[time-nuts] Wavecrest DTS 2070

[Ed Palmer]

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@**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
>