wrote in message news:blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com...
On Wed, 26 Mar 2014 16:04:35 -0400, Fred McKenzie <fmmck@aol.com>
wrote:
>In article <E_adnTWFNK9GVK_OnZ2dnUVZ_qGdnZ2d@earthlink.com>,
> bitrex <bitrex@de.lete.earthlink.net> wrote:
>
>> Anyone have any experience with how dual gate mosfets perform in
>> a crystal oscillator role, at low voltages (< 3 v), at
>> frequencies say 200 - 500 MHz?
>
>Do you mean an oscillator that works with a 200 - 500 MHz crystal? Are
>there such crystals?
Two decades ago, the highest frequency I had seen was a 116 MHz 5th
overtone crystal, but as far as I understand a lot higher frequencies
are currently available.
>With overtone crystals, you need a tank (LC) circuit at the required
>frequency, otherwise the crystal might oscillate at the fundamental
>frequency :-).
And it can get quite tricky. Depending on type, there is a very close
unwarranted mode. e.g. a 35MHz fundamental, with 100MHz desired OT, with an
unwanted 110MHz. A mode trap of a series LC with a parallel cap all in
series with the xtal is usually used to knock it out. A resister across the
xtal can often be used to reject the fundamental by way of phase change.
Regards
Kevin Aylward B.Sc.
kevin@kevinaylward.co.uk
www.kevinaylward.co.uk
Reply by Jan Panteltje●March 28, 20142014-03-28
On a sunny day (Fri, 28 Mar 2014 10:21:47 +0000 (GMT)) it happened bitrex
<bitrex@de.lete.earthlink.net> wrote in
<lImdnUyYI885CajOnZ2dnUVZ_rmdnZ2d@earthlink.com>:
>> Some of the synthetic oscillators, like the Fox Xpresso and the Silabs
>> parts, go to really high frequencies and are cheaper than you can buy
>> the parts to make an oscillator.
>>
>>
>> --
>>
>> John Larkin Highland Technology, Inc
>>
>> jlarkin att highlandtechnology dott com
>> http://www.highlandtechnology.com
>>
>>
>
>Ilooked at Mouser for the silabs parts...for a 500 MHz module
> they wanted 40 bucks, and it needed 3.3 volts...and it was non
> stock. :(
> On a sunny day (Fri, 28 Mar 2014 08:38:58 -0400) it happened Phil Hobbs
> <hobbs@electrooptical.net> wrote in <53356D62.5030804@electrooptical.net>:
>
>> On 3/28/2014 6:38 AM, Jan Panteltje wrote:
>>> On a sunny day (Fri, 28 Mar 2014 03:28:29 -0700 (PDT)) it happened whit3rd
>>> <whit3rd@gmail.com> wrote in
>>> <ec3d7829-dfd2-43fe-8673-7304e39e0424@googlegroups.com>:
>>>
>>>> On Thursday, March 27, 2014 12:46:57 AM UTC-7, Jan Panteltje wrote:
>>>>> On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
>>>>>
>>>>> upsidedown@downunder.com wrote in
>>>>>
>>>>> <blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
>>>>
>>>>> I bought a bunch of 100 MHz oscillator modules from ebay...
>>>>
>>>>
>>>>> At that price I would think 200 MHz must exist too:-)
>>>>>
>>>>> And sure enough:
>>>>>
>>>>> ebay 261319059458
>>>>>
>>>>> 4$49 200 MHz US
>>>>
>>>> Oscillator modules, of course, come in lots of varieties; some
>>>> are PLL and locked to a quartz crystal well below the output
>>>> frequency; it isn't just small-integer-multiple 'overtone' tricks that
>>>> are in these modules!
>>>> See <http://www.silabs.com/Support%20Documents/TechnicalDocs/SI530.pdf>
>>>
>>> Right and who cares what is in it as long as it meets specs.
>>>
>>
>> The phase noise of some of those synthesized modules has to be seen to
>> be believed.
>
> That pdf says:
>
> Parameter Symbol Test Condition Min Typ Max Unit
> Phase Jitter (RMS)1 J 12 kHz to 20 MHz (OC-48) -- 0.25 0.40 ps
> for FOUT > 500 MHz
> 50 kHz to 80 MHz (OC-192) -- 0.26 0.37 ps
> Phase Jitter (RMS)1 J 12 kHz to 20 MHz (OC-48) -- 0.36 0.50 ps
> for FOUT of 125 to 500 MHz
> 50 kHz to 80 MHz (OC-192)2 -- 0.34 0.42 ps
> Phase Jitter (RMS) J 12 kHz to 20 MHz (OC-48)2 -- 0.62 -- ps
> for FOUT of 10 to 160 MHz
> CMOS Output Only 50 kHz to 20 MHz2 -- 0.61 -- ps
> Notes:
> 1. Refer to AN256 for further information.
>
> BTW the 100 MHz from ebay is direct I think,
> I use it the DVB-S modulator, and the constellation is very stable,
> mm and a free running VCO on top of that to mix it up.
> But I do not have the nice equipment to check it with that you have, only this:
> http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/xdipo_locked_to_raspberry_pi_datv_transmitter_IMG_3938.JPG
> The pictjure looks good, :-)
>
> Sure, synthesized, I dunnit with FPGA as I posted here for GPS generation...
> bit of low-pass to drive the VCO, no problem.
Any idea what bandwidth that's in? DC to 100 MHz->good, 1 Hz bad.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Jan Panteltje●March 28, 20142014-03-28
On a sunny day (Fri, 28 Mar 2014 08:38:58 -0400) it happened Phil Hobbs
<hobbs@electrooptical.net> wrote in <53356D62.5030804@electrooptical.net>:
>On 3/28/2014 6:38 AM, Jan Panteltje wrote:
>> On a sunny day (Fri, 28 Mar 2014 03:28:29 -0700 (PDT)) it happened whit3rd
>> <whit3rd@gmail.com> wrote in
>> <ec3d7829-dfd2-43fe-8673-7304e39e0424@googlegroups.com>:
>>
>>> On Thursday, March 27, 2014 12:46:57 AM UTC-7, Jan Panteltje wrote:
>>>> On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
>>>>
>>>> upsidedown@downunder.com wrote in
>>>>
>>>> <blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
>>>
>>>> I bought a bunch of 100 MHz oscillator modules from ebay...
>>>
>>>
>>>> At that price I would think 200 MHz must exist too:-)
>>>>
>>>> And sure enough:
>>>>
>>>> ebay 261319059458
>>>>
>>>> 4$49 200 MHz US
>>>
>>> Oscillator modules, of course, come in lots of varieties; some
>>> are PLL and locked to a quartz crystal well below the output
>>> frequency; it isn't just small-integer-multiple 'overtone' tricks that
>>> are in these modules!
>>> See <http://www.silabs.com/Support%20Documents/TechnicalDocs/SI530.pdf>
>>
>> Right and who cares what is in it as long as it meets specs.
>>
>
>The phase noise of some of those synthesized modules has to be seen to
>be believed.
That pdf says:
Parameter Symbol Test Condition Min Typ Max Unit
Phase Jitter (RMS)1 J 12 kHz to 20 MHz (OC-48) -- 0.25 0.40 ps
for FOUT > 500 MHz
50 kHz to 80 MHz (OC-192) -- 0.26 0.37 ps
Phase Jitter (RMS)1 J 12 kHz to 20 MHz (OC-48) -- 0.36 0.50 ps
for FOUT of 125 to 500 MHz
50 kHz to 80 MHz (OC-192)2 -- 0.34 0.42 ps
Phase Jitter (RMS) J 12 kHz to 20 MHz (OC-48)2 -- 0.62 -- ps
for FOUT of 10 to 160 MHz
CMOS Output Only 50 kHz to 20 MHz2 -- 0.61 -- ps
Notes:
1. Refer to AN256 for further information.
BTW the 100 MHz from ebay is direct I think,
I use it the DVB-S modulator, and the constellation is very stable,
mm and a free running VCO on top of that to mix it up.
But I do not have the nice equipment to check it with that you have, only this:
http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/xdipo_locked_to_raspberry_pi_datv_transmitter_IMG_3938.JPG
The pictjure looks good, :-)
Sure, synthesized, I dunnit with FPGA as I posted here for GPS generation...
bit of low-pass to drive the VCO, no problem.
Reply by Phil Hobbs●March 28, 20142014-03-28
On 3/28/2014 6:38 AM, Jan Panteltje wrote:
> On a sunny day (Fri, 28 Mar 2014 03:28:29 -0700 (PDT)) it happened whit3rd
> <whit3rd@gmail.com> wrote in
> <ec3d7829-dfd2-43fe-8673-7304e39e0424@googlegroups.com>:
>
>> On Thursday, March 27, 2014 12:46:57 AM UTC-7, Jan Panteltje wrote:
>>> On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
>>>
>>> upsidedown@downunder.com wrote in
>>>
>>> <blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
>>
>>> I bought a bunch of 100 MHz oscillator modules from ebay...
>>
>>
>>> At that price I would think 200 MHz must exist too:-)
>>>
>>> And sure enough:
>>>
>>> ebay 261319059458
>>>
>>> 4$49 200 MHz US
>>
>> Oscillator modules, of course, come in lots of varieties; some
>> are PLL and locked to a quartz crystal well below the output
>> frequency; it isn't just small-integer-multiple 'overtone' tricks that
>> are in these modules!
>> See <http://www.silabs.com/Support%20Documents/TechnicalDocs/SI530.pdf>
>
> Right and who cares what is in it as long as it meets specs.
>
The phase noise of some of those synthesized modules has to be seen to
be believed.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Reply by Jan Panteltje●March 28, 20142014-03-28
On a sunny day (Fri, 28 Mar 2014 03:28:29 -0700 (PDT)) it happened whit3rd
<whit3rd@gmail.com> wrote in
<ec3d7829-dfd2-43fe-8673-7304e39e0424@googlegroups.com>:
>On Thursday, March 27, 2014 12:46:57 AM UTC-7, Jan Panteltje wrote:
>> On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
>>
>> upsidedown@downunder.com wrote in
>>
>> <blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
>
>> I bought a bunch of 100 MHz oscillator modules from ebay...
>
>
>> At that price I would think 200 MHz must exist too:-)
>>
>> And sure enough:
>>
>> ebay 261319059458
>>
>> 4$49 200 MHz US
>
>Oscillator modules, of course, come in lots of varieties; some
>are PLL and locked to a quartz crystal well below the output
>frequency; it isn't just small-integer-multiple 'overtone' tricks that
>are in these modules!
>See <http://www.silabs.com/Support%20Documents/TechnicalDocs/SI530.pdf>
Right and who cares what is in it as long as it meets specs.
Reply by whit3rd●March 28, 20142014-03-28
On Thursday, March 27, 2014 12:46:57 AM UTC-7, Jan Panteltje wrote:
> On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
>
> upsidedown@downunder.com wrote in
>
> <blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
> I bought a bunch of 100 MHz oscillator modules from ebay...
> At that price I would think 200 MHz must exist too:-)
>
> And sure enough:
>
> ebay 261319059458
>
> 4$49 200 MHz US
Oscillator modules, of course, come in lots of varieties; some
are PLL and locked to a quartz crystal well below the output
frequency; it isn't just small-integer-multiple 'overtone' tricks that
are in these modules!
See <http://www.silabs.com/Support%20Documents/TechnicalDocs/SI530.pdf>
Reply by bitrex●March 28, 20142014-03-28
John Larkin <jlarkin@highlandtechnology.com> Wrote in message:
> On Wed, 26 Mar 2014 16:51:12 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>On 03/26/2014 03:32 AM, bitrex wrote:
>>>
>>> Anyone have any experience with how dual gate mosfets perform in
>>> a crystal oscillator role, at low voltages (< 3 v), at
>>> frequencies say 200 - 500 MHz?
>>>
>>
>>Probably noisy. Plus their f_max is usually around 700 MHz, so they
>>don't have a lot of gain up there, which is a problem with high overtone
>>crystals. (Or are you using one of the fancy-schmance high fundamental
>>ones?)
>>
>>Cheers
>>
>>Phil Hobbs
>
> It's pretty much not worth building your own XOs these days. Packaged
> oscillators are so good and cheap.
>
> Some of the synthetic oscillators, like the Fox Xpresso and the Silabs
> parts, go to really high frequencies and are cheaper than you can buy
> the parts to make an oscillator.
>
>
> --
>
> John Larkin Highland Technology, Inc
>
> jlarkin att highlandtechnology dott com
> http://www.highlandtechnology.com
>
>
I
looked at Mouser for the silabs parts...for a 500 MHz module
they wanted 40 bucks, and it needed 3.3 volts...and it was non
stock. :(
--
----Android NewsGroup Reader----
http://www.piaohong.tk/newsgroup
Reply by bitrex●March 28, 20142014-03-28
John Larkin <jlarkin@highlandtechnology.com> Wrote in message:
> On Wed, 26 Mar 2014 16:51:12 -0400, Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>On 03/26/2014 03:32 AM, bitrex wrote:
>>>
>>> Anyone have any experience with how dual gate mosfets perform in
>>> a crystal oscillator role, at low voltages (< 3 v), at
>>> frequencies say 200 - 500 MHz?
>>>
>>
>>Probably noisy. Plus their f_max is usually around 700 MHz, so they
>>don't have a lot of gain up there, which is a problem with high overtone
>>crystals. (Or are you using one of the fancy-schmance high fundamental
>>ones?)
>>
>>Cheers
>>
>>Phil Hobbs
>
> It's pretty much not worth building your own XOs these days. Packaged
> oscillators are so good and cheap.
>
> Some of the synthetic oscillators, like the Fox Xpresso and the Silabs
> parts, go to really high frequencies and are cheaper than you can buy
> the parts to make an oscillator.
>
>
> --
>
> John Larkin Highland Technology, Inc
>
> jlarkin att highlandtechnology dott com
> http://www.highlandtechnology.com
>
>
Don't those oscillator
modules usually require a supply voltage of
3.3 to 5 volts to work, though?
--
----Android NewsGroup Reader----
http://www.piaohong.tk/newsgroup
Reply by Jan Panteltje●March 27, 20142014-03-27
On a sunny day (Thu, 27 Mar 2014 09:13:24 +0200) it happened
upsidedown@downunder.com wrote in
<blj7j996e0a6i6812lbrjd7n555dj58akh@4ax.com>:
>On Wed, 26 Mar 2014 16:04:35 -0400, Fred McKenzie <fmmck@aol.com>
>wrote:
>
>>In article <E_adnTWFNK9GVK_OnZ2dnUVZ_qGdnZ2d@earthlink.com>,
>> bitrex <bitrex@de.lete.earthlink.net> wrote:
>>
>>> Anyone have any experience with how dual gate mosfets perform in
>>> a crystal oscillator role, at low voltages (< 3 v), at
>>> frequencies say 200 - 500 MHz?
>>
>>Do you mean an oscillator that works with a 200 - 500 MHz crystal? Are
>>there such crystals?
>
>Two decades ago, the highest frequency I had seen was a 116 MHz 5th
>overtone crystal, but as far as I understand a lot higher frequencies
>are currently available.
>
>With overtone crystals, you need a tank (LC) circuit at the required
>frequency, otherwise the crystal might oscillate at the fundamental
>frequency :-).
I bought a bunch of 100 MHz oscillator modules from ebay...
ebay item 261003544995
6 for 9$ free shipping, cannot make it for that...
logic output, works great.
At that price I would think 200 MHz must exist too:-)
And sure enough:
ebay 261319059458
4$49 200 MHz US
And that was a 5 second search.