Kvindesland

Electronics home brew

My electronics design and home brew is driven by interest and available time-resources. The brewing is usually closely connected to my amateur radio interests and hence the instrumentation setup is catering for that.

Here I am busy working on a PSU for a 145MHz PA.

Instruments

Most instruments are aquired second, third and even more hand. This ensures a comfortable accurancy. Enough to show its going the right or wrong way, but not enough to indicate the finer details that seperates my gear from the commercial stuff. Well, here is a brag list over some of the stuff I have on my shelves:

Voltcraft digital multimeter
Tektronics 100 MHz oscilloscope
HP digital analyzer
MFJ-259 antenna analyzer
1.3 GHz frequency counter, self made!
AF sine and square oscillator, old valves
HF oscillator, old valves

I enjoy making both analog and digital circuits. This attidude surely prevents me from beeing an expert in either field, but I do it for fun. The enjoiment factor is very much present.

The results

My work attitude is to initiate anything that looks fun. Therefore I do several projects in paralell. This delays each of them. From my completed list I so far have among others:

CW filter described in the Norwegian Amateur Radio Magazine Amatørradio January 1980 by LA2IJ.
Control unit for Kenwood radio. TTL to RS232 converter.
AF generator, from the 1994 Maplin Catalogue.
Various battery chargers, NiCD and Pb gel. Mostly own designs.
8031 Microcontroller card. Described in OZ the Danish Amateur Radio Magazine 1991 by OZ1BOV.
PCB exposure box for making my own PCB boards. My design.
Baycom modem. Designed by LA1BR.
5 el Quad for 2 meters, described in QST the American Amateur Radio Magazine January 1995. The project as such is finished, but I still experiment to get the best F/R and gain.
Frequency Counter, described by SM7RIN in the Sweedish amateur radio magazine QTC no 7 and 8 1994. I intend to extend it with an X-tal oven to improve accurancy.
Resistance meter for small resistances.

Outside we find toys for boys of all sizes. The big one is tuning up his 2m quad with an MFJ-259.

The backlog

Due to my project method described above, the backlog is always depressingly long. Projects tend to be prosponed when problems are encountered. Published designs which do not behave as expected tends to mature. Well, here is the list of future joy:

EPROM Programmer, from the German Elektor. Problems with communication with PC. Suggestions????
28 V PSU from the ARRL Handbook 1987. Crow bar does not trig thyristor, I'll try a transistor to trig it. Also tries to find an easy way to implement a variable current limit on the LM723 design.
80 W, 28 V PA for 145 MHz from a design of LA7EU. Haven's really started yet. Want the PSU mentioned above first.
RF signal generator from design in Elector Electronics July/August 1995. Missing some semiconductors.
Variable PSU. My design. Low priority. Haven't needed it desperatly yet.
Power amplifier to my radio. Planning to use a pair of 3-500z, as described the PA project.

The end

All pages must have links. Well, I have my bookmark file but try Motorola datasheets

To make PCB's I scan the image as line art. If necessary I can fix it in a photo-editing program. Then I print it out on a laser printer onto transparent foils. This can easily serve as the positive film used with a coated board and an UV-light source.

Comments, ideas or some wisdom? please mail me at clank@c2i.net.

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This page has been created in a text editor by a real programmer.