[hpsdr] High Accuracy Timing for HPSDR

Wed May 10 20:58:13 PDT 2006

GIBRALTAR is the perfect name for the board. I agree that we are on the verge of a design.

Here's a potential issue

Steve, your design has a header for the SiRF daughterboard?  Wouldn't we have clearance problems with the card spacing on ATLAS if GIBRALTAR is installed in anything other than slot 6 (opposite end from power connector)? The answer might simply be only install GIBRALTAR in slot 6.

Bob, What GPS engine is AMSAT using? Are you using the SiRF units?

Would it make sense to use the Altera Cyclone II instead of the Altera MAX II for commonality? Would be easier to purchase larger quantities of parts...

My offer still stands to be persuaded into ponying the money up for a couple alpha boards.

Alex, N3NP

----- Original Message ----
From: Robert McGwier <rwmcgwier at comcast.net>
To: Steven Bible <n7hpr at tapr.org>
Cc: hpsdr at hpsdr.org
Sent: Wednesday, May 10, 2006 11:33:32 PM
Subject: Re: [hpsdr] High Accuracy Timing for HPSDR

***** High Performance Software Defined Radio Discussion List *****

It sounds ALMOST like Gibraltar is designed with one potentially fatal 
flaw so let me open the can of worms here and put it openly on the table.

http://hpsdr.org/

On this page,  there is a clear cut statement about Open Source Design.  
Without open CPLD source,  it violates that principle.  I would not 
compromise this if I could.  We should take the hardware design you 
offer, but roll our own verilog and we certainly have more than one 
person capable of doing so.   If you believe no one will get lynched 
over doing this with what was clearly Luis original design modified for 
this project's purposes, then we ought to do this.

Bob
N4HY

Steven Bible wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hi Alex,
>
> I'd be willing to help with this board since I was the one that laid out the
> Reflock II PCB.
>
> As to a GPS engine, we need to look for a timing GPS.  A timing GPS can
> perform a self survey and then lock its position for a more accurate 1PPS
> signal.  The older 8-channel Oncode UT, UT+, and VP, or the newer 12-channel
> M12, M12+, and M12+ Timing have been timing GPS of choice for hams since we
> could buy them and using W2GPS's TAC32 program to operate them.  Since
> Motorola sold off its Oncore line to SiRF, and the dust is about to settle,
> the M12 line will come out later this year as the M12M.
>
> I have already started on a PCB that integrates the GPS, Reflock II, and 10
> MHz OCXO (I am looking at the Crystek CO27VH15DE-12-10.000 available from
> Mouser).  The goal I have is to design the board such that all the parts can
> be readily purchased.  I really don't want to rely on surplus GPSs and
> OCXOs.  This entire lash up will be tested in N8UR's timing lab.  The GPS
> footprint would accomidate the Oncore UT/VP and M12 GPSs.  So if you can
> populate which ever one you have on hand, or can purchase surplus or a new
> M121M.
>
> 73,
>
> - Steve, N7HPR
>  (n7hpr at tapr.org)
>
>
>
>   
>> -----Original Message-----
>> From: Alex [mailto:harvilchuck at yahoo.com]
>> Sent: Wednesday, May 10, 2006 2:44 PM
>> To: hpsdr at hpsdr.org
>> Cc: Steven Bible
>> Subject: High Accuracy Timing for HPSDR
>>
>>
>> Would it make sense to have a frequency reference board for the HPSDR?
>>
>> How about an ATLAS version of the Reflock II board with an integrated GPS?
>> Say the Sony CXD2956AGL-1 baseband processor and the Sony
>> CXA3355TQ downconverter - basically the guts from an OnStar (tm)
>> GPS receiver...
>>
>> CXD2956AGL-1 -
>> http://www.sony.co.jp/~semicon/english/img/sony01/a6808473.pdf
>> CXA355TQ - http://www.sony.co.jp/~semicon/english/img/sony01/a6807578.pdf
>>
>> add an appropriate VCXO, put some SMA connectors across the top
>> of the card (modifying the TAPR TADD-1 design) to distribute the
>> reference signal and  then you've got a necessary building block
>> for use by transmitter and receiver board designs ...
>>
>> Just a bit of circut design to add the new parts, the Altera MAX
>> II coding is done for the Reflock II. Will need to add a bit of
>> code for the GPS baseband processor control, it looks like there
>> are enough I/O lines available on the MAX II (based on the docs
>> on CT1DMK's website) unless you let OZY control it. Plus
>> interface the MAX II to the OZY.
>>
>> I could even be persuaded to pony the money up for a couple alpha boards.
>>
>> Alex, N3NP
>>
>>
>>
>>
>>
>>
>>
>>     
>
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>   

-- 
AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats,
NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman
Laziness is the number one inspiration for ingenuity.  Guilty as charged!

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