Conference vicki::boats

    Carl
    Whoever wired your loran & most likly the rest of your electronics
    violated the first basic rule of marine electric fitting. You have a
    textbook case of someone being too cheap or lazy to run seperate power
    and ground lines for the electronics.
    
    Its Ok to have a complete buss with breakers for Loran,VHF,Depthsounder
    and Radar only. But no other items should be on this buss. All Power
    wires must be of sufficient size to handle peak current draw plus. Also
    all power and ground lines must be twisted pair to minimize EMF
    radiation.
    
    Keep electronic wires as far as possible from ignition wires (and Tach
    wire) and insure your loran has a very good earth/water ground ( Like a
    Dyna Plate) on its referance ground lug.
    
    Sounds like youv'e got some work ahead of ya for the winter.
    
                                     Walt
    

    Well,like most of us I have two batteries.The engine buss is hooked to
    number one battery.The Loran power cable is directly connected to
    battery number 2,plus I have grounded the the loran to a ground plate
    on the hull.I can have the Loran on and power the engine on or off and 
    I never have any problems.I suggest if you haven't done this yet to
    connect directly the loran power cable to the batterry that the engine
    buss is NOT connected to,the + to the + stud of the Battery and the -
    to the _ stud of the buttery.If you still have problems you may need
    some filters.
     Happy motoring.

While .1's advice is good, most loran crashes are due to battery voltage
dropping too far when starting the engine. Lorans will crash when their input
voltage is less than 10 or 11 volts (some -- possibly including the Raynav --
are much more prone to this problem than others). Battery voltage can easily
drop below 10 volts when starting a cold engine. 

A solution is to use separate batteries for starting the engine and powering 
the electronics. This does have some drawbacks -- more complicated battery 
switching and charging arrangements. Another solution is to power the loran 
from a small battery (eg, a motorcycle battery). This small battery is 
connected to the ship's power bus through a small diode. This automatically 
keeps the small battery (re)charged. 

re .2:

Yes, but with this arrangement (using a battery solely for engine starting) 
has some drawbacks -- the most obvious being that you must run your engine to 
recharge the batteries more often. Optimum battery life is when a battery is
about half-discharged before recharging. If your engine starting battery
develops a problem, you may not realize it until it won't start the engine. If
you use each battery in turn for ship's power, you'll be able to discover a
degrading battery before it fails completely. 

    The ONLY circuit ever to be wired to the batterys directly is the
    Bildge pumps automatic. Everthing else should be interfaced thru the
    main breaker switch. If an electrical fire should occur it is
    imperitive to be able to fully isolate the system ASAP! A secondary
    advantage is the total shutdown of all systems whenever you leave the
    boat. Allways shut off the main battery breaker.
    
    If you have a special need such as a 12 V fridge or something that has
    to remain powered while your away from shorepower but on a mooring,
    then a third isolated battery should be used. Its a shame that the beer
    gets warm if the battery goes dead, but much bettere than not having a
    bildge pump when you need it.
    
    The perfect solution is a 100+ AMP DEEP CYCLE batt for constant acc.
    use and a set of two 100 Amp + batts for charging
    
                                   Walt
    

    My Apelco 6100 has seen action on 2 boats (1 with a single battery
    and 1 with 2 bats) and has never had a problem losing its signal
    when I started the engine. My loran is wired direct to the batery
    with a seprate switch and fuse.
    
    

    Other than the Loran Shutting down there is another problem your
    should avoid:  (I also have a 570 & recall reading this in the manual,
                    along with seeing it in the mags)
    
    When you start your engine there is a fair degree of Noise (V spikes)
    on your 12v lines -- a lot of this is at a fairly high frequency
    and some reasonable amplitudes.
    
    This noise can make it into your lorans power system & wipe out
    memory -- normally just the contents (WPTs, Set-up, etc..); but,
    indeed could wipe out (read: destroy) the memory chips themselves.
    
    Almost all manuals recommend not having the Loran on when starting
    your engine for this reason - although it's not in an obvious spot
    for some reason.
    
    Best overall bet is to leave it off when starting the engines --
    if it hasn't linked up by the time you warm up the engines , hoist the 
    hook or cast off lines - there is another problem you ought look
    into.
    
                                  Think Spring,
                                                 Lou

        p.s. Same applies to your depth finder - esp. the better ones (LCD,
             Chart,...) and some of the newer radios.

    Hmmm -
    
    This note reminded me of another question -
    
    My 570 manual suggests that the internal battery be replaced every
    3 years (to insure it never forgets WPT's at a bad time)
    
    Has anyone done this yet?   Am I in for any suprises?
    
    Any strong reasons for sending it out to be done or should I melt
    the etch myself :>)
    
                              Again,
                                      Lou
    
    

    The battery in your Raynav 570 is simple to replace yourself. 
    
    The original battery in the unit has a small glob of material bridging
    the battery itself and the contact/holder. The reason for the glob
    could be.... so the battery doesn't come ajar from the holder during
    shippment OR so the manufacture (should the unit ever be returned
    for repair) can tell if the original battery was ever replaced.
    
    /MArk          (the battery is approximately the size of a nickel)
    

re .7:

Very true. The voltage spikes from starter motors can damage lorans, etc. The 
small motorcycle battery/diode scheme I mentioned previously solves this 
problem also. The are times when one would rather not wait for the loran to 
reacquire after starting the engine(s).

 I think the comments on low voltage during engine start-up is the 
applicable point.  NO short-cuts were taken during installation of anything 
on this boat (testimony of wallet).  The Loran was installed in my Bertram 
by Land & Sea Marine in Harwichport and they are quite good (i.e. no 
short-cuts, high quality work).

As relates to the use of separate batteries, I do have 2 batteries as well 
as 2 engines, each with its starting power source.  I do have a control 
switch that enables me to start either engine off the other battery should 
the need ever present itself.  Based on the comments offered I might  just 
try to start off the battery that the loran is not hooked up to.

The third battery is an idea that I am pursuing...see the note on 12vDc & 
110vAC recently started.

Carl

    you also might be able to get away with a capacitor/choke filter
    on the power input to the Loran; in fact, if the capacitor is large
    enough and the drain is small enough adding a diode would allow
    the capacitor to ride through the low spots during cranking.. 
    
    
    
      bat+ ------oo----i>|---()()()()------- loran +
              circuit diode   choke    |
              breaker                 --- capacitor
                                      ---
                                       |
      bat- --------------------------------- loran -

    where the diode is some Schottky diode (like an MBR340, $1.03 at
    Active), the choke is a Radio Shack car stereo noise filter, and
    the capacitor is around 100,000 uF; this value will droop 1 volt
    in 100ms at 1 amp drain, and the line voltage will pop up between
    compression strokes to recharge the capacitor..
    
    Just a thought, if you want to avoid having another battery hanging
    around..
    
    ...tom
    

re: .12

Tom, 

This approach seems like an ideal solution.

Can you get a little more specific about the ckt components, and where I 
might obtain diode and capacitor?

Should any other precautions be taken?    
>    
>      bat+ ------oo----i>|---()()()()------- loran +
>              circuit diode   choke    |
>              breaker                 --- capacitor
>                                      ---
>                                       |
>      bat- --------------------------------- loran -
>
>    where the diode is some Schottky diode (like an MBR340, $1.03 at
>    Active), the choke is a Radio Shack car stereo noise filter, and
>    the capacitor is around 100,000 uF; this value will droop 1 volt
>    in 100ms at 1 amp drain, and the line voltage will pop up between
>    compression strokes to recharge the capacitor..

Thanks>    

    The diode can be gotten at Active (westboro, woburn); MBR340P, active
    #10344. The capacitor might be a little trickier - if you can find
    a large linear power supply laying around it might have something
    that big, else find some electronics hobbyist (or a ham) who is
    a packrat and see what s/he has in the junkbox.
    
    The idea of using two diodes, one from each battery, might let you
    get away with something more like 10,000uf; but then you'd need
    two breakers (for safety; we don't need any fires on board!). This
    way, assuming you don't start with the two batteries in parallel,
    the loran would always be powered by the higher-voltage (non-cranking)
    battery.

      bat+ ------oo----i>|-+
                           |
      bat+ ------oo----i>|-+-()()()()--+---- loran +
              circuit diode   choke    |
              breaker                 --- capacitor
                                      ---
                                       |
      bat- ----------------------------+---- loran -


    Just FYI, the reason I'm specifying an MBR340 diode (an SD41 would
    be better, but is a harder-to-mount stud-type diode) is because
    the Schottky diodes have a lower forward voltage drop; typically
    .3 volts instead of .7 volts for silicon. 
    
    If you need more details on construction, send mail. 
    
    ...tom

    Moved by moderator...
    
================================================================================
Note 826.0             help, radar interfereing with loran            No replies
SMURF::AMATO "Joe Amato"                             20 lines  21-APR-1991 09:27
--------------------------------------------------------------------------------
    I just put a furuno 1720 radar on my boat and when I power it up it
    blows my loran (micrologic explorer) away.  This happens even when 
    the radar is in stand-by mode when the unit isn't transmitting.  
    I've got the loran in a radio box at the helm station, and the radar 
    on the pot side of the boat.  Its only 2-3ft apart, but I've got a 
    small cuddy (grady white offshore 24) and that's as far apart as I can get
    them.  The radar is connected to its own battery that's not even
    attached to a guest switch (yet).  The loran is connected diretly to
    the main power feed that feeds the fuse panel which is run by the main
    battery, on the guest switch.  Electrically, they're isoloated so I
    don't believe that an inline filter (newmar) will help.  My
    color fish finder also whacks my loran, but nowhere near as bad.  As
    soon as I power either of them up, the SNR's on the loran drop.  In the
    case of the ff, they drop from 80-90's down to 60's.  The radar
    drops'em to 0's.  The only thing I haven't tried to move my loran
    antenae away from the radar cable.  To do this I'll have to move it to
    the other side of the boat.  Has anybody else experienced this problem,
    or is this possibly just a problem with my micrologic?  If the latter's
    teh case, I've got a micrologic explorer for sale for $200...
    

    Could it possible be the ground?  Do both/all units use the same common
    ground?  I remember reading the installation guide on my loran, Sitex
    EZ7, and the recommendation was a separate ground plate mounted on the
    bottom of the boat.  I have a Ray Jefferson color fishfinder mounted
    about 2' from the loran and have no problems (come to think of it the
    antennae cables run down different sides of the boat).
    
    Gordon
    

Joe,
	Although I'm tempted, I won't slam your LORAN.	;^)

	How is it grounded now? Do you have a dynaplate?

	I've got mine installed with both the RADAR and LORAN powered off 
the main panel. I use a dynaplate for the LORAN. Both units operate in close
proximity to each other with no problem. If you already have a dynaplate
we'll have to do some more head scratching.

Paul

    Paul you have an apleco 6100 loran right? (I have one and bought the
    same radar as Joe, I'm trying to guess if I will have a problem).
    My loran has never had a signal loss problem (has lived on 2 boats).
    
    Whens the Joannie-B hitting the suds? Cod fishing is hot down my way!
    
    Bruce

    re .-2
    
    Paul
    
    Just got back from voyager marine where they spent all afternoon with
    me tracking down the problem.  My loran is grounded to a dynaplate, but
    that's not the problem.  The first thing he said was to through out the
    little 39" stainless antena that came with the loran and upgrade to a
    6' fiberglass.  Micrologic upgraded the loran with that, and for anothr
    $150 they've got new software and mother board that really brings it up
    to par.  And as far as slamming the loran, they all said that the
    micrologic is an excellent loran, that usually is able to take care of
    external noise.  So there ;-) 
    
    That's why they wanted to see the units together, this
    is not a common problem between these units.  It turns out that my
    display is very noisy.  We covered the front with tin foil and they
    played together very nicely.  Suggestion, wrap  some reynolds wrap
    around the sun visor.  Also I might try a product called sonar shield.   
    Furuno's low end units (that's ours Bruce) tend to be noisy, some just
    worse than others :-(.  Bruce, the good news for us is voyager has had
    lots of probs with the r10x so far.  Raytheon always sorts it out, but
    the early units...  Back to the soldering iron.
    
    Joe
    

    Re .18>
    Bruce,
    	Yes I have an Apelco 6100. You probably recall my RADAR is the low
    end Apelco LCD. I beieve the transciever is the same as the low end
    Raytheon.
    	As far as when the fishin starts up here, I'm running into the
    usual conflicts with my other vocations...farming and Little
    League. Joanie B can go any time if I can get a day to get her ready 
    and another to go. The inshore cod action should be hot now.
    	I found some info on a good bottom fishing area that isn't too far
    offshore. I'm dying to try it. I also got some info on wrecks that I'd
    like to pursue this season. Information is a rare comodity up here. The
    whole coast is underfished and local knowledge is hard to come by.
    	I'm straying off the topic so I guess I'll sign off. Have a good 
    season.
    
    Re .19>
    
    Joe,
    	I'm glad you found a fix for the problem. Now you'll have no excuse
    to stay at home. RADAR is nice. I use mine to go down the Kennebec when
    I can't even see 10' in front of the boat.
    	Maybe we'll try to rendezvous offshore again this year.
    Sea ya,
    
    Paul
     
    
    Re .19>
    Joe,
    	I'm glad you worked out the problem. 

    re .-1
    
    Paul
    
    Did a little experiment last night with the radar and loran.  Took an
    emi screen from a terminal and just held it over the radar and wala! 
    alls wonderful in the land of electronix.  called furuno today and
    ordered an emi screen.  it'll be here this weekend.  also got
    confirmation on my mooring in hampton today.  now all i'm waiting for
    is that check...  
    
    See ya on jeffries!
    
    Joe
    

    I powered up the rader and put it right next to the loran (6100) and
    not even a a glitch on s/n ratio. I love that loran!
    
    Bruce