Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-22 Thread Mike Millen
On 22/12/2016 16:04, David wrote: On Wed, 21 Dec 2016 19:29:00 +, you wrote: You may be able to identify the initial steady current drawn by the TCXO heater, then the cycling once it's hit the right temp? If there's no change at all in average current as it warms then it may not have a

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-22 Thread David
On Wed, 21 Dec 2016 19:29:00 +, you wrote: > Can anyone comment on the following data, and whether they think the > oscillator in "my" M8N is a XO or a TCXO ? > >Can you monitor the current draw from cold (ambient)? > >You may be able to identify the initial steady current drawn by

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-22 Thread Didier Juges
TCXO usually refers to Temperature Compensated Crystal Oscillator (no heater), as opposed to Oven Controlled Crystal Oscillator (OCXO) which has an oven. I would not expect a TCXO to become warm or draw more current at power up. An OCXO would. Didier KO4BB On December 21, 2016 1:29:00 PM CST,

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-22 Thread EB4APL
TCXO is not an OCXO, they don't have an oven. They compensate the temperature induced drift using a temperature sensor, a microcontroller and a table or parameter set for adjusting the output frequency. BTW, for some applications they are unsuitable as they adjust the frequency in steps.

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-22 Thread Mike Millen
Can anyone comment on the following data, and whether they think the oscillator in "my" M8N is a XO or a TCXO ? Can you monitor the current draw from cold (ambient)? You may be able to identify the initial steady current drawn by the TCXO heater, then the cycling once it's hit the

[time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Mark Sims
Lady Heather does issue the MON-VER command. If you write a log file (W L W) the info is written as header comments in the log. The 5.0 release only writes the first entry from the ROM info section. The next spin will write all the available ROM info. My M8N returns 6 lines of ROM info (plus

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Kiwi Geoff
Mike Cook wrote: > It wouldn't surprise me, but you have a reference for this? I first read about this issue in the official Ublox forum Mike - try this link, http://tinyurl.com/Fake-M8Ns - at time of writing it leads to some of the messages that discuss the issue with photos and examples of

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Bob Camp
Hi Given the short term stability limits on the frequency source (TCXO or XO) it’s a pretty good bet that the crystal in both oscillators is very similar. There’s not a lot of difference between a “normal” crystal and a “TCXO” crystal other than the angle of cut tolerance. Since the XO has

[time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Mark Sims
I have used Reyax modules with RS-232 outputs for a long time. The company seems to be quite good. I trust them to be a reliable supplier and have never had any problems with any of their units despite being used in some rather harsh conditions. > Some time ago, I

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Peter Reilley
You seem to be assuming that the crystal in the TCXO is the same as the crystal in the XO. Wouldn't it be likely that the crystal would be higher quality in the more expensive product; the TCXO? How would a cheap crystal vs an expensive crystal appear different in the GPS data presented

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Joseph Gray
Some time ago, I bought two different modules from Reyax on ebay. One module had a ublox M8N. Recently, I did some reading on several drone forums about fake ublox modules from China. It seems that modules from quite a few vendors are not genuine. From the information presented about identifying

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Bob Camp
Hi > On Dec 21, 2016, at 4:20 AM, Mike Cook wrote: > > >> Le 21 déc. 2016 à 00:08, Kiwi Geoff a écrit : >> >> Hello All - and Seasons Greetings, >> >> One of the advantages of the recent hobby drone phenomena - it has >> brought to the market a lot of

Re: [time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-21 Thread Mike Cook
> Le 21 déc. 2016 à 00:08, Kiwi Geoff a écrit : > > Hello All - and Seasons Greetings, > > One of the advantages of the recent hobby drone phenomena - it has > brought to the market a lot of low cost GNSS modules that are > lightweight for drone flight control systems. Those

[time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-20 Thread Mark Sims
I don't know if you can tell the oscillator type from the receiver data. The ADEV info isn't a true adev since it does not have and independent reference. Heather has a keyboard command for making the lat/lon of your evil mad scientist secret volcano lair private (G L P) so you don't have to

[time-nuts] Ublox M8N - have I a XO or TCXO ?

2016-12-20 Thread Kiwi Geoff
Hello All - and Seasons Greetings, One of the advantages of the recent hobby drone phenomena - it has brought to the market a lot of low cost GNSS modules that are lightweight for drone flight control systems. Those of us with other hobbies, like "Time Nuts" and RTK - these low cost modules can