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Date: Sun, 6 Dec 2015 21:59:39 +0000
Message-ID: <CAA8k23Tdm1UCu0tye08FRPp6VJENQLe2sMCsWV7+Y=9cBW9tFg@mail.gmail.com>
From: Andy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
Subject: Re: Re[2]: LF: Is this frequency locking enough for EbNaut?
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Status: O

Be careful, it 'may' be OK, but I have heard that slippages can occurt.
Due to difference in sample rates between the USB itself and 12MHz
clock of the chip,  when using USB isochronos mode (used for time
dependent data like audio), it can slip occasional samples as the
clocks slide past each other.

I have used that chip, or at least a close relation,  but never in a
synchronous manner - so it may be worth testing see if slippages do
occur.

Andy  G4JNT

On 6 December 2015 at 21:37, Chris Wilson <chris@chriswilson.tv> wrote:
> Hello Paul,
>
> Sunday, December 6, 2015
>
>
> I  have  had  a poke through the schematics and it uses a PCM2903B USB
> chip  with its own external 12MHz xtal, so it's not tied to the master
> oscillator... :(
>
>
> I  find  the  kit  works  well enough for my current needs, but intend
> doing  some  back to back tests against the TS-590 RX and also with my
> TX aerial versus my active whip on both receivers. I use it with HDSDR
> software and Argo. Thanks for the info.
>
>
>
>> Chris wrote:
>
>  >> the  590  has a built in USB sound card
>
>> Ideal if its conversion clock is derived from the XRef
>> board.   No good if it has its own xtal though.
>
>> Digressing a bit...
>
>  >> http://icas.to/lineup/idc-136ii-kit-eng.htm
>
>> How do you get on with that one, does it work ok?
>
>> I've been thinking about making up something like that but
>> it would be quicker and easier just to order three of those.
>
>> The LO is a bit close, wonder what the image rejection is like.
>> I'd want to use 120kHz or lower but there's loran on the
>> other side.  Maybe a high side LO is better.
>
>> Are there other suggestions for a simple rx for LF?
>
>> --
>> Paul Nicholson
>> --
>
>
>
>
>
>
>
> --
> Best regards,
>  Chris  2E0ILY                          mailto:chris@chriswilson.tv
>
>