Tuesday, September 21, 2010

Back to studying

Well its been a while since I've regularly had a toasty soldering iron on the workbench. Well for that matter its been a while since I've had a workbench. I have a bench in the shed, but its been so cold and wet that it is really not any fun spending any time there. Also there have been some house renovations that have made space an issue, to the point that I boxed up a bunch of books. I put them "somewhere".

So last weekend I dug out those "missing" books and flicked through looking for ideas. I have some work to do and need to brush up on a number of things. I downloaded the standard and advance syllabus as well so that I can tick off all the topics once I've covered them.

I also picked up a couple of Drew Diamonds books on the week end at the symposium; Radio Projects for the Amateur, volumes 3 & 4. I have been wanting to get my hands on these for some time. They were the first homebrew books I laid eyes on, on the WIA book store. However funds have been an issue for a while so they have been out of reach. Gladly no more is that a problem =)

I've made it through the scary bills part of the year and will be saving up for the "tome" of radio theory from the WIA, Radio Theory Handbook for Amateur Operators (5th ed.) by Fred Swainston, along with EMRFD.

How ever the cost of these seems to sky rocket every year and the postage is becoming outrageous! Oh well, heres hoping that I'll get the reading material before the end of year break to read during those lazy days of summer when work closes down for a bit... Mabye even get the chance to get away for a bit to unwind and read.

In the mean time, I want to read SolderSmoke the book again.

There were some rather crafty ideas presented in there that I need to get my head around again. Need more time on the workbench tinkering. Core things being to straighten out the mutual coupling/inductance and the whole transistor holes thing in my head =) Most the other ideas work for me. I need to tinker with the math around power calculations too. I kind of get it, but nothing backs it up like doing. I figured out current limiting resistors on the last read through =) Also can't wait for Bill to get another SolderSmoke podcast out. Its funny I miss that more than any other regular release HAM radio news. Would be great if it was monthly even. I keep thinking about putting together a podcast, but am still too shy of a microphone.



Monday, September 20, 2010

Word of the day: flum

flum, v: to move or position an item on a quickly setting glue.

Yesterday I went along to the AHARS symposium. I had a wonderful time. The impact of the event probably won't be fully realised for some time yet. However, I took some notes and a few photos. Also will put together a couple of posts here about the symposium and ideas gleaned from it.

I like to write down words of phrases that I haven't heard before. 'flum' was one such word that I noted yesterday. Thank you to Drew Diamond, VK3XU, for extending my vocabulary. I have more notes to read through and plenty of googling to do =)



Thursday, September 16, 2010

Exciting things at work

There is much cheer here at work at the moment. This is the season for the anual University rankings and we did pretty well.

Also this week, I am working on posting the videos of OpenDay Blog from last month. We also put them up on our vimeo channel.

We've been pretty busy for a while and next week we are interviewing for another programmer. So its a happy time here after lots of work leading up to OpenDay and other campaigns we've been working on.

73, Kim

Friday, September 10, 2010

junk code

Today I was tidying up my junk code directory. I cut this up one lunch time when I couldn't focus on the FTP server code I was bashing my head against - now sorted.

So, whats this for? There was a challenge a while back on the Brainwagon blog, using /dev/urandom to generate a list of 'random' characters to fit a pattern, ten blocks of five characters, each block separated by spaces.

This is used for testing cyphers and other fun stuff =) I spent some time when I was back in London working on some cypher and compression code. So I can vouch for the need for tools to generate large random sets - one time pads - that you can play back over and over to make sure that you reproduce that bug, with different versions of your code. Correctness was the issue at hand. Later came the performance issues.

So, Mark posted a "Unix/sh challenge". My brain needed a break and who can resist a bit lunch time shell coding? Well I tried and I got it pretty close. Anyway I decided to try a Perl version to see if I could make it easier to read, then make it faster.

my $limit = 10_000;
my @cypher;
while (<>) {
my @chars = split(undef, $_);
for my $char (@chars) {
if ($char =~ m/[A-Z]/ ) {
push @cypher, $char;
if ($limit <= scalar(@cypher)) {
my $offest = 0;
while (@cypher) {
for (1..10) {
print " ";
for (1..5) {
print pop @cypher;
print "\n";

72, Kim