Hi Jim -

And on what delay timescale it works?

regards -
Henry


"RST Engineering" schrieb im Newsbeitrag
...
And by varying the reverse bias through a current source (or moderately
large fixed resistor) you can make them into nifty phase shifters.

Jim


I wrote: NOT PIN - Diodes - as they wouldn't snap.

i mean Band Switching diodes for TV-Tuners like the BA244 and the
BA682.

BA682 Datasheet:

http://www.vishay.com/docs/85530/85530.pdf

- and they snap! Try it!

Jorgen
dj0ud

On Fri, 25 Nov 2005 12:46:17 +0100, Jorgen Lund-Nielsen
wrote:

John Larkin wrote:
On Thu, 24 Nov 2005 18:30:06 +0100, Jorgen Lund-Nielsen
wrote:


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

Tuner Switching Diodes like the european BA244 (NOT PIN-Diodes!) work
well as medium fast Step Recovery Diodes.



Tell me about it. I tried some pins to see if they would snap, and
they turn out to have incredibly mushy reverse recovery, Slop Recovery
Diodes.

I'll have to try the varicaps.

John

Hello John,

I wrote: NOT PIN - Diodes - as they wouldn't snap.


I got that!

i mean Band Switching diodes for TV-Tuners like the BA244 and the BA682.

BA682 Datasheet:

http://www.vishay.com/docs/85530/85530.pdf

- and they snap! Try it!

OK, I'll try some.


Thanks

John

"John Larkin" wrote in message
...
Tell me about it. I tried some pins to see if they would snap, and
they turn out to have incredibly mushy reverse recovery, Slop Recovery
Diodes.

I've always been led to believe that this wasn't a bug, but a feature.
Really! (E.g., you can often get away with one diode when you'd otherwise
need two if the things actually recovered quickly...)

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



A 1N4007 can also be used as a drift step-recovery diode and as a
plasma avalanche diode. Together, two can generate a kilovolt edge
with a 100 ps risetime.

GAASfets make good fast analog switches; they behave pretty much like
jfets.

Wide-open LDO regulators make nice resettable fuses.

Ferrite beads do all sorts of interesting stuff.

Power mosfets make good heaters, and TO-220 bipolar transistors make
nice temperature sensors.

LVDS line receivers are surprisingly good comparators, and *fast*


I could go on...

John

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

The LM317 as a radio transmitter

http://web.telia.com/~u85920178/tx/317-tx.htm

On Thu, 24 Nov 2005 18:20:57 GMT, "CA" wrote:

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

The LM317 as a radio transmitter

http://web.telia.com/~u85920178/tx/317-tx.htm


Cool. 3T regulators, 317 and LM1117 types, can be neat power amps, for
driving unipolar loads like motors and such. Sort of a follower with a
largish offset.

Hmmm, an LM1117 followed by a monster darlington becomes a
super-follower with roughly zero offset.

John

John Larkin wrote:

A 1N4007 can also be used as a drift step-recovery diode and as a
plasma avalanche diode. Together, two can generate a kilovolt edge
with a 100 ps risetime.

Okay, so I'm intrigued already. I have all the hardware available--two
1N4007s and a 3 kV adjustable power supply! How do I build one?

Cheers,

Phil Hobbs

On Thu, 24 Nov 2005 14:47:37 -0500, Phil Hobbs
wrote:

John Larkin wrote:

A 1N4007 can also be used as a drift step-recovery diode and as a
plasma avalanche diode. Together, two can generate a kilovolt edge
with a 100 ps risetime.

Okay, so I'm intrigued already. I have all the hardware available--two
1N4007s and a 3 kV adjustable power supply! How do I build one?

Cheers,

Phil Hobbs

Google "Grekhov diode." A lot of the papers are for members only, but
this one gives the general idea:

http://www.ece.jhu.edu/~pps/ECE777/A...ano-pulse1.pdf

Grekhov discovered both the DSRD and the plasma avalanche effects in
cheap power diodes. The core of the DSRD effect is that, if a PIN
diode is forward biased for not too many nanoseconds, the carriers
don't have time to float all around the place so the charge profile is
good for a nice reverse snap. HP did the same thing in their classic
1430 12-GHz sampling head, circa 1965 roughly.

This box used the DSRD effect, in a semiconductor that one would not
expect to be used in an application like this...

http://www.highlandtechnology.com/DSS/T220DS.html

We bias the snap diode +48 volts (yes, forward direction) for about 80
ns before we turn the drive around for the snap. It was originally
designed for use in a LEAP atom probe.

John

John Larkin wrote:

TO-220 bipolar transistors make nice temperature sensors.

I like that trick. Esp the isolated tab type.

Graham

On Fri, 25 Nov 2005 09:07:38 +0000, Pooh Bear
wrote:



John Larkin wrote:

TO-220 bipolar transistors make nice temperature sensors.

I like that trick. Esp the isolated tab type.

Graham

There's also an LM35 in a TO-220 package! Ideal way to monitor a
heatsink.

John