electronics

images soon

offset attenuator
this is an "active attenuator" that shifts the receive frequency by 1mhz and attenuates the signal. the amount of attenuation is altered using a 1k-ohm potentiometer. useful when direction finding, allowing you to determine the bearing of a received signal by gradually adding more attenuation to isolate the source direction.

images soon

hacktronic portable 12-volt power supply
last week i needed to test a piece of gear i was building outside. my bench supplies consist of a very heavy 30-amp astron supply, and a slightly less heavy variable supply, both requiring mains power. not the most portable supplies out there. anyways, all three of my 12v gel cells were toast. solution? a 12 volt supply built using 9 D cells, some battery holders from radio shack, lots of electrical tape and a couple of binding posts. hey, it works.

hacktronic 12v power supply

10ghz wbfm transceiver
a friend of mine and i are working on building 10ghz wideband fm transceivers using surplus 10ghz gunnplexer modules. we haven't done much (if any) experimentation in the microwave region, and this is an easy place to start. the transceivers consist of a 10-meter receiver that is used to demodulate the IF output from the gunnplexer module, along with a modulator to vary the voltage to the gunnplexer for transmitting fm voice.

10ghz wideband fm transceive

cheeseball lcd programming interface
i recently discovered (was told) how easy it is to work with hitachi lcd displays, so i decided to play around with one. the result was a cheeseball switch based programming interface. you set the bits using toggle switches, then press a momentary pushbutton switch to strobe the "bus" and get the lcd controller to read the instruction or character code you have defined using said toggle switches. it then displays the character on the lcd. cheesy, but i was amused by it for a while.

manual lcd programming interface