[time-nuts] retry: PRS10 has spurious frequencies

Dave Brown tractorb at ihug.co.nz
Wed Apr 25 21:38:48 UTC 2007


Henk
Do any of the spurious signals show on the SA with a search antenna 
(located in your lab environment)connected instead of the PRS10?
DaveB

----- Original Message ----- 
From: "Henk ten Pierick" <henk at deriesp.demon.nl>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, April 26, 2007 8:42 AM
Subject: Re: [time-nuts] retry: PRS10 has spurious frequencies


> Hi Poul-Henning,
>
> 1. It is not a stupid question but a very valid one.
>
> 2. I was aware of the EMI possibility and tried ferrites on the
> supply and signal wires with no result.
>
> 3. I will try batteries but have to find enough of them.
>
> 4. On the spectrum analyzer, I checked the amplitude setting and 
> 10dB
> change gave 10dB change of signal level. Also a mixer level change
> had no influence on the spurious.
>
> Henk
>
>
> On Apr 25, 2007, at 22:07, Poul-Henning Kamp wrote:
>
>>
>> I'm going to ask a seemingly stupid question, but bear with me:
>>
>> Are you sure those signals are really present on the output ?
>>
>> The reason why I ask is that you are in a frequency territory where
>> EMI is both radiated and conducted so you have to be really careful
>> with your setup, grounding in particular, to make sure you do not
>> actually measure the PRS10 acting as an antenna.
>>
>> The best way to ensure this, is to run your PRS10 off batteries,
>> Sealed Lead Acid for instance, and the only other connection to
>> the PRS10 should be the coax to the spectrum analyzer.
>>
>> Poul-Henning
>>
>> -- 
>> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
>> phk at FreeBSD.ORG         | TCP/IP since RFC 956
>> FreeBSD committer       | BSD since 4.3-tahoe
>> Never attribute to malice what can adequately be explained by
>> incompetence.
>>
>> _______________________________________________
>> time-nuts mailing list
>> time-nuts at febo.com
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> 




More information about the Time-nuts_lists.febo.com mailing list