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Old September 21st 04, 08:42 AM
Toni
 
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Hi richard.


En Richard Clark va escriure en Mon, 20 Sep 2004 16:20:45 GMT:

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.


Now, this is a good idea, I'll try it. I know you can get those
cores from online shops, I just don't like buying over the
internet.

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.


No, but now I know it is probably quite high, so I can try the
reversed 4:1 (or more) balun idea.

73s

--
Toni

"Auto" = prefijo griego que significa "no funciona"