Monday, May 31, 2010

Arduinos in from Little Bird Electronics today

Last Sunday I ordered a few components from Little Bird Electronics.

A Arduino Duemilanove, several bare Arduino Atmel328, 74HC595, DIP sockets and a bunch of sparkfun stickers. The RTFM stickers are popular ;)

So, some of these bare Arduinos will be used for the lantern prototypes. Some for mcpu for the Nintendo controllers with the ISM band wireless stuff I got last time, one for a controller for a VFO/DDS for my receiver projects and some for temperature logging with a DS18B20. I got one full Duemilanove board to do the initial prototyping on and to program the rest. Should be fun =)



80 meter DC Rx - Debugging lack of mixing

Hit the issue with nothing coming out of the mixer. Using the signal injector feeding into the RF input port, I could hear RF static type noises.

So, I spoke to a few folks at the last AHARS meeting. Specifically what drive level from the LO is needed to turn on the 1N4148s. Jim, VK5TR suggests that I will need +7dB. Darryl, VK5JDS suggest about +6dB.

So I made an RF probe, a 10nF capacitor / 1N34 diode / 47M resistor style probe that I attached to the front of the DVM. A simple T shaped arrangement, on a little scrap of copper clad board and put a BNC socket on one end for a CRO probe, the other to a pair of banana plugs to attach to the DVM.

Wonderful; 0.4 volts from the LO. Now to match +7dB up to what volts output that should be...



Sunday, May 16, 2010

80 meter DC Rx - Debugging AF Amp

This morning I dug out the old signal injector, that I picked up at an auction a while back and proceeded to fumble my way around the AF Amp from the crystal ear piece back towards the input. Signal from the input of the PNP, but not from the input of the NPN. So out with the datasheet, original circuit diagram from G3RJV and my hand drawn copy. I was looking for mistakes in my copy again, when I noticed that the CBE notation on the PNP and NPN. I had correctly copied them down, but wondered if my implementation on the board was correct. The 2N3904 datasheet said no, I had swapped the C for E on the NPN... Fired up the soldering iron, and went off to make a cup of coffee. Ten minutes later I had the signal injector sending a wave through the whole amplifier now. Success at last!

So I reassembled the AF Amp board on the main board and turned it all on. Still no HF static, so I proceeded to poke around with the signal injector, when I put it on the antenna input I could hear some HF static. Well I think it is. It is quite possible that the RF oscillator isn't puting out enough power to turn on the diodes in the ring mixer. Now to make a RF power meter and test the mixer.

You will note in the images, the 'temporary' work bench with tools, the radio shack signal inject has been a good investment and the NPN transistor - 2N3904 - now in the correct orientation.


Saturday, May 15, 2010

How about a DDS tuned from an Arduino?

I received my Arduino back in 2009 at LCA. I've tinkered with it a bit and really haven't had to many bright ideas about what to use it for. I've been cutting some code recently for the magic lantern project, but the short version is, I need to place another order to get Atmel328s because the Atmel168s ran out of stock.

Anyhow, in the last order I to Little Bird Electronics I got some DS1077 programmable oscillators. They are a tiny little 8 pin SOIC. Been reading up about how to use them now. They have a I2C bus and there is a library for Arduino to bitbang out the commands to send out over I2C. Benlemasurier's DS1077 Library looks like it should do the job nicely. Now to find a carrier board to solder them up to, or perhaps make one...

What will I use them for? Well, a general coverage receiver is the obvious project. I think that that will be a while off yet, but its on the cards.


Monday, May 10, 2010

80 meter DC Rx step 3 - VFO built and working

Built up the VFO yesterday, put it on the frequency counter. Seems to even been in the right part of the band. I drew up the circuit on a little note pad, however I miss drew the tuning inductor and the tuning capacitors. So after assembling most of it, I thought that I would double check the original photo and noticed that my selection of capacitors was quite incorrect! The tap also needed extra reading, after I had to calculate the different number of turns from the original T68-2 to us a T50-2 instead. I had to unwind and add a tap six turns from the grounded end, worked it out in the end. Its stable enough once warm, although it was sitting on the washing machine with the back door open with a gentle breeze. I need to find some polystyrene glue or "Q Dope", I believe its called, for gluing the inductor windings. Now to build the filter and find why the AF amp isn't working.


Tuesday, May 04, 2010

30 meter dipole down

high winds in the night snapped the poly cord holding the high end =(
it was old and sun affected.
need to rethink materials.
i've heard about dacron rope.
found none locally yet.


Monday, May 03, 2010

looking for an interactive perl shell...

Been playing with Devel::REPL. Its interesting but segfaults a bit. Not sure of thats a problem in my local::lib install, but that much flail is irritating. I like the way most things work, but need to get my head around some strange ness in for loops =)

So tinkering with it to do interactive DBI and DBD::Oracle stuff. sqlplus is fail on a stick without readline support =( I wish that Oracle would move catch up to at least the mid 1990's and add at least basic readline functionality. I wonder if you have to pay extra for that?

I'd like to try Zoidberg, but the current version fails to build. Maybe next version. ;)

Perl 5.12.0 has been released

Reposting the new release of Perl 5.12. I can't believe that Perl 5.10.0 was release over two years ago, on December 18th, 2007. Has it really been that long?

Perl 5.12.0 has been released!

Release notes follow.

FromJesse Vincent
DateMon, 12 Apr 2010 22:28:04 -0400
SubjectPerl 5.12.0 is now available

'Please would you tell me,' said Alice, a little timidly, for she was not quite sure whether it was good manners for her to speak first, 'why your cat grins like that?'

'It's a Cheshire cat,' said the Duchess, 'and that's why. Pig!'

She said the last word with such sudden violence that Alice quite jumped; but she saw in another moment that it was addressed to the baby, and not to her, so she took courage, and went on again:--

'I didn't know that Cheshire cats always grinned; in fact, I didn't know that cats COULD grin.'

'They all can,' said the Duchess; 'and most of 'em do.'

-- Lewis Carroll, /Alice's Adventures in Wonderland/

On behalf of Perl's development team, It gives me great pleasure to announce the release of Perl 5.12.0.

Perl 5.12.0 represents approximately two years of development since version 5.10.0 and contains over 750,000 lines of changes across over 3,000 files from over 200 authors and committers.

SHA-1 signatures for this release:

f533687077e2da113b48a6c5e578f4a206fbf173 perl-5.12.0.tar.bz2
5341e60d099fdda71bc33b2a36e417fc0926518f perl-5.12.0.tar.gz

You can download this release from your nearest CPAN mirror or from:

This release cycle marks a change to a time-based release process. Beginning with version 5.11.0, we make a new development release of Perl available on the 20th of each month. Each spring, we will release a new stable version of Perl. One month later, we will make a minor update to deal with any issues discovered after the initial ".0" release. Future releases in the stable series will follow quarterly. In contrast to releases of Perl, maintenance releases will contain fixes for issues discovered after the .0 release, but will not include new features or behavior.

Notable changes in Perl 5.12 include:

  • Perl now conforms much more closely to the Unicode standard.
    Additionally, this release includes an upgrade to version
    5.2 of the standard.

  • New experimental APIs allow developers to extend Perl with "pluggable" keywords and syntax.

  • Perl now has a better sense of time and will be able to keep accurate time well past the "Y2038" barrier.

  • New syntax allows developers to specify package version numbers directly in "package" statements

  • Perl now warns the user about the use of deprecated features by default.

Perl 5.12.0 features numerous new features, optimizations and bugfixes. You can find a complete list of these changes on the web at:

As specified in the licenses for Perl (see the files named Artistic or Copying in the Perl distribution), THIS PACKAGE IS PROVIDED WITH ABSOLUTELY NO WARRANTY.

Based on extensive testing over the past 3 months, we believe that Perl 5.12.0 is ready for production deployments. However, you should never blindly trust any software vendor. It is imperative that you test new software before deploying it in production.

While we have worked tirelessly to ensure that Perl 5.12.0 will be a solid platform for your software, it's possible that issues will be found after release day. You can find a current list of known issues with Perl 5.12.0 at

Perl continues to flourish into its third decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.12.0:

Aaron Crane, Abe Timmerman, Abhijit Menon-Sen, Abigail, Adam Russell, Adriano Ferreira, Ævar Arnfjörð Bjarmason, Alan Grover, Alexandr Ciornii, Alex Davies, Alex Vandiver, Andreas Koenig, Andrei Yelistratov, Andrew Rodland, Andy Armstrong, Andy Dougherty, Jose Auguste-Etienne, Benjamin Smith, Ben Morrow, bharanee rathna, Bo Borgerson, Bo Lindbergh, Brad Gilbert, Bram, Brendan O'Dea, brian d foy, Charles Bailey, Chip Salzenberg, Chris 'BinGOs' Williams, Christoph Lamprecht, Chris Williams,
chromatic, Claes Jakobsson, Craig A. Berry, Dan Dascalescu, Daniel Frederick Crisman, Daniel M. Quinlan, Dan Jacobson, Dan Kogai, Dave Rolsky, David Cantrell, David Dick, David Golden, David Mitchell, David M. Syzdek, David Nicol, David Wheeler, Dennis Kaarsemaker, Dintelmann, Peter, Dominic Dunlop, Dr.Ruud, Duke Leto, Enrico Sorcinelli, Eric Brine, Father Chrysostomos, Florian Ragwitz, Frank Wiegand, Gabor Szabo, Gene Sullivan, Geoffrey T. Dairiki, George Greer, Gerard Goossen, Gisle Aas, Goro Fuji, Graham Barr, Green, Paul, Hans Dieter Pearcey, Harmen, H. Merijn Brand, Hugo van der Sanden, Ian Goodacre, Igor Sutton, Ingo Weinhold, James Bence, James Mastros, Jan Dubois, Jari Aalto, Jarkko Hietaniemi, Jay Hannah, Jerry Hedden, Jesse Vincent, Jim Cromie, Jody Belka, John Malmberg, John Peacock, John P. Linderman, John Wright, Joshben Jore, Jos I. Boumans, Karl Williamson, Kenichi Ishigaki, Ken Williams, Kevin Brintnall, Kevin Ryde, Kurt Starsinic, Leon Brocard, Lubomir Rintel, Luke Ross, Marcel Grünauer, Marcus Holland-Moritz, Mark Jason Dominus, Marko Asplund, Martin Hasch, Mashrab Kuvatov, Matt Kraai, Matt S Trout, Max Maischein, Michael Breen, Michael Cartmell, Michael G Schwern, Michael Witten, Mike Giroux, Milosz Tanski, Moritz Lenz, Nicholas Clark, Nick Cleaton, Niko Tyni, Offer Kaye, Osvaldo Villalon, Paul Fenwick, Paul Gaborit, Paul Green, Paul Johnson, Paul Marquess, Philip Hazel, Philippe Bruhat, Rafael Garcia-Suarez, Rainer Tammer, Rajesh Mandalemula, Reini Urban, Renée Bäcker, Ricardo Signes, Richard Foley, Rich Rauenzahn, Rick Delaney, Risto Kankkunen, Robert May, Roberto C. Sanchez, Robin Barker, Tomoyuki Sadahiro, Salvador Ortiz Garcia, Sam Vilain, Scott Lanning, Sébastien Aperghis-Tramoni, Sérgio Durigan Júnior, Shlomi Fish, Simon Schubert, Sisyphus, Slaven Rezic, Smylers, Steffen Müller, Steffen Ullrich, Stepan Kasal, Steve Hay, Steven Schubiger, Steve Peters, Tels, The Doctor, Tim Bunce, Tim Jenness, Todd Rinaldo, Tom Christiansen, Tom Hukins, Tom Wyant, Tony Cook, Torsten Schoenfeld, Tye McQueen, Vadim Konovalov, Vincent Pit, Hio Yamashina, Yasuhiro Matsumoto, Yitzchak Scott-Thoennes, Yuval Kogman, Yves Orton, Zefram and Zsban Ambrus.

This list is woefully incomplete as it's automatically generated from version control history. In particular, it doesn't include the names of the (very much appreciated) contributors who reported issues in previous versions of Perl that helped make Perl 5.12.0 better. For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl 5.12.0 distribution.


Jesse Vincent

30 meter receive dipole up

On Saturday Karl, VK5FOSS came over and we hacked together a new antenna for 30 meters. Its amazing what a second pair of hands can help achieve, with masts and measuring. The dipole is for 10.140MHz receive for QRSS. Runs approximately North-South, so should have VK2ZAY broadside off the eastern lobe. Maybe VK1AA also.

I no longer have a dipole for 40 meters. To be honest I wasn't using it very much. There just isn't space at the moment. Everything on the work bench/kitchen table is a little bit crowded, aiming to take a week off work soon and get stuck into the painting in the spare room that will become a study for the XYL, then shuffle things around and prepare my study/shack.


Sunday, May 02, 2010

80 meter DC Rx step 2 - AF Amp

Spent a few hours drawing up and building the AF Amp for George Dobbs, 1968 80 meter receiver.

I now have a small board that I can mount inside a tin intended for the receiver. The tin is a bit smaller than A5 sized and about two inches high. The next couple of days should yield an oscillator. I never cease to be amazed at how the time flies when building...

Now moving on to test it. =)