Re: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-21 Thread Bob Camp
Hi > On Mar 21, 2017, at 1:07 AM, Chris Albertson > wrote: > > I built one of these using a PWM DAC also. The design was posted to this > list so I can't take credit for the idea. But we used two PWM output > pins. The PWM provides more voltage range than is

Re: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-21 Thread Chris Albertson
I built one of these using a PWM DAC also. The design was posted to this list so I can't take credit for the idea. But we used two PWM output pins. The PWM provides more voltage range than is needed by the OXO's EFC. To the output was scaled by a voltage divider. This also scaled down thew

[time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Mark Sims
The "DAC" was PWM based, but used a separate voltage regulator for the "reference". I never tried it using the USB power as the reference. The OCXO (+board) uses less than 500 mA warming up (which it does rather quickly). It's in a small hermetic package about twice the size of a standard

Re: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Attila Kinali
Moin, On Mon, 20 Mar 2017 17:11:36 -0400 "William H. Fite" wrote: > You are talking about product design, development and optimization, not the > production of a one-off for home use. Since performance standards are > already well established, it is only necessary for the

Re: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Jim Harman
On Mon, Mar 20, 2017 at 4:14 PM, Mark Sims wrote: > $3 for an Arduino chip on a PCB with proto area from China (should have > bought a lot more when they were available),$10 for a small ovenized 5V > TTL output OCXO (also should have bought a lot more), and $5 for misc

[time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread William H. Fite
Attilla, You are talking about product design, development and optimization, not the production of a one-off for home use. Since performance standards are already well established, it is only necessary for the developer to test the bench built instrument against published standards and determine

[time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Mark Sims
I did it for $25... $7 for the GPS+antenna module, $3 for an Arduino chip on a PCB with proto area from China (should have bought a lot more when they were available),$10 for a small ovenized 5V TTL output OCXO (also should have bought a lot more), and $5 for misc parts (OK, beer money

Re: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Bob Stewart
e time and frequency measurement <time-nuts@febo.com> Sent: Monday, March 20, 2017 2:01 PM Subject: [time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO) On Thu, 16 Mar 2017 00:06:49 -0700 Chris Albertson <albertson.ch...@gmail.com> wrote: > I actually did use

[time-nuts] time-nuts equipment verification from scratch (was: WTB: GPSDO)

2017-03-20 Thread Attila Kinali
On Thu, 16 Mar 2017 00:06:49 -0700 Chris Albertson wrote: > I actually did use your method. I have a Rb and Thunderbolt, a pair > of freq. counters and so on.But still I wanted to see if I could > build from scratch and verify proper operation and keep the budget