Month: September 2010

  • Arnie Coro and the Super Islander

    Looking back over some older email list posts today I came across an interesting exchange of posts on the QRPp list.

    In early August Arnie Coro CO2KK announced latest progress on the ‘Super Islander Version 5 QRP transceiver project’. Key design criteria include using “as much as possible parts that could be recycled from easy to find sources of electronic components” such as toroids from PC boards salvaged from failed compact flourescent globes, and other treasures from broken VCRs, TVs and fax machines.

    Via the short Wikipedia bio of Arnie Coro I discovered a link to more than seven years of transcripts of his weekly radio program ‘DXers UNnlimited’ broadcast by Radio Habana Cuba. Earlier transcripts are here. He also has a blog last updated in June. They’re practical and full of useful ideas.

    One transcript is reproduced on dxzone.com and is an undated description of the project detailing what appears to be the first valve version of the project – I think designed by his friend Pedro, CO7PR. It brings home in a softly stated way the challenges and barriers facing radio enthusiasts in countries which for one reason or another don’t enjoy relatively high wages to afford factory made gear, and who have to be much more resourceful in making do with what they have available to get on the air.

    A rude dismissive comment on the QRPp list prompted a firm but calm response from Arnie.

    “Yes amigos, it is very easy for people having access to the money and the possibility of buying factory built radios or even well designed kits with full instructions and each and every part required… even washers , to just sign a check or complete and electronic transaction that will bring to  their homes a nice piece of equipment…

    But that is not the case for many of us, that do enjoy very much the amateur radio hobby, and think not only about ourselves, but also about those that may benefit from also well designed, easy to assembly and to adjust radios that can be built using locally available parts.

    Try to find even the lowest cost ceramic filter for building a single sideband rig in no less than 130 countries around the world and you will meet with the fact that they are impossible to locate, and the same goes for ferrite and powdered iron toroids, IF transformers, RF power transistors, small relays , RF connectors, resistors and capacitors, not to mention quartz crystals and integrated circuits !”

    SolderSmoke named Arnie ‘Homebrew Hero’ earlier this year.

    Arnie Coro CO2KK – photo by Rodger WQ9E c 2000

    Arnie ended one of his missives to the QRPp list with this plea:

    “Maybe one day the International Amateur Radio Union could sponsor a similar project to help promote amateur radio among young persons that live in poor nations where buying a factory made transceiver may be equal to the full salary of a worker during five years or more !!!”

    I remember that one of the first QRP designs I ever built (back in the late 1970s) was a simple VXO controlled 6 W 20 m CW transceiver that appeared in QST (Dec 1978). It was later suggested as a prototype IARU transceiver as ham aid for developing nations. (This radio certainly worked for me, with a first contact into the US west coast with W6QR from a camp site in Kangaroo Valley!)

    Arnie’s idea appears much more economical and self reliant, drawing on the potential of recyclable components. It’s also a design thought through from a Cuban perspective rather than a first world one.

    You can even hear an interview with Arnie Coro recalling the Bay of Pigs invasion in 1961. [audio].

  • Guide to A123 battery packs

    Charles Preston, a member of the Buddipole User Group email reflector has just posted links to two clear and useful guides to using the A123 Battery Packs available from Buddipole. While the Buddipole site links to documents about the batteries there’s very little practical information available about how to nurture these batteries. Similarly the Cellpro Multi4 charger documentation is more geared to the primary market – radio controlled airplane enthusiasts – so it’s great to see advice directly relevant to our intended use.

    The Revolectrix CellPRO Multi4 charger

    The first document is a Guide for Buddipole A123 Battery Packs and it explains how to maintain them and likely operating times for popular transceivers. The core of the document is how to charge the A123 Packs using the Multi4 charger (also available from the Buddipole site). There’s also mention of how to approach charging the Battery Packs with a solar panel and mention of the Genasun GV-4 Li 14.2 V MPPT controller. BatterySpace.com also sell a version of this charger designed for LiFePO4 batteries. Prices between US$110-119.

    It’s great to have all of this information available.

    The second document is Charging a Buddipole 4S2P or 4S4P A123 battery pack with a Cellpro 10s charger and focusses on the larger charger.

    Three cheers for Charles Preston!

  • webSDR

    I’ve spent a little time playing with websdr over the last day or so. This is certainly one way to achieve the subliminal morse background mentioned a couple of posts ago! (Assuming of course the workload is low and the wifi is up!!). You can see even before you ‘tune in’ if a CW signal might be the right speed.

    I’m impressed with the easy usability of the remote websdr enabled receivers.

    It’s also fantastic to get a clear sense of the band conditions and activity in another part of the world like Reston, VA. No signs of an Australian based webSDR station yet. Bandwidth charges probably have something to do with that.

    The only downside so far is that as the site depends on Java there’s no way of accessing it with the iPad. And the absence of Flash on that device means you can’t use it for the best source of morse ambience – lcwo.net.

  • Subliminal morse

    Tim G4VXE posted an interesting ‘random’ thought about one suggestion he’d heard recently on air to raise your CW speed:

    “one of the ways to improve your speed and competency is to listen to as much morse as you can – for example, have the rig running whilst your watching TV or reading. It’s almost as if the subconscious brain starts to process it and it becomes a ‘background process’.

    This will help you if you want to be able to send/receive morse at the same time as doing something else.”

    It can’t hurt – apart from driving all those around you crazy – and convincing them of all the doubts they already had about you! But maybe that’s what the headphones are for.