Minicircuits VCOs

[Paul Burridge]

Nice to get away from politics...

I've been browsing through MC's website for plug-in VCOs and came
across this page:

http://www.minicircuits.com/dg03-226.pdf

But the tuning range of some of these things (Mhz/V) baffles me as it
seems to imply that to hold any given frequency with any practical
degree of stability would require a very precise voltage reference of
something like 6.6758V (for example). How the hell does one derive
such a precise voltage??
As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Don Pearce]

On Wed, 03 Nov 2004 17:21:09 +0000, Paul Burridge
<pb@notthisbit.osiris1.co.uk> wrote:

Nice to get away from politics...

I've been browsing through MC's website for plug-in VCOs and came
across this page:

http://www.minicircuits.com/dg03-226.pdf

But the tuning range of some of these things (Mhz/V) baffles me as it
seems to imply that to hold any given frequency with any practical
degree of stability would require a very precise voltage reference of
something like 6.6758V (for example). How the hell does one derive
such a precise voltage??
As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.

You hold them on frequency with your synthesiser loop.

As for the other, have you tried typing in lingam to see what you get?

d
Pearce Consulting
http://www.pearce.uk.com

 

[Paul Burridge]

On Wed, 03 Nov 2004 17:41:46 GMT, donaldun@spamfreepearce.uk.com (Don
Pearce) wrote:

You hold them on frequency with your synthesiser loop.

Oh. I hadn't thought of that.

As for the other, have you tried typing in lingam to see what you get?

I get no entry (no pun intended).
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Andrew Holme]

Paul Burridge wrote:

I've been browsing through MC's website for plug-in VCOs and came
across this page:
http://www.minicircuits.com/dg03-226.pdf
But the tuning range of some of these things (Mhz/V) baffles me as it
seems to imply that to hold any given frequency with any practical
degree of stability would require a very precise voltage reference of
something like 6.6758V (for example). How the hell does one derive
such a precise voltage??

Put the VCO in a phase locked loop (PLL).

 

[Bob Stephens]

On Wed, 03 Nov 2004 17:21:09 +0000, Paul Burridge wrote:

Nice to get away from politics...

I've been browsing through MC's website for plug-in VCOs and came
across this page:

http://www.minicircuits.com/dg03-226.pdf

But the tuning range of some of these things (Mhz/V) baffles me as it
seems to imply that to hold any given frequency with any practical
degree of stability would require a very precise voltage reference of
something like 6.6758V (for example). How the hell does one derive
such a precise voltage??
As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.

Lip service?

 

[martin griffith]

On Wed, 03 Nov 2004 17:21:09 +0000, in sci.electronics.design you
wrote:

As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.
How on earth did you know the Hindi for vagina?

martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.

 

[Rene Tschaggelar]

Paul Burridge wrote:

Nice to get away from politics...

I've been browsing through MC's website for plug-in VCOs and came
across this page:

http://www.minicircuits.com/dg03-226.pdf

But the tuning range of some of these things (Mhz/V) baffles me as it
seems to imply that to hold any given frequency with any practical
degree of stability would require a very precise voltage reference of
something like 6.6758V (for example). How the hell does one derive
such a precise voltage??
As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

I once made a synthesizer with a 16bit DAC driving this input.
Otherwise make a PLL.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Rich Grise]

On Wed, 03 Nov 2004 19:01:51 +0100, martin griffith wrote:

On Wed, 03 Nov 2004 17:21:09 +0000, in sci.electronics.design you
wrote:

As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.
How on earth did you know the Hindi for vagina?

Kama Sutra.

Cheers!
Rich

 

[Paul Burridge]

On Wed, 03 Nov 2004 19:01:51 +0100, martin griffith
<martingriffith@yahoo.co.uk> wrote:

On Wed, 03 Nov 2004 17:21:09 +0000, in sci.electronics.design you
wrote:

As an aside, does anyone know why MC have chosen to call their
internal search facility after the Hindu name for "vagina"?

Thanks,

p.
How on earth did you know the Hindi for vagina?

Because I'm better at languages than electronics.
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Don Pearce]

On Thu, 4 Nov 2004 09:02:18 +0100, "Robert Lacoste"
<see-www-alciom-com-for-email-adress> wrote:

The difficulty with wideband VCOs is usually more the phase noise than the
required DC precision itself, as this one is corrected by the surounding
PLL. However just calculate how much phase noise will be generated by some
mV of noise on the input... in addition to the phase noise of the VCO
itself...

Cheers,

Robert Lacoste
ALCIOM - The mixed signal experts
www.alciom.com

Not sure I am following you fully here. You speak of some mV of noise
on the input - which input are you referring to? A PLL doesn't have an
input as such - just an output.

And of course the phase noise of the output signal is a fairly complex
function determined by the phase noise of the VCO and the reference as
well as the loop bandwidth.

d
Pearce Consulting
http://www.pearce.uk.com

 

[Don Pearce]

On Thu, 04 Nov 2004 11:34:25 +0000, Paul Burridge
<pb@notthisbit.osiris1.co.uk> wrote:

On Thu, 04 Nov 2004 08:13:23 GMT, donaldun@spamfreepearce.uk.com (Don
Pearce) wrote:

On Thu, 4 Nov 2004 09:02:18 +0100, "Robert Lacoste"
see-www-alciom-com-for-email-adress> wrote:

The difficulty with wideband VCOs is usually more the phase noise than the
required DC precision itself, as this one is corrected by the surounding
PLL. However just calculate how much phase noise will be generated by some
mV of noise on the input... in addition to the phase noise of the VCO
itself...

Cheers,

Robert Lacoste
ALCIOM - The mixed signal experts
www.alciom.com

Not sure I am following you fully here. You speak of some mV of noise
on the input - which input are you referring to? A PLL doesn't have an
input as such - just an output.

He must be referring to the control voltage.
I notice in most representations, the phase comparitor is fed to a
charge pump before application to the VCO. Why the need for a charge
pump? The VCO control is presumably just a back-biased varactor with
very little current draw.. :-/

You need the integrator function to both suppress sampling rate
sidebands and provide the correct phase response. The charge pump will
do that.

d
Pearce Consulting
http://www.pearce.uk.com