[hpsdr] Excalibur & Gibraltar

[Graham / KE9H]

Hi Steve:

Thanks for the pointers.

I guess it all depends on what you are trying to accomplish.

If you want to set the frequency of an HF rig for normal operating,
that is plenty good enough.

But, if you are going to compete in the frequency measuring contests,
then you will need at least three orders of magnitude of improvement.

I note that the winners in the frequency measuring contests are measuring
accurately, with HF radio propagation distortions, to about 1 milliHz.

I built something very similar to Burt, VE2ZAZ's GPSDO, and get
about 2 milliHz accuracy, which he also reports.  Which would not
be sufficient to be competitive in the FMTs.  Talking to John, N8UR
I was pointed at the results comparison on

http://www.leapsecond.com/pages/gpsdo/

where the better GPSDO setups are hitting 0.1 to 0.01 milliHz. accuracy.

So, I have some software work to do.

If you want to dig deeper, consider joining the "Time Nuts" mailing list at

http://www.leapsecond.com/time-nuts.htm
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

--- Graham / KE9H

==

Steven Doyle wrote:
> Hi,
>
> This months EPE Magazine also outlines a simple construction project 
> for a GPS-Based 10Mhz frequency reference which would make an ideal 
> pairing with Excalibur. Its based on the Garmin GPS-15L receiver 
> module and can be built for arround £140. The PCBs are also avaliable 
> from www.epemag3.com . The 10MHz output is accurate to within 0.2Hz 
> averaged over 30sec even more accurate when averaged over longer periods.
>
> Features include
>
> 1Mhz & 10Mhz outputs
> GPS 1Hz output
> Phase error pulse output
> LCD display for GPS information, typically the time.
>
> cheers
>
> Steve
> G1YLB
>
>
> ----- Original Message ----- From: "Graham / KE9H" <KE9H at austin.rr.com>
> To: "Alexander Geckeler" <alexander.geckeler at gmx.de>
> Cc: "HPSDR discussion list" <hpsdr at lists.hpsdr.org>; <hpsdr at hpsdr.org>
> Sent: Friday, April 03, 2009 5:40 PM
> Subject: Re: [hpsdr] Excalibur & Gibraltar
>
>
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Alexander:
>>
>> Here are some references:
>>
>> General Information:
>>     http://www.leapsecond.com/pages/gpsdo/
>>
>>     http://www.gpstime.com/
>>
>>
>>
>> Do-it-yourself Project examples:
>>
>>     http://ve2zaz.net/GPS_Std/GPS_Std.htm
>>
>>     http://gref.cfn.ist.utl.pt/cupido/reflock.html
>>
>>     http://home.teleport.com/~oldaker/10mhz_construction.htm
>>
>>     http://www.rt66.com/~shera/index_fs.htm
>>
>>
>>
>> Commercial  modules / subsystems
>>
>>     http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm
>>
>>     http://www.jackson-labs.com/
>>
>>
>> Commercial systems
>>
>>     HP 58540A
>>
>>     http://www.cnssys.com/cnsclock/CNSClockII.php
>>
>>     http://www.trimble.com/timing/thunderbolt-e.aspx?dtID=overview
>>
>>
>> Cellular radio pull-outs / Surplus market
>> Information
>>     http://www.realhamradio.com/GPS_Frequency_Standard.htm
>>
>> Search eBay for
>>     Z3801A
>>     Z3816A
>>     58540A
>>     58503A or B
>>     59551A or B
>>
>>     Lucent RFG
>>
>>     Trimble Thunderbolt
>>
>>     Rubidium
>>
>>     EFRATOM LPRO-101
>>
>> ==
>> --- Graham / KE9H
>> ==
>>
>> Alexander Geckeler wrote:
>>> ***** High Performance Software Defined Radio Discussion List *****
>>>
>>>
>>> Hello together!
>>>
>>> On the Wiki I saw that Excalibur Alpha version cards are currently 
>>> in a test run. Regarding Gibraltar, what is the status of that project?
>>>
>>> If Excalibur is ready as bare board or kit, what is an alternative 
>>> to Gibraltar if a GPS signal is desired as reference? Are there 
>>> other "modules", maybe commercial ones which are usable as simply 
>>> plug&play devices?
>>>
>>> Looking forward to your answers.
>>>
>>> 73,
>>> Alexander
>>>
>>>
>>>
>>>
>
>


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