[time-nuts] Loran-C ICs

John Day johnday at wordsnimages.com
Tue Jan 2 19:40:07 EST 2007


Funny you should ask, we had to get some of these to replenish spares 
stock in a client site for some gear we built YEARS ago. The MC1357P 
is available as the NTE708 (around $7.25 each it seems) and the 
MC1350P is an NTE746. The next generation of that design (the MC1350P 
as okay in TV's, but really not a lot of good elsewhere) used some 
VGA chips from Analog Devices, AD6xx series, but I cannot recall 
which. Possibly AD602. We used one of the AD log detectors, possibly 
like an AD8302 to complete the AGC loop. In another design we had the 
FM demodulator in an FPGA and we recovered amplitude information 
after the ADC to close the AGC loop - we need not have rapidly 
varying signals, and then used another small 10 bit ADC to control 
the IF amp chip.

John

At 04:56 PM 1/2/2007, you wrote:
>Hi Poul:
>
>I'm trying to make a micro controller based unit, not a PC type.  So
>there's much less horsepower available.  That's why I like the envelope
>detector by Burhans.  An email from Dave Mills indicated that you had
>one of his ISA card receivers but that a 12 bit PCI version would be better.
>
>Have Fun,
>
>Brooke Clarke
>
>w/Java http://www.PRC68.com
>w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
>http://www.precisionclock.com
>
>
>
>Poul-Henning Kamp wrote:
>
> >In message <459ACCD5.201 at pacific.net>, Brooke Clarke writes:
> >
> >
> >>Hi:
> >>
> >>I found a Loran-C circuit from 1984 done by Ralph Burhans that uses the
> >>MC1350 Video-IF amplifier and the MC1357 Sound-IF amp and Quadrature
> >>detector, but these are no longer available.  Does anyone know of
> >>replacement parts?  The circuit appears in "Low-Frequency Receiving
> >>Techniques, Building and Using VLF Antennas" a Gernsback publication.
> >>
> >>
> >
> >Don't bother.  You will get much better results by putting an
> >A/D converter on the signal and spending a bit of CPU power.
> >
> >(see http://phk.freebsd.dk/loran-c for inspiration)
> >
> >
> >
>_______________________________________________
>time-nuts mailing list
>time-nuts at febo.com
>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts




More information about the time-nuts mailing list