[time-nuts] Grounding a Z3801A
I'm finally getting around to reinstalling my Z3801A after frying and then fixing the on-board power supply, but I'm really paranoid about doing it again (I had forgotten that the unit has a positive ground). The external supply had floating outputs, the AC input was grounded to the chassis and the case of the Z3801A was grounded. I also realized that the external clock display board was grounded to both the chassis and the internal ground of the Z3801A, which is probably where the short came from. In this next attempt, the external PS AC input ground will be eliminated and it's case will be isolated from the chassis. The Z3801A will also be isolated from the chassis, as will the display assembly. That leaves the RS232 cable, which is grounded as it passes through the front of the chassis, and the signal outputs. Should I isolate the rs-232 as well? What about a double dc block on the output signals? I realize this all sounds a bit extreme... -Dave. ___ 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] Grounding a Z3801A
Talking of the Z3801A, has anybody added a small fan to it ? Mine is very hot inside, especially the large VLSI chips on the upper board. I contemplated adding a couple of small DC fans, to push out the hot air, but first would like to know your opinions and your experiences, if any, about that. Thanks Alberto I2PHD ___ 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] Grounding a Z3801A
Dave: Keep in mind that you can do grounding of the noise/ RF using a capacitor; not risking any potential shorts. Of course, all cousions about 'ground loops' still apply. Tom At 08:54 AM 7/27/2008 +, you wrote: >I'm finally getting around to reinstalling my Z3801A after frying >and then fixing the on-board power supply, but I'm really paranoid >about doing it again (I had forgotten that the unit has a positive >ground). The external supply had floating outputs, the AC input was >grounded to the chassis and the case of the Z3801A was grounded. I >also realized that the external clock display board was grounded to >both the chassis and the internal ground of the Z3801A, which is >probably where the short came from. > >In this next attempt, the external PS AC input ground will be >eliminated and it's case will be isolated from the chassis. The >Z3801A will also be isolated from the chassis, as will the display >assembly. That leaves the RS232 cable, which is grounded as it >passes through the front of the chassis, and the signal outputs. > >Should I isolate the rs-232 as well? What about a double dc block >on the output signals? I realize this all sounds a bit extreme... > >-Dave. > >___ >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 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.
