[time-nuts] Wavecrest DTS 2070

Mon Sep 9 20:50:08 UTC 2013

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_palmer at 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_palmer at 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-bounces at febo.com [mailto:time-nuts-bounces@**fe**
>>>>> bo.com <http://febo.com><time-nuts-bounces at febo.**com<time-nuts-bounces at 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
>>>>>
>>>>
>>
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