Conference vicki::boats

    Sure, you can gain much good experience at home and even watch
    you house "move" around. The first season with my Sitex I used 
    the winter month to practice and to load up several sets of 
    Waypoint I thought would be useful. 
    
    A good 12V DC power supply is not to expensive and they are availible
    from many sources, Radio Shack for one. Be sure that you get a unit
    which is well filtered and has ample capacity (3-5 amps, most Loran
    don't require more than 2-3, but you'll find other uses for the
    power supply). I could not easily position the whip antenna to 
    receive a strong signal, so I removed the whip from the coupler
    and hooked up a five foot length of 22 gauge wire in it's place.
    Worked like a champ.
    
    The only caution would be to be sure that you observe the polarity
    of the DC connections. BTW many Lorans have an NVRAM (non-volatile
    Random Access Memory) to remember waypoints when power is lost and
    this winter time practicing will TOP OFF the charge on the Nicad
    used to power the NVRAM.
    
    The house "movement" comes from small variations in the Loran chain's
    signal propagation and is due mostly to changes in humidity over
    large areas.
    
    Jerry
    

    I didn't have a 12v Supply; but, when I first bought my R570 2 years
    ago it took about 5 min to hook it up to my lawn tractor and within
    the next half hour I had not only learned how to use the basics
    but also loaded some key waypoints & I now know the Lat/Lon of the
    four corners of my lot & where the house sits upon it.
    Now I get home without getting lost!
    
    Really - I did indeed do the above & found it to be a very constructive
    learning experiance.   Tis more fun to play with your new toy in
    solitude than with 5+ pairs of friendly eyes saying "wad ya git?",
    "hows it go?"
                                                                    
    As warned -- watch the polarity.
    
    The 570 is a snap to learn,       Have Fun,
                                                 Lou "Phanta Sea"
                                                                 

    This winter I hooked up may apelco 6600 to the car batery. Just
    ran the wires up stairs from the garage and put the antenna out
    on the back porch and I was locked on the 9960 GRI in a couple of
    minutes. I then went through all 100 way points and listed them
    and have been sorting them out ever since. I will have a good plan
    of attack come spring.
                                      
    
    Capt. Codfish

I also requested inputs regarding the question of using a LORAN at home in 
the sailing notesfile.

Any comments regarding the following warning:
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
                                     Sailing
Created: 12-MAR-1986 08:48         1116 topics        Updated: 31-JAN-1989 19:42
                       -< wanted/for sale: use note 263 >-

================================================================================
Note 1115.2                       LORAN at Home                           2 of 2
NSSG::BUDZINSKI "Just when you least expect it... The unexpected!" 4 lines  31-JAN-1989 15:13
--------------------------------------------------------------------------------
                               -< Don't Do It! >-

    Don't do it without a battery in the circuit.  Some converters generate
    high peak voltages that may damage the power supply in the LORAN.
    Always use a battery in the circuit to provide a load to absorb and
    filter the high voltage spikes that a converter/charger might generate.

    Re .4 That's way I said "WELL FILTERED". I assumed and should not
    have, that most people would know to power the Loran on and off
    after the power supply is already on and stablized. DO NOT use the
    the supply's main switch to apply and remove power from the Loran.
    
    BTW many newer marine electronics devices are able to operate over
    much wider voltage ranges. 9-40 in becoming almost common place.
    This is a good item to check out when shopping.
    
    Jerry
    

The attempt was overwhelmingly successful.

I followed the best of the advice given, bought a high quality regulated 
13.8vDC power supply and powered up my RAYNAV 570 this weekend.

The antenna was a bit of a problem. Discovered that the more vertical its 
orientation the better.  Only made a few dB of difference as to whether the 
antenna was in the house or out on the deck in the back.  

I strongly recommend this capability to anyone new at using a loran.  I am 
confident that I saved myself a good number of "training" hours on the 
water.  I was able to load waypoints and connect them into potential trips.

In fact, it almost felt like I toured Nantucket Sound, fished the Middle 
Ground, visited Cuttyhunk and Block Island this weekend.  

I can also see that having the capability to operate the loran at home can 
allow one to prepare for a cruise without utilizing valuable boating time.

Carl

I just got a loran which has a built in simulator, which allows me to use it
within the house to learn its operation. It asks for the longitude and latitude
values at my current position. 

How accurate do these values have to be in normal operation. For instance,
does your starting position at the harbor have to be within +/- ?. How would
an inaccurate value affect the loran operation?

I suppose that these longitude an latitude values are normally gotten from USGS
type charts, correct? Or is there another source?

	Steve

    The greater the error you put in, the greater its gonna lie
    back to you.
    
    It should be able to tell you where it is, in the normal 
    operating mode. Take this data and put it in the unit
    when your in the simulation mode...
    
             JIm

    Re: .-1 depends on the Loran.   The Apelco Lorans ask you the L/L
    of where you are when you first turn on the unit.  This seems to
    be used in the automatic GRI/secondary selection mode to figure out
    which to use (the book says "approximate" L/L - doesn't have to be 
    changed unless you move a long distance).
    
    However, if you enter the exact L/L of the unit location, you can then
    use it to apply automatic corrections when computing L/L from TD so
    your charted position agrees with the Loran exactly.  Kind of the
    same idea as ASF corrections for TDs.
    

    Seems to me you need to enter the GRI, then choose the stations
    
    for tracking the TD's. Once this has been done, the TD's of
    
    your location should appear. The unit should be able to 
    
    convert these to the L/L.
    
    Unless the Apelco's have different requirements than what i am
    used to.
    
    JIm.

    Nope.  While you can enter the GRI if you want, the unit normally picks
    its own based on your location - that's why it needs an "estimate" of
    where you are.
    
    The unit will also pick the secondaries to use but I haven't determined
    (and the manual is no help) whether it does that by picking them out of
    the same table it got the GRI from, or whether it dynamically picks
    them based on signal strength.    I suspect the former since it always
    picks the same two.   
    

When I first got my Micrologic loran I really sweated the same question
out. Bought a topographical map and found my location to the second of
arc.

A couple of weeks later I did something that wiped all memory clean, and
just for the hell of it I entered the lat/lon as 43� 00' 00'' 71� 00' 00"
and it picked right up from there. Seems all it wanted to know was where
in the world it was in gross terms.

Art

    Re -1>
    	I agree, all it wants is to know your locations in gross terms. I
    think my Apelco asked for it to the nearest 0.1 degree. I think it just
    needs to know what part of the world your in so it can pick the right
    set of internally stored correction tables i.e. magnetic variation, ASF 
    corrections etc.
    	More accuracy is needed when entering your home port correction
    information. This is used to fine tune your set so that you can be more
    accurate than these rough, stored values.
    	At least thats my understanding of it.
    Paul

    I'm getting more confused.  I have a Loran. You put in the GRI 
    and it knows which part of the world your in. Shortly after 
    this it starts rolling thru the available stations,
    --you see 43xxx 14xxx 25xxx etc. you need 2, you choose them,
    and it will tell you exactly where you are. If you have to tell
    it where you are, why do you have a Loran..
    
    JIm.

    You are right if you want to pick the GRI.
    
    If you want the unit to pick the GRI it needs to know approx where you
    are.
    

    I think your in Mass. Then your GRI is 9960.
    
    JIm.   

    You've accused me of previously pulling my leg, now I think you're
    pulling mine :-)
    
    Actually I agree with you, auto GRI selection is a pretty dumb feature
    unless your boat is a hydroplane that zips up the Atlantic coast so
    fast it would be cumbersome to reset the GRI as you pass from chain
    to chain.   The Loran memory could be used to better advantage...

Having just moved my boat and LORAN to the opposite coast, (without keeping it
powered on) I couldn't get the D%^&M thing to lock onto where it was. I tried to 
manually enter the GRI chain for the Western US, but it told me the preferred GRI
was for the Solomon Islands. In desperation, I got out the manual and went to
the "NEW INSTALLATION" section, where it told me to enter the approx. L/L. I used
L/L I found in a one page encyclopedia entry (to give an idea how ROUGH) and
viola...I'm in the Western Canadian chain and it knows right where it is. (I
did get charts at the boat show and they agree with where my King 8001 says.


...Larry