[hpsdr] Excalibur/PowerSDR/HPSDR behavior questions

[David McQuate]

Excalibur working here. What a nice kit! Well done! Thank you!

What jumpers should be installed / removed on Mercury & Penelope
when Excalibur provides the 10MHz ref on Atlas C16?

Removal of Mercury JP8 removes power from its 10 MHz oscillator.
Is there a C16 driver on Mercury that needs to be disconnected?
How about similar on Penny?

Dave / WA8YWQ

Graham / KE9H wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Dan:
>
> John is correct.
> The current and recent versions of both Mercury and Penelope
> will free run in the absence of a reference clock. There is no 
> indication or alarm
> if they are not locked. Even when free-running they seem to stay 
> within about 30
> to 100 Hz of the indicated frequency. If a 10 MHz signal is present on 
> Atlas bus line
> C16, they will lock to it, whether it comes from Mercury, Penny, or an 
> external
> source like Excalibur.
> Just don't have multiple 10 MHz sources feeding the bus 
> simultaneously. I don't
> think it will break anything, but it things will behave strangely.
>
> Very early versions of the Mercury and Penelope software would lock up 
> and
> stop operation in the absence of a reference.
>
> --- Graham / KE9H
>
> ==
>
> John Ackermann N8UR wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>> Dan, I *think* that Merc and Penny use the 10 MHz signal to lock 
>> their on-board 122.88 MHz oscillator. If the 10 MHz goes away, the 
>> 122.88 TCXO keeps free running, but the frequency may jump noticeably 
>> and Merc and Penny will no longer be locked together in frequency.
>>
>> John
>> -----
>>
>> Dan Quigley said the following on 11/17/2009 08:36 PM:
>>> ***** High Performance Software Defined Radio Discussion List *****
>>>
>>>
>>>
>>> ------------------------------------------------------------------------ 
>>>
>>>
>>> Happy to report that Excalibur is working great here in my shack. A 
>>> big thank you to Graham and the rest of that team. I have a couple 
>>> questions about how the PowerSDR/HPSDR system handles the 10Mhz 
>>> reference clock.
>>>
>>>
>>>
>>> What happens if Excalibur stops broadcasting its 10Mhz reference 
>>> clock onto the Atlas bus? I didn’t see an indication on PowerSDR or 
>>> notice that Mercury stopped receiving. Is there a way in software to 
>>> detect and indicate what card is supplying the clock?
>>>
>>>
>>>
>>> Best 73’s
>>>
>>> Dan (N7HQ)
>>>
>>>
>
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