pa0r

It is done. The next release of the PSKmail client will offer the possibility to use Evolution (or PINE, or Mutt, Mailx etc.) as a mail integrator. PSkmail has a menu item 'send mail to mbox',  and when you click on 'get mail' in Evolution the emails you just downloaded with PSkmail are integrated in the mail client. You can do this off-line, PSKmail does not have to run to do this.

The mail send facility works even easier. You write your email in Evolution (reply, forward, address book, all the bells and whistles) and push the send button, as if you are connected to the internet. Evolution will hand the mail over to Postfix, which is the send mail client in most Linux distro's. As your machine is not connected to the net, Postfix will put the mail into the 'deferred' queue.

A cron job (running as root) which runs every 5 minutes picks up the stuff in the outgoing mail queue, reformats (simplifies) it for pskmail and delivers it to the pskmail send queue... All but the necessary (To:, Subject:) headers are stripped, to adapt the format to the 70wpm pskmail data stream. The headers are added back by the pskmail server, which has the necessary data in its user database.

Now you just connect to the pskmail server, push the send button, and off you go... After receiving the "Message sent" from the server the email is deleted from the queue (after adding a copy to the 'Sent' file).

This adds quite a bit of comfort. Of course "There Is More Than One Way To Do It" in pskmail. There is still the 'NEW' routine to write a fast email message without starting Evolution, or you could simply send a single line APRS email message ("We have a new cat")  from the command line....

The next release is due when I get back from our sunny spot in Spain, until then I will be the only one to enjoy this :)

EA/PA0R/P

Since yesterday I can read my PSK mail using Evolution, or with the standard UNIX 'Mail' client (and of course with all mail readers that use the mbox file standard. Here is a pic...

We are now testing the new features of PSKmail; APRS compatibility and rig control.

PSKmail is now able to send and receive short messages via the APRS backbone, rendering a world-wide messaging service. It even has a built-in answering machine, which lets you read your message history in connected mode, even if you have not been 'on-line' for a considerable time. I can now exchange messages with stations active in the 2 meters band in California, and I do it via Per's PSKmail server in Stockholm on 30 meters.

I also implemented a frequency scheduler. The hamlib library does all the work, I only have to make up a frequency schedule and the server will follow. Provided of course that the rig is remote controllable.

UBUNTU-5.10 now supports my USB/RS232 converter (Sitecom) out of the box, and I have tested the stuff with the ORION, which worked fine.

We are planning to set up a server in a rural area here, which will switch between 30 and 80 meters depending on time of the day. I will try to use my old OMNI VI plus which has a 250 Hz filter. The only thing is the multband antenna. Hopefully we get it installed before we leave for the GREAT TRIP in a few weeks.

The 'connect' sequence of PSKmail is rather long. It looks like 00cPA0R:1024 PI4TUE:24 4EDF1. When link conditions are bad, or the server has qrm on the channel sometimes it is impossible to know if the server is active at all. Of course you can wait for an hour to catch a beacon transmission, but that is impractical for the mobile station who just wants to do a quick APRS update. The beacon transmissions are meant for the server sysops to see if the system is alive. (and to gather propagation info of course).

To overcome this practical problem I have written a 'ping' service. The link layer sequence is '00uPA0R:7 ABCD' , short enough to penetrate most qrm. If this is not working, the link will be unuseable anyway...

The 'u' in the header is an indication that this is a datagram service, not unlike the packet 'UI' sequence. This saves a lot of time on the channel. The client has been changed to include this. A ping is started with ctrl-p, and the server will answer with a similar packet with its call inserted. An adjustable delay at the server will allow more than 1 server to answer to a ping, so you can see very quickly which server has the bes chance of being useable.The ping service will be included in version 0.1.6. More to come...

After 3 days x 8 hours of testing I have decided to release the next PSKmail beta from the lab. I have not been able to crash the server anymore. I have also been able to add a status messaging system to the client. Now it is time to tweak the timing. This will need a lot of testing, as there are a lot of variables. The varicode makes blocks of different length. The automatic block length corrector makes blocks of 8 - 128 characters. We don't want the server and client to end up sending synchronous polls to each other. Don't laugh, it does happen.... If you make the idle times of both client and server self-adjusting they will get into step with each other, transmitting polls at the same time.

If somebody has a strategy to prevent this, I'd be delighted to implement it. Meanwhile, I will start thinking... For the moment the best strategy seems to be to fix the server times and make the client choose from a set of times that will prevent deadlock. This idea is implemented in version 0.1.4. But the times have not been optimized yet, I have to do that empyrically.

I visited the server at the TU Eindhoven this afternoon. I measured the antenna SWR at 4:1. Which is not too good at the end of a 2-wavelength cable. When I connected the antenna to the transceiver I must have fixed the connector (it is often disconnected when there is a contest over the weekend), as when I came home the signal had improved from S0 to S7. Which if I calculate correctly is a difference of 36 dB.

The system worked well with the S0 signal, and I had throughput even when there was S9+ QRN.

My connectivity problems are solved, and I can throw the MFJ pactor 1 controller away.

Today I have been testing the newest feature of PSKmail - the dynamic block length adjuster - it really is fun to watch the server adapt to the channel conditions whilst they are changing. The length of the payload block now changes from 16 characters to 32 to 64. Even 128 and 256 character blocks are possible, they can be used on a channel with little QRM, but it is much more fun to watch the shorter blocks... For a 'normal' HF channel 16 - 64 is near optimum, as the arq protocol overhead of a 64 character block is only 12.5% and still only 50% on 16 characters (overhead is 8 characters per block).

The PI4TUE test server has an intermittent contact somewhere in the antenna or in the coax, as the signal jumps from S7 to S0 during daytime, and from S3 to S0 with heavy QRM during the evenings. PSKmail does not mind. Even on an S0 signal the block length settles on 64 chars during the daytime, whereas in the evening (S8-9 QRN) the block length goes down to 16 payload characters.

I found another bug today. The NEW MAIL panel does not send quotation marks to the application... I will have to find out if that is a 'GTK2 feature' or a PERL quirk.

I guess I will be able to release the changes somewhere around sunday night.

All information about PSKmail has been transferred to the PSKmail WIKI. There you can follow the rest of the adventure.I am quite enthousiastic about it, as it brings all information together in 1 place.

We are now doing a test installation on a virgin Mandrake system in Sweden, which is giving exremely helpful information. If you have any remarks, comments, wishes, or just want to gab, please use the WIKI for that, it has a communication channel dedicated to PSK63, PSKmail and other digital modes, and there is lots of space for users to exchange information.

The WIKI also allows other people to work with it, it has taken me a lot of time to come this far, and I need time for the background here, and I must go back to TLF for a maintenance round. Maybe I should also make a WIKI for Tlf?

This afternoon I will go shopping with the XYL....

I wanted to play with antennas, but it rained all day. So I finished the GUI for PSKmail. The menu system works now like I need it. I also upgraded the 'NEW' window, so you can now write the whole email without going into 'gedit'. Neat.

It was not easy, GTK2 is not documented well. I spent hours on the net looking around for a method to read the text from a GTK::TextView widget into a string. I do have the FAQ online, but that did not do a good job of typing the parameters to call. And the man page you will find on Google is from Hong Kong (1000 x) and only tells 5% of the story.

Anyway, I did it. I added capability in the menu to save the mailfile and the send file for the next session. And yes, you can now view the readme from within the client....

I also got first contacts for server deployment. Nice. If you need help, you can try to message me at pa0r@jabber.ccc.de, we can always use world-convers (channel 4791) afterwards. Of course jabber also supports chat..

I wondered how the news got around so quickly, but then I found an email from pe1icq who daid he had added PSKmail to the LINUX HAM list.

My son says, if I don't stop messing with it, PSKmail will soon include emacs.

Come to think of it...

I have improved the special gMFSK-0.6 version today. Until now I needed separate versions for client and server use. Moreover I did not like the way I prevented the server from wandering around the band....

Now gMFSK-for-servers does the following:

For the client:

• Send a file gmfsk_autofile if it finds one in your home directory. You can test it with: echo "test" > gmfsk_autofile.

For the server:

• Send a file gmfsk_autofile if it finds one in your home directory. You can test it with: echo "test" > gmfsk_autofile.
  
• Before sending anything, reset the waterfall frequency to 1000 Hz, as to make sure the server stays put.
• Limit AFC to work between 985 Hz and 1015 Hz. This window has been defined experimentally. The 30 Hz window is small enough to enable immedite signal acquisition (lock) when using PSK63, while allowing the client enough freedom to remain in lock during a frame.

You can switch between the 3 modes:

• For client operation: put a file PSKmailclient into your home directory
• For server operation put a file PSKmailserver into your home directory
• For normal, keyboard-to-keyboard operation make sure above files are absent :)

The new binary is at: http://sharon.esrac.ele.tue.nl/~pa0r/pskmail/gmfsk

You can now use gMFSK to build your own servers... 

O.k., the stuff is out for beta.... Both the server and the client software is available from the web sites:

http://sharon.esrac.ele.tue.nl/~pa0r/pskmail/ for the description...

http://sharon.esrac.ele.tue.nl/~pa0r/pskmail/client for the client programs...

http://sharon.esrac.ele.tue.nl/~pa0r/pskmail/server for the server programs...

http://sharon.esrac.ele.tue.nl/pub/linux/ham/pskmail for the archives....

Please try this stuff and report what you find to PA0R at EUDXF.ORG . Keep the bug reports coming!!!!