| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 10.1 | | PIXEL::DICKSON | | Wed Mar 28 1984 23:37 | 31 |
| At the boat show in Hynes Auditorium I saw a tiny little Loran
receiver called the MLX, made by SRD Labs. List price $1095.
It had all the features listed above for the TI, plus autopilot
coupling and 99 waypoints.
The really nifty things were its small size (6.25 wide by 2.6 high
by 10.5 deep), and the fact that it had only six buttons on the
front panel. You could make it do all its tricks with just
those buttons (entering a waypoint might be a little tedious -
I didn't try it - probably like setting a digital watch, the
kind without a numeric pad).
Once you determine your local lat/long error, you put that
into waypoint zero, and it corrects from then on.
It also could remember a sequence of up to 10 waypoints and
automatically switch to the next one when it got there (watch
out for the boom!). It did set off an alarm shortly before
reaching a waypoint.
Besides the cross-track read-out, it had a settable cross-track
distance alarm.
At anchor, enter the scope length, and the MLX will set off an
alarm if you drag outside the radius of the scope by more than
300 feet. (I would think you would want to know before that,
but this is only Loran.)
The distributor handing out the brochures was Yankee Marine, in
Newburyport.
|
| 10.2 | | PIXEL::DICKSON | | Thu Mar 29 1984 11:10 | 7 |
| An easy way to keep track of your waypoints is to mark them on
your charts, each with its number beside it. When setting course,
just consult the map and call up the appropriate waypoint. It
would be a good idea to check the corrdinates when you call it
up, to make sure someone hasn't moved it, or the memory battery
ran down, and you end up heading for the Azores.
|
| 10.3 | | GIGI::JCR | | Fri Mar 30 1984 13:02 | 18 |
| I mentioned in another note that I was considering the Northstar 800
Loran. It's a new model this year but I'm wondering if anybody has any
comments on it. (Other than it's VERY high price)
King (noted for top quality aircraft electronics) has a new tiny Loran
unit also. Has anybody played with one of these? I think I saw a comment
in Practical Sailor that King was having problems with chip availability
for some of their new line so I don't know if these units are actually
available yet.
For a while I was contemplating the Datamarine unit. Seems to be very easy
to use - but then it didn't seem to be overendowed with features either.
The thought of combining the VHF and Loran antenna in one unit at the
masthead was probably the gimmick that attracted me the most.
This feature has been downgraded by a couple of competitors I've talked to.
However, somebody at a show said that Metz was coming out with an antenna
similar to this for general use.
|
| 10.4 | | PIXEL::DICKSON | | Fri Mar 30 1984 14:02 | 6 |
| LORAN runs at VERY LOW frequencies. VHF runs at VERY HIGH frequencies.
A short VHF antenna can't be tremendously efficient at LORAN
frequencies. I think it's a gimmick. Sure it would WORK, but
not well. And you also have a single point of failure - lose your
mast and you lose both the VHF AND the Loran.
|
| 10.5 | | GIGI::JCR | | Tue Apr 03 1984 12:23 | 13 |
| I share your concern about the single point of failure issue. While I'm
not the owner of a Maxi flyer with twice the sail hanging out, a dismasting
is not somthing I'd ignore either. A backup 8' antenna stored away would
possibly be prudent. I think that the possibility of breaking the Loran
antenna mounted on the stern rail is a much more common problem.
Antenna length is commonly adjusted with capacitors and coils. The
Datamarine design appears to make use of a coil to electronically lengthen
the VHF size whip. I guess my real question is this: Is there any
significant loss in gain, Db's, etc. inherent in this design which is not
offset by having the antenna mounted 40+ feet higher. Are there any
EE's or ham radio operators out there who can explain the tradeoffs?
|
| 10.6 | | MOTHER::BERENS | | Tue Apr 03 1984 12:55 | 42 |
| The reason for mounting VHF antennas as high as possible to extend the
line of sight range of VHF signals (150 MHz or so). Loran signals (100
kHz remember) propagate both along the surface of the earth (for 600
miles or so) and via reflection from the ionosphere. Loran accuracy is
based on the ground wave -- there can be substantial errors when using
the skywave due to the uncertain length of the longer propagation path.
I don't think that mounting a Loran antenna at the masthead will improve
Loran reception significantly. After I bought my TI9900 I stood the
8' antenna on my front porch and just for laughs asked the Loran where
my dining room table is using the North Atlantic chain (stations in
Newfoundland, Greenland, and somewhere else). After a pause the
Newfoundland and Greenland stations were acquired and tracked. I have
always been able to get excellent signal-to-noise ratios on the
Northeast US and Canadian chains with the antenna at deck level.
Some Lorans (like my TI) have a fixed length antenna cable that is not
long enough to reach the masthead. TI will, I think, supply a longer
cable, but they discourage it. Harbor Electronics, where I bought my
unit, was not in favor of masthead mounting. Certainly a cable long
enough to reach the masthead will have more loss than a shorter one.
You are right -- mounting the antenna on the stern pulpit makes it
vulnerable to clumsy crew and boats running into you. I finally bought a
stanchion base and a 6' piece of tubing and mounted the antenna atop
that. Now at worst I have to saw off a few inches of tubing if somebody
bends it.
Just another opinion.
By the way. Pay some attention to warranty provisions and repair costs.
TI will repair/replace my unit for a fixed fee (now about $275) once the
warranty expires. Upon receipt of your broken unit they will within a
day ship you a repaired unit using the same shipping method. Nice if you
are in some distant place and need a fast fix. Sitex a couple of years
ago was changing about $2000 for a non-warranty replacement of the
mother board. At that time the discount price of a new unit of the same
model was around $1800. Neat pricing.
Alan
|
| 10.7 | | NETMAN::GARDINER | | Tue Apr 03 1984 16:02 | 35 |
| An example of stern pulpit caution may be the solution I devised
for my LORAN coupler/antenna. Using 3/4" teak I fashioned a block
to clamp around my stern pulpit stanchion for the base. Positioning
the top of the coupler (and base of the antenna) about an inch above
the rail. With this mount it was so flimsy that when docking an
over zealous dock hand grabbed the coupler an broke the whole unit
off of the teak bracket.
Back to the drawing boards!
I made the same mount for the base and positioned it the same way,
but then made another teak bracket in a figure "8" shape that
clamped around the stanchion and the top of the coupler. It is
split to provide a clamping tension on the coupler and through
bolted with two stainless bolts. The coupler is now a solid part
of the pulpit.
It does not allow for lowering the antenna on the ratchet base, but
I have never needed that feature anyway. The antenna is still
vulnerable, but most people wouldn't grab that, I hope. For winter
storage I just remove that antenna (which is good practice) and
throw a piece of carpet over the coupler before the cover.
There is no foolproof way to protect electronics from fat fingered
klutz's, but by double bracing the coupler I have minimize the
danger.
Good luck!
P.S. - Be aware that stern mounting should ensure that the antenna
is not near ANY metal. This includes rail, stays, etc. A 90 degree
"cone" should be measure from slightly below the base of the antenna
and the antenna adjusted (or moved) to eliminate any metal from the
"cone".
|
| 10.8 | | MANANA::DICKSON | | Wed Apr 04 1984 11:02 | 27 |
| I am an EE and ex-ham, and I also checked with another ham.
Putting the Loran antenna on top of the mast will have no effect on
reception, for reasons described in a previous reply. Putting the VHF
antenna up there, however, is a good idea.
Watch out for cable-losses, though. The thin coax cable (RG-59/U) has a
loss at VHF frequencies of around 7dB per 100 feet. The larger RG-8/U
cable (about half an inch in diameter) has around 3 dB of loss per 100
feet. The difference, 4dB, is more than half your power. RG-8 costs about
twice as much as RG-59, and is quite a bit heavier, depending on the kind
of internal insulation used.
The general rule for metal close to antennas is that any largish metal
within one-quarter wave-length will distort the directional pattern of the
antenna and also de-tune it. A quarter wavelenth at Loran frequencies is
around 2400 feet, so there is nothing you can do about it. The back-stay,
etc, are so close that they become "invisible" to the antenna.
At VHF, a quarter-wave is about 20 inches, so you have to be much more
careful. Whip antennas are not particularly directional, but the de-tuning
effects can reduce your effective power, and if bad enough even damage the
transmitter. (Tho I assume most marine VHF radios have internal protection
against this.) For example: a metal wind-pointer at the masthead is
probably too close to the VHF antenna, unless the antenna is raised
slightly so that its base is above the pointer.
|
| 10.9 | | GIGI::JCR | | Wed Apr 04 1984 16:29 | 11 |
| I'm starting to get the picture. Thanks for everybody's help. My electronic
background consists of a military tech school 25 years ago. I retained
just enough to be dangerous.
Think I'll pass on the Datamarine antenna for now. Since they're hyping
it quite a bit in their ads I don't think it'll be too long before success
and/or failure reports start to show up.
Maybe I'll rethink the issue after I've broken my 4th stern mounted antenna.
That's the approximate cost tradeoff point.
|
| 10.10 | Loran in the U.K. | CSSE::COUTURE | Abandon shore | Thu Apr 14 1988 11:25 | 5 |
| I read in Practical Sailor that there is some sort of a service
charge in the U.K. for utilizing Loran (kind of like pay T.V.).
I'd like to be enlightened on this, or at least informed that I've
been had by Practical Sailor.
|
| 10.11 | Tax supported!!!! | CIMNET::CREASER | SUPER STRING | Thu Apr 14 1988 12:34 | 14 |
| If so, it uninforceble, and if memory serves me right the loran
stations are maintained by the U.S. Coast Guard....even overseas!
Not sure if that is all overseas units....there may be exceptions,
but for the sake of compatibility and quality of service, I understood
that the U.S. "volunteered".
There are radio navigation services...all over the place. Perhaps
they have user fees.
Hate to pay for things twice!
Jerry
|
| 10.12 | LORAN & UK | CHEFS::GOUGHP | Pete Gough @REO (7)-830-6603 | Thu Apr 14 1988 12:35 | 10 |
| Loran has no real coverage in UK waters. Coverage in the English
Channel stops at about Biscay. There is No Charge for usage of LORAN
where it is utilised. How would they police it.? The most popular
form of electronic navaids in the UK are based on the DECCA chains
(No charge for usage same rationale applies). The DECCA based systems
can be accurate upto one tenth of a nautical mile. Sets cost from
200 pounds Sterling up. I would be interested to know who Practical
Sailor thinks collects the revenue & how......
|
| 10.13 | My 2 cents (or 2 pence)... | IND::SAPIENZA | Knowledge applied is wisdom gained. | Fri Apr 15 1988 14:22 | 18 |
|
>> Channel stops at about Biscay. There is No Charge for usage of LORAN
>> where it is utilised. How would they police it.? The most popular
>> 200 pounds Sterling up. I would be interested to know who Practical
>> Sailor thinks collects the revenue & how....
This is just a wild quess, but IF some government agency wanted
to collect a usage fee for LORAN or SATNAV or any of those electronic
navigation systems, I'm sure they could find a way to add a tax
to the purchase price of the receiving units. (But then, they'd
still have a problem tracking the sale of used units.)
Frank
|
| 10.14 | antennas are obvious | CADSYS::SCHUMANN | | Tue Apr 19 1988 11:01 | 11 |
| It is standard practice in several European countries to tax radio and
television receivers, on a user-fee basis. The revenues are typically used to
support the state-run radio and television networks. Although the taxes are
difficult to enforce, there are some clues that the government can use. Most
obviously, if you have an antenna, you probably have a receiver. To improve
compliance, stiff fines are levied against tax-avoiders who are caught.
(I don't know whether any countries tax LORAN receivers.)
--RS
|
| 10.15 | Purchase "tax" | AYOU17::NAYLOR | Purring on all 12 cylinders | Thu Apr 21 1988 10:11 | 7 |
| The other way of "taxing" the use is to incorporate a fee in the
initial purchase price of the receiver. This was the method used
by Decca in European waters. Used equipment sales couldn't be caught
in the same way though!
Brian
|
| 10.16 | Coverage for the Mediterranean? | MORGAN::KENT | Don't forget the homeless | Wed Apr 27 1988 18:05 | 5 |
| Can LORAN C be used in the Mediterranean? I noticed an earlier
reply that said it wasn't covered in the UK.
Anyone used the Heathkit LORAN?
|
| 10.17 | Waypoints | CAMELS::MCGARRY | | Thu Apr 28 1988 11:29 | 6 |
|
Does anyone have waypoints for buzzards bay??
|
| 10.18 | | GRAMPS::WCLARK | Walt Clark | Fri Apr 29 1988 11:24 | 4 |
| The Better Boating chart packs have waypoints listed now.
Walt
|
| 10.19 | buoy list | SPCTRM::BURR | | Fri Apr 29 1988 13:01 | 5 |
| There is a book which publishes observed TDs and Lat/Lon for every
buoy from St. John's to the entrance to New York Harbor. I do not
know the title but I have seen it at several boatyards and marine
stores. It is expensive tho...$89.95!
|
| 10.20 | Your mileage may vary | SAGE::RODENHISER | | Fri Apr 29 1988 17:09 | 70 |
| Re: Buzzard Bay waypoints.
I'm not sure what you're really after. If all you want is some
'ballpark' numbers for your first, or maybe only, transit thru the
bay then the Chartkit, or any number of published lists would be
adequate. Also the scale of the Small Craft chart for that area
will allow you to plot coordinates with sufficient accuracy.
If you want to be *exact* then you've really got to record your own
waypoint coordinates with your own specific loran unit. The
accuracy, sensitivity, and repeatability of various units can
give widely differing readouts for the same location.
Since this is my home waters I have recorded much of the area. I
hadn't got around to it yet but I was going to put this info together
in some sort of single sheet, plastic laminated, quick reference format.
For what it's worth, here's a sample of data I recorded for a course
from my harbor (Marion) thru Woods Hole to Edgartown. Unit is a
Northstar 800X.
Marion Harbor - Centerboard Shoal | Vineyard Sound
--------------------------------- | --------------
R "8" 41 41.99 | "26" 41 30.34
Fl R 4 Sec 70 44.97 | Fl R 4 Sec Bell 70 38.56
|
C "7" | Vineyard Haven Harbor
| ---------------------
| BW "NW" 41
N "6" 41 41.69 | Mo(A) BELL 70
70 44.76 |
| West Chop
C "5" 41 40.92 | ---------
70 44.13 | R "2" 41 29.22
| Fl R 4 Sec GONG 70 35.41
G "3" 41 |
Fl G 2.5 Sec 70 | East Chop
| ---------
CB Shoal "2" 41 39.78 | "23" 41 28.43
Fl R 4 Sec 70 43.40 | BELL 70 33.34
|
Woods Hole | Cape Poge - Edgartown Harbor
---------- | ----------------------------
"13" 41 31.76 | R "2"
Fl G 4 Sec Bell 70 41.71 | BELL
|
C "11" 41 31.51 | R N "4" 41 25.38
70 41.50 | 70 29.24
|
R "10" 41 31.28 | R "6" 41 24.59
Fl R 4 Sec 70 41.26 | 70 29.18
|
R N "8" 41 | R N "8" 41 23.53
70 | 70 29.80
|
R N "6" 41 |
70 |
|
R "6" 41 31.02 |
Fl R 4 Sec 70 40.01 |
|
R "4" 41 30.91 |
Fl R 4 Sec 70 39.68 |
|
N "2" 41 30.79 |
70 39.41 |
|
| 10.21 | TD's vs Lat/Lon | ECADSR::FINNERTY | | Fri Apr 29 1988 17:36 | 12 |
|
re: .20
Your Northstar probably has a good lat/lon conversion algorithm,
but LORAN locations really ought to be reported as TD's because
the person who copies those coords may have a LORAN which uses
a different algorithm. Nobody likes TD's, but at least they
are repeatable between different units.
Irish Mist
|
| 10.22 | Right. | SAGE::RODENHISER | | Fri Apr 29 1988 18:23 | 17 |
| Agreed that in theory TD's are more accurate because no matter how
good the algorithm, there's still some mathematical error introduced.
No one should use *my* lat/lon coordinates for the all the reasons
I stated.
I prefer lat/lon's since I'm using the SC chart (doesn't have TD's)
and I care more about repeatable accuracy than absolute accuracy
anyway.
Also, as you noted, the Northstar has especially good lat/lon accuracy
due to it's ability to make judgements about the best TD pair based on
line crossing angles, spacing, and signal strength.
John_R
|
| 10.23 | Waypoints | CAMELS::MCGARRY | | Mon May 02 1988 09:02 | 12 |
|
Thank you for the numbers, I got a loran this winter
and wanted to compare the numbers of other lorans to
see how close it is and to aid in learning how to
use mine. Thanks.
richard
|
| 10.24 | RAYNAV 570? | YACHTS::CORKUM | I'd rather be sailing.... | Fri May 20 1988 17:36 | 10 |
|
One LORAN I've heard of but haven't seen is the RAYNAV 570. Is there anyone
out there with experience with this model? If so, I'd like to contact you
for your opinion.
thanks,
bc
|
| 10.25 | Raynav 570 | AD::GIBSON | | Wed May 25 1988 13:59 | 12 |
| Hi I just bought the Raynav 570 for the new boat "Rainbow Chaser"
and so far I am plesed with it. I set it up with a Dyna plate for
grounding and gave it a test on the trip up from Old Saybrook Conn.
To Newburyport Ma. A I left the Eat end of the Canal we ran in fog
right up to Glouster Light. Right on the money!!
It is compact and took the pounding of 20 to 25 ft breaking waves
with 45 kt winds. Yes its waterproof!
So far so good. and not too expensive.
Walt
|
| 10.26 | Apelco = Raytheon = RayNav | IND::SAPIENZA | Knowledge applied is wisdom gained. | Thu May 26 1988 19:41 | 18 |
|
I have looked at (and admired) the RayNav 570 for some time now,
though I haven't yet made my LORAN purchase. One thing I found out
at boat shows and such is that Raytheon (the makers of RayNav) owns
Apelco and the Apelco 6100 (?) is basically the same unit as the
570 but it is a little cheaper.
In fact, if you look at the two units you will see that the controls
and display have the same labels, it's just that the 570 has them
to the right of the display and the 6100 has the controls below the
display. From a comparison chart in some buying guide, I seem to recall
that both units had identical features, so you may want to look at the
Apelco and save some bucks.
Frank
|
| 10.27 | Decided on Apelco 6100 | YACHTS::CORKUM | I'd rather be sailing.... | Tue Aug 02 1988 10:24 | 25 |
|
I bought the Apelco 6100.
Yes it is the same as the Raynav 570. In fact the manual refers to the Raynav
570 in places. After 3 weeks with it I've been able to get very comfortable
with using the set and now trust it (but not soley depend on it obviously).
I would recommend the unit to others. (BTW it's on sale at Boat US!)
There are a number of errors in the manual however. It was noted that a new
manual was being published and I sent in my card to get it when it's available.
A few of these errors were critical (like what key to hit to turn on ASF, Auto-
matic routing and Auto Magnetic Variation). Once I got around the errors the
accuracy was right-on.
With the lousy weather we experienced over the last two weeks on our vacation it
really came in handy! (The hand-held RDF was helpful too!)
< next toy - radar? >
BC.
"A Crewed Interest"
|
| 10.28 | LORAN WAYPOINT LOG SHEET | YACHTS::CORKUM | I'd rather be sailing.... | Thu Aug 18 1988 13:49 | 78 |
|
FWIW..
Attached is a form that I prepared to keep a log of my Loran Waypoints. I found
that organization and practice is the key to successful use of this nifty
navigational tool. I included space on the form to note the Chartkit page(s)
and both the observed vs charted coordinates. Perhaps you've been trying to
prepare something like this yourself...
(It's 8.5 x 11 and fits nicely in a loose leave notebook.)
bc
W A Y P O I N T L I S T I N G
AREA ___________
PAGE __ OF __
|WPT|CHART| CHARACTERISTICS | O B S E R V E D | CHARTED |
|No.| PG | (DESCRIPTION) |DATE | LAT/LONG | T/D's |LAT/LONG(source) |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
| | | | | | | |
| | | | | | | |
|___|_____|_______________________|_____|___________|________|_________________|
|
| 10.29 | Loran Offshore | LILEDS::SCHED_DEV | | Wed Aug 24 1988 00:52 | 14 |
| I recently crewed on a Boston to Bermuda sail. We had both a Satnav
and Loran. The Loran was an older Ratheyon unit (whose model escapes
me) - it was a bulky unit in a 12x12x3 metal case. The two nav systems
matched within a couple of miles for the whole trip. We had heard
that Loran wouldn't reach all the way to Bermuda, but except for
some noisy periods, we got good readings. Wouldn't you know it
- Satnav which had faithfully acquired a satellite every 45 - 90
minutes couldn't get a fix for the last three hours of our approach
to Bermuda. The Loran led us right to our first visual buoy sighting.
It was a great feeling of security having both systems in agreement.
Sextant was relegated to backup duty...
Vince Miccio
|
| 10.30 | uncertain reliability | MSCSSE::BERENS | Alan Berens | Wed Aug 24 1988 10:57 | 15 |
| Loran reception/tracking isn't reliable as far offshore as Bermuda. The
groundwave signals are quite weak, and the skywave signals, if
inadvertently acquired, give a position substantially in error. When we
sailed to Bermuda last summer, our TI 9900N loran lost the groundwave
signals about 50 miles from Bermuda. Apparently when propagation
conditions are favorable, lorans will track all the way to Bermuda, but
don't depend on it.
Bermuda has two long range RDF stations (one wasn't functioning during
our approach) that provide reasonably good position fixes when
approaching from the north. Bermuda was upwind as we approached the
islands. About 30 miles out, around midnight, we were able to smell the
flowers, damp earth, etc. An hour later we sighted Gibbs Hill light.
|
| 10.31 | Apelco 6600 Loran | PBA::SCHLEGEL | | Thu Sep 08 1988 15:53 | 19 |
| I purchased the Apelco 6600. The plot function is uncanny!!
However, following my plot down the C.C. Canal showed that I was
cruising along route 6A due to offset. I wouldn't appreciate that
error entering Nantucket breakwater!! I set in corrections for
"home port" but am still finding substantial errors after long
runs. Any suggestions as to whether I should re-establish a
"home-port" (e.g. correction) after 30 to 40 miles of travel?
After over 30 years of dead-reckoning, I almost felt using the
Loran was doing something "illegal". One super example was when
I was coming back from the cape, I had to take a long hitch practically
to "P" town upwind, trying to make Scituate at night in 35 knots.
I could have hauled out the RDF, but it was beautiful to verify
my TD's and tack so I could make Scituate without staying out in
the slop any longer than necessary. By the way, to comment on Alan's
mention of fewer waypoints, I set up approximately 30 waypoints
and just called out those needed along the way. Saved a lot of
twiddling while under way.
|
| 10.32 | LORAN and land don't mix | LEODLN::BAHLIN | | Fri Sep 09 1988 16:38 | 25 |
| I spent two years maintaining LORAN transmitters for the U.S.C.G.
a loooong time ago so this is [dis]qualified advice.......
The LORAN TX frequency is so low that it is propagated as a groundwave.
This means that its propagation time is very much a function of
the conductivity of the surface over which it travels. Since your
accuracy is a function of this prop time, the best consistancy is
always going to be obtained when your signal path is over sea water.
Land has a very inconsistent conductivity (varies with soil type
and moisture content) so when the path from transmitter to you contains
some time over land, your accuracy is questionable. There was
an experiment in its early days to try LORAN C as a mobile navigation
resource for the Army and I believe it was scrapped due to inability
to get repeatable results.
Since you were using it in the canal (essentially surrounded by
land) I'm not surprised that it was off. It could also have been
off from the things you mentioned in your memo. My advice to all
LORAN users is to be increasingly skeptical of it as you get inland
and the transmission path is interrupted by land. Try to pick
stations [paths] that are over water to you.
|
| 10.33 | Unrepeatable or "inaccurate"? | ECADSR::FINNERTY | | Fri Sep 09 1988 17:40 | 14 |
|
re -.1
>> i believe it was scrapped because of an inability to get
>> repeatable results
I thought that the results would be repeatable but "inaccurate"
with respect to the theoretical propagation factors. if they're
not repeatable then does the conductivity of the surface vary
as a function of weather/snow cover/humidity/.../?
- jim
|
| 10.34 | repeatability = accuracy | LEODLN::BAHLIN | | Mon Sep 12 1988 09:56 | 22 |
| re: .33 repeatability vs. inaccuracy
I'm not quite sure this isn't a semantic nit but in a navigation
system repeatability = accuracy. If you weren't hitting the
theoretical delay times but you were PREDICTABLY missing them you
could always build in a constant offset.
The problem I was alluding to may have been better stated as a
predictability problem. You are correct about snow, rain, drought,
etc. If it effects moisture content it effects conductivity of
the soil. A loran path over land would always have an unpredictable
propagation time which equals poor repeatability which means you
couldn't build in offsets and this ultimately leads to inaccuracy.
All of the LORAN stations in the world are specifically located
in such a way as to maximize the 'over water' coverage area. This
puts them in some of the most incredibly hostile places you could
imagine and usually within a few hundred yards of the beach. This
technical necessity had a lot to do with my becoming a civilian.
Hope this helps.
|
| 10.35 | Absolute vs Repeatable | SAGE::RODENHISER | | Mon Sep 12 1988 13:16 | 24 |
|
re: .34 repeatability vs. inaccuracy
> I'm not quite sure this isn't a semantic nit but in a navigation
> system repeatability = accuracy. If you weren't hitting the
Accuracy is defined in two ways: absolute, which measures the ability to
determine geographic position (latitude-longitude) and repeatable, which
measures the ability to return to a previous position.
> All of the LORAN stations in the world are specifically located
> in such a way as to maximize the 'over water' coverage area. This
Is this still true? I'm not a pilot but I thought that loran was getting to
be very popular with the flying fraternity. Do they depend only on the coastal
chains for coverage across the whole country?
John
|
| 10.36 | anything repeatable can be flavored accurate | LEODLN::BAHLIN | | Mon Sep 12 1988 13:57 | 37 |
| Remember, I'm talking 20 years ago (I was in the U.S.C.G. from
'65-'69). Things may have changed :^). I think another important
point here is that I'm not talking about huge errors. For example
we might be talking about plus or minus 500 yard absolute error
over water and plus or minus 1000 yards over land (these are just
guesses).
My guess is that absolute error for an aircraft is probably a lot
less important than for a yacht when you are talking about general
navigation. Small planes have VERY accurate systems for in close
(to an airport) navigation. I think one system is called OMNI and
I know very little about it's long range accuracy. A pilot would
conceivably use loran for general purpose on a long hop and use
OMNI in close????? I've even read some articles about boats that
use OMNI on the east coast.
In a military application (artillary for instance) even 200 yards
error is probably unacceptable [excepting nuclear weapons of course].
The original note stated that the LORAN position while in the C.C.
canal was route 6A. That might mean the section of 6A which runs
right beside the canal so the fix (if this is so) was well within what
you should expect for LORAN. LORAN was not ever intended for use in
navigating up a channel.
By the way, I intend to have it on my boat as soon as I can afford
it so don't imply from this that I am not advocating LORAN. At today's
prices no serious cruiser should be without it for long. I'll just
use mine with a degree of skepticism and always corroboration (when
I can get it).
Could some of you who have systems now place data here on what their
respective manufacturers claim for accuracy in the manuals. This
might be quite informative.
Another interesting side topic might be what the various manufacturers
suggest for selecting stations, advice, cautions etc.
|
| 10.37 | OMNIs and LORANs | MEMV03::LATHAM | | Mon Sep 12 1988 14:27 | 26 |
| Being both pilot and sailor does not make me an expert by any means
but I am used to using both navagation systems. The OMNI is basically
an omni directional radio beacon that you can tune into via a radio
receiver. You choose which radial (basically equivalent to which
degree out of 360 degrees out from the OMNI station you wish to
home in on) and enter that into the radio receiver which also drives
a course indictor. If the needle is centered on the course indicator
you are centered somewhere on the given radial for the given OMNI
station. If you do the same with a second NAVCOM radio tuned into
a second OMNI and also have its needle centered, you , by definition,
are positioned at the intersection of the given radials. Just like
the
intersection of TD's on the LORAN. Aeronautical charts have the
location of the OMNI stations marked out with the equivalent of
the compass rose so you can chart your radial intersection easily..
like charting intersecting bearings on a sailing chart. However,
OMNI stations are located much closer together than the stations
in a GRI chain for LORAN. OMNI stations are around 100 miles or
so apart and given predetermined radials between them form VICTOR
routes which are the in air version of the interstate highways on
the ground.
Bottom line..the concept of calculating position based on the
intersection of radio signals is basically the same..the difference
is the type of radio and signal being used.
|
| 10.38 | Simple definitions... | BMT::SAPIENZA | Knowledge applied is wisdom gained. | Mon Sep 12 1988 19:05 | 18 |
|
We've probably heard enough on this already, but here's my 2
cents. Repeatability is not the same as accuracy.
Accuracy: Is the LORAN reading correct? That is, if you go to
point x does your LORAN display the correct Lat/Lon for that point?
Repeatability: Does the LORAN give you the same answer, time
after time? That is, if you go to point x today and get a Lat/Lon
reading on your LORAN, can you go back to that same exact spot next
week and get the same, identical Lat/Lon reading? (Note that you
don't have to get the correct (accurate) reading, just the same
one you got last time.)
Frank
|
| 10.39 | Rat hole | SAGE::RODENHISER | | Tue Sep 13 1988 09:53 | 17 |
| Re .38
> cents. Repeatability is not the same as accuracy.
Just shows you how gullible I am. I copied those definitions straight
out of the Northstar manual and I thought they knew what they were
talking about.
Frank, now we definitely are into semantics. The point is: how WELL
a unit repeats can be defined in terms of accuracy and how CLOSE
to the correct lat-lon position can be defined as another form of
accuracy. That's all.
John
|
| 10.40 | | TFH::MARSHALL | hunting the snark | Tue Sep 13 1988 10:27 | 17 |
| re .39:
.38's definitions of "repeatability" and "accuracy" are the standard
definitions used in Statistical Process Control:
Accuracy: "refers to the absolute correctness of the measurement
as compared with some known standard."
Precision: "refers to the reproducibility of the measurements: that
is, the ability of the measurer or measuring instrument
to repeat or duplicate readings."
{from _AT&T Statistical Quality Control Handbook_ section B-3.11,
p90}
Sm
|
| 10.41 | Little work, better results. | CIMNET::CREASER | SUPER STRING | Wed Sep 14 1988 11:14 | 41 |
|
Several good points have been made about LORAN performance and the
caution you should always have for any single navigational aid.
If you're looking to get the most out of your LORAN's performance
you may want to consider the following example. Note the details
will vary with your model of LORAN, but most modern unit have features
which allow you to perform the same corrections.
As noted earlier in this note, one source of error is the seasonal
indeed possible daily signal variations due to "ground" effects
and weather. The resultant change usually take place over periods
longer than a typical boating day, so the a single correction per
day is normal all that's required.
1. Since we mostly leave from a known location, record the position
(I have loading it as Waypoint 00) for use during correction.
2. After the LORAN has settled, compare the known location with
the LORAN current position. If it is different apply corrections
until they agree. This could be a simple as turning ASF on. I
prefer to use individual correction on the secondary stations.
This is done in a seperate mode and it allows increments of time
to be added or subtracted to each TD. I could apply the same
type of correction to the master station but this has not been
necessary yet. Resolution of the correction is good, but not
perfect.
Once the correction are complete (a few key strokes and perhaps
one minute of my time) I'm ready to go. The set is now tuned for
the day's outing and I've never had to repeat on a single outing.
The use of manual correction has usually reduced absolute position
errors by 50% and the overall accuracy approachs the accuracy limits
of the LORAN system itself.
The key is knowing your set, settling on a correction routine and
faithfully using it at the dock or mooring.
Jerry
|
| 10.42 | | SAGE::RODENHISER | | Wed Sep 14 1988 14:10 | 17 |
| Re .40:
Those are very good definitions... and far be it from me to suggest
that "Statistical Process Controllers", especially those who work
for AT&T should ever use otherwise, ;^)
but,
for sailors interested in the practical application of loran and
how the terms 'positional accuracy' and 'repeatable accuracy' are
used in that context, I would refer them to Chapman's (Ed. 58, Pg.
552).
John
|
| 10.43 | (+) or (-) I don't know | MPGS::KTISTAKIS | Mike K. | Fri Jan 27 1989 15:06 | 8 |
| Quote from Micrologic Operator's manual
"The loran is designed to use (-) negative ground.For boats with a
positive bias grounding, DO NOT CONNECT THE CASE GROUND DIRECTLY.
Use a "MAR-LC" filter.
The capital letters scare me.Could anyone care to explain and let me
know how I find what kind of bias polarity the boat has before I do
any demage when I install the loran? Thanks
|
| 10.44 | one way to determine | MSCSSE::BERENS | Alan Berens | Fri Jan 27 1989 16:04 | 10 |
| re -.1:
So far as I know, negative ground is used on all US built boats and
maybe on all boats. Anyway, the battery switch is in the non-ground
wiring from the battery to the rest of the electrical system. For a
negative ground system, you'll find that the cable from the positive (+)
battery terminal goes to the battery selector swicth. The cable from the
negative (-) battery terminal will be connected directly to a ground
such as the engine block.
|
| 10.45 | Loran Manual - Help | AKOV12::BILLINGS | | Mon Feb 19 1990 10:08 | 23 |
| A friend has just recently bought a Cape Dory 30 that has a Si-Tex/
Koden Electronics Loran C Receiver, Type 767C, Serial # 7678362. Boat
is an '82, so Loran could be 7 yrs old or so.
Problem is that a previous looker at the boat thought he needed all the
manuals (loran, radar, engine, etc.) more than the seller or new buyer,
and thus my friend got no operating directions with the boat.
He has tried the manufacturer and several chandleries with no avail,
since this model is "so old" (? - they obviously prefer for him to buy a
new one).
Does anyone have this particular unit, or a manual for this unit that
could be copied ? Or know of anyone who might have a source for older
manuals ? Or know how to operate this unit without a manual ?
Any help would be appreciated by my friend, and I have a dinner on-
board riding on the generosity of Sailing noters.
Thanks,
R.
|
| 10.46 | Treated Me Right | WAV14::PARSHLEY | | Tue Feb 27 1990 14:02 | 6 |
| I'm quite surprised that Si-TEX would not help. 1 year ago, I sent the
same type of unit to Si-TEX for tune up and also asked for some updated
info on lat/lon usage. They sent me manuals and a tape which provided
step by step instructions. Since that time I have sold the boat so I
no longer have the manuals. Try SI-TEX once more and ask for their
Customer Services office.
|
| 10.47 | Hand Held Loran ? | CSOA1::WACKER | | Wed May 23 1990 12:23 | 9 |
| Has anyone had the chance to try the Micrologic Voyager SportNav
Hand Held Loran unit? From the catalog (E & B Discount Marine) it looks
like a nice unit. Has 100 waypoints , 5 notch filters , waterproof ,
full steering info , ect......
Would like your feedback on this unit as I like to " talk to my
friends " before I purchase these type of things.. Any info will fall
on appreciative ears ( eyes ).
Thanks in advance,
Hank
|
| 10.48 | My two cents | MEMORY::PARE | | Wed May 23 1990 15:58 | 9 |
| I spoke to a salesman a the Newport boat show last fall. I questioned
him about the Voyager handheld mentioned in -.1. He said that the
circuitry was the same as in the Voyager base unit. The only drawback
that I recall was that (I believe) the batteries only last about 8 hrs.
Since most Lorans stress the need for solid grounding, I would also be
sceptical of the performance.
John
|
| 10.49 | Voyager SportNav is good! | DISCVR::BARTHEL | Fred Barthel | Wed May 30 1990 13:31 | 26 |
| I have one of the Voyager SportNav handhelds. I am quite delighted with it
so far. I just hang it on the rail (lifelines) near the helm and it works
fine. It seems to have a slightly better signal noise ratio when I ground it
to the lifelines, but it works without it. It has a display which shows the
signal quality from the master and two slaves that you can use to optimise
the location. Although I expected all sorts of problems with reception,
there were none. Even with an outboard running nearby, the results were good.
I have used it on land walking around with good repeatable results. I save
a bench as a waypoint and walk some distance away. When I return the location
is repeatable within about 100 feet! I have done this over a period of weeks
and the results are the same. It even shows the speed that I am walking
AND the MAGNETIC bearing of the course... An interesting side use on my boat
is as a speedo/log. The waters I sail in sometimes clog my thru hull sensor
before I get out of sight of the mooring! This device gives good speed readings
if you hold a course for a couple of minutes. Don't expect to trim your sails
with it however.
The batteries last about 20 hours and there is a timer to show about how much
time is left. All functions of the full size Voyager seem to be available.
This unit is cheaper than a repeater and you just bring it in and put it away
when you are done with it. Good fun and seems to be accurate by my chart
checks. It clearly shows the movement from swinging at mooring...
Fred
|
| 10.50 | Loran in Italy? | ROYALT::FGZ | Federico Genoese-Zerbi | Fri Nov 30 1990 20:37 | 9 |
|
I'm planning a Charter off the norhtern coast of Sicily next spring, and
some of the sailing we're planning on will involve some amount of blue
water cruising. It sure would be nice to be able to bring a handheld
Loran with us, but I have no idea if there is any coverage in that area
of the world. Does anybody know? Should I refresh my sextant skills instead?
F.
|
| 10.51 | Different Software | HAEXLI::PMAIER | | Mon Dec 03 1990 10:11 | 5 |
| No problem with Loran.But you must buy it in Europe.Different Software.
Peter
|
| 10.52 | | ROYALT::FGZ | Federico Genoese-Zerbi | Mon Dec 03 1990 11:16 | 6 |
|
Any units that have replaceable software modules so they can be used either
place?
F.
|
| 10.53 | | MSCSSE::BERENS | Alan Berens | Mon Dec 03 1990 14:34 | 7 |
| re .51:
Different software? Huh? The manual for my old TI loran indicates that
it is usable with the European loran chains. I can certainly understand
that the notch filters might need readjusting between a US cruising area
and Europe, but I'd be very surprised if different software is needed.
|
| 10.54 | | TOOK::SWIST | Jim Swist LKG2-2/T2 DTN 226-7102 | Tue Dec 04 1990 08:23 | 7 |
| Also, it there's any way to avoid buying electronic *anything* in
Europe, it's worth trying to find it. I just got back from a trip
over there and while the price of most everything was steep, consumer
electronics were ridiculous. I can imagine that with the smaller
small boat market coupled with the usual marine product ripoff
markup that the prices must be laughably high.
|
| 10.55 | Filters are the problem | STAR::KENNEY | | Tue Dec 04 1990 09:12 | 7 |
|
Alan is correct, it is the notch filters, and possibly the automatic
correction code. I was helping a person from France last year to try
and track down a unit.
Forrest
|
| 10.56 | | HAEXLI::PMAIER | | Tue Dec 04 1990 09:57 | 7 |
| I helped last year a friend to install his new Loran.The userguide
said: Unit has been adjusted and set up for use in European waters.
If my memory is correct,in this notesfile some time ago somebody was
looking for ROMS to upgrade his Loran.
Peter
|
| 10.57 | | ROYALT::FGZ | Federico Genoese-Zerbi | Tue Dec 04 1990 12:55 | 12 |
|
RE: last few.
Ok, so the question still stands, albeit differently. Are there any handheld
units available in the U.S. which will also work in Europe unmodified? It
seems like if notch filters are an issue, it would be trivial for a manufacturer
to provide a unit that has both modes, and can be switched between them.
No?
F .
|
| 10.58 | Call and ask | STAR::KENNEY | | Tue Dec 04 1990 14:18 | 10 |
|
In fact the very expensive units that you install have this built in.
You would have to call the manufacturer of the hand held(s) and ask
them. Try the technical support/repair folks instead of the marketing
types. That was how we discovered that the major problem was notch
filters, the automatic correction software is just a 1+ not really
essential.
Forrest
|
| 10.59 | More info, please... | ROYALT::FGZ | Federico Genoese-Zerbi | Tue Jan 22 1991 17:32 | 14 |
|
I called Micrologic, and they confirmed that the notch filters need tweaking
before their Loran units can be used in Europe. They charge $50 for each
adjustment, so I'd be looking at $100/charter--rather expensive trick. I would
like to try other manufacturers of hand-held Loran units. Could somebody
provide me with a list of these--names of manufacturer, hand-held model
numbers if you happen to know them, and city (and state) that the company
is in?
Does Apelco have a hand-held unit? Where are they located?
Thank you very much in advance.
F.
|
| 10.60 | Too good to be true??? | ROYALT::FGZ | Federico Genoese-Zerbi | Thu Jan 24 1991 17:28 | 36 |
|
I've called several Loran manufacturers, and the story seemed all the same:
If I wanted to use the device in both U.S. and Italian waters, I'd have to
get the unit's notch filters retuned at the factory at big bucks a pop.
Then I called Ray Jefferson. They have a handheld unit, that sells for
$230 at Bliss. I was told by one of their techs (who seemed VERY
knowledgeable--quoted the loran lines in the area of Italy I was interested
in from memory--but maybe he had a chart in front of him) that their
unit has software that compensates in software for the differences. You
just punch in a code for Sicily (which he told me, but I forgot. I
assume it's in the user manual) and the unit knows what to do. This
struck me as odd, and I asked why the notch filters did not need tuning.
No clear answer, but definitely, he insisted, there's no need for that.
Software takes care of it all.
I almost called Bliss right away to order one of these marvels. Use it
anywhere in the world, only $230? Seemed too good to be true....so I
stopped. It seems like the software could adjust for different notch
filters only if the filters are implemented digitally. Seems unlikely given
the LORAN frequencies, the sampling rate and processing speed
necessary to do that kind of convolution in real time. Not for $230 it
seems, unless they are doing something else. On the other hand the guy
seemed to know what he was talking about, and I don't know enough about
LORAN to be sure.
Any ideas? I could really use some advice here 'cause I'm really confused.
If the claims are true, then this LORAN is perfect for me. I'd gladly give
up some accuracy (if indeed this unit is less accurate than other ones--on
paper it's really feature laden) if I can freely use it in Italy and U.S.
Thanks for some suggestions.
Federico.
|
| 10.61 | Software Controlled Notch | GUIDUK::RADKE | | Thu Jan 24 1991 18:53 | 11 |
| Re: .60
It is possible to have a software controlled IF (Intermediate
Frequency) passband or notch frequency. These features are commonly
found on most current amateur radio transceivers (although they are
manually controlled rather than by software). I would expect to see
this feature on high-end Lorans first, then migrate to the less
expensive units. A reference from a customer who has actually used the
Loran on both systems might provide the most direct answer.
Howard
|
| 10.62 | Could it be? | ROYALT::FGZ | Federico Genoese-Zerbi | Thu Jan 24 1991 19:58 | 13 |
|
RE: -.1
The Ray Jeff LORANs in the Boat U.S. catalog are listed as having
"Internally adjustable notch filters" rather than the "Preset notch
filters" that Boat U.S. claims other units have. Could this be what
you're referring to? If so, is there any reason why more expensive
(albeit older--the PL99 is a brand new recently introduced product)
units would not do this? Seems like a great way to do things--if
it works.
F.
|
| 10.63 | no LORAN needed | HAEXLI::PMAIER | | Fri Jan 25 1991 02:49 | 9 |
| Why LORAN ? There are no strong currents,no tides,no sandbars (only in
Livorno),no fog,no rocks,no obstacles to shipping in Italy.Navigation can
be done by eye.You hardly need a compass.I have never seen any of the major
lights out of order during the last 8 years.
(do you have your booking ? I have seen an ad for chartering from
Capri)
Regards Peter
|
| 10.64 | Must be different part of Italy :-) | ROYALT::FGZ | Federico Genoese-Zerbi | Fri Jan 25 1991 09:40 | 21 |
|
You are right, no fog. But haze and lots of it. < 6 mile visibility
is sometime all I got going from Amalfi to Capri. Could not see
li galli from cape Conca. Not a big deal 'cause I could see the
coast to my right. Very different if I do blue-water passages like
Alicudi-Palermo or Stromboli-Capri, where I'll be seeing no land for
several hours/day.
If, for instance, I go from Capri to Stromboli, I'll be out of sight of land
for significant portions of the trip. If the wind is from the west
north-west, then it's conceivable that I'll have enough lee drift to
go right past Stromboli and not see it (visibility < 6 miles in haze). Next
thing I know, the Calabrese coast or Messina is coming up, and I have lengthened
the trip a lot. I agree though that it's not a safety issue, but it would
be convenient to have a LORAN.
In order to navigate by eye, you need to see land.
BTW, I did find an outfit that will charter me a boat in Portorosa Marina
(see pg. 236 Rod Heikell's book) for a reasonable amount. Still, if you
have info about a boat charter place in Capri, I'd like to hear about it.
|
| 10.65 | What length of antenna do you use with your Loran? | DECWIN::WOODBURY | | Mon Apr 01 1991 14:11 | 10 |
| I would like to poll readers on the length of their Loran C antennas.
I read that in many cases a four foot or 39" antenna picks up signals
as well as an eight footer. This antenna will be mounted on the stern
stanchions, on a wooden boat with wooden spars. The 39" Metz Labs
stainless loran whip is tempting because of the smaller length.
What do you use on your boat?
Thanks,
Mark
|
| 10.66 | ex | RECYCL::MCBRIDE | | Mon Apr 01 1991 16:38 | 4 |
| We used a stainless whip last season with no apparent problems. Much
lighter thn the glass ones and not as easily broken.
Brian
|
| 10.67 | | MSCSSE::BERENS | Alan Berens | Mon Apr 01 1991 18:10 | 9 |
| re .65:
According to a report in Practical Sailor, the performance of some
lorans is degraded less with a short(er) antenna than others. The 39"
antenna was better than the 52" one. The performance degradation varied
from severe (ie, don't use a short antenna) to minimal (ie, an 8'
antenna is needed only in weak signal areas). We've been using the same
8' fiberglass antenna since 1982. The weight difference is hardly
significant unless you are a fanatical racer.
|
| 10.68 | How about an aircraft antenna? | MUDHWK::LAWLER | I'm not 38. | Tue Apr 02 1991 08:22 | 12 |
|
I don't know if this is feasible for a boat or not, but
have you considered an Aircraft Loran antenna?
They are typically about 15 inches long, and consist of
a fiberglass whip with a pre-amp built into the base.
-al
|
| 10.69 | Weight is no issue | AKOCOA::DJOHNSTON | | Tue Apr 02 1991 10:01 | 10 |
| I'm a fanatical racer, and we have both. The 8' whip goes to the
Trimble and a short metal antenna goes to our Micrologic. The two
lorans read consistently and both suffer from signal loss at about the
same places. For example, Eastern Point off Gloucester is well known
for no wind and no loran signal reception.
Weight is no issue. Breakage is. I recommended putting the whip on
deck angling outward. Since we did that there has been no problem.
Dave
|
| 10.70 | Fold it down. | BOMBE::ALLA | | Tue May 28 1991 11:56 | 9 |
| We use the 8' with our Raytheon 570. It's mounted on the stern pulpit
with a fold down mount.
When docking I can fold it down on the lifeline and breakage is not
such a problem.
Repeatability with this setup is very good in the Buzzards bay area,
however I always maintain a plot with charts, compass, depth sounder,
speedo/log as I've been out when the signal was not available.
|
| 10.71 | Is the 9960 Chain working o.k.? | UNIFIX::BERENS | The Moderator | Mon Jul 06 1992 13:48 | 36 |
| [restored by the Moderator]
================================================================================
<<< $1$DUA14:[NOTES$LIBRARY]SAILING.NOTE;4 >>>
-< SAILING >-
================================================================================
Note 10.71 Lorans 71 of 75
UNIFIX::FRENCH "Bill French 381-1859" 26 lines 15-JUN-1992 09:17
-< Is the 9960 Chain working o.k.? >-
--------------------------------------------------------------------------------
A couple of questions:
1. My loran had been displaying a lot of "No Signal" lately and
either the Northeastern U.S. chain has been completely down
a lot lately or I have an intermittent problem. A couple of times
the signal has come back after I fiddled with the cable entering my
coupler. Has the 9960 chain been working o.k. for others -
like this past weekend, for instance?
2. Can anyone suggest how to check for a dead coupler? my Apelco
DXL 6300 has an active coupler and attempting to connect
anything passive (like a vhf antenna) to the antenna connector
on the loran doesn't allow the loran to come up.
Since it is a few months out of warranty, if I could determine that
it was actually the couipler, it would probably be cheaper just to
buy a new coupler from Apelco rather than sending everything in
for repair to Apelco. Any Ideas?
I have to do something very soon as the boat comes off the lake
and will be sailing the coast of Maine in 3 weeks.
Thanks,
Bill
|
| 10.72 | | UNIFIX::BERENS | The Moderator | Mon Jul 06 1992 13:48 | 13 |
| [restored by the Moderator]
================================================================================
<<< $1$DUA14:[NOTES$LIBRARY]SAILING.NOTE;4 >>>
-< SAILING >-
================================================================================
Note 10.72 Lorans 72 of 75
TOOK::SWIST "Jim Swist LKG2-2/T2 DTN 226-7102" 4 lines 15-JUN-1992 11:11
--------------------------------------------------------------------------------
I have the same Loran and the weekend of Jun 13-14 picked up 9960 in
the Mid-Coast Maine area with no dropouts at all. In fact for a large
part of that time I forgot to ratchet up the antenna and it was working
just great - sideways.
|
| 10.73 | single data point | UNIFIX::BERENS | The Moderator | Mon Jul 06 1992 13:48 | 14 |
| [restored by the Moderator]
================================================================================
<<< $1$DUA14:[NOTES$LIBRARY]SAILING.NOTE;4 >>>
-< SAILING >-
================================================================================
Note 10.73 Lorans 73 of 75
VOX::HTINK 4 lines 15-JUN-1992 11:11
-< single data point >-
--------------------------------------------------------------------------------
My Loran worked fine all day Sunday (6/14) in Boston Harbor,
Henk
|
| 10.74 | | UNIFIX::BERENS | The Moderator | Mon Jul 06 1992 13:49 | 14 |
| [restored by the Moderator]
================================================================================
<<< $1$DUA14:[NOTES$LIBRARY]SAILING.NOTE;4 >>>
-< SAILING >-
================================================================================
Note 10.74 Lorans 74 of 75
DNEAST::POMERLEAU_BO 5 lines 15-JUN-1992 11:26
--------------------------------------------------------------------------------
I also have a 6300, I powered it up for the first time this season in
Belfast Harbor and had a no signal warning. Slave #1 had bad signal. I
powered it down and then up again and it came up fine. There may have
been a problem with one of the stations. That was friday evening, It
worked fine saturday sailing from Belfast to Rockland.
|
| 10.75 | bad ground? | UNIFIX::BERENS | The Moderator | Mon Jul 06 1992 13:49 | 17 |
| [restored by the Moderator]
================================================================================
<<< $1$DUA14:[NOTES$LIBRARY]SAILING.NOTE;4 >>>
-< SAILING >-
================================================================================
Note 10.75 Lorans 75 of 75
EPIK::FINNERTY "The bug stops here" 7 lines 16-JUN-1992 12:53
-< bad ground? >-
--------------------------------------------------------------------------------
re: .71
perhaps your ground (dynaplate, ...) needs cleaning or replacement?
/Jim
|
| 10.76 | I found the problem! | UNIFIX::FRENCH | Bill French 381-1859 | Tue Jul 07 1992 00:12 | 33 |
| I recently had an interesting experience with my loran that I wanted to share.
A few weeks ago, my Apelco DXL6300 stopped working - all it would give is
a continuous "No Signal" display. After talking with a helpful gentleman
at the Apelco repair center in Hudson, N.H. he confirmed my suspicion that
it was most likely either the active antenna coupler or the coax cable.
On the boat, it was dead, at home on a power supply (13.8v) it worked fine.
Back and forth 3 times between home and the boat - the same each time.
Sunday, when I brought the boat home from the lake in preparation for a month
of salt water adventures, I found it was working fine in the driveway off the
boat's battery. I looked for what was different. We had taken down the solar
cell from the stern rail and packed it in a compartment for trailering.
As soon as it got it out of the compartment (still wired to the battery)
the signal-to-noise numbers took a dive into the unusable range. As soon as
I covered the solar cell up, they come back to excellent values.
This was a small 5" "Solargizer" that I had picked up at an auction for $5.
The card it came on indicated that it "conditioned" batteries with a
pulsating current. I should have been suspicious at that point. Anyhow,
with the loran and the Solargizer connected directly to the battery,
there was so much electrical noise that the loran was unusable.
I'm very glad that I did the troubleshooting myself rather than paying
Apelco $159 flat rate to "fix" a problem that didn't exist in the loran.
I'll probably keep the Solargizer, despite its rather meager output current,
but it will definitely have an on-off switch installed very soon.
Bill
|