Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I have sent all my E1938A documentation to Brooke Clarke. He will be posting it. Regarding pinout: I sent him a really definitive pinout diagram consisting of a photograph of the top and bottom of the board with red arrows pointing to pins and giving the functions. This is totally idiot proof. Due to various shenanigans with mounting connectors on the wrong side of the board, and using special connectors, etc., there is some chance of getting the numbering wrong. I think you should only go by the photographs with the circles and arrows (this is reminding me of the lyrics to "Alice's Restaurant" about the "27 8x10 color glossy photos with circles and arrows" etc). Rick N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY In a message dated 8/27/2007 17:29:05 Pacific Daylight Time, [EMAIL PROTECTED] writes: > Seems one of those "GND" pins is actually a "heater on" type of pin. >It might be the return for the heater so the IR drop in the high current >heater path doesn't offset the ground for the control signals. That's what I thought at first too, but in Tom's description all GND pins are named the same. Isn't it fun to experiment with these ?! bye, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY In a message dated 8/27/2007 17:56:45 Pacific Daylight Time, [EMAIL PROTECTED] writes: >is ovenized provides a stable 2.5V to bias the diode if >you >do NOT want to use the EFC. >*** Hi Kit, that's what I thought! I guess it's better to use the internal reference since it's ovenized, even though it's not exactly 2.5V. BTW: the 0V to 5V EFC range and 10MHz output makes it a perfect target for disciplining by our Fury GPSDO with OCXO SMA connector-option. Will report later on how that works out. bye, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Thank you Bruce Griffiths wrote: > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > Dick, W1KSZ wrote: >> I have one of these E1938A's. Where is this site you are referring to ? >> >> Thanks, Dick, W1KSZ >> >> > Dick > > E1938A: > http://www.leapsecond.com/museum/e1938a/ > > Z3815A: > http://www.leapsecond.com/museum/z3815a/ > > > Bruce > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- 73, Dick, W1KSZ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Said, The DB25 pinning is as per TVB's web site: http://www.leapsecond.com/museum/e1938a/ The EFC voltage info is as follows (courtesy of Rick K): *** The 10811 was bipolar +/-5V as you said. The cathode of the tuning diode was connected to a 6.2V zener diode that was sort of ovenized. The concept was that if you did NOT want to use the EFC, you simply grounded the EFC pin. The E1938A has unipolar 0V to 5V EFC with the anode of the tuning diode grounded. A 2.5V reference IC that really is ovenized provides a stable 2.5V to bias the diode if you do NOT want to use the EFC. *** I concur with Bruce's on-board LED description. My experience is that the "hockey-puck" oven takes close on 15 minutes to "stabilise" (settle) - in the Z3815 at least ! Regards, Kit VK2LL Sydney (user of many Z3815A GPSDO's) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Dick, W1KSZ wrote: > I have one of these E1938A's. Where is this site you are referring to ? > > Thanks, Dick, W1KSZ > > Dick E1938A: http://www.leapsecond.com/museum/e1938a/ Z3815A: http://www.leapsecond.com/museum/z3815a/ Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > Hi Bruce, > > I got it to work, it even locks to -5Hz within 5 minutes and the Amber LED > goes off. > > The problem was that I had only applied GND to the shield of the connector. > I added a wire to the EFC pin to EFC return, and connected the three GND pins > of the connector, and magically it started working. > > Seems one of those "GND" pins is actually a "heater on" type of pin. > > Now I will do some experiments, it seems EFC should be 2.5V for the output > to be on frequency (not 0V). > > Another interesting observation: my unit has 2.532V on the reference output. > I could probably try to locate the reference, and replace it with something > more modern and stable. > > Lastly, the unit seems to have a slow 2-4 second sinusoidial drift in parts > to the -11 when measuring it's output on my 53132A after about 10 minutes > warmup. Wonder if that's the oven heater control loop... > > bye, > Said > > Said There are 3 LT1121I 2.5V references on the board, one located near the ADC, one near the devices with heatsinks and yet another near the 4 pin header at the rear of the board (end nearest the D - connector). There may also be one inside the oven - the osc.pdf paper indicates this. As long as the voltage is stable the exact value is unimportant. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY I have one of these E1938A's. Where is this site you are referring to ? Thanks, Dick, W1KSZ Bruce Griffiths wrote: > ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] RETRY > > [EMAIL PROTECTED] wrote: >> Thanks Bruce, >> >> I hooked +12V and +5V up to it, but there is no heater current, and no >> LED's >> go on. There is however a small current into the +12V (90mA) and the >> 10.0MHz >> are being generated with a significant error since the crystal is at room >> temp. >> >> Wonder what I am doing wrong? >> >> bye, >> Said >> >> > Said > > Look at the Z3815A and the E1938A on TVB's website and note the subtle > difference between the E1938A installed in the Z3815A which only has a > single DAC and the other E1938A which appears to have 2 DACs. > > Which E1938A version do you have? > > Bruce > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- 73, Dick, W1KSZ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY > Seems one of those "GND" pins is actually a "heater on" type of pin. It might be the return for the heater so the IR drop in the high current heater path doesn't offset the ground for the control signals. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY In a message dated 8/27/2007 17:09:17 Pacific Daylight Time, [EMAIL PROTECTED] writes: >Which E1938A version do you have? Hi Bruce, I've got the "two-dac" version with the connector bottom-mounted... bye, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Hi Bruce, I got it to work, it even locks to -5Hz within 5 minutes and the Amber LED goes off. The problem was that I had only applied GND to the shield of the connector. I added a wire to the EFC pin to EFC return, and connected the three GND pins of the connector, and magically it started working. Seems one of those "GND" pins is actually a "heater on" type of pin. Now I will do some experiments, it seems EFC should be 2.5V for the output to be on frequency (not 0V). Another interesting observation: my unit has 2.532V on the reference output. I could probably try to locate the reference, and replace it with something more modern and stable. Lastly, the unit seems to have a slow 2-4 second sinusoidial drift in parts to the -11 when measuring it's output on my 53132A after about 10 minutes warmup. Wonder if that's the oven heater control loop... bye, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > Thanks Bruce, > > I hooked +12V and +5V up to it, but there is no heater current, and no LED's > go on. There is however a small current into the +12V (90mA) and the 10.0MHz > are being generated with a significant error since the crystal is at room > temp. > > Wonder what I am doing wrong? > > bye, > Said > > Said Look at the Z3815A and the E1938A on TVB's website and note the subtle difference between the E1938A installed in the Z3815A which only has a single DAC and the other E1938A which appears to have 2 DACs. Which E1938A version do you have? Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > > Thanks Bruce, > > I hooked +12V and +5V up to it, but there is no heater current, and no LED's > go on. There is however a small current into the +12V (90mA) and the 10.0MHz > are being generated with a significant error since the crystal is at room > temp. > > Wonder what I am doing wrong? > > bye, > Said > > Said Yes with the oven cold the frequency error is much larger than for an AT crystal. One LED on the front of the PCB flashes green when the device is powered up OK, another glows orange until the oven reaches temperature. The LED near the input connector glows green. LEDS near front of board: Amber OFF | | OFF Green | _ The oven current is quite high at startup. The GPSDXO version requires around 24V@ 60W to startup (it has dc-dc converters on the main board to produce +12V, +12V etc). Amber led starts ON then after a while it flashes. Then it turns off when OVEN is at operating temperature. The green LED flashes throughout. The other 2 LEDS indicate other conditions. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > Hi there, > > I'll break the silence :) > > does anyone know about the EFC voltage compatibility range for the E1938A > oscillator? Is it 0V to 5V, or -5V to +5V etc? > > How about the serial interfaces mentioned on Tom's website, are there any > datasheets, user-manual, schematics etc available that explain these in more > detail? > > Thanks, > Said > Said The E1938A may have several variants as at least one of them only uses a single DAC (AD7243AR), presumably for the oven controller. There is an LT1054I nearby, presumably to provide -12V for the DAC Vss supply. The only opamp on the board is an LMC660AIM quad CMOS opamp However readback of the EFC voltage is possible (presumably via the AD7714). Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY In a message dated 8/27/2007 15:36:31 Pacific Daylight Time, [EMAIL PROTECTED] writes: >There is also an EFC DAC (at least according to the osc.pdf paper on >Rick's site) which suggests that it may be possible to eliminate an >external DAC when the E1938A is locked to an external reference such as >the PPS output of a GPS timing receiver. >Bruce Thanks Bruce, I hooked +12V and +5V up to it, but there is no heater current, and no LED's go on. There is however a small current into the +12V (90mA) and the 10.0MHz are being generated with a significant error since the crystal is at room temp. Wonder what I am doing wrong? bye, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY [EMAIL PROTECTED] wrote: > Hi there, > > I'll break the silence :) > > does anyone know about the EFC voltage compatibility range for the E1938A > oscillator? Is it 0V to 5V, or -5V to +5V etc? > > How about the serial interfaces mentioned on Tom's website, are there any > datasheets, user-manual, schematics etc available that explain these in more > detail? > > Thanks, > Said > > > > ** Get a sneak peek of the all-new AOL at > http://discover.aol.com/memed/aolcom30tour > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > Said Since the AD7714 (0 - +5V input range with gain = 1 and 2.5V reference) monitors the EFC voltage, unless there is an input attenuator and/or level shift circuit in front of the AD7714, the EFC voltage will not exceed 5V nor go below 0V. There is also an EFC DAC (at least according to the osc.pdf paper on Rick's site) which suggests that it may be possible to eliminate an external DAC when the E1938A is locked to an external reference such as the PPS output of a GPS timing receiver. Bruce ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] E1938A oscillator pinning
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Hi there, I'll break the silence :) does anyone know about the EFC voltage compatibility range for the E1938A oscillator? Is it 0V to 5V, or -5V to +5V etc? How about the serial interfaces mentioned on Tom's website, are there any datasheets, user-manual, schematics etc available that explain these in more detail? Thanks, Said ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
