[time-nuts] WWVB d-psk-r update. Seems a reasonable solution

[paul swed]

Indeed thats the problem. The VCO needs to be available grabbing something
from ebays good for me but not you. Also the oscillator does need to be an
integer of 240 Khz and Ideally divide on a separate chain to 1 or 2 Mhz so
it could be multiplied to 5 or 10 Mhz as an example. Though for the d-psk-r
thats not really of interest. A seperate item is that just ahead of the
divide by 4 sine and cosine divide it may want a 50% duty cycle though
thats most likely not true. Right now with 12 Mhz I do get 50% duty cycle.
Could with 9.6 also.

Also I have as an example some 9.6 Mhz Vectron VCOs (How could you go wrong
its a vectron) and the tuning voltage and range are simply to large. As I
mentioned the homebrew osc is .5V for .1 Hz. The challenge I have with
Digikey and Mouser is figuring out from the info what one to buy. I have no
plans to try and buy 10 different oscillators hoping one hits some target.

So thats a piece of the puzzle. I did get much of the rcvr into ExpressSCH
last night and will revalidate what I have in the diagram tonight.
Regards and thanks for the coments.
Paul
WB8TSL


On Fri, Mar 29, 2013 at 10:16 AM, Bob Camp <lists at rtty.us> wrote:

> Hi
>
> Silly me to not dig all the way to the bottom of the data sheet ….
>
> Looks like the auction sites may be the better choice.
>
> Bob
>
> On Mar 29, 2013, at 9:35 AM, dlewis6767 <dlewis6767 at austin.rr.com> wrote:
>
> > The data sheet indicates the Fox924B is not voltage controllable, wever.
>   -Don
> >
> >
> >
> >
> >
> >
> > -----Original Message----- From: Bob Camp
> > Sent: Friday, March 29, 2013 7:37 AM
> > To: Discussion of precise time and frequency measurement
> > Subject: Re: [time-nuts] WWVB d-psk-r update. Seems a reasonable solution
> >
> > Hi
> >
> > There are a variety of VCXO's and TCVCXO's on the Mouser site. Prices
> seem to range from $3 to $10 for the reasonable candidates.
> >
> >
> http://www.mouser.com/ProductDetail/Fox/FOX924B-10000/?qs=sGAEpiMZZMsBj6bBr9Q9afDupvxlfd2QBmF8W0236Ww%3d
> >
> > Is one of the many. It runs at 10 MHz, CMOS output, and actually *is* in
> stock. Price is $6.41 for a single piece. I'm sure that a bit more digging
> could get that down a bit. The auction sites also have similar parts.
> >
> > Bob
> >
> >
> > On Mar 28, 2013, at 9:01 PM, paul swed <paulswedb at gmail.com> wrote:
> >
> >> OK it has been a while and I have promised to share results. In the next
> >> few days I will put whats on paper into a schematic and share. I won't
> >> dwell on all of the stuff from October to now. But several front end
> rcvrs,
> >> and several analog Costas loops were built using MC1496s and another
> using
> >> AD633 multipliers. Various other glue.
> >> Nothing to rave about.
> >>
> >> What I will detail is what I have done with quite common parts. But
> what it
> >> isn't is a kit or absolute or anything else. It can be made better.
> Don't
> >> doubt that for a second.
> >> So what I do have are 4 pretty simple and reasonable parts of the
> solution.
> >> It really does work even on the east coast. Though MSF can really cause
> >> issues ocasionally. One key part the costas loop is a design I stumbled
> >> across from 1971 designers casebook electronics magazine ca herbst. Was
> >> cleaning out old papers. The article left a lot of detail out. But the
> >> principle is solid. It was surprising at how well it worked the first
> time.
> >> So what I will share with the Time-nuts are the following schematics.
> >>
> >> A 60 KHz TRF receiver. Takes a 1uv signal and increases it to 2-4 V PP
> with
> >> AGC and soft limiter. It includes a 60 Khz xtal filter to set the
> passband
> >> and a tuned stage or 2. There are quite a few possibilities on the
> >> internet. Tried a few. This is my version. But others would work just as
> >> well.
> >>
> >> Digital costas loop using nothing more the a 74hc86 quad exclusive or.
> >> Resistors and caps to integrate.
> >>
> >> The 12 Mhz VCO. Why 12? Thats the crystals I have. Boy can this area use
> >> some help.
> >>
> >> The divider. Cmos 12 Mhz to 0 and 90 degrees at 60 Khz. This is straight
> >> out of any digital application manual. No magic at all.
> >>
> >> When combined this creates a complete WWVB costas loop solution that
> >> delivers a 60 Khz output locked to wwvb without the phase modulation. A
> >> byproduct is the digital data from the new signal. Not used. Not even to
> >> drive a led.
> >>
> >> A path could be added that literally inverts or not the original AM
> signal
> >> so that spectracom 8170s and Truetime DC60s would work and recover time
> >> correctly. That is a piece O cake.
> >>
> >> So I will get this into a schematic to share over the next day or two.
> >> By the way on performance the system handles sun rise and sets and keeps
> >> ticking. Using a fluke 207 driven by a Rb ref to watch for failures.
> This
> >> is recorded on a 4 channel chart recorder program on a laptop. I have
> used
> >> the system to drive 2 X HP VLF 117s and they track as w
> >> Lots of areas that might be improved AGC control and time constants.
> Adding
> >> a opamp to the 0 degree phase VCO control voltage and also adjusting
> Time
> >> constants. Though the 12 Mhz oscillator is really standard parts just
> could
> >> not find something reasonable and off the shelf. Digikey or Mouser
> stuff.
> >> something with 4 pins and a few $. By the way the control voltage is
> >> .5V/.1Hz.
> >>
> >> Regards
> >> Paul
> >> WB8TSL
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>