[time-nuts] Couple of questions for Racal 1992 owners

[Ed Palmer]

Thanks for the info Antonio.  Racal didn't spec the warmup 
characteristics of the counter as a whole and it seemed a little odd 
that the warmup drift for the counter was as large as 10 days of 
oscillator drift.

Ed

iovane at inwind.it wrote:
> I have two 1992, and actually one has to terminate the output to see the real waveform.
> They have both the 04E option, that I believe is a nice one. In long term measurements, I've found that mine have an aging rate in the range of 1x10E-10 per day, or better (compared to Rb). The crystal is cut to 5 MHz, then doubled.
> The time required to stabilize after power on is normal.
> Antonio I8IOV
>
>
>   
>> My 1992 has a similarly ugly reference output - until I terminate it.  
>> Then it's a fairly nice square wave between 0 and 1 volt.  Rise & fall 
>> times are in the range of 5 ns.  The manual doesn't state what the wave 
>> shape is, only that it's > 600 mVp-p into 50 ohms. I have a brochure 
>> that says "TTL levels giving approx. 1Vp-p into 50 ohms".  My phase 
>> measurements also have a similar amount of 'noise' to yours.
>>
>> Which timebase does yours have?  I've got option 4E (similar to 4B).  
>> Although the timebase appears to be stable, I've noticed that the 
>> counter drifts about 5e-9 during warmup, even when the oscillator has 
>> been on standby for many days.  It takes a couple of hours to settle 
>> down.  Does yours do anything similar?
>>
>> Ed
>>
>> John Green wrote:
>>     
>>> Just acquired a used 1992 off eBay. Excellent, almost like new with manual
>>> and even spare fuses. I noticed that the internal reference's waveform is
>>> more like a nasty sawtooth than a nice sine wave. Is that normal? Also, when
>>> I hook my GPSDO through a two way splitter and two different length cables
>>> and measure phase, I get a +\- 3 LSD ambiguity. Is that about right?
>>>
>>>       
>