pa0r

This is a copy of the email I just sent to my ADSL provider. Sorry it is in Dutch.

They are pestering me with spam offering to join their music stream service, and give 40 downloads per month free. But they are only supporting IE6. They suggest I 'UPGRADE to WINDOWS XP' To help you a little with the translation: ACHTERLIJK means BACKWARD (as in medieval).

To: customerservice @ planet.nl

quote

Ik had niet gedacht dat jullie zo **ACHTERLIJK** zouden zijn om Firefox niet te ondersteunen met jullie mediastream gedoe. Ik stel dan ook geen prijs meer op 'aanbiedingen voor gratis download'. Dit is een FARCE!!
UPGRADE (???) naar Window$ XP? Ik dacht dat ik het met professionals te doen had.Misschien moet ik mijn ADSL service maar eens upgraden.

Ik heb dan liever dat jullie mijn abonneeprijs lager maken.

Ik ben hierover bijzonder geschokt.

Hebben jullie aandelen Miro$oft?

Groeten,

Rein Couperus (sinds 20 jaar tevreden Linux gebruiker).

P.S.: Ik heb me dus maar weer afgemeld.

unquote

We are back home. The weather forecast for the next week is miserable, and we had a fine sailing week. Temperatures of 15 degrees C during the daytime are not good for my Rheuma-struck hands and feet. We don't mind having that in the evening, or when we are in a harbor or just sitting hi and dry on a sand bank. Our Diesel heater does a perfect job of making the boat a cosy place. We did a lot of reading (I read Dan Brown's 'Digital Fortress"), and I did not have enough power to run the computer all day. Which made it a real relaxed operation. I could not prevent getting a few good ideas for pskmail though, so the next few days will be quite busy :)

We took all the stuff from the boat, as we can take the camper when we go next time to lay the mast and make water tanks and sanitary system ready for the winter. Then the boat can rest for 5 months on shore. We have decided to go early next year so we don't run into the time trap like this year. Plans are to visit the German tidal waters in May 2006 with some friends , and if the weather is good enough to continue to Denmark. But that's still some time off.

First we have to clear the mess we have taken home. You cannot imagine (we cannot) the size of the heap of clothes, books, shoes, radio gear, canned food, etc... our boat is hiding during the season...

I have suggested we just put all the stuff into the camper...

At the moment we are sailing on the frisian lakes. We have hit the nice weather, and we think we will be here for at least a week. Meanwhile I am preparing the next goodies for PSKmail.

I had problems when I ran several programs like firefox, gMFSK, gprsdrive, Glade, together. It would just lock up the laptop (256 MB, 1.2 GHz). Somehow I had messed up the swap space when I upgraded from UBUNTU 0.4 to 0.5.

Swapon did not work. It said 'Unvalid parameter /dev/hda3'. cfdisk revealed that /dev/hda3 was available as type 82 (Linux swap partition). 'Free', however, showed no swap partition. And 'top' showed Swap:0.

The problem has been solved; the swap partition was not initialized. After a 'mkswap /dev/hda3' and 'swapon' I now have 1 GB of swap space available again.

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.

We are momentarily in the field day location of our local ham radio club, and as there are hardly any activities I could spend the afternoon testing various antennas for use on the camper.
Firsst I made sort of an half sized inverted Vee which is linear loaded and folded back onto itself for 60% of the length.
With this antenna, which remains inside the footprint of the camper I could work my own server at home on 80 meters (26 km) and the PI4TUE server in Einhoven on 30 meters. The 80 meters signal was S7 max. with steady QSB down to S2, The signal on 30 meters was only S0 but workable with a lot less QRM.

Then I used the 20 meters wire for a straight horizontal quarter wave ntenna. This gave less QRM and a steady S8 on 80 meters. Good going for such a simple antenna. he wire was only 2 meters high, so I did not need the fishing rod mast!!

- via PSKmail -