Showing posts with label pic. Show all posts
Showing posts with label pic. Show all posts

7 May 2013

The £20 decent HF transceiver thoughts

I never fail to be impressed by what other people know and that I don't.  Several people have responded to my post about the "£20 decent HF transceiver challenge" with ideas that use PICs and similar micro-controllers in novel ways to generate SSB signals. In all honesty I wouldn't have a clue about how to start doing this, so I am VERY impressed.

My own approach to the £20 transceiver would be very low tech indeed: not an IC in sight probably and certainly no processors. Having said that, I would be very interested to see how such novel approaches could help to realise a low cost decent HF transceiver. As an example of this look at the HF WSPR transmitters produced entirely using a Rasperry Pi PC.

One thing that life has taught me is that it is impossible to know about everything: some of us know lots about RF (I am only a surface scratcher) whereas others know lots about software or something else. Some very talented people have a wide span of knowledge.

We should be grateful for the unique knowledge WE have and gracefully accept that others know lots more than us about something else. It never does any good to be stressed about what we don't know. In my work days I always told my staff never to be afraid to ask the dumb questions as there are lots of others waiting for someone to ask them!

Incidentally I have done nothing yet towards this design. Weather has been too nice to be inside engineering, HI.

8 Mar 2013

Gaps in my knowledge

Sometimes I feel a complete fraud: people drop me emails and ask me questions and I am completely at a loss how to answer. The reason is there are an awful lot of things that I should know about that I don't. As an example, PIC programming: many of the things I want to do, like make a simple VLF frequency generator with FSK keying could probably be done very easily with a PIC, but I have never, ever, used a PIC and certainly never programmed one. There are whole areas of circuit design in which I'm very weak, for example digital logic, microprocessors etc.  Even my RF knowledge is frankly far from expert.  In my professional life I managed to get promoted into management roles where my "hands on" RF skills were not an embarrassment! You'd be surprised how many managers in RF jobs are not actually that hot at RF design.  Mind you, it helps to have a "jizz" (instinctive feel) for RF and I did (and still do) have this.

The reason I raise this is to give others hope. Even without knowing too much a lot can be done and we are never too old to learn new tricks. There are far too many things to know about to be experts in everything and the best we mortals can do is try our best in a limited area. This is why I concentrate on simple HF and low VHF QRP projects, optical and VLF work which I can get my head around. I'll leave the complex stuff to people far better than me.

http://uk.farnell.com/productimages/farnell/standard/1701537-40.jpg
At some point I may have a go at PIC programming but writing software was never my strong point. Neither was maths for that matter. Talking about PICs, if I wanted to have a go at PIC programming what do people recommend for going about it? What is the best (simple please) book and what is the best development kit on which to try out the programmed devices?

31 Oct 2009

LC Meter - a nice kit

Some months ago I bought a PIC based LC meter kit from the Cambridge Radio Club (CDARC). This was a club project and the unit allows very accurate measurements. The kit had remained unbuilt until today when I decided to build it. I'm impressed: it went together well and worked first time. The quality of the kit is first class with a custom case, silk screened PCB and good instructions on the club website. This little box will measure from low pF and nH right through to uF and mH. I can see it being used almost daily. I believe CDARC is to make these kits available more widely. Go and buy one for £50.