On Mon, 20 Sep 2004 08:56:22 +0200, Toni
wrote:
Build one: 4 resistors, Zener diode, battery.

That is the easy part, the not so easy is that AFAIK you need a
(mediumly good) transformer to get the signal from the noise
bridge to a receiver without altering the bridge.

Hi Toni,

Not necessary, but not impossible either. We will proceed as if you
do need one.

I had thought about building a simple bridge, but ferrite cores
are close to impossible to get in Barcelona (Spain). You get them
but with no info at all, just size and color.

Then those have a high chance of being Powdered Iron core. Wrong
cores.

Find a swap meet where old computers are being offered, especially old
cables. Look for those power or video connectors that have a plastic
cylinder at one end, 1 or 2 cm near the actual connector. Cut away
the plastic, cut away the wires: you have a high chance that you are
holding a ferrite core that will work.

Appart from that, I have finally found the schematics of my
receiver. Some low-pas and diode limiter and strait to the gate
of a fet. This explains the "not exactly 50 ohms" thing.

But it doesn't tell you what Z it IS.

73's
Richard Clark, KB7QHC