Hi One DB-25, one 10 MHz output, one pps output, square 3 pins in a row AMP power connector = 3801
Two DB-25's, two 10 MHz outs, two pps outs, circular XLR power connector = 3805 Either one can be 24 or 48 volt power. Normally that's pretty well marked. Either one can also apparently be RS-232 or RS-422. Most 3801's are 48 volts and RS-422. Most 3805's are 24 volts and RS-232. There are indeed exceptions to that. Bob On May 23, 2010, at 1:51 PM, Robert Benward wrote: > Bob > > Looking at al these pictures, I'm beginning to think I have a Z3801A, not a > 05A. After a few hours, the unit still has not locked. It is possible the > antenna is bad. I have a few more that I know are working. I also took the > precaution of connecting an antenna before powering up, as the manual says > it will go into an extensive search mode if it can't find satellites. > > Bob > > ----- Original Message ----- From: "Bob Camp" <[email protected]> > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Sent: Sunday, May 23, 2010 12:42 PM > Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) > > >> Hi >> >> The Symmetricom 3805's have an area on the lower board right behind the >> "control" DB-25. It's very similar to the 3801. There are three rows of >> holes for 0.025" post connectors. One row pair is labeled RS-232. The other >> row pair is labeled RS-422. The original intent appears to be to jumper the >> unit for what ever standard the customer desired. It's not at all clear that >> the later units are even stuffed for the RS-422 option. There are a number >> of unstuffed IC locations on the pc board. >> >> Your unit sounds like it's either blown, or running RS-422. I have never >> seen one of the earlier HP 3805's so I don't really know how much they have >> in common with the older units. There are indeed USB to RS-422 converters >> out there that will run on a normal PC. >> >> A good picture of the area in question on the 3801 is shown at: >> >> http://support.ntp.org/bin/view/Support/Z3801AReceiverModifications >> >> The picture you want is the third one down the page, under "RS-232 and PPS >> modification. >> >> The parts layout on the later 3805's is essentially identical to what's >> shown in the picture. The LT1180A RS-232 IC is present on the 3805. The chip >> next to it labeled U5 in the picture is absent. I suspect that is the RS-422 >> level converter. The labeling of the jumper locations on the 3801 is easier >> to read in the picture than the equivalent labels are on my 3805. >> >> Since the region obviously dates to the HP era, I'd be quite surprised if it >> was not pretty similar on the early 3805's. >> >> Bob >> >> >> On May 23, 2010, at 11:30 AM, Robert Benward wrote: >> >>> Ulrich, >>> On pin 2 of the DB9, I get -0.5V, and on pin 3 (TX) I get +2.0V. Doesn't >>> sound good. I have a 3805 that has only the bottom DB25 connector. The >>> person who sold it to me made a 3 wire cable, DB25 to DB9, with pins 2&3 >>> reversed and pin 7 grounded. >>> >>> Bob >>> >>> >>> ----- Original Message ----- From: "Ulrich Bangert" >>> <[email protected]> >>> To: "'Discussion of precise time and frequency measurement'" >>> <[email protected]> >>> Sent: Sunday, May 23, 2010 6:29 AM >>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>> >>> >>>> Bob, >>>> >>>> even without a computer connected the beast should do SOMETHING. In >>>> conjunction with a pc and a running communication it is easier to judge >>>> WHAT >>>> it currently does. >>>> >>>> To establish communication first find out what pinning the RS232 connector >>>> has: with the negative cable (black) of a voltmeter connected to Pin 7 of >>>> the RS232 connector check pins 2 & 3 with the positive cable (red) for the >>>> presence of a NEGATIVE voltage of a few Volts. If you can measure a >>>> negative >>>> voltage on one of the pins, you have successfully identified the Z3805's >>>> TRANSMIT pin. The other pin of 2/3 is the receive pin. >>>> >>>> Then solder a cable in this way >>>> >>>> Z3805 Transmit pin -> Pin 2 of pc RS232 port (9 pole D-Sub assumed) >>>> Z3805 Receive pin -> Pin 3 of pc RS232 port (9 pole D-Sub assumed) >>>> Z3805 Ground (7) -> Pin 5 of pc RS232 port (9 pole D-Sub assumed) >>>> >>>> Should you have a 25 pin connector for RS232 at your pc then the cable is >>>> >>>> Z3805 Transmit pin -> Pin 3 of pc RS232 port >>>> Z3805 Receive pin -> Pin 2 of pc RS232 port >>>> Z3805 Ground (7) -> Pin 7 of pc RS232 port >>>> >>>> No other connection is needed. With a cable like this start Z38XX and check >>>> that you that you choose the correct Com-Port for communication in the >>>> Parameters window. And yes, I know, being an owner of a Z3805 I should know >>>> exactly but I don't remember the day that I made the cable and I currently >>>> cannot access the back of my Z3805. >>>> >>>> Best regards >>>> Ulrich Bangert >>>> >>>>> -----Ursprungliche Nachricht----- >>>>> Von: [email protected] >>>>> [mailto:[email protected]] Im Auftrag von Robert Benward >>>>> Gesendet: Sonntag, 23. Mai 2010 05:31 >>>>> An: Discussion of precise time and frequency measurement >>>>> Betreff: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>>> >>>>> >>>>> Thank you all for these inputs! >>>>> >>>>> Most importantly, the big question is: Regardless of RS-232 >>>>> or 422, will the unit do ANYTHING without communications? >>>>> Do I need a computer to get anything beyond the "power" led? >>>>> >>>>> I bought this at the Dayton convention ham flea market, and >>>>> the guy told me it was already modified for RS-232. The >>>>> board inside says RS-422 near the connector. Without the >>>>> other LEDs blinking, I'm worried I bought a dead unit. I had >>>>> a GPS antenna on it, but it never locked on. Do I need a >>>>> computer to enable this thing? >>>>> >>>>> Thanks, >>>>> Bob >>>>> >>>>> ----- Original Message ----- From: "Bob Camp" <[email protected]> >>>>> To: "Discussion of precise time and frequency measurement" >>>>> <[email protected]> >>>>> Sent: Saturday, May 22, 2010 10:54 PM >>>>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>>> >>>>> >>>>> > Hi >>>>> > >>>>> > In this case the RS relates to Radio Shack ...... >>>>> > >>>>> > Not a lot of standardization in the RS-232 world. Take a >>>>> look at the >>>>> > slew rate limiting requirements in the original >>>>> > document ... >>>>> > >>>>> > Bob >>>>> > >>>>> > On May 22, 2010, at 9:47 PM, Robert Darlington wrote: >>>>> > >>>>> >> Was there ever a standard? I always thought the "RS" stood for >>>>> >> Recommended Standard, as in "you *should* do the following" as >>>>> >> compared to "you shall do the following" I've seen >>>>> inverted TTL talk >>>>> >> to the RS232 port on laptops and I even sometimes use the max233's >>>>> >> (+/- 10 volts instead of 12), but always use the full max232 with >>>>> >> external charge pumps when it's a gadget that needs to >>>>> work everytime >>>>> >> with systems from multiple countries. >>>>> >> >>>>> >> -Bob >>>>> >> >>>>> >> On Sat, May 22, 2010 at 7:21 PM, Didier Juges >>>>> <[email protected]> wrote: >>>>> >>> Bruce, >>>>> >>> >>>>> >>> Thanks for the additional information. >>>>> >>> >>>>> >>> +/- 14V is quite unusually low in my experience. I typically use >>>>> >>> +Maxim parts such as the MAX220 series, which is >>>>> >>> specified at +/-25V for no damage on the inputs (some >>>>> parts in that >>>>> >>> series go to +/-30V). >>>>> >>> >>>>> >>> The bottom line is that as I pointed out earlier, there >>>>> is no such >>>>> >>> thing as an RS-232 standard any more. >>>>> >>> >>>>> >>> Didier >>>>> >>> >>>>> >>> ------------------------ Sent from my BlackBerry Wireless thingy >>>>> >>> while I do other things... >>>>> >>> >>>>> >>> -----Original Message----- >>>>> >>> From: Bruce Griffiths <[email protected]> >>>>> >>> Date: Sun, 23 May 2010 10:39:21 >>>>> >>> To: Discussion of precise time and frequency >>>>> >>> measurement<[email protected]> >>>>> >>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>>> >>> >>>>> >>> Didier Juges wrote: >>>>> >>>> Bill, I think you got it backwards. +/- 12V is typical >>>>> for RS-232, >>>>> >>>> 0/+5V is for RS-422 and RS-485. >>>>> >>>> >>>>> >>>> No RS-232 receiver should be damaged with +/- 12V or >>>>> even +/- 15V >>>>> >>>> because that is their normal operating voltage. >>>>> >>>> >>>>> >>>> Also, RS-422 and RS-485 have something like 25V common mode >>>>> >>>> tolerance (not sure what the actual spec is there,) so that the >>>>> >>>> RS-422 and RS-485 receivers should not be damaged by 15V either. >>>>> >>>> The RS-422 drivers are pretty low impedance, while the RS-232 >>>>> >>>> drivers are current limited, so I don't think that connecting an >>>>> >>>> RS-232 driver into an RS-422 driver will damage either. >>>>> >>>> >>>>> >>> Picking one RS485 receiver (ADM1485) at random the >>>>> receiver absolute >>>>> >>> maximum (no damage) input range is -14V to +14V. The >>>>> RS485 receiver >>>>> >>> operating common mode range is -7V to +12V. RS422 >>>>> receivers have an >>>>> >>> input operating range of -7V to +7V. The no damage RS422 receiver >>>>> >>> input ratings may be higher. >>>>> >>>> However, most recent (<10 years?) RS-232 receivers will >>>>> work with a >>>>> >>>> 0/+3V or 0/+5V input, conveniently having a threshold a >>>>> few 10's or >>>>> >>>> 100's of mV above ground, even though the original RS-232 spec >>>>> >>>> required receivers that work with as low as +/- 3V, and drivers >>>>> >>>> that deliver +/- 9V minimum. Many commercial systems use +/- 5V >>>>> >>>> drivers for RS-232 (B&B Electronics sells a lot of >>>>> converters with >>>>> >>>> these voltages). This is a deliciously sloppy spec that >>>>> nobody has >>>>> >>>> met in the last 25 years probably, yet works most of the time. >>>>> >>>> >>>>> >>>> The one thing to avoid is to short an RS-422 (or RS-485) >>>>> driver to >>>>> >>>> ground, as that can actually cause damage, maybe not every time, >>>>> >>>> but definitely not recommended. These have relatively >>>>> high current >>>>> >>>> output capability to drive long lines. >>>>> >>>> >>>>> >>>> Didier KO4BB >>>>> >>>> >>>>> >>>> >>>>> >>>> >>>>> >>> Bruce >>>>> >>>> -----Original Message----- >>>>> >>>> From: [email protected] >>>>> >>>> [mailto:[email protected]] On Behalf Of Bill Hawkins >>>>> >>>> Sent: Saturday, May 22, 2010 3:09 PM >>>>> >>>> To: 'Discussion of precise time and frequency measurement' >>>>> >>>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>>> >>>> >>>>> >>>> When all else fails, get out the voltmeter. >>>>> >>>> >>>>> >>>> Do you have power to the antenna? Is it the right >>>>> voltage? All the >>>>> >>>> way to the antenna? >>>>> >>>> >>>>> >>>> What volts are on pins 2 or 3 relative to pin 7 in the comm >>>>> >>>> connector? >>>>> >>>> >>>>> >>>> If you see 12 volts, that's RS-422. You may have burned out your >>>>> >>>> computer's serial port. >>>>> >>>> >>>>> >>>> If you see less than 5 volts, that's RS-232 and all >>>>> should be well, >>>>> >>>> unless you see zero volts. >>>>> >>>> >>>>> >>>> I may have the RS-xxx volts somewhat off because my memory isn't >>>>> >>>> what it used to be. >>>>> >>>> >>>>> >>>> The guy you bought it from should be able to help with >>>>> comm basics. >>>>> >>>> >>>>> >>>> Bill Hawkins >>>>> >>>> >>>>> >>>> >>>>> >>>> -----Original Message----- >>>>> >>>> From: [email protected] >>>>> >>>> [mailto:[email protected]] On Behalf Of Robert Benward >>>>> >>>> Sent: Saturday, May 22, 2010 2:08 PM >>>>> >>>> To: Discussion of precise time and frequency measurement >>>>> >>>> Subject: Re: [time-nuts] Z3805 utility, Was: AW: (no subject) >>>>> >>>> >>>>> >>>> Hi All, >>>>> >>>> I hooked everything up and I still get nothing. I can't seem to >>>>> >>>> establish communications with the Z3805. I tried a >>>>> null modem as >>>>> >>>> well, in case the cable (supplied) was wired with the wrong >>>>> >>>> connector gender. I see a green blinking light inside, >>>>> it he left >>>>> >>>> rear corner of the box. Everything is warm, but nothing >>>>> else. Any >>>>> >>>> ideas? >>>>> >>>> >>>>> >>>> Bob >>>>> >>>> >>>>> >>>> >>>>> >>>> >>>>> >>>> >>>>> >>>> _______________________________________________ >>>>> >>>> time-nuts mailing list -- [email protected] >>>>> >>>> To unsubscribe, go to >>>>> >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> >>>> and follow the instructions there. >>>>> >>>> >>>>> >>>> >>>>> >>>> _______________________________________________ >>>>> >>>> time-nuts mailing list -- [email protected] >>>>> >>>> To unsubscribe, go to >>>>> >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> >>>> and follow the instructions there. >>>>> >>>> >>>>> >>>> >>>>> >>> >>>>> >>> >>>>> >>> >>>>> >>> _______________________________________________ >>>>> >>> time-nuts mailing list -- [email protected] >>>>> >>> To unsubscribe, go to >>>>> >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> >>> and follow the instructions there. >>>>> >>> _______________________________________________ >>>>> >>> time-nuts mailing list -- [email protected] >>>>> >>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> >>> and follow the instructions there. >>>>> >>> >>>>> >> >>>>> >> _______________________________________________ >>>>> >> time-nuts mailing list -- [email protected] >>>>> >> To unsubscribe, go to >>>>> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> >> and follow the instructions there. >>>>> >> >>>>> > >>>>> > >>>>> > _______________________________________________ >>>>> > time-nuts mailing list -- [email protected] >>>>> > To unsubscribe, go to >>>>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> > and follow the instructions there. >>>>> > >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
