[hpsdr] Precise receive frequency measurement

[John Sager]

Or measure the actual error in the onboard 10MHz reference. I did that using
a standard frequency broadcast (RWL), and the 'fmt' program in Joe Taylor's
WSPR software. Mine is about 1.5Hz high after it warms up.

73 John G8ONH

On 08/03/13 08:06, Phil Harman wrote:
> ***** High Performance Software Defined Radio Discussion List *****
> 
> Yes,  but it will be if you use an external 10MHz reference that has your
> required accuracy.,
> 
> 73 Phil...VK6APH
> 
> 
> 
> -----Original Message----- From: Bruce Beford
> Sent: Friday, March 08, 2013 10:05 AM
> To: hpsdr at lists.openhpsdr.org
> Subject: Re: [hpsdr] Precise receive frequency measurement
> 
> ***** High Performance Software Defined Radio Discussion List *****
> 
> Thanks, Phil.
> Doesn't the overall accuracy of this formula assume that the 122.88 MHz
> clock -is- in fact, exactly correct?
> 
> 73,
> Bruce, N1RX
> 
>> The frequency is sent to Hermes/Mercury as a 32 bit value in Hz.  This is
>> converted to a 32 bit phase word as follows:
> 
>> phase =  frequency * 2^32 / 122880000
> 
>> You will be able to calculate the actual frequency from the above.
> 
>> 73 Phil...VK6APH
> 
> 
> 
> 
> 
> _______________________________________________
> HPSDR Discussion List
> To post msg: hpsdr at openhpsdr.org
> Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
> HPSDR web page: http://openhpsdr.org
> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/
> _______________________________________________
> HPSDR Discussion List
> To post msg: hpsdr at openhpsdr.org
> Subscription help: http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
> HPSDR web page: http://openhpsdr.org
> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/

-- 
John Sager

Computer Security Consultant

Tel:	01473 736620
Mobile:	07920 867261
E-mail:	john at sager.me.uk

 1362733691.0