LORAN C reference question

Bob Bruhns bbruhns@erols.com
Fri, 23 Jun 2000 10:18:13 -0400


How bad is the jitter?  If it is only a few degrees, I would try locking to your reference and watching the 100 KHz from the LORAN unit.  I would guess you may see jitter, but with stable frequency between jumps, or some sort of steady trend.  Then go for the middle of the variations.

And as Frank suggests, you may find a better 100 KHz signal somewhere inside the receiver, or abandon LORAN altogether for GPS.

  Bob, WA3WDR

"Paul A. Cianciolo" wrote:
> Hello Folks,
> I finally have a frequency standard here to drive my house system.
> Receivers are a RACAL 6790GSM and a Harris RF 590 both have the ability to
> utilize an external reference.
> My reference has a 100Khz out and I am trying to trigger a scope using the
> 100Khz as
> an input and the Loran C as the trigger signal,  so I can see the drift
> overtime, Although it may take days.
> What I cannot seem to do is get a jitter free 100KHZ LORAN signal.
> I am using a LOWRANCE antenna coupler which looks as though it has most of
> the reciever
>  elements in it as well as all the bandpass filtering.  There is a
> microproceesor on the antenna as well
> 5 or 6 other surface mount chips and a 8 Mhz TCXO.
> Can someone help me locate a point on this thing where I can get a 100Khz
> signal
> to lock my source.  I have been through this thing with a scope and found
> lots of squarewaves but
> all seem to be derived from the TCXO, and do not change when an antenna is
> applied.
> In the RF portion of the unit I can see what looks like 3 100Khz signals
> that are time sharing the freq.
> They are all varing amplitudes. Loran is very strong here.  I have read that
> most devices that do this
> sort of thing use the 3rd cycle in of the RF pulse.
> Any help would surely be appreciated.   Sorry about all the cross posts but
> this email is in an
> effort to get an ultra stable freq. reference for LF, DSP and laser
> experiments
> Thank you
> Paulc
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