[time-nuts] FRSc RB lamp experiment

paul swed paulswedb at gmail.com
Sun Feb 13 22:50:18 UTC 2011


Thanks Bruce turned out to be C7 leaky. I actually used a LM358 dip with
wires kind of a ugly bug. Then realzed that really was not the issue. It was
c7.
I do not have any lm158s can or dip. Pretty sure they would be hard to come
by these days also.
Something to look for at hamfests this year.
Regards
Paul.

On Sun, Feb 13, 2011 at 2:01 PM, Bruce Griffiths <bruce.griffiths at xtra.co.nz
> wrote:

> paul swed wrote:
>
>> Startup circuit looks like a bad op amp used as a comparator. U1 section
>> a.
>> This is a LM 158. I have a LM 148 on hand suspect they are different in
>> temperature quality. So will look it up and see. This is a common op amp
>> so
>> if the 148 does not work for some reason any numbers of more modern ones
>> will. Accept one issue its a T08 can. What pin was 8? ;-)
>> Regards
>>
>>
>>
> The LM148 (quad 741) and LM158 (dual opamp) have different input common
> mode ranges, that of the LM158 extends to the negative supply it is also
> rated for a large input differential voltage.
> LM158 pin 8 is the positive supply pin.
>
> Bruce
>
>  On Sun, Feb 13, 2011 at 1:24 PM, Magnus Danielson<
>> magnus at rubidium.dyndns.org>  wrote:
>>
>>
>>
>>> Dear Paul,
>>>
>>>
>>> On 13/02/11 18:50, paul swed wrote:
>>>
>>>
>>>
>>>> Magnus it indeed does look very good.
>>>>
>>>> I have re-assembled the various boards and the system locked up as
>>>> normal
>>>> after the warm up period. I do indeed have a failure in the lamp control
>>>> startup crkt.
>>>>
>>>>
>>>>
>>> My R&S does not have a startup circuit, so I can't help on that
>>> particular
>>> detail. I'm sure you will debug it yourself.
>>>
>>>
>>>  The reference after warm up and adjusting the c field is down in the
>>>
>>>
>>>> 1x10-11
>>>> area. Anyhow I adjusted the c field and the systems not fully assembled
>>>> nor
>>>> has it really been stabilized long enough. Was simply curious so I do
>>>> not
>>>> think this is really a very accurate assessment. Especially since this
>>>> is
>>>> time-nuts territory.
>>>>
>>>>
>>>>
>>> At least it proves that you are up and running at least, modulus quirks.
>>>
>>>
>>>  So next steps is to let the unit cook in or maybe I will further
>>> assemble
>>>
>>>
>>>> it
>>>> and troubleshoot the startup crkt. Add the unlock counter. (A pedometer
>>>> and
>>>> opto coupler) and let the system run for a long while perhaps a week or
>>>> so
>>>> to see what really happens.
>>>>
>>>>
>>>>
>>> Sounds like a plan.
>>>
>>>
>>>  Thanks for your guidance and help Magnus. Who would have thought there
>>> was
>>>
>>>
>>>> a
>>>> recovery technique for FRS-c RB references.
>>>>
>>>>
>>>>
>>> Happy to help. Happy to learn of your progress! Happy to hear I
>>> contribute.
>>>
>>>
>>> Cheers,
>>> Magnus
>>>
>>> _______________________________________________
>>> 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.
>>>
>>>
>>>
>> _______________________________________________
>> 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.
>>
>>
>>
>
>
>
> _______________________________________________
> 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.
>


More information about the time-nuts mailing list