AE EP#44 Simple Electronic Dummy Load

Several years ago Dave Jones posted a vid about a very simple current sink and I wasn’t too successful replicating it then on prototyping board and went on to make one a little different. lately I wanted to go back and do it properly this time to test the mini-psu’s and the sources on my broken Tektronix 2236. I think it became a neat little build and plan to expand on it putting it into the multi module case with some atmega and 7-segment displays. Here is the vid:

A zip file containing everything is here: DC_load

The rendering of the Design…
…and the real version:

whoop whoop

AE EP#40 Not Quite An Insulation Transformer

So I put the old insulation transformers case to retirement and put it into this new space-saving case to fit my bench perfectly besides the old Heathkit VTVM. I can just repeat my warning: THIS IS NOT legally an insulation transformer! I do NOT use it to be able to touch its output, I only use it as a current limiter on newly built circuits. So enough for the legal crap, enjoy the video:

C1-94 BNC Adapter

So my Tek 2236 grew some problems in the Display control section. Luckily I stumbled across a Russian C1-.94 (speak S1-94) with some DIN-5 Plug for input. I asked the guys on Fingers’ Forum for help and voilà some parts out of the grab box and my adapter is ready:

Here I still ha a little GND connection problem, fixed now (the C1-94 is floating atm, I’ll replace the old calble asap)

Thanks again shpank, Henning and Reutron!


I just could not control myself this time: some guy sold these two units on ebay for 1 € and I just could not resist. Now I’m the owner of 3 “SRA Svenska Radio AB CN-504” – and there is alsmost nothing to be found on them. Only one website has some info on them. it says, that it goes from 138 to 179 MHz, so it should be able to work in the 2m amateur radio band.

So now it’s searching for a manual and more important a circuit diagram.
Inside we have a lot of 70ies electronic goodness, there’ll be a video of the inside soon.

your AE

Luxury Junk

I just couldn’t resist bidding on some ebay deal where a guy sold his cellar of HIFI-electronics.
There was /much/ more than shown here. This are the parts, I probably gonna use in some way.

JVC GR-SX9 Video Camera

Some very old (1991) Camcorder, I gotta look into connecting it do the pc to finally get some descent webcam input.

AIWA AD1250 Stereo Cassette Deck

This is some very solid case, it will probably house a synth or a mixer in the future.

Blaupunkt 60W 3 Ohm Car Speakers

Just that, they’ll go into a boom-box.

Premier CB 2000 Citizen Broadcast Radio

This one is interesting because i want to get a ham license in the near future. It does not work atm but I’m on it. the amp on top is known as a “Brenner” (afterburner) or “Oma” (grandmother) here in austria. using such an HF-amp with CB is strictly forbidden. (4W only, 12W with SSB)

Hornyphon 6391 Stereo Amplifier, front face

Hornyphon 6391 Stereo Amplifier, inside

Yeah this one needs some serious cleaning and testing but it could very well become a good mate in the future.