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[time-freq] State of manuals for RefLock II?

Christopher T. Day CTDay at lbl.gov
Tue May 9 18:47:47 UTC 2006


Steve,

The envelope with - I presume, I haven't opened it yet - the replacement
resistors arrived yesterday. Otherwise, I've mostly finished the board.
I only lost one more part, a 0.1uF capacitor, through stupidity; I
placed it on its pads, forgot it was there and then picked up the board
to look at something else. Ah, well. I will try to put together some
build notes for Shane this evening.

I've looked a bit more closely at the schematic, so I think I know the
answer to this, but I thought I'd check before taking the action. The
row of binary selection pads along the bottom edge of the board - R and
N divisors - are meant to default to high => all the resistors should be
installed on the '1' pads, and zeros are selected by adding the 0 ohm
jumpers on the appropriate '0' pads. So, no matter which of Luis'
configuration files I eventually load into the CPLD, all the '1'
resistors should be soldered in place?

Otherwise, the board seems quite generic absent a configuration file.
The non-CPLD components are basically conditioning to feed an I/O pin of
the CPLD. There are symmetric pads to divide either the VCXO or the Ref
signal depending on what gets populated. Then what you do with the
signals is up to you and what the configuration file loads into the MAX
II. Software defined hardware - I love it!


	Chris - AE6VK


P.S. - It might make an interesting project to write some OpenSource
Verilog to implement the PLL counters, et al., so we could be free of
Luis' contractual restrictions.


-----Original Message-----
From: Steven Bible [mailto:n7hpr at tapr.org] 
Sent: Friday, May 05, 2006 8:25 PM
To: TAPR time and frequency projects
Subject: RE: [time-freq] State of manuals for RefLock II? 

Hi Chris,

>  Where do R32-R49 go? Are they alternates for the 0 ohm jumpers?
Thanks.

They go in the jumpers positions in the "1" position.  You will see
there
are two rows in the R and N jumpers.  The 10Kohm resistor go into the
row
with the "1".  These are the pull-ups that make the CPLD see a logic 1.

> Also, what happened to R17? There is a place for it on the board, but
> nothing about it on the parts sheet.

It appears I goofed on the note on the schematic.  I say: "NOTE:
populate R9
only if Reflock VCXO IN requires 50 ohm termination."  It should say
R17.
But here's the rest of the story...

As you may have already learned, the prescaler U2 is optional.  U2
allows
VCXO IN operation up to 1.1 GHz.  So all the part associated with U2
should
not be populated if you are operating about 250 MHz and below.  So
populate
R11, and C15.

R17 is optional only if you need a specific termination resistance for
VCXO
IN.  I thought it would be needed and placed it just in case.  If you
connect a 50 ohm load to VCXO OUT, then the VCXO IN will see that same
50
ohm load.  R11 and C15 taps off the signal from the VCXO.  You can
change
the value of R11 to match the impedance of VCXO IN and OUT combination.
I
ran the VCXO IN and OUT on a network analyzer and choose R11 = 200 ohms
as
it kept the VCXO IN and OUT impedances at 50 ohms.  Thus, if you have
something other than 50 ohm system, you may need to change the values.

I hope this helps.

Your questions are very valuable in writing the assembly manual.  Keep
the
questions coming.


73,

- Steve, N7HPR
 (n7hpr at tapr.org)



> -----Original Message-----
> From: time-freq-bounces at lists.tapr.org
> [mailto:time-freq-bounces at lists.tapr.org]On Behalf Of Christopher T.
Day
> Sent: Friday, May 05, 2006 7:46 PM
> To: TAPR time and frequency projects
> Subject: RE: [time-freq] State of manuals for RefLock II?
>
>
> Steve,
>
>  Where do R32-R49 go? Are they alternates for the 0 ohm jumpers?
Thanks.
>
>
> 	Chris - AE6VK
>
>
>
> -----Original Message-----
> From: Steven Bible [mailto:n7hpr at tapr.org]
> Sent: Sunday, April 30, 2006 2:39 PM
> To: TAPR time and frequency projects
> Subject: RE: [time-freq] State of manuals for RefLock II?
>
> Hi Chris,
>
> You are right, save the 0-ohm resitors (jumpers) for last.  The ones
you
> will populate depend on the application you choose.  Luis has
documented
> the
> jumpers in the text files that come with the configuration files on
his
> web
> site:
>
> http://gref.cfn.ist.utl.pt/cupido/reflock.html
>
> There are the jumpers of the N and R registers (which really generic
> jumpers
> now).  Also, note that you will need a jumper in the choice of the
phase
> detector output (JP3, JP4, or JP5).
>
> Start with the the lowest profile parts first.  That will be the
> resitors
> and caps.  The parts sheet make it easy to go one value at a time.
Mark
> off
> the designator as you populate the parts.  If you need help in knowing
> where
> the part goes, take a look at the assembly file on Luis' web site.  It
> has a
> magnified view of the silkscreen.  You can double check with the
> schematic.
>
> All the parts should solder onto the board in a straight forward
manner.
>
> I trust you have done surface mount parts before?  I use a magnifying
> glass
> for most parts.  But the CPLD I soldered down under a stereo
microscope.
> All the remaning parts can be done under a lighted magnifying glass.
>
> If you have any questions, please ask on the list.  We'll jump in to
> help
> you.
>
> 73,
>
> - Steve, N7HPR
>  (n7hpr at tapr.org)
>
>
>
>
> > -----Original Message-----
> > From: time-freq-bounces at lists.tapr.org
> > [mailto:time-freq-bounces at lists.tapr.org]On Behalf Of Christopher T.
> Day
> > Sent: Sunday, April 30, 2006 9:39 AM
> > To: TAPR time and frequency projects
> > Subject: RE: [time-freq] State of manuals for RefLock II?
> >
> >
> > Shane,
> >
> > Sure, I'd be happy to help if I can. I haven't worked though all of
> the
> > existing archives yet, but at least I have concluded that I want to
> skip
> > installing the 0 ohm jumpers on first assembly. Are there any other
> > special construction quirks I should know about before starting?
> > Otherwise, I'll give it a go over the next week or so with just my
> > magnifying lamp and see how it goes. I will keep notes and forward
> them
> > to you.
> >
> >
> > 	Chris - AE6VK
> >
> >
> > P.S. - There are so many cool kits out there, I hate seeing any of
> them
> > just stalled.
> >
> > P.P.S. - And I thought 0805s were small.
> >
> >
> > -----Original Message-----
> > From: Shane Justice [mailto:ke7tr at cox.net]
> > Sent: Saturday, April 29, 2006 10:45 AM
> > To: time-freq at lists.tapr.org
> > Subject: RE: [time-freq] State of manuals for RefLock II?
> >
> > Chris,
> >
> > I am on the hook to do the manual. I am waiting to receive an
> > inspection microscope, then I'll start putting the Reflock II
> > together, and writing the manual at the same time.  If you'd like to
> > collaborate, drop an E-mail directly to me. I'm going to have to get
> > this going soon, as I may have my hands full with work for many
> > months to come.
> >
> > 73,
> >
> > Shane
> > KE7TR
> >
> > _______________________________________________
> > time-freq mailing list
> > time-freq at lists.tapr.org
> > https://lists.tapr.org/cgi-bin/mailman/listinfo/time-freq
> >
> >
> > _______________________________________________
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>
>
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