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-   -   Varactor tuning diodes. (https://www.radiobanter.com/homebrew/22067-varactor-tuning-diodes.html)

Active8 January 5th 04 10:22 AM

On Mon, 05 Jan 2004 02:40:07 +0000,
said...
On Sun, 4 Jan 2004 16:22:32 -0800, "Tim Wescott"
wrote:

The varactor capacitance change is instantaneous -- think of a capacitor
who's plate spacing is dependent on it's voltage. This is why varactors are
used for frequency multiplication -- that capacitance change "squeezes" the
pulse to generate lots of harmonics.


Rubbish. Varactors are not used for freqency mulitplication. They are
freequenty used in VXCOs for modulating (or otherwise varying) the
oscillator output frequency by means of applying a DC bias voltage
which alters the capacitance of the PN junction.

Dude, please.
--
Best Regards,
Mike

GPG January 5th 04 11:06 AM


Rubbish. Varactors are not used for freqency mulitplication.

Google"varactor multipliers", still used. Popular technique in
the 60's for getting 70 cm output from 2m TX.
As osc control keep RF across diode low, high levels produce harmonics
and reduce tuning range. Most tuning varieties have max V = 30.
At low freqs power diodes work ok and have high V rev.

GPG January 5th 04 11:06 AM


Rubbish. Varactors are not used for freqency mulitplication.

Google"varactor multipliers", still used. Popular technique in
the 60's for getting 70 cm output from 2m TX.
As osc control keep RF across diode low, high levels produce harmonics
and reduce tuning range. Most tuning varieties have max V = 30.
At low freqs power diodes work ok and have high V rev.

Paul Burridge January 5th 04 03:46 PM

On 4 Jan 2004 19:27:25 -0800, Winfield Hill
wrote:


Your own rubbish, Paul. In truth of fact, varactors are nicely used
for frequency multiplication, just as Tim stated.


You're right. I can't believe I posted that load of nonsense. Maybe
it's a case of "late onset mad cow disease." :-|
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill

Paul Burridge January 5th 04 03:46 PM

On 4 Jan 2004 19:27:25 -0800, Winfield Hill
wrote:


Your own rubbish, Paul. In truth of fact, varactors are nicely used
for frequency multiplication, just as Tim stated.


You're right. I can't believe I posted that load of nonsense. Maybe
it's a case of "late onset mad cow disease." :-|
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill

Winfield Hill January 5th 04 04:23 PM

Paul Burridge wrote...

You're right. I can't believe I posted that load of nonsense.
Maybe it's a case of "late onset mad cow disease." :-|


OK, you are forgiven, my son. Go and sin no more.

Thanks,
- Win

whill_at_picovolt-dot-com


Winfield Hill January 5th 04 04:23 PM

Paul Burridge wrote...

You're right. I can't believe I posted that load of nonsense.
Maybe it's a case of "late onset mad cow disease." :-|


OK, you are forgiven, my son. Go and sin no more.

Thanks,
- Win

whill_at_picovolt-dot-com


Jim Weir January 5th 04 05:14 PM

If you aren't using the turnip truck you just fell from, could I borrow it for a
while? {;-)


Jim


Paul Burridge
shared these priceless pearls of wisdom:


-
-Rubbish. Varactors are not used for freqency mulitplication.
Jim Weir, VP Eng. RST Eng. WX6RST
A&P, CFI, and other good alphabet soup

Jim Weir January 5th 04 05:14 PM

If you aren't using the turnip truck you just fell from, could I borrow it for a
while? {;-)


Jim


Paul Burridge
shared these priceless pearls of wisdom:


-
-Rubbish. Varactors are not used for freqency mulitplication.
Jim Weir, VP Eng. RST Eng. WX6RST
A&P, CFI, and other good alphabet soup

Paul Burridge January 5th 04 09:09 PM

On 5 Jan 2004 08:23:16 -0800, Winfield Hill
wrote:

Paul Burridge wrote...

You're right. I can't believe I posted that load of nonsense.
Maybe it's a case of "late onset mad cow disease." :-|


OK, you are forgiven, my son. Go and sin no more.


Yes, m'lud. In mitigation I'd like to plead Jack Daniels. :-)
--

"I expect history will be kind to me, since I intend to write it."
- Winston Churchill


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