[time-nuts] wwvb d-psk-r updated general purpose reciever

[paul swed]

Clint
Like you I considered that and easy enough to do. But by that point you
have built well over half the receiver. So I just said to heck with it and
built the whole thing. The other issue is getting those pesky chips. There
is one fellow time-nut that has a stash of CME chips he offered. Never
heard that anyone accept me took him up on them. I built the regenerator
with the cme and another with the 8160 chips just to insure they would both
work for any time-nut that wanted to try.
So by all means give it a shot isolate your new gain chain and use lots of
limiting. The two I mention should deliver 50-70db worth. But the fact is
the 3356 is at 50 db and the ad806 is no place close but sure puts out one
nicely limited signal.
I would believe simply a fet driving one of these chips would do the trick.
Regards
Paul.


On Fri, Nov 1, 2013 at 6:06 PM, Clint Turner <turner at ussc.com> wrote:

> When I was messing with my SkyScan WWVB clocks to determine if something
> that WWVB's signal had done "broke" them, preventing them from setting
> properly and so-doing, I wanted to see what the receiver module was seeing.
>
> (Spoiler:  They didn't - they just break if the date is something later
> than approx. August, 2012 - I mentioned this some months ago on this list,
> providing a link to a blog entry where this was discussed in detail.)
>
> What I did to see what the clock chip was seeing via a 'scope was to hang
> a JFET source follower on the "narrow" (downstream) side of the 60.003 kHz
> bandpass filter crystal coupled with a small value cap and a with a 10 meg
> resistor from the gate to ground:  That didn't seem to adversely affect
> performance, and I could see the phase flopping back and forth.  (The
> signal was pretty low - but usable.)
>
> At that point the AM was still present, so the "key up" portions of the
> waveform were expectedly weaker - but it seemed to me at the time that I
> could have used it for something more complicated down the line.
>
> What I was thinking at the time, were I to proceed farther, would have
> been to take that buffered signal off-board, amplify it a bunch and then
> run it through a limiter.  In theory, this - along with the demodulated
> time code - would have provided both the amplitude and phase components.
>
> Clint
> KA7OEI
>
>
> On Fri, 1 NOV 2013 saul swed said:
>
>> Hello to the group. It has been a while since I have sent anything. The
>> last was the wwvb regenerator for time clocks.
>> However I have been working on a general purpose wwvb receiver. One that
>> is
>> inexpensive, uses parts available today, is inexpensive, single supply,
>> low
>> power, and uses parts I don't need a microscope for. There are lots of
>> older designs out there and at least one quite nice design is by one of
>> our
>> fellow time-nuts that started me thinking. But many of the designs use
>> inductors that have become difficult to obtain.
>> As much as I would have loved to hack one of the one chip wwvb clock chip
>> wonders they simply did not work out. They are hot receivers actually
>> because there was no way to pull the amplified wwvb signal out. Tried a
>> number of schemes like 2 chips in parallel. One detecting the AM signal
>> and
>> providing AGC control to chip 2 that had no AGC or demod caps.
>>
> <snip>
>
>
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