[time-nuts] EFRATOM LPRO-101

Wed Feb 3 17:37:08 UTC 2010

Hi

I would second that as well. 

I got an LPRO in that had a "rattle" when it arrived. After some thought, I
popped the can and figured out what the issue was. Since it might have been
gong back, I kept Bob in the loop during the entire process. He was very
supportive through it all. Definitely a first class guy. 

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Doug Parker
Sent: Wednesday, February 03, 2010 9:23 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] EFRATOM LPRO-101

Hi,

I'd like to confirm that Bob is a very good seller and been great with the
things I've had off him. 

He's also a member of this group

Doug
G4DZU

--- On Wed, 3/2/10, EB4APL <eb4apl at cembreros.jazztel.es> wrote:

From: EB4APL <eb4apl at cembreros.jazztel.es>
Subject: Re: [time-nuts] EFRATOM LPRO-101
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Date: Wednesday, 3 February, 2010, 13:20

Hi,

Bob Mokia is a very good seller and you'll not have problems with him.  
In  order to avoid paying the return shipping and the delays I would ask 
him to let you open the unit and try to find an obvious fault such a 
loose connection.  When I bought my Rb (from another source) I opened it 
even it was working ok, and I found one of the connector pins touching 
its PCB pad without any trace of solder on it; nevertheless it worked 
perfectly but it was just a question of time before the unit will begin 
to act intermittently so I fixed it.  Thinking about I realized that 
maybe this unit showed problems and it was retired from active service 
and maybe it has very low hours on it.
Do your unit sweeps its frequency above and bellow 10 MHz when warming 
up the first minutes? it is the normal operation before a lock is 
obtained and if it is not done it will never lock the oscillator to the 
Rb frequency.

Good luck,
Ignacio, EB4APL

-----------------------------------------------------------------------
Bob Camp wrote:
> Hi
>
> A little more data from a group of recent units:
>
> The XTAL pin is looking at the VCXO control voltage, It should move around
(sweep) at turn on. It will settle in the vicinity of 6 volts. I have seen
units anywhere from 5.5 to 7.2 volts on this pin.
>
> The BITE is a logic level pin, it's either high or low. 
>
> The lamp voltage on "early" units runs around 6 volts. On "later" units
it's up around 9 volts. This may be a better bulb, or it just may be a
different photo detector. Every time I've asked about lamp voltage, the
answer has been "in range is ok". Trying to predict life from lamp voltage
apparently is more complex than it might seem.  I would not throw out a 6
volt unit simply because it's not a 9 volt ....
>
> Bob
>
>
> On Feb 3, 2010, at 7:08 AM, Roy Phillips wrote:
>
>   
>> Hi Jim
>> This would appear to be a faulty unit, I also purchased the same unit
from Bob Mokia two weeks ago and its performing very well.  It gives a
frequency of 10.000,000,005 Mhz.
>> One very obvious fault is the BITE voltage - - this should initially be
4.5 volts, which falls to less than 30 mV. within a few minutes. The XTAL
Control Volts, after a short while falls to 6.145 V., so yours, at 14.67 V,
would seem to be wrong ! The Lamp volts settle to 6.736 V, and the Ext  C
Field is 2.426 V. , which checks with your result.
>> I'm  sure you will get a replacement.
>> Roy
>>
>> --------------------------------------------------
>> From: "Jim" <jim at commo.com>
>> Sent: Tuesday, February 02, 2010 9:08 PM
>> To: <time-nuts at febo.com>
>> Subject: [time-nuts] EFRATOM LPRO-101
>>
>>     
>>> Hello all.
>>>
>>> I received an EFRATOM LPRO-101 last week from eBay Fluke 1, and wired it
up last night. The results are not good.
>>>
>>> Using a HP 5370B counter with calibration less than one year old, the
frequency reads = 10,000,146,012.9
>>> Power Applied = 24.9Vdc @ 0.30 amps after warm up
>>> Lamp Voltage = 5.9 Vdc
>>> Ext C Field = 2.437
>>> XTL V Mon = 14.67
>>> Bite = 4.57
>>>
>>> Bite never goes low.
>>>
>>> I just sent an email to the outfit I purchased it from, but would like
to get this working instead of waiting a month or so.
>>>
>>> Is it dead?  Any thing I can do to revive it?
>>>
>>> Any suggestions?
>>>
>>> Thanks to all.
>>>
>>> Jim N0OBG
>>>
>>>
>>> -- 
>>>
>>>
>>>
>>> The heart of the wise inclines to the right, but the heart of the fool
to the left. Eccl 10:2 (NIV)
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>       
>> _______________________________________________
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>>     
>
>
> _______________________________________________
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>   

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