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Sci.Electronics.Design is a worldwide Usenet news group that is used to discuss various aspects of Electronic Circuit Design.
We found 109 threads matching "vco"
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The most relevant threads are listed first
Re: HCT4046 VCO noise
Bill Sloman - 2010-06-17 09:11:00
On Jun 17, 2:19=A0pm, "GBaars" wrote:
> For narrow (fdev ~ 0.05 %) FM detection the phase noise of the CD74HCT404=
6
> PLL's VCO
> causes poor S+N/N ratio. Has a smaller / larger oscillator C any influenc=
e
> and also the values of R1 and R2 of the VCO.
> Do the 74HC(T)7046 or 74HC(T...
Re: Uses for old TVs?
2009-06-23 13:52:00
The analog tuners make great spectrum analysers. figure out the
bandswitching and control inputs before dismantling the TV.
Just add a ramp and a 62 or 68 or 45 mhz IF , get one with a pll and
one thats analog VCO and do a tracking generator.
PLL ones can often be modified to step in much s...Unused mod input on VCO
bart - 2009-11-05 10:52:00
Hi all,
I have an obsolete (no data sheet available) Z-Comm VCO that I'm using
for a low buck signal generator.
Yes, I know it's noisy & unstable.
It looks like there's a Vmod input on it.
I'm mounting this to a "slash & cut" PCB - surface mount.
I couldn't find any documentation at Z-comm on ...Re: mobile jammer
maxfoo - 2008-02-24 14:03:00
On Sun, 24 Feb 2008 12:45:28 +0100 (CET), sky465nm@trline5.org wrote:
> san wrote:
> > im planning to do a mobile bug along with a mobile jammer as my mini
> > project.. can anyone tell me how to do a mobile jammer? does any1 hav
> > its circuit???
>
> You can proberbly just send some bu...Re: Non-linear functions ...
Frank Buss - 2009-11-24 18:52:00
Jan Panteltje wrote:
> On a sunny day (Wed, 25 Nov 2009 00:06:16 +0100) it happened Frank Buss
> wrote in :
>
>
> > http://www.frank-buss.de/vco/
>
> Is not a 74HC4046 a much simpler VCO with a lot bigger range?
> hehe
But the requirements were lower limit and upper limit...goofy frequencies
John Larkin - 2009-06-15 12:03:00
Suppose I really want a crystal oscillator at, say, 122.167958 MHz.
And I'd like to have the option of phase locking it to some standard
reference, 5 or 10 MHz maybe. And I'd like cheap ones for low-end
products, and TCXO or OCXO stability for better versions.
I can have custom XOs and TCXOs...Re: Variable Square Wave to Sine Wave
oopere - 2010-03-09 02:38:00
FyberOptic wrote:
> Hiya folks. I've been interested in trying to build myself a radio
> receiver for various bands, primarily as a learning experience. The
> thing is, though, I've heard that it's kind of hard to build a stable
> VFO above 50mhz. One of the bands I'd eventually like to r...CD4046 Question
Chris - 2010-02-23 13:51:00
The data sheet just gives some ancient reference for finding the
values for R1, R2, and C1.
Is the RC network for the VCO is (R1, R2, C1)? Would I just use the
cutoff frequency for the R1 and C2 RC filter (i.e. fc=1/(2*Pi*R1*C1)).
Thanks,
Chris KQ6UP
...MAX038 replacement
Christian Riesch - 2009-03-16 10:40:00
Hi,
I am looking for a VCO with sine output like the MAX038, which is
unfortunately no longer available. Thank you for your help.
Best regards,
Christian
...Re: The phase noise of the MCU generated signals
Chris Jones - 2009-02-08 09:44:00
John Larkin wrote:
> On Thu, 05 Feb 2009 18:27:23 -0500, Phil Hobbs
> wrote:
>
> > John Larkin wrote:
> > > On Thu, 05 Feb 2009 21:03:51 +0000, Chris Jones
> > > wrote:
> > >
> > >
> > > > Charles Wenzel has a nice idea here:
> > > > http://www.wenzel.com/documents/fine...Re: Lower time jitter in PLL
John Larkin - 2008-02-24 17:55:00
On Sun, 24 Feb 2008 14:06:06 -0800 (PST), ElectricQuadrupole@gmail.com
wrote:
> Hi,
>
> I have a litte problem with some measurements. I made a simple PLL
> (analog phase detector, active PI filter, loop filter bw=100 kHz, by 8
> prescaler) to multiply 10MHz from quartz generator to 80MHz.
...Re: PLL jitter and tracking filters
MooseFET - 2010-06-16 10:32:00
On Jun 16, 2:09 pm, crasic wrote:
[... PLL ...]
> As it turns out, the PLL is working too much as an ideal bandpass. On
> a scope you can see a clearly mimicked signal, i.e. it is following
> the input signal with all its jitter and the output jitter of the pll
> matches the input jitt...Re: micro-controlled IH
2010-04-22 18:41:00
On Apr 22, 12:44=A0pm, "amdx" wrote:
> "Tim Wescott" wrote in message
>
> news:JK6dndA70_uEHU3WnZ2dnUVZ_sOdnZ2d@web-ster.com...
>
>
>
> > MooseFET wrote:
> > > On Apr 22, 7:20 am, "Michael Robinson" wrote:
> > > > the video:
>
> > > > http://www.youtube.com/watch?v=...Re: [?] Audio VCO design
John Fields - 2009-11-21 07:36:00
On Sat, 21 Nov 2009 13:42:37 +1100, "Phil Allison"
wrote:
>
> "John Fields"
> David Chapman
>
> >
> > > As part of a larger system, I need to design and build an audio VCO
> > > which will produce tones ranging from around 50Hz to 4KHz or so when the
> > > applied DC input volt...Re: Ultra low frequency VCO
Joel Koltner - 2010-07-12 13:13:00
"Jim Thompson" wrote in
message news:dcim36poktoi3gc0keapvnbjlpsri0lqj4@4ax.com...
[coaxial ceramic resonators]
> I've been "using" them... designing them into GPS LO's since before
> you were born ;-)
What's the advantage -- for you -- over crystals? Just lower cost?
---Joel
...1 GHz synthesizer
Andrew Holme - 2010-02-24 15:16:00
I'm developing a 1 GHz fractional-N synthesizer. The reference input is a
50 MHz sine wave which I'm converting to LVDS as follows:
1. 50 MHz sine wave arrives at board mounted SMA in 50-ohm system
2. Converted to 100 ohms differential using Mini-Circuits ADT2-1T
transformer
3. Carried 10m...Re: Phase Locked Loop Phase Shift
Phil Hobbs - 2008-01-22 18:39:00
JimFraser100@googlemail.com wrote:
> Hi All,
>
> I'm trying to design a PLL frequency multiplier which will track a
> 50Hz +- 1Hz sinusoidal signal and generate a clock at a rate of
> 12.8Khz nominal, synchronised to that signal. (*256 multiplication)
>
> I've got an LM565 phase lock...Ceramic capacitors
E - 2009-09-14 14:27:00
Just made oscillator from 74HC14, 1k resistor and Taiyo Yuden Y5V 10uF
capacitor.
Results:
Capacitor other end biased to 2V => 126 Hz out
At 36 V bias 2470 Hz out
That means 1:19 change in capacitance!
Maybe I can build some low frequency VCO out of these...
Amazing things.
-ek
...Re: I need Help For My project
2009-04-28 15:02:00
Book: Experimental Methods in RF Design
Wayward, Campbell and Larkin
The first edition is on sale cheap as the second one just came out.
While not FM specfic, its a lot better then most texts out there if
you need to learn something like front end design from scratch and
experiment as the ...Re: Theremin...
Ecnerwal - 2009-11-20 23:22:00
In article
,
Greegor wrote:
> http://www.thereminworld.com/schematics.asp
Well, I can report that the University of Glasgow digital version (from
that page) both uses a VCO that's more or less unobtainable these days,
and the circuit was not functional when a high school student ...DAC with variable sample rate
Oliver Glassl - 2008-02-28 03:19:00
Hello!
Is it possible to control the sample rate of a DAC (no oversampling,
of course) with an analog VCO, variable within a wide range (few Hz up
to 10Mhz), also frequency-modulated?
First without consideration how to feed it properly.
Regards,
Oliver
...Re: Ultra low frequency VCO
whit3rd - 2010-07-09 13:22:00
On Jul 8, 12:29=A0pm, Phil Hobbs
wrote:
> I don't know that -100 dBc/Hz is that hard at 60 Hz. =A0I bet you could d=
o
> that by running a bog standard multivibrator at 1024*1024*60 Hz and
> dividing down. =A0You'd need a sine shaper, but the phase noise goes down
> by N**2
Eh? I'...Re: Wideband quadrature generation
Joel Koltner - 2008-06-18 18:15:00
"Joerg" wrote in message
news:dlf6k.5892$89.2108@nlpi069.nbdc.sbc.com...
> Thing is, once you reach a bandwidth of 10:1 and you want less than a few
> degrees of phase error things tend to become iffy. Laser trim became available later and made life easier.
10:1 is plenty for my purp...Re: Reason why DC mag field disturbs communications on a train
Frithiof Jensen - 2009-03-17 13:38:00
skrev i meddelelsen
news:f3301c84-01f2-4013-b50c-3bc3a24253f4@v38g2000yqb.googlegroups.com...
> Ferrite pot cores and similar inductors can have their core
> permeability modulated by magnetic fields which are a very long way
> below saturation.
Excellent point - *now*, of course...Re: Precision wirewound pot wiper bounce?
ehsjr - 2010-07-14 00:39:00
oparr@hotmail.com wrote:
> > We use a lot of the Bourns 3590 sereis ten turn pots.
>
>
> I'm using the pot to vary the voltage to the VCO input of a function
> generator. A 1-turn pot is a bit coarse and I estimate that a 10-turn
> pot is going to be too fine. The 3-turn pot is just rig...Re: icl8038 , 8038
Tim Shoppa - 2008-12-08 10:29:00
On Dec 7, 3:22=A0pm, o...@uakron.edu wrote:
> did anybody besides harris/intersil ever second source the 8038 sine/
> triangle oscillator chip?
>
> =A0Its out of production, so is max038
>
> I refuse to pay 51$ for the nte equavalent.
Do you need that exact chip and pinout, or just th...Re: 24Hz to 60Hz PLL?
John Larkin - 2010-02-18 12:31:00
On Thu, 18 Feb 2010 12:23:49 -0500, Phil Hobbs
wrote:
> On 2/18/2010 10:51 AM, Jim Thompson wrote:
> > On Thu, 18 Feb 2010 10:22:36 -0500, "Michael A. Terrell"
> > wrote:
> >
> > >
> > > Jim Thompson wrote:
> > > >
> > > > Michael A. Terrell wrote:
> > > > >
> > > > > ...Custom semi-custom or what other ideas.
MooseFET - 2009-07-30 20:47:00
I have a system that has just about a dozen 12 bit DACs, a VCO in the
MHz range, a bunch of analog switches, matched resistors and opamps in
it. I would like to reduce it all to one IC.
One of the amplifiers is low noise (3nV/sqrt(Hz)) other than that
fairly ordinary rail-rail op-amps would...Re: SMPS inverter voltage feedback methods
D from BC - 2008-01-26 12:44:00
On Sat, 26 Jan 2008 16:13:46 GMT, Jamie Morken
wrote:
> Hi,
>
> For this circuit:
>
> http://rocketresearch.nekrom.com/new/split%20phase%20240VAC%20inverter/240VAC%2060Hz%20split%20phase%20inverter.jpg
>
> For measuring the "120VAC-x" signals at 200kHz bandwidth what would a
> good...Re: low jitter PLL
Rene Tschaggelar - 2008-08-09 18:31:00
bigcaboy@gmail.com wrote:
> dear all:
>
> what's the best low jitter PLL on the market? I want to achieve ~20-50
> fs jitter from clock generator. $60 is okay.
It is not the PLL that does the jitter, it is
the divider ratio and it is the VCO. And not at
least it is the frequency. At ...Re: overloading wirewound resistors
Joel Koltner - 2009-03-02 18:56:00
"Jim Thompson" wrote in
message news:03soq49q52f2kdpq6r7hqsl8msak8mt63j@4ax.com...
> I've not used spirals for any thing other than in VCO's... at around
> 5GHz.
I would think that the phase noise of such a VCO wouldn't be that great, but
such an oscillator is probably just the heart o...Re: Square + triangle = sine (almost)
Darwin - 2010-03-08 16:10:00
On 7 Mar, 13:47, "Ban" wrote:
> > http://www.national.com/an/AN/AN-263.pdf
>
> > (see "Approximation Methods" paragraph beginning at page 8)
>
> > Hope it helps.
>
> I downloaded the paper, but what they call *logarithmic* is IMHO *tanh* and
> that opamp is not connected very ...Re: Uart through an audio transformer
Jan Panteltje - 2008-10-04 17:38:00
On a sunny day (Sat, 04 Oct 2008 23:07:31 +0200) it happened Martin Griffith
wrote in
:
> > Tam
> 9600 baud is not exactly DC
> No it's the standard non inverted uart o/p, and a longish sq wave
> syncword, seems to be ok (in LTspice).
>
> I've want to insert some bytes of data into ...Re: ESR meter project, again.
whit3rd - 2008-12-10 17:48:00
On Dec 6, 5:42=A0am, The Phantom wrote:
> > > A while back a proposal was put forth in the group to come with a good=
, low cost
> > > ESR meter, but it never went anywhere.
> =A0My aim in this thread isn't to avoid bother;
> it's to attack bother head on, to do our own design usin...Re: FRONT END WITH PLL
MooseFET - 2009-02-03 07:35:00
On Feb 3, 12:49=A0am, "RealInfo" wrote:
> Hi all
>
> In a PLL contrlolled Rf amplifier front end how exactly the 1st RF stage
> frequency of the tuned circuit is contrlolled so it
> will be exactly the PLL freq+ IF frequncy ?
The tuned circuit has a wide enough band width that a simp...Negative frequencies on spectrum analyzers
Joel Koltner - 2008-11-03 16:48:00
I realize that historically swept spectrum analyzers could have negative
center frequencies due to signal detection being performed at some IF, wherein
back at the mixer if your VCO went low enough you'd start tracing out the
shape of your RBW filters, eventually hit DC, and then just alias ri...Re: 24Hz to 60Hz PLL?
John Larkin - 2010-02-19 01:37:00
On Thu, 18 Feb 2010 18:54:22 -0800 (PST), MooseFET
wrote:
> On Feb 18, 9:31 am, John Larkin
> wrote:
> > On Thu, 18 Feb 2010 12:23:49 -0500, Phil Hobbs
> >
> >
> >
> > wrote:
> > > On 2/18/2010 10:51 AM, Jim Thompson wrote:
> > > > On Thu, 18 Feb 2010 10:22:36 -0500, "Mi...Re: 24Hz to 60Hz PLL?
Spehro Pefhany - 2010-02-12 17:31:00
On Fri, 12 Feb 2010 14:14:04 -0800 (PST), Chris
wrote:
> I need to make a PLL that slaves to a 24Hz square wave. The output of
> the loop would be a 60Hz square wave. Any CMOS level chips that would
> be good for this? I understand that I would need to divide by a
> decimal value of 2.5...Re: laser FM detector
John Fields - 2008-02-24 08:19:00
On Sat, 23 Feb 2008 18:13:59 -0800 (PST), j2.macalinao@gmail.com
wrote:
> I'll just put clearer, straight-forward question, since I feel that
> we're getting off-topic here:
>
> Is there a way to make an FM signal using an AC output and a
> photodiode? (AC output for the carrier, photodiode...Microphonic film capacitor
Andrew Holme - 2009-05-28 17:15:00
I'm developing a frequency synthesizer.
I was worried about ceramic capacitor microphonics, so I used these film
capacitors in my loop filter:
Panasonic ECPU1C105MA5 1uF, 16V, 1210, PPS (Farnell 969-4315)
AVX CB017D0223JBA 22 NF, 50V, 1206, PEN (Farnell 165-7961)
The 1uF is microphonic....