[time-nuts] Wavecrest DTS 2070

Bruce Griffiths bruce.griffiths at xtra.co.nz
Mon Sep 9 19:43:16 UTC 2013


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@**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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>>      
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