Yes indeed it would be reasonable. The good news is that if you have a dead short supply for 2V those are the easiest to troubleshoot. Fixed numbers of pieces of test equipment because of faulty caps that shorted.
On Mon, Sep 9, 2013 at 4:42 PM, Ed Palmer <ed_pal...@sasktel.net> wrote: > That's possible. The only outputs are the CAL1 and CAL2 signals which are > square waves at -0V4 and -0v8 into 50 ohms at 8KHz, 1MHz, or 200MHz and the > oscillator monitor output at 100 MHz. My spectrum analyzer suggests that > it's a square wave. The DTS measures it as +0V2124 and -0V2154. It > wouldn't be hard to generate the -3V2 for those locally from -5V0. > > Ed > > > On 9/9/2013 1:43 PM, Bruce Griffiths wrote: > >> Possibly +2V for ECL Vcc and -3.2V for ECL Vee allowing it to drive 50 >> ohm loads connected to ground. >> Otherwise with 0V Vcc and -5.2V Vee the ECL loads must be connected to >> -2V (or its Thevenin equivalent) >> >> Bruce >> >> paul swed wrote: >> >>> 2.1 volt hmm maybe they are doing something with ECL. Say the common >>> logic >>> was 3.3 V adding a -2.1 would get you close to the 5.2V of ECL. Though >>> these look new enough that ECL should not be in the mix. >>> Regards >>> Paul >>> WB8TSL >>> >>> >>> On Mon, Sep 9, 2013 at 2:54 PM, Ed Palmer<ed_pal...@sasktel.net> wrote: >>> >>> Hi Marki, >>>> >>>> >>>> On 9/9/2013 12:15 PM, Mark C. Stephens wrote: >>>> >>>> Amazing Ed, I just had a invasive discography last Thursday! >>>>> I have been a bit quiet because of a back injury too. >>>>> >>>>> You're creeping me out Marki! >>>> >>>> >>>> We must be living parallel lives, fortunately my telly is still good, >>>> my >>>> >>>>> 9 year old son has discovered Dr. Who so we are having great time >>>>> watching >>>>> it :) >>>>> Some of the original series are a hoot :) so overdone but the Dalek's >>>>> back then couldn't fly... >>>>> >>>>> I remember watching it when it was new in the early '60's. Scary. >>>> >>>> >>>> Only 1000 for a crown, It would be cheaper for me to fly to Canada to >>>> get >>>> >>>>> crown >>>>> My last crown was disaster as a result the clown that put the crown in >>>>> stuffed up and the crown snapped off at the root >>>>> So added to the $2400 for the crown, I am now up for around 7K for an >>>>> implant. >>>>> >>>>> Geez, I hope I don't follow in your footsteps! Your 'parallel lives' >>>> comment now has me really worried. >>>> >>>> >>>> The standby PSU tranny is dead short, zero ohm as compared to the >>>> 2v/6A >>>> >>>>> supplies 8-10 ohm. >>>>> Any idea what that 2V supply is for?, >>>>> >>>>> Sorry, no clue. But my mainboard has a +2.1 volt test point so >>>> there's >>>> certainly a 'family resemblance' between our units. Mine must generate >>>> the >>>> +2.1 volts on the mainboard. >>>> >>>> >>>> If I can lose the 2 linear PSU, I'll lose a ton of weight, but >>>> possibly >>>> >>>>> at the expense of electrical noise. >>>>> I was thinking that is why they used optics between the control board - >>>>> to keep spurious noise to a minimum. >>>>> >>>>> Yes, but I would have thought that optoisolators would have been >>>> cheaper >>>> than optical transmitters, receivers, and cables. >>>> >>>> >>>> Yeah, I did play roulette by powering it up like that but I was a tad >>>> >>>>> annoyed as I was told it was a working unit. >>>>> The bottom board on this one has millions of tiny surface mount caps >>>>> mounted on there sides. >>>>> It looks terribly fragile. Much of a job to get it out? >>>>> >>>>> Well, I described my process in the teardown. Is your board similar? >>>> Other than the front panel stuff, board removal is just a matter of >>>> unplugging connectors and unscrewing the mounting screws. >>>> >>>> >>>> All the PSU screw heads are under it (of course) >>>> Yup. I needed to get at the mounting screws for the cardcage so that I >>>> could inspect the motherboard. >>>> >>>> Ed >>>> >>>> >>>> -----Original Message----- >>>> >>>>> From: time-nuts-boun...@febo.com [mailto:time-nuts-bounces@**fe** >>>>> bo.com >>>>> <http://febo.com><time-nuts-bounces@febo.**com<time-nuts-boun...@febo.com> >>>>> >] >>>>> On Behalf Of Ed Palmer >>>>> Sent: Tuesday, 10 September 2013 1:53 AM >>>>> To: Discussion of precise time and frequency measurement >>>>> Subject: Re: [time-nuts] Wavecrest DTS 2070 >>>>> >>>>> Sorry, the oracle is out of the office today - I'm the janitor. :) >>>>> >>>>> I see you've already replaced the 24V supply and powered the unit up. >>>>> I >>>>> would have removed all output connections on the supplies and tested >>>>> them >>>>> seperately. Are you sure about that transformer short? Remember that >>>>> primaries on decent size line transformers only have something ike >>>>> 2 to 4 ohms resistance at most. I wondered why yours was 12 lbs >>>>> heavier >>>>> than mine. Linear supplies - that would do it! >>>>> >>>>> The expanded/exploded capacitors could be just from age, or they could >>>>> be >>>>> from an output fault on the power supply that caused the voltage to go >>>>> high. That's why I would have tested both power supplies offline. >>>>> >>>>> You said it's alive, but you haven't mentioned if it actually works. >>>>> >>>>> By the way, it turns out that I paid dearly for my good luck with the >>>>> repair of my 2077. In the two weeks following that, I got a pinched >>>>> nerve >>>>> in my back that's still giving me trouble, I broke a big chunk off a >>>>> tooth >>>>> and am now scheduled for a crown at a cost of about $1000, and my >>>>> big-screen TV died! :( >>>>> >>>>> Ed >>>>> >>>> >> > ______________________________**_________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<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.