simple frequecny multiplier

[colin]

Hi,

I need to multiply the 40mhz output from my nice CMAC TCVCXO up to 1ghz, ie
multiply by 25, to feed a gilbert cell mixer.

I know this should be fairly simple and i know the throey of operation but
the problem is I wil be doing it blind as i do not have the equipment to do
much testing above 100mhz.

already i have a simple test circuit wich takes the output directly and
feeds it into a C-C-LC tank and amplifies it with a rf dual gate mosfet
bf988 wich drives a coax cable. runing at a low 3v at 3x multiplication i
get 0.2 v pk -pk at 120mhz wich is ample and is probably twice as high as
this as my scope is only 100mhz bw, and at 5x multiplication i can just
detect the 200mhz signal on my scope at about 30mv but ive no real idea how
much atenuated it is.

However i am not sure what would be best to provide the next x5 of
multiplication, i was thinking of simply putting a C-L-C 1ghz tuned circuit
in the source of the mosfet and adding an emiter folower and hoping the
mosfet is driven hard enough at 200mhz to give enough 5th harmonics.

As my ability to test it is limited to a RF sniffer probe i would be very
grateful if anyone could share anything that is tried and tested. Im
wondering if it would be beter to use 1 or 2 cmos inverters in place of the
mosfet/emiter folower.

google search throws up so many hits but all i looked at so far arnt that
helpfull.

COlin =^.^=

 

[colin]

"Mark" <makolber@yahoo.com> wrote in message
news:1112838867.605964.21180@l41g2000cwc.googlegroups.com...

probably better off with a pll

mark

i dont see how it'l be better, it can only add to the phase noise wich im
trying hard to avoid, and lot more complication wich is probably harder to
debug then a single stage distorting amplifier with tuned output. maybe the
fundamental wil be beter supresed but this wil be easy to supres further
with another filter.

Colin.

 

[colin]

"Frank Raffaeli" <SNIPrf_man_frTHIS@yahoo.com> wrote in message
news:1112843892.580277.247660@o13g2000cwo.googlegroups.com...

The advice Mark gave to use a PLL is pretty sound. What is the phase
noise requirement?
You could end up with lower phase noise using a PLL than with a
multiplier. If you do use
a multiplier, consider a step recovery diode if you're trying to do it
in one go. Otherwise,
consider a two or three stage multiplier.

The best you can do with a 25x multipler is 25x the phase noise offset
of the source. The phase
noise of the PLL will be dominated by the VCO if you do it right, and
that is determined
mostly by the loaded Q.

see the following text:
Microwave Circuit Design Using Linear and Nonlinear Techniques
by Vendelin, Pavio, and Rohde.

thanks il look into that, arnt SRD hard to get now? i was not trying to do
it in one go as such the harmonics from the xtal oscilator contain suficent
5th harmonic to drive the tuned input of a mosfet quite well.

subsequent tuned filter would extract the next 5th harmonic of that asuming
it it was distorting enough. so it is a 5x 5x rather then 25x but i just
wont be able to see the results with my scope. the frequency is fairly
flexible i could use more stages with less multiplication. say 3x 3x 2x

i had asumed a good crystal oscilator would outperform a LC type of vco, and
i know PLL can wander slightly as they can have dead spots in the edge
detector, i hadnt considered the efect of multiplying on the phase noise, i
asumed the Q of the tank circuits will have the same efect
as the Q of the PLL VCO ? the jitter/phase noise/stability of the oscilator
im using is extremly good.

basicaly its one of those projects where it needs to be as good as i can get
without going to extremes (atomic clocks are too expensive) and the phase
noise is integrated over 100ms or so. but nevertheless needs to be
ridiculously small. the reason for multiplying the frequency is to increase
the sensitivity of the phase detector to phase changes in the 40mhz signal
to detect phase change coresponding to changes in delays of less than a
picosecond.

my albeit limited experience of PLL is that it can sometimes take quite a
while to get them to work as well as you hope if you are trying for such
small jitter.

im not sure exactly of the nature of phase noise and what hapens when you
integrate it over such a long period, or how to compare the integreated
noise from a multiplied XO compared to a PLL VCO of a higher frequency.

idealy of course i would like a 1ghz crystal oscilator but ...

Colin =^.^=

 

[John Larkin]

On Thu, 07 Apr 2005 01:39:23 GMT, "colin"
<no.spam.for.me@ntlworld.com> wrote:

Hi,

I need to multiply the 40mhz output from my nice CMAC TCVCXO up to 1ghz, ie
multiply by 25, to feed a gilbert cell mixer.

I know this should be fairly simple and i know the throey of operation but
the problem is I wil be doing it blind as i do not have the equipment to do
much testing above 100mhz.

already i have a simple test circuit wich takes the output directly and
feeds it into a C-C-LC tank and amplifies it with a rf dual gate mosfet
bf988 wich drives a coax cable. runing at a low 3v at 3x multiplication i
get 0.2 v pk -pk at 120mhz wich is ample and is probably twice as high as
this as my scope is only 100mhz bw, and at 5x multiplication i can just
detect the 200mhz signal on my scope at about 30mv but ive no real idea how
much atenuated it is.

However i am not sure what would be best to provide the next x5 of
multiplication, i was thinking of simply putting a C-L-C 1ghz tuned circuit
in the source of the mosfet and adding an emiter folower and hoping the
mosfet is driven hard enough at 200mhz to give enough 5th harmonics.

As my ability to test it is limited to a RF sniffer probe i would be very
grateful if anyone could share anything that is tried and tested. Im
wondering if it would be beter to use 1 or 2 cmos inverters in place of the
mosfet/emiter folower.

google search throws up so many hits but all i looked at so far arnt that
helpfull.

COlin =^.^=

One interesting way to do it would be to use a step-recovery diode to
generate harmonics, and use a single high-Q resonator - preferable a
coaxial ceramic resonator - to pluck out the 25th. It would only take
a few parts. But anything like this takes equipment to evaluate. You
really ought to have a several-GHz sampling scope or a spectrum
analyzer to do this... this sort of stuff is tough flying blind.

John

 

[colin]

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:aee951hutv7f9v0b8g4hru1s3e89sbg6hd@4ax.com...

On Thu, 07 Apr 2005 01:39:23 GMT, "colin"
no.spam.for.me@ntlworld.com> wrote:

One interesting way to do it would be to use a step-recovery diode to
generate harmonics, and use a single high-Q resonator - preferable a
coaxial ceramic resonator - to pluck out the 25th. It would only take
a few parts.

hmm yes thats interesting, id not heard of one of those resonators, maybe i
can just use a length of transmision line/coax instead, shldnt be too long
at 1ghz lets see asuming V = 0.7C ... 1/4 Y = 75mm. short circuited at the
end i asume.

But anything like this takes equipment to evaluate. You
really ought to have a several-GHz sampling scope or a spectrum
analyzer to do this...

yes i agree, hence i was hoping for anything tried and tested.

this sort of stuff is tough flying blind.

a good chalenge tho ..

thnks for the help

Colin =^.^=

 

[colin]

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:qve95150hjeho69si4nqn7raqsvtn2qqg9@4ax.com...

Why are picosecond delays interesting here?
What's the application?

its for an experiment trying detect any relative change in speed of light.

1 ps RMS jitter over 100 ms time will be very difficult. A good
crystal oscillator can do a few tens of ps over 100 ms; a very good
ocxo can hit 1 ps over that time.

im using the latest VCTCXO from cmac cfpt-9000 series wich are suposed to be
very good, certainly from stability anyway although they dont quote phase
noise/jitter explicitly, i think its suposed to be one of the lowest,
certainly stability is very good. maybe better over short term than an ocxo
as it operates at lower temperature and has no thermal feedback loop. i
beleive you can also now get these as a oven controled version too. its
useful to know the figures you mentioned tho.

i think it might be posible, even if it means integrating over many cycles,
although this isnt something i have planed for at this stage.

Any following circuitry must be very
good to not add picoseconds of jitter.
If you're trying to characterize the phase change of a 40 MHz signal,
multipling may not make things better and could well make things a lot
worse. Measuring anything analog to one part in 25,000 will always be
tricky.

yes wich is why i was reluctant to go with a PLL i assumed a humble
multiplier wouldnt add much jitter at all over 100ms. the voltage output
from the phase detector would be very small at 40mhz and hence suceptable to
noise at that point. maybe a more moderate multiplaction of x3/x5 that i can
easily acheive now would be more optimal, il probably try that for now but
leave room for the x25 circuit, or maybe try x3 x3.

there realy isnt a lot of circuitry between the frequency generators and the
phase comparator, heck there isnt actualy any ! wel apart from a length of
coax/trasnmison line wich i hope isnt going to misbehave. the phase
comparator would be a gilbert cell aranged to give a null output on matching
phase i think its aranged like this .. (A-B) X J(A+B). the two clocks would
be synchronized within a PLL with an exceedingly long response time so as
not to cancel out the result.

Colin =^.^=

 

[Rene Tschaggelar]

colin wrote:

"Frank Raffaeli" <SNIPrf_man_frTHIS@yahoo.com> wrote in message
news:1112843892.580277.247660@o13g2000cwo.googlegroups.com...

The advice Mark gave to use a PLL is pretty sound. What is the phase
noise requirement?
You could end up with lower phase noise using a PLL than with a
multiplier. If you do use
a multiplier, consider a step recovery diode if you're trying to do it
in one go. Otherwise,
consider a two or three stage multiplier.

The best you can do with a 25x multipler is 25x the phase noise offset
of the source. The phase
noise of the PLL will be dominated by the VCO if you do it right, and
that is determined
mostly by the loaded Q.

see the following text:
Microwave Circuit Design Using Linear and Nonlinear Techniques
by Vendelin, Pavio, and Rohde.


thanks il look into that, arnt SRD hard to get now? i was not trying to do
it in one go as such the harmonics from the xtal oscilator contain suficent
5th harmonic to drive the tuned input of a mosfet quite well.

subsequent tuned filter would extract the next 5th harmonic of that asuming
it it was distorting enough. so it is a 5x 5x rather then 25x but i just
wont be able to see the results with my scope. the frequency is fairly
flexible i could use more stages with less multiplication. say 3x 3x 2x

A tuned filter is a rather hard to achieve with
almost no tools. This frequency range you intend
to work in is the crossover. It is above where
discrete L & C behave as they should, and below the
range where microstripline is feasible.
I was calculating a 1 GHz stripline filter recently
and the achievable Q is not that brathtaking.

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

 

[Rene Tschaggelar]

colin wrote:

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:qve95150hjeho69si4nqn7raqsvtn2qqg9@4ax.com...

Why are picosecond delays interesting here?
What's the application?

its for an experiment trying detect any relative change in speed of light.

1 ps RMS jitter over 100 ms time will be very difficult. A good
crystal oscillator can do a few tens of ps over 100 ms; a very good
ocxo can hit 1 ps over that time.

im using the latest VCTCXO from cmac cfpt-9000 series wich are suposed to be
very good, certainly from stability anyway although they dont quote phase
noise/jitter explicitly, i think its suposed to be one of the lowest,
certainly stability is very good. maybe better over short term than an ocxo
as it operates at lower temperature and has no thermal feedback loop. i
beleive you can also now get these as a oven controled version too. its
useful to know the figures you mentioned tho.

i think it might be posible, even if it means integrating over many cycles,
although this isnt something i have planed for at this stage.

Any following circuitry must be very
good to not add picoseconds of jitter.
If you're trying to characterize the phase change of a 40 MHz signal,
multipling may not make things better and could well make things a lot
worse. Measuring anything analog to one part in 25,000 will always be
tricky.

I'd recommend borrowing a ready synthesizer with a
low phase noise 1GHz output. You'll never get below a
1ps jitter with a makeshift setup. As to calculating the
jitter from phasenoise :

http://www.ibrtses.com/products/index.html
there with screenshot and such :
http://www.ibrtses.com/products/PhaseNoise102.exe

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

 

[John Larkin]

On Thu, 07 Apr 2005 05:36:27 GMT, "colin"
<no.spam.for.me@ntlworld.com> wrote:

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:qve95150hjeho69si4nqn7raqsvtn2qqg9@4ax.com...
Why are picosecond delays interesting here?
What's the application?

its for an experiment trying detect any relative change in speed of light.

1 ps RMS jitter over 100 ms time will be very difficult. A good
crystal oscillator can do a few tens of ps over 100 ms; a very good
ocxo can hit 1 ps over that time.

im using the latest VCTCXO from cmac cfpt-9000 series wich are suposed to be
very good, certainly from stability anyway although they dont quote phase
noise/jitter explicitly, i think its suposed to be one of the lowest,
certainly stability is very good. maybe better over short term than an ocxo
as it operates at lower temperature and has no thermal feedback loop. i
beleive you can also now get these as a oven controled version too. its
useful to know the figures you mentioned tho.

TCXOs have a temperature transient problem: the temp comp sensor never
has the same thermal time constant as the crystal itself, so whereas
the compensation averages very good, a millikelvin delta-t over 100 ms
can cause a lot of phase shift. A good OCXO will have a huge thermal
isolation system and also operates the crystal at its "turning
temperature" where the inherent TC is zero. All that makes a huge
difference in close-in phase noise. If you use a TCXO, put it in a
heavy aluminum can to slow down temperature transients; that alone can
cut thermally-induced phase noise 10:1.

A good SC-cut OCXO is a few hundred dollars new and is the best you
can do without going atomic. You can get a used rubidium for about the
same, but I'm not sure the short-term stability is necessarily better
than the SC.

Considered an optical interferometer?

John

 

[John Larkin]

On Thu, 07 Apr 2005 05:00:23 GMT, "colin"
<no.spam.for.me@ntlworld.com> wrote:

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:aee951hutv7f9v0b8g4hru1s3e89sbg6hd@4ax.com...
On Thu, 07 Apr 2005 01:39:23 GMT, "colin"
no.spam.for.me@ntlworld.com> wrote:

One interesting way to do it would be to use a step-recovery diode to
generate harmonics, and use a single high-Q resonator - preferable a
coaxial ceramic resonator - to pluck out the 25th. It would only take
a few parts.

hmm yes thats interesting, id not heard of one of those resonators, maybe i
can just use a length of transmision line/coax instead, shldnt be too long
at 1ghz lets see asuming V = 0.7C ... 1/4 Y = 75mm. short circuited at the
end i asume.

Any practical transmission line will have a bad temperature-frequency
coefficient. Coaxial cable and pcb traces are usually rotten. So tiny
temperature shifts will cause big (by your standards) phase shifts.

What's the physics here? Can you just use baseband (40 MHz) processing
along with a lock-in sort of technique to correct for noise and drift?

John

 

[colin]

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:b6ka511h2lrb9v09flm6tblohsmscamh4h@4ax.com...

TCXOs have a temperature transient problem: the temp comp sensor never
has the same thermal time constant as the crystal itself, so whereas
the compensation averages very good, a millikelvin delta-t over 100 ms
can cause a lot of phase shift. A good OCXO will have a huge thermal
isolation system and also operates the crystal at its "turning
temperature" where the inherent TC is zero. All that makes a huge
difference in close-in phase noise. If you use a TCXO, put it in a
heavy aluminum can to slow down temperature transients; that alone can
cut thermally-induced phase noise 10:1.

A good SC-cut OCXO is a few hundred dollars new and is the best you
can do without going atomic. You can get a used rubidium for about the
same, but I'm not sure the short-term stability is necessarily better
than the SC.

I gues ive been looking at to much of the sales blurb, .. yes a good thermal
slug and wind proofing might be a good idea, also the device is basicaly on
its own exept for decoupling and is lightly loaded. its also all on a single
SMD chip.

i had considered OCXO or puting a peltier device to keep it at constant
temp, maybe even at its lower temp turning point. even the idea of having a
temp sensitive oscilator as a sensor and using a PLL to keep the temp
constant. however low power batery operation would make things a lot easier.
however thinking about it i might wel have to resort to a ocxo. the whole
thing should fit into an aluminium or steel tube.

lots of things i havnt realy considered seem to be poping up i gues il just
have to try it now and see just how much everything adds up. theres not
actualy a great deal to it.

Considered an optical interferometer ?

yes i am thinking about that, however i cant simply use the same light
source and bounce it back to meet the original as this would cuase an
imeasurable result, the Sagnac effect is measured with a single source, but
i would need 2 lasers and be able to tune one of them and keep it in synch
with the other one. im not sure how feasable this is. maybe two closly
matched laser diodes cld be kept in synch by controling the temperature, i
gues they must have some temperature sensitivity.

Colin =^.^=

 

[colin]

"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:spka51lp2d9cpdlbqli41qdtgp659vboo7@4ax.com...

Any practical transmission line will have a bad temperature-frequency
coefficient. Coaxial cable and pcb traces are usually rotten. So tiny
temperature shifts will cause big (by your standards) phase shifts.

What's the physics here? Can you just use baseband (40 MHz) processing
along with a lock-in sort of technique to correct for noise and drift?

im realy relying on the whole device remaining at a constant temperature at
least throughout each cycle, it only needs to be operated at standard room
temperature.

the upshifting is purly to increase the sensitvity of the phase detector to
any time diference so its a compromise of phase noise to detector noise.

the cycle time is less than 1 second, averaging over as many cycles as
necessary is posible and probably is necessary, but would be realy nice not
to have to.

of course any mechanical flexing would severly afect the result, and is
probably my bigest concern as it might flex more at one point in the cycle.
(the whole thing rotates at a slowish speed).

Colin =^.^=

 

[Rene Tschaggelar]

John Larkin wrote:

On Thu, 07 Apr 2005 05:36:27 GMT, "colin"
no.spam.for.me@ntlworld.com> wrote:


"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:qve95150hjeho69si4nqn7raqsvtn2qqg9@4ax.com...


A good SC-cut OCXO is a few hundred dollars new and is the best you
can do without going atomic. You can get a used rubidium for about the
same, but I'm not sure the short-term stability is necessarily better
than the SC.

Considered an optical interferometer?

Forget an interferometer. The mechanical noise in an
optical system is tremendous. It picks up whatever
accoustical vibration that couples into the case.
A sort of expensive microphone. There you achieve a
10:1 reduction in phase noise by putting the system
onto a pressurized table used in optical labs.
Ans don't forget to switch the flow box off.

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

 

[colin]

"Rene Tschaggelar" <none@none.net> wrote in message
news:42557a1c$0$1160$5402220f@news.sunrise.ch...

Forget an interferometer. The mechanical noise in an
optical system is tremendous. It picks up whatever
accoustical vibration that couples into the case.
A sort of expensive microphone. There you achieve a
10:1 reduction in phase noise by putting the system
onto a pressurized table used in optical labs.
Ans don't forget to switch the flow box off.

If i was using light I could use fiber optics wich i would assume would
largly overcome this accoustical problem.

Colin.

 

[colin]

"Mark" <makolber@yahoo.com> wrote in message
news:1112898942.129273.311120@f14g2000cwb.googlegroups.com...

so you are trying to measue the phase of the 40 MHz and you are
multiplying it up to increase the gain or accuracy of the measurment?

so you don't really care about 1 GHz, but just want to measure the
phase of the 40 MHz?

Why 40 MHz then, why not start out with a 1 GHz or whatever oscilator?

yes im wondering that myself now haha!

it realy needs the stability of a TCXO or OCXO as basicaly im comparing two
almost free runing oscilators.

40mhz was the highest freq oscilator i could find with impresive stability.
most OCXO only seem to be 10mhz too.

but yes im just measuring a small delay diference and so using high
frequency as posible to get good resolution. its just finding a compromise
between high frequency for good resolution and rock solid stability.

but im limited a bit to what i can get from places like RS and Farnell. I
just asumed that it would be such a simple and efective solution to do some
frequency multiplication.

if anyones got a couple of small low power high frequency high stabilty
oscilators lying around unused ....

i wonder how long it wil be before someone comes up with an increase
instability in silicon based oscilators like that when bandgap devices
replaced zener diodes.

Colin =^.^=

 

[John Larkin]

On Thu, 07 Apr 2005 20:21:08 +0200, Rene Tschaggelar <none@none.net>
wrote:

John Larkin wrote:

On Thu, 07 Apr 2005 05:36:27 GMT, "colin"
no.spam.for.me@ntlworld.com> wrote:


"John Larkin" <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
message news:qve95150hjeho69si4nqn7raqsvtn2qqg9@4ax.com...


A good SC-cut OCXO is a few hundred dollars new and is the best you
can do without going atomic. You can get a used rubidium for about the
same, but I'm not sure the short-term stability is necessarily better
than the SC.

Considered an optical interferometer?

Forget an interferometer. The mechanical noise in an
optical system is tremendous. It picks up whatever
accoustical vibration that couples into the case.

If the problem is to measure a path length by timing the speed of
light, any mechanical distortions of the path make the same noise,
whatever the detector mechanism.

Is this a ring gyro? Lots of work has been done on them! And the
detectors are usually optical interferance.

John

 

[mike]

colin wrote:

Hi,

I need to multiply the 40mhz output from my nice CMAC TCVCXO up to 1ghz, ie
multiply by 25, to feed a gilbert cell mixer.

I know this should be fairly simple and i know the throey of operation but
the problem is I wil be doing it blind as i do not have the equipment to do
much testing above 100mhz.

already i have a simple test circuit wich takes the output directly and
feeds it into a C-C-LC tank and amplifies it with a rf dual gate mosfet
bf988 wich drives a coax cable. runing at a low 3v at 3x multiplication i
get 0.2 v pk -pk at 120mhz wich is ample and is probably twice as high as
this as my scope is only 100mhz bw, and at 5x multiplication i can just
detect the 200mhz signal on my scope at about 30mv but ive no real idea how
much atenuated it is.

However i am not sure what would be best to provide the next x5 of
multiplication, i was thinking of simply putting a C-L-C 1ghz tuned circuit
in the source of the mosfet and adding an emiter folower and hoping the
mosfet is driven hard enough at 200mhz to give enough 5th harmonics.

As my ability to test it is limited to a RF sniffer probe i would be very
grateful if anyone could share anything that is tried and tested. Im
wondering if it would be beter to use 1 or 2 cmos inverters in place of the
mosfet/emiter folower.

I need to replace a piston in my Ford engine. But all I have is a beer
can and a used ice cream stick. Can someone please provide a ready-made
solution?

For any endeavor, there's some minimum set of tools required.
(props to McGuyver not withstanding)
We can argue all day about what that minimum is for this case, but I
don't think your sniffer is gonna hack it. You need to buy something
already configured and tested...or borrow some tools.
mike

google search throws up so many hits but all i looked at so far arnt that
helpfull.

COlin =^.^=

--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Wanted 13" LCD for Mitac 6133 Samsung HT13X13-201
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[colin]

"mike" <spamme0@netscape.net> wrote in message
news:42559297.2090409@netscape.net...

I need to replace a piston in my Ford engine. But all I have is a beer
can and a used ice cream stick. Can someone please provide a ready-made
solution?

For any endeavor, there's some minimum set of tools required.
(props to McGuyver not withstanding)
We can argue all day about what that minimum is for this case, but I
don't think your sniffer is gonna hack it. You need to buy something
already configured and tested...or borrow some tools.
mike

haha very funny (not), wel somthing already configured and tested would be
fine and cheaper than the test equipment to check it, but theres only a few
components in a x5 multiplier and if you carefully folow an exising design
its not too far fetched to expect it to pick out the right frequency. you
can easily fine tune it to maximum output with a snifer probe asuming there
isnt more than one frequency selectable within the tuning range.

Colin =^.^=

 

[mike]

colin wrote:

"mike" <spamme0@netscape.net> wrote in message
news:42559297.2090409@netscape.net...

I need to replace a piston in my Ford engine. But all I have is a beer
can and a used ice cream stick. Can someone please provide a ready-made
solution?

For any endeavor, there's some minimum set of tools required.
(props to McGuyver not withstanding)
We can argue all day about what that minimum is for this case, but I
don't think your sniffer is gonna hack it. You need to buy something
already configured and tested...or borrow some tools.
mike


haha very funny (not), wel somthing already configured and tested would be
fine and cheaper than the test equipment to check it, but theres only a few
components in a x5 multiplier and if you carefully folow an exising design
its not too far fetched to expect it to pick out the right frequency. you
can easily fine tune it to maximum output with a snifer probe asuming there
isnt more than one frequency selectable within the tuning range.

Colin =^.^=

Ok, so we're gonna argue all day about it.
How do you propose to determine the frequency coming out of your
multiplier with that beer can and popsicle stick? Tweek on it and you
get more...more what???...who knows...maybe you got lucky...maybe...
Of course, you can build a resonant cavity from the beer can.
Good luck.
I gots a piston to change. My beer can is almost empty and the popsicle
stick is sharp.

On a more serious note, there are 100MHz x 5 and 500MHz x 2 multipliers
in the Tektronix TG501 Time Mark Generator. Sounded like a good idea at
the time...30 years ago. But it was a nightmare. You really do need to
control the drive waveform and have idler paths for the undesired
harmonics. Amplitudes can get very high and you loose all your energy
in losses at the frequencies of undesired harmonics.
And we had the BEST equipment available to work on it.
mike

--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Wanted 13" LCD for Mitac 6133 Samsung HT13X13-201
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[John Larkin]

On Thu, 07 Apr 2005 19:48:41 GMT, "colin"
<no.spam.for.me@ntlworld.com> wrote:

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:gn1b51tq1dq7jkfvb9da18rmdvfdqqu5rj@4ax.com...

If the problem is to measure a path length by timing the speed of
light, any mechanical distortions of the path make the same noise,
whatever the detector mechanism.

Is this a ring gyro? Lots of work has been done on them! And the
detectors are usually optical interferance.

wel yes its pretty much like a ring gyro, exept its for detecting linear
motion rather than rotational motion. this has been more dificult becuse a
rotational gyro can use the same laser to transmit the signal and compare it
with the received signal, but you cant do this with a linear device becuase
the comparison signal would have to travel the same path as the transmited
signal to arive at the detector and so would undergo the same propagation
delay change. however the Silvertooth experiment did it with a single light
source but i dont realy understand the explanation as to how it avoided this
problem, also it required a highly specialised detector and elaberate
optical setup and was i beleive rather tempermental, and i have not heard of
it being repeated so i am interested in doing this.

im therfore using two clocks 1 meter apart that are synchronised to be
precisly in phase over a long average time then rotating them say about
60rpm+ and detecting the cyclic phase diference. I estimate that if the
earth is moving at 100,000 kmh wich i have heard banded about somewhere then
the diference i would be looking for would only be ~0.5 ps wich is indeed
small, but i reckon isnt entirly beyond the realms of detection.

Colin =^.^=

Are you trying to measure the speed of the earth through the aether?

John