Message-ID: <501C44D1.3000005@freenet.de>
Date: Fri, 03 Aug 2012 23:38:25 +0200
From: wolf_dl4yhf <dl4yhf@freenet.de>
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References: <501BFCA8.2010401@legal-medicine.de>
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Subject: Re: LF: 100 kHz I/Q
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Hi Peter,

I don't think the duty cycle feeding the sychronous output counter will 
be a problem.
Single-edge triggered flipflops for that counter (400 kHz in, 100 kHz 
out)... doesn't matter where the "other" edge is.

Out of curiosity : You aren't building a Loran-synchronized 10 MHz 
reference by chance ?

Cheers,
   Wolf DL4YHF ( -> DF0WD soon, on 472.5 kHz in CW )


Am 03.08.2012 18:30, schrieb pws:
> Hi,
>
> I found some 10 MHz double-OCXOs in the junk-box and
> I need two 100 kHz LO-signals at 90deg. of phase shift.
>
> The idea is using 74HC390 for dividing down to 400 kHz
> (25:1) feeding a phase shifting network consisting of
> two flip-flops (4:1), commonly found at SDRs.
>
> Q: Does that work or could I run into trouble due to the
> non-symmetrical output train from the 25:1 dividers?
>
> May be a stupid question but it's ~40 years ago when I
> was busy doing nasty things with flip-flops [^_^]
>
> Peter, df3lp
>
>
>