with Cx, a CT Linux clone developed by a team of people from the BCC (Bavarian Contest Club). It looked like Cx was dead. So tlf was included on a 2-disk Debian distribution especially for contesting.

I had never planned to follow this up, and concentrated on finishing tlf. The TS7N exercise triggered the first live CD based on Morphix, a Knoppix variant of Linux. The idea was to show the Linux community how easy it was, and I hoped someone would pick it up as a project. Of course this did not happen, and I put the ideas on ice....

In January 2005 I could not resist having another go at it, and made the system even more flexible by allowing logging to USB stick or floppy disk, and even using the underlying Windows hard drive to store the configuration data, allowing 1 floppy to hold 70.000 qso's. I am now waiting for reactions, and when nobody picks up the project I will freeze it (or develop it further for my own purposes).

The second version is described in http://www.iae.nl/users/reinc/dxpedition_disk.html.

To sum it up, it allows most Window$ laptops to run a variety of Linux programs without writing to the window$ drive. (The log goes to USB or floppy). And allows me to configure a network of laptops all running exactly the same software.

When you can spare a few GB on the hard drive of the laptop, partitioning and using it as a dual boot system is definitely the way to go. Remember that a live CD steals time from the system. As soon as the application is running it
will be fast enough on a 250 MHz system (especially tlf, as it does not use graphics). But you will spend quite some time starting the system and loading apps. I recommend the free UBUNTU distribution. It is based on Debian, the most stable distribution around, and it is updated every 6 month. Actually I switched from SuSE to UBUNTU quite a while ago, and have it running on most of my systems now... it runs tlf and gpsdrive (what about a nav system for your tricycle... wouldn't that be ultra cool?) in my camper. You can find out if it likes your hardware by trying the UBUNTU live CD... (http://UBUNTU.com).
If I am not mistaken they are working on an on-the-fly partitioning system... And if you are stuck there is TONS of people able to help you on the net (try me...).

Hint: If you want a dual boot system, first put windows on it, and Linux afterwards (after partitioning of course). On my laptop each OS has 10 GB space (I need Windows XPpro to update my ORION hehe...)..

Wilbert, ZL2BSJ, said he would like to have the "start sending now" feature of Trlog implemented in tlf. Until now I had been hesitant to implement it, as it does not fit my style of working pile-ups.
During the last years I have learned to type the call into the computer during, not after reception. That means when the calling station is finished sending his(/let's not forget her) call, I have only one more character to type. Moreover this way I use the computer as a 'scratch pad' so I don't have to remember the call.
"Start sending now" also means an ADDITIONAL key to press. Which means 10.000 extra keys during a typical CQWW-CW weekend (we only run at CT9L, hardly any time for S&P). But o.k., not all of us need this speed.
I took the easy approach... First I had to find a key that is not too difficult to find. I think the only one that qualifies is the space key. It is the largest one, and provided you have at least one thumb, a little training will do the job.
After 30 minutes it worked. You type e.g. ZL2 [space] and the cwdaemon starts outputting crisp morse code. At 28 wpm, there is more than enough time to add the suffix before tlf adds the '5NN Whatever...
Your Mileage May Vary, it does not work for me.

Then I thought I might as well have a go a the "start sending after x characters" function, which is quite similar, only you actually SAVE a keystroke...

It works like this: I send ZL2, and the cw output starts... I type the suffix and tlf sends the rest of the message without having to type ENTER. Now if that's not efficiency...
I then experimented a bit with different speeds, and found that for me 4 characters is best over 40 wpm... it takes a while before you have learned to wait before typing the 4th character, as the other station will need time to switch back to rx.

So we now have both methods available, I uploaded tlf-0.9.23 to the websites

All in all some nice stuff to experiment with. And that's why we're in it....

Any comments?

tlf-0.9.23
==========

- incorporated patch from W9WI fixing a bug in the voice keyer
- changed cw speed control: now default active in call and exchange fields, even if field is not empty
- changed qso save logic: RETURN now always logs the qs in SSB and in general qso mode.
- New parameter: CHANGE_RST. If set in logcfg.dat, Pg-up and Pg-down will change RST instead of CW speed if field is not empty. Default: off.
- manpage updated for version 0.9.23

Tested o.k., ready for release into the cruel world. If I have some time tomorrow I will have a look at the "Start CW before call is complete" requirement... will be fun to program.

Until today I have kept a journal on my PALM... An IBM C3 Workpad, generously offered by one of my employers who thought it would increase my efficiency. I am mainly using it as a reading device for ebooks (I am in the middle of Robert Jordan's Wheel of Time serial). And for taking notes of course. I hope this blog will be a worthy successor. I need something I can read in a cyber cafe down the road. They are available in most medium sized cities now, even on our favourite Island Vlieland.
This morning I have spent 3 hours testing the new release of (tlf). It is raining anyway. Southern Spain really beats Holland with respect to sunshine...