Conference unifix::sailing

    Alan, I dont think that you need to worry about "adapting" a cooupler.
    I had a Combi Loran, vintage 1983, with fried coupler that worked fine
    with an new Apelco coupler.  In fact I run both my new Apelco and
    the old Combi off the same coupler simultaneously.  Of course, one
    of the Lorans had to be capacitively coupled to avoid DC feed short.
    By looking into my coupler I found it to be very simple, although
    I did not attempt to trace the circuit, since it works.  I doubt
    that either the voltage or the impedance matching (at 100 KHz)
    is that critical.
    
    I would suggest that you look into buying a replacement coupler for
    any one of the modern popular brands.  I seem to recall that the feed
    to my Apeclo (vintage 1992 I dont remember the model No), is about 9-10
    V, and I imagine they all run off similar valtages with large margins.
    
    /Dimitri

re .1:

Thanks for the suggestions. 

I finally did what I should have done in the first place -- I called
Texas Instruments. The phone number in our owner's manual now belongs to
a real estate company. AT&T information for 800 numbers gave me a number
for TI's customer response group. The woman who answered didn't say
"loran?", she just immediately transferred me to Elgin, a pleasant
fellow who said, "yes, we still have those couplers in stock,  $150
each, would you like it shipped 2nd day air or will UPS ground do?"
Wow, what a pleasant surprise. We bought this loran in early 1982, and
since TI has been out of the marine electronics business for a while (so
far as I know), I was fully expecting no help at all. The entire call 
was less than five minutes. If only every vendor were so helpful and 
organized. 

Alan

PS As to why I want to continue using an old loran ...... It has a very 
bright display that can be read from the cockpit (it is mounted at the 
back of the chart table) and, even more importantly, I know how to use 
it without (re)reading the owner's manual. I just don't want to learn to 
use another box if I don't have to. After a year, I still have to
frequently refer to the manual for our GPS. 

    $150? What a rip-off!
    
    I can buy a used Loran unit complete with antenna for $50 around
    here...

    Just to steer this topic a few degrees off course, has anyone out there
    updated their Loran for the new 7930 Chain ?  I would be interested in
    finding out what is involved in general and in particular with
    RAY-Jeff.
    
    Thanks 

    
    Which chain is 7930?  I have flown coast-to-coast with a PL-99.
    They updated my software beforehand and I had no coverage problems
    anywhere.  Just sent them the unit beforehand.  It came back in
    maybe three weeks.  I seem to remember the update costing $50-$60.
    
    Hope this helps.

re .3:

I'm sure I could buy a used loran for less. But I chose not to. I know 
how to use my present loran, I know that it is reliable, accurate, and
has been well taken care of. With a new coupler I will be able to
depend upon it for many years to come. A used loran is of uncertain
reliability, especially a very cheap one. 

You may choose differently.

    7930 is the Labrador Sea chain.  Probably not an issue for most Noters
    as the coverage is North Atlantic, Greenland, Northenr Newfoundland
    etc. 
    
    The Master was moved from Iceland to Newfoundland a few months ago and
    consequently the software needs updating.  I have never been too
    pleased with the PL-99 ... when it works it works fine but there are
    times it is too tempramental for my liking, so I have been wondering if
    I should stick the cost of the change into a bank account to go towards
    a nice GPS system.  Your $50-60 will translate to $100 Canadian .... I
    would think that I could get a GPS for $600 CDN plus 20% sales tax so
    say $720.  that $100 would be a nice start.

    
    Labrador Sea - Haven't gotten up there.  I note that my PL-99
    performs much more temperamentally without a pre-amp on the
    antenna.  The pre-amp cost $50 USD and is half the size of a
    pack of cigarettes.  THe down side is that it chews up battery
    power so connection to external power becomes pretty mandatory.
    Since I only paid $165 USD for mine used, added a pre-amp and
    a software update, and its taken me from Atlantic to Pacific,
    and Carribean to Canada, I've gotten my money's worth.  But the
    minute GPS's drop into that price range, I'll jump.....
    
    I too vote for simplicity and reliability.  Stuff that is too
    high tech, that requires too many keystrokes and function
    sequences, too often becomes useless in a jam when you really
    need it.  I dumb box you can work in your sleep is much better
    than a smart box that you have to use every day to be able to
    remember the key strokes when you need them.

    The pre-amp is a coupler that fits on the PL-99's whip atntenna ?  I
    assume that yours was totally hand-held ?
    
    

    
    I used the antenna, power, and ground connectors on the lower rear
    of the unit.  About 8' of coax runs from the PL-99 to the pre-amp.
    about 1" of coax connects the pre-amp to the short whip antenna.
    The PL-99 is velcro-ed to my knee most of the time.  Sometimes
    I pass it over to the passenger.  So, yes, I am holding the actual
    PL-99, but not the antenna.  An easy set up to duplicate.  And the
    antenna that I use is only 2/3 the length of the standard extendible
    whip that is supplied.
    
    Hope this helps.

    I agree with Alan. New and low cost Lorans seem to be garbage. I sold
    my LC90 when the boat went on the hard for a few years.  Plugged in an
    Apelco 6400 last summer.
    
    Forget it: 1.4mi repeatability, only from 2-4pm, 2nd and 4th tuesdays,
    odd months.
    
    The rest of the time I'm navigating between Indianapolis and Terre
    Haute.  
    
    Needless to say, it sits in a cardboard box waiting until I find the
    time and motivation to send it on a "voyage" to Hudson NH.
    
    If it works, keep it!