[time-nuts] 60 KHz Receiver

[K3WRY at aol.com]

All
All of this design and mod info is wonderful and great to fill an  
engineering project workbook.  You can spend about $500US and get a  complete HP 
working system including GPS antenna which I have been monitiring to  10-12 for 
14 mos now and it is stable--------------------------------
 
Dr Joe
 
 
In a message dated 10/4/2010 3:12:18 P.M. Eastern Daylight Time,  
sandeenpa at yahoo.com writes:



Gents,

Thanks for all the input on the HP 3586B and the  Austron Loran C receiver. 
 I’ll try to distill what’s been  said.

It appears that using the HP 3586B for a WWVB receiver isn’t a  good idea 
unless I would use my HP 3336B or some other method to phase lock  the BFO.  
Since this seems to be way out of the KISS principle, I will go  to plan B.

I appreciate the clever circuit to convert the Austron to a  phase detector 
but the effort required to get just a phase detector alone  isn’t cost 
effective for me.

Opening up the Austron shows that there is  a great deal of space.  If the 
three Loran boards are gutted one of my  Lucent Rubidium or Xtal standards 
will just fit in their place.  The  power supply appears to be robust for the 
power required.  If not, there  is space to add on. 

So to try to maximize the salvage of my purchase  it looks like I should do 
the following.

1.  Gut the Loran boards  and get a Lucent unit installed and working.

2.  Build a big  honkin’ quality 60 KHz loop antenna.  I live in the 
country so I can put  up any size I can afford.

3. Convert the Austron RF amp boards to 60  KHz if I can get a schematic 
and get lucky.  Does anyone have one or know  where I could download it?

4.  If I don’t get lucky, build a TRF  receiver in place of the Austron RF 
boards.  60 KHz crystals are cheap  from Mouser.  Does anyone have 
experience building a ladder or similar  crystal filter? 

5.  After I get a good working 60 KHz signal,  I‘ll divide it by six and 
apply it to a Talbot 10 KHz phase detector.   The Talbot circuit divides the 
10 MHz reference oscillator to 10KHz using  74HC390 decade dividers.  It then 
provides a correction circuit to the  reference oscillator from its phase 
detector.  Since the Talbot circuit  on uses about six IC’s it will fit 
nicely in the rear chassis area.

The  goal, when completed, is to have a WWVB phase locked oscillator (yes I 
have to  figure out what to do about diurnal shift) a reference frequency 
output and  perhaps add a second Talbot phase detector circuit and meter for 
calibrating  other oscillators.

Yes, the GPS is more accurate more quickly but the  issue is to have a 
second independent source for cross-checking.  Though  highly unlikely, GPS 
satellites can be shot down, disabled or turned off or  have their outputs 
modified at any time.

Comments?  

Regards,

Perrier






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