Re: [time-nuts] TCXO drift - related to TVB's posting

I periodically check that. On Nov 12, 2016 5:43 PM, "Adrian Godwin" wrote: > What if your shop reference were drifting up ? > > > On Sat, Nov 12, 2016 at 11:25 PM, Joseph Gray wrote: > > > TCXO, not OCXO, but related. Sorry, but I have no graphs. > > > >

Re: [time-nuts] TCXO drift - related to TVB's posting

What if your shop reference were drifting up ? On Sat, Nov 12, 2016 at 11:25 PM, Joseph Gray wrote: > TCXO, not OCXO, but related. Sorry, but I have no graphs. > > I work for a municipal radio shop. We service radios that span 20 > years (through acquisitions, it was GE,

Re: [time-nuts] TCXO drift - related to TVB's posting

Hi In *general* the crystal in an OCXO should drift positive. The reason often mentioned is fairly simple: You can only get the blank + base plate + calibration just so clean. You can go crazy getting the enclosure clean. The result is a long term mass transfer from the blank (it’s “dirty”,

Re: [time-nuts] tcxo

Some of the Arduinos (not sure about Mini 04 but I am suspicious) use ceramic resonators rather than real crystals and thus may have extremely poor frequency stability. See here http://jorisvr.nl/arduino_frequency.html for an example. ah! Very intriguing material, those crystals. I wonder

Re: [time-nuts] tcxo

More Arduino clock and timekeeping notes: If the part connected to the processor's XTAL1 and XTAL2 pins has 2 pins and external capacitors it is a crystal. If it has 3 pins and no caps it is a ceramic resonator. If you have a crystal, you can fine-tune its frequency by replacing one of the

Re: [time-nuts] tcxo

I'm experimenting a bit with time keeping. For that I use cheap low power hardware like raspberry pies and arduinos. Hi people, Thanks for all the replies! Took a bit to respond but I had the flu. My objective is, to get the best precision/accuracy possible with said hardware. The first

Re: [time-nuts] tcxo

Some of the Arduinos (not sure about Mini 04 but I am suspicious) use ceramic resonators rather than real crystals and thus may have extremely poor frequency stability. See here http://jorisvr.nl/arduino_frequency.html for an example. Is there some reason you are using a 16.9344 MHz oscillator

Re: [time-nuts] tcxo

. :) - Original Message - From: Bob Camp kb...@n1k.org To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Sunday, December 07, 2014 8:51 PM Subject: Re: [time-nuts] tcxo Hi On Dec 7, 2014, at 8:14 PM, Hal Murray hmur...@megapathdsl.net wrote

Re: [time-nuts] tcxo

You can go as simple as a PTC glued on the crystal to start with. Alternatively take a look here: http://www.w6pql.com/crystal_oven_controller.htm On Sun, Dec 7, 2014 at 9:53 PM, folkert folk...@vanheusden.com wrote: Hi, I'm experimenting a bit with time keeping. For that I use cheap low

Re: [time-nuts] tcxo

http://www.romanblack.com/xoven.htm Joe Gray W5JG On Sun, Dec 7, 2014 at 1:53 PM, folkert folk...@vanheusden.com wrote: Hi, I'm experimenting a bit with time keeping. For that I use cheap low power hardware like raspberry pies and arduinos. I noticed that the accuracy of a crystal makes a

Re: [time-nuts] tcxo

Hi On Dec 7, 2014, at 3:53 PM, folkert folk...@vanheusden.com wrote: Hi, I'm experimenting a bit with time keeping. For that I use cheap low power hardware like raspberry pies and arduinos. I noticed that the accuracy of a crystal makes a big difference. Did a bit of googling and I

Re: [time-nuts] tcxo

On Sun, Dec 7, 2014 at 12:53 PM, folkert folk...@vanheusden.com wrote: Hi, I noticed that the accuracy of a crystal makes a big difference. Did a bit of googling and I learned that a txco may help solve that. The very first thing you need to do is figure out what your requirements are. How

Re: [time-nuts] tcxo

On Sun, 7 Dec 2014 21:53:48 +0100, you wrote: Something that keeps a constant temperature that is that I can then glue/solder to the crystal of those systems. A ready to go version (QH40A):

Re: [time-nuts] tcxo

albertson.ch...@gmail.com said: The very first thing you need to do is figure out what your requirements are. Except that this is time-nuts, so the only requirement for some of us is having fun. But yes, you are correct in that thinking about the big picture is a good idea. -- These are

Re: [time-nuts] tcxo

Hi On Dec 7, 2014, at 8:14 PM, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: The very first thing you need to do is figure out what your requirements are. Except that this is time-nuts, so the only requirement for some of us is having fun. The original

Re: [time-nuts] tcxo

: [time-nuts] tcxo Hi On Dec 7, 2014, at 8:14 PM, Hal Murray hmur...@megapathdsl.net wrote: albertson.ch...@gmail.com said: The very first thing you need to do is figure out what your requirements are. Except that this is time-nuts, so the only requirement for some of us is having fun

Re: [time-nuts] tcxo

Thermal control circuits could oscillate at very low frequencies there is a tricky time constant -- the heat propagation between theater and the temperature sensor! 73 Alex On 12/7/2014 1:01 PM, Azelio Boriani wrote: You can go as simple as a PTC glued on the crystal to start with.

Re: [time-nuts] tcxo

A TCXO does not keep a constant temperature.  But an OCXO does.  The TCXO compensates for the temperature effect, while the OCXO holds the temperature. Bob On Sunday, December 7, 2014 1:47 PM, Joseph Gray jg...@zianet.com wrote: http://www.romanblack.com/xoven.htm Joe Gray W5JG

Re: [time-nuts] tcxo

Folkert, You don't make your detailed requirements clear, but you might be interested in this module http://www.adafruit.com/product/255 It uses a DS3231 chip, which is a 32.768 khz oscillator with built-in temperature sensing. Based on the temperature, it automatically switches in internal

Re: [time-nuts] tcxo

folk...@vanheusden.com said: I noticed that the accuracy of a crystal makes a big difference. Did a bit of googling and I learned that a txco may help solve that. Something that keeps a constant temperature that is that I can then glue/solder to the crystal of those systems. My question now