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Old November 24th 05, 08:07 PM posted to rec.radio.amateur.homebrew
 
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Default Unusual functions of cheap parts

On Thu, 24 Nov 2005 09:40:27 +0100, "Henry Kiefer"
wrote:

Hi all -

After my first thread going from "standard" cheap parts for up to vhf
frequency to a discussion about the usefulness of Spice simulator...... I
try it another time hopefully get attention of frustrated co-readers:

For example the rechtifier diode 1N4007 can be used as a rf switching diode,
for example as rx/tx-switch. This is because it is a pin structure diode.
This type is cheap and you can get it almost everywhere. It shows good
performance for the price. Surely for high-end you should do it with another
type tuned to the application it is made for. But anyway it works in some
circuits.

Do you know of other interesting devices or circuits good for misuse?

Best regards -
Henry


1n4007 as varactor (freq multiplier) and also Varicap.
You already mentioned RX/TX swich.
Also in PIN attenuator circuits.

Glass cased rectifiers (1n4007 in glass rather than epoxy)
as photodiode.

1n914 as 2ghz multipler (as varactor) to 100mw output.

1n914/4148 as silicon temperature sensor. (forward bias)

Base emitter of NPN silicon transistors as Zeners (5-8Vrange).
Makes a decent noise diode that way too.

Base collector of NPN si transistor as Varicap

Collector emitter of silicon transistors reverse biased as negative
resistance device.

Open GE and SI transistors are sensitive photodetectors.

Opened SCRs as photoswitches.


Allison