Sunday, July 18, 2010

Whats on the bench

Its been a while since I've done an update, so though I'd do that now...

Since I saw 'Three More Words' play a while back at Fowlers, I've been reading up on guitar pedals. I the gig was at a Triple J band competition. There were a few interesting bands. My nephews played a good set, but to my ears at least, I think were let down by the guys on the mix desk. Other bands sounded good and were mixed very differently. Perhaps its as the lads intended, perhaps their pedals?

Any how, there is plenty to read on guitar pedals. A lot more than I expected anyway. There seems to be a religious divide between Hi-Z, unit gain, buffers/amps before pedal and not. Why is this so? I can only put it down to the desire for minimalism/simplicity and/or the old school. The reasons for using Hi-Z buffers and drivers sounds reasonable.

Anyhow, I think I'll do some more work with the audio oscillators and tinker a bit. Thinking about these things as audio 'filters'. I expect it can only help later with debugging AF blocks in radios.

Also on the bench is another lantern prototype. Needs a lot more work, but there is a 28 pin socket, RGB LEDs and associated stuff. Next to add is the ISM band qrpp radios and drop in the ATMEL328 and program it up. =)

Along with an 80 meter receiver project. Using the shottky diodes and ferrite toroids in a component draws that I purchased at a club auction at least a month ago, I built up a doubly balanced mixer. Its now connected to the AF amp and LO on the direct conversion receiver. Now to finish the band pass filter and graft on an antenna input. I found the same circuit in 'Understanding Amateur Radio' from 1977.

So I wonder if this radio was put out as a paper or article by Wes Haywood around 1968? The one that George Dobbs found and built in 1968. In fact I wonder if this is the 'missing' direct conversion receiver that Bill Meara found back in the mid seventies and tried to build as a teenager?

Given I had a birthday recently, I'm inspired to build a radio that is vintage from around the year of my birth. Something designed in the late sixties or early seventies suits and using parts from the early seventies is what I'm aiming for. When I've upgrade my license I'll build a transmitter to match. I suppose it all depends on finding suitable parts, as leaded components are becoming harder and harder to find I might have to find some vintage kit to rebuild my project from. We shall see...

Last weekend I went to a 'zine workshop by the guys from Format. Yes thats how to make 'zines. Pronounced 'zeens'. Little homemade, often short booklets on all sorts of topics. Some examples of zines at the workshop were; mini comics, howtos, short stories, poems, lots of art and collage, just to name a few. I made a 'how to make a Pixie ][' on an A4 page folded to make 8 little pages. Worked out pretty well. Thinking about what other little projects; AF or RF kits, I can fit into that format. Or perhaps it might be better to get 8 A5 pages on two sheets of A4 folded in the middle... more options to explore. I think the first one needs to be about ugly and manhattan construction.

Oh and I picked up a 'little' oscilloscope. Should get in contact David Rowe and return the one I borrowed. Has been a wonderful tool to have. Looking forward to work on gear in the higher part of the HF bands.