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[time-freq] RE: Reflock II assembly

Luis Cupido cupido at mail.ua.pt
Wed Mar 14 11:04:46 UTC 2007


Hi Chris,

The universal version you refer is available for the reflock I.
(not for reflock II)
For the moment the configurations available for the reflock II
are the ones on the list.txt in the r2_conf*.zip.

In fact the flexible version, the one that is intended to
lock something to a 10MHz standard (or to 5MHz) couldn't do
the 144075 as it only has steps of 100, 125, 133.3(3), 166.6(6)
200, 250, 333.3(3) and 400kHz
This one would require a step of 25kHz. (w/ the division rates you 
mentioned)

This is the second time (at least) that higher rates are
required, I think I have made a configuration for that, let
me check my files and I will make it available to all.

About the filter on board, it is dimensioned for the flexible
version for about  100kHz comp freq. so it will work well with all
other higher f comps.

One needs to change it for the 1pps version (off course) and
for the new version I'm about to release one has to multiply
cap values by 10.

Let me have a day or two.

Luis Cupido.
ct1dmk.



Christopher T. Day wrote:
> Randy,
> 
> Your board has passed the no-smoke test. Voltages at the regulators are
> fine. I threw together a tiny Verilog program to light the LEDs and they
> are fine.
> 
> [N.B. - Randy wants to lock a 144.075MHz VCO to a 10MHz reference.]
> 
> On further examination, I find that I don't actually understand the
> simple solution. It seems to be referred to in the paper
> < http://gref.cfn.ist.utl.pt/cupido/univlock01.pdf > but I can't make
> that paper jibe in my head with the notes in any of the available
> configurations. I'm hoping Luis Cupido, the author of the paper and the
> configurations will see this mail and comment. I had thought from the
> paper referenced that I could set things up to lock at any multiple of
> 25kHz, but the notes all talk about either GPS 1pps locking or dividing
> both the reference and the VCO. Unfortunately, the prime factors of 113,
> 17, and 3 in 144.075 make for a division of 5763 which seems to be
> beyond what is available in the standard CPLD configuration. 
> 
> While I don't know this stuff well at all, I could try to put together a
> Verilog file that divides your VCO by 5763 and the reference by 400 and
> feed it to the phase/frequency detector used on the HPSDR Janus board. I
> don't off the top of my head know what that would mean for the PWM
> filter values, but I suspect that the default ones on the board may not
> be right. Nor am I certain that it would really work and I don't have
> the VCO to test it. Phil, Luis, I'm fishing here. Help, please.
> 
> 
> 	Chris - AE6VK
> 
> 
> 
> 
> -----Original Message-----
> From: Randy [mailto:hamradio at oz.net] 
> Sent: Tuesday, March 13, 2007 10:15 PM
> To: Christopher T. Day
> Subject: RE: Reflock II assembly
> 
> Hi Chris and thanks for the update.  I will have to build some kind of
> VCO
> or adapt something.  I would assume that with some experimentation I
> will be
> able to build/configure something that will pull the needed amount.  Go
> ahead with the 'simple solution' and I will build around it.  I do not
> have
> the means to program the CPLD.
> 
> Thanks!
> 
> Randy
> 
> 
> ****************************************
> 
> 
> -----Original Message-----
> From: Christopher T. Day [mailto:CTDay at LBL.Gov] 
> Sent: Tuesday, March 13, 2007 8:29 AM
> To: Randy
> Subject: RE: Reflock II assembly
> 
> Randy,
> 
> I was looking over the available configurations. If you know it, would
> you tell me the range over which your 144.025MHz VCO can be pulled?
> There seems to be a simple solution if it is <25kHz. There are other
> possibilities, though. Thanks.
> 
> 
> 	Chris - AE6VK
> 
> 
> -----Original Message-----
> From: Randy [mailto:hamradio at oz.net] 
> Sent: Monday, March 12, 2007 5:52 PM
> To: Christopher T. Day
> Subject: RE: Reflock II assembly
> 
> Great!  My eyes hurt just thinking about those tiny parts.  Too bad
> designs
> these days have to be so "high tech" instead of "builder friendly".  I
> know
> for some things small size (low inductance, etc.) is essential but it
> seems
> like everything is that way now whether it is really necessary or not.
> Oh
> well.  Thanks to you this is one project I won't have to miss but
> usually
> when I see surface mount parts to assemble I have to pass it by.  Thanks
> for
> the update.
> 
> Randy
> 
> **********************************
> 
> 
> -----Original Message-----
> From: Christopher T. Day [mailto:CTDay at LBL.Gov] 
> Sent: Sunday, March 11, 2007 6:24 PM
> To: Randy
> Subject: RE: Reflock II assembly
> 
> Randy,
> 
> As an update, all the SMD parts are now down. Tomorrow evening, I hope,
> when I'm fresher, I will inspect them carefully and touch-up what is
> needed, then get to the through-hole parts.
> 
> 
> 	Chris - AE6VK
> 
> 
> -----Original Message-----
> From: Randy [mailto:hamradio at oz.net] 
> Sent: Friday, March 09, 2007 8:48 PM
> To: Christopher T. Day
> Subject: RE: Reflock II assembly
> 
> Ok, I understand.  Sort of the reverse to what I am doing with a GPS
> receiver with 10 KHz output and a 10 MHz OCXO with a simple /1000 PLL
> circuit, only in this case we would be using a more elaborate circuit to
> divide a 144.075 oscillator down to a 10 MHz reference. I am not sure if
> it
> can be made to work on 144.075/10 MHz either but hopefully there would
> be
> some common multiple that might allow it to work (25 KHz?).  Thanks.
> 
> Randy
> 
> 
> 
> *********************************************
> 
> 
> 
> -----Original Message-----
> From: Christopher T. Day [mailto:CTDay at LBL.Gov] 
> Sent: Friday, March 09, 2007 8:35 PM
> To: Randy
> Subject: RE: Reflock II assembly
> 
> I'll see, but let me make sure we're talking about the same thing. The
> RefLock II is only a PLL. You have to supply both the precision
> reference at 10MHz, in your case, and the output of the 144.075MHz VCO;
> the RefLock II will then supply the steering voltage to the VCO. The
> RefLock II has no oscillator of its own.
> 
> I'll have to check about what the readily available frequency ratios
> are.
> 
> 
> 	Chris - AE6VK
> 
> 
> -----Original Message-----
> From: Randy [mailto:hamradio at oz.net] 
> Sent: Friday, March 09, 2007 8:22 PM
> To: Christopher T. Day
> Subject: RE: Reflock II assembly
> 
> Great, Chris!  I sure appreciate your efforts.  I think I had originally
> mentioned I was interested in using it at 66.666667 MHz but since then I
> have come up with a better application.  If it will work, I would like
> it to
> operate on 144.075 MHz.  Not sure if it will do it as-is but if so, that
> is
> the frequency I need from the RefLock from a 10 MHz reference input.  If
> that is somehow not possible then go ahead with the 66.666667 MHz set
> up. 
> 
> Randy, W7HR
> Port Orchard, Wa
> 
> 
> 
> ******************************************
> 
> 
> -----Original Message-----
> From: Christopher T. Day [mailto:CTDay at LBL.Gov] 
> Sent: Friday, March 09, 2007 4:37 PM
> To: Randy
> Subject: RE: Reflock II assembly
> 
> Randy,
> 
> The RefLock II kit arrived in yesterday's mail. I'll see if I can get
> started this weekend.
> 
> 
> 	Chris - AE6VK
> 
> 
> -----Original Message-----
> From: Randy [mailto:hamradio at oz.net] 
> Sent: Sunday, February 11, 2007 5:39 PM
> To: Christopher T. Day
> Subject: RE: Reflock II assembly
> 
> Ok, thanks.
> 
> Randy
> 
> ***************************
> 
> 
> 
> -----Original Message-----
> From: Christopher T. Day [mailto:CTDay at lbl.gov] 
> Sent: Sunday, February 11, 2007 5:18 PM
> To: Randy
> Subject: RE: Reflock II assembly
> 
> FYI
> 
>>From the TAPR office - 
> 
> "Just to let you know that I'm temporarily out of stock.  Should be able
> to ship within a week or so. 
> 




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