Garman 4208 loran readings

[Little Chum]

Hi GW enthusiasts,

I am the proud owner of a recently purchased 2004 Marlin with 225 4-stroke Yammys.I have retired-downsized from a 46 Post(great boat)-and moved down to the Rhode Island shore line. I have purchased a Garman 4208 which will be installed in the spring. I would appreciate some information on the following:

I want to use loran numbers as I have many waypoints from my previous boating. A Garman representative mentioned something about"offsets" for my area. Could someone out there please explain this and how to incorporate this with the new set.
Thanks

 

[megabytes]

Well Chum,

I have the same boat and after 5 years it still rocks!

As for offsets, they are specific to an area. The ones we use are set for SE NC and are based on observed variances from land and sea (LORAN waves change due to land and sea terrain). Some units (Northstar) have these preset. Others you must enter the offsets. The best way to handle this is to get the numbers from locals. Once entered, the offsets should be accurate for all your LORAN number conversions.

 

[ocnslr]

The "offsets" are known as Additional Secondary Factors. They are dependent on geographic location, and season of the year.

Brian

 

[Hookup1]

LORAN

I downsized a year ago from a 42 Egg Harbor with a Northstar Loran. I just installed a Garmin 4210. Garmin's manual doesn't show a Loran capability but the unit does support it.

Main Menu>Configure>Unit>Position Format>Loran. You will have to switch the unit over to Loran format, enter your numbers and switch back to LL. If your going to use the offsets you can correct the converted LL numbers.

If you have a big book of good numbers you may want to install a Loran too. Convert the numbers as you go.

FYI - Loran has good accuracy and excellent repeatability. That basicly means your unit can get you back to the same spot over-and-over (repeatability). Those same numbers in a different unit or converted to Lat/Lon are not as precise (accuracy). Once converted your going to need to re-find exact locations with your sounder and save them to your GPS. Offsets can help improve the accuracy. http://www.loran.org/Coordinates.htm

GPS with WAAS and SA off will give you both excellent accuracy and excellent repeatability.

 

[Little Chum]

Garmin 4208

Thanks for the info guy's. I guess I have some homework to do.I hope getting the "offsets" from the locals is not akin to asking them for their favorite fishing hole. If any Capt. from the R.I. - Montauk area wants to respond , Iwould appreciate it. Thanks again.

 

[Curmudgeon]

My experience is that LORAN conversions by GPS units are rather poor accuracy even with local offsets. Conversion formulas may be just too complicated [meaning file size] for most GPS units to deal with. I'm sure there are some that give dead-on accuracy, but I've never seen it even with offsets taken from the LORAN on the console beside it ... :?

 

[gulfcart]

Re: LORAN

Main Menu>Configure>Unit>Position Format>Loran. You will have to switch the unit over to Loran format, enter your numbers and switch back to LL. If your going to use the offsets you can correct the converted LL numbers.

If you have a big book of good numbers you may want to install a Loran too. Convert the numbers as you go.

http://www.loran.org/Coordinates.htm[/url]

GPS with WAAS and SA off will give you both excellent accuracy and excellent repeatability.[/quote]

He's right that is the best way. I have a Furuno Loran C I bought off of Ebay. I also have a new Nav Net xx2 with dual screens. I have anchored at a spot, then taken the difference between the Loran C TD's and The Nav Net TD's and enterd the corrections in the correction screen, Now when I set my NavNet for Loran readout it's right on.

I have also converted many numbers by going to the Lowrance web sight. You can download the simulater for LCS112c.. It works just like it would be in your boat. But you enter the stations for your area and enter all your wayopoints as Loran then go in and tell it to readout in GPS and they all convert. I sat in front of the TV and did over 200 this way. They weren't perfect but very close. Now of course, with the Loran C it's not an issue.

No matter what you still will have to do a little searching. Thats also why I bought a Humminbird side scan...