Furuno GPS to Loran Conversion Problem

[Stone]

My Furuno GP-31 is suppose to convert GPS to Loran-C and vise versa.

As an example, a particular GPS number converted to:

TD1 = 13764.9
TD2 = 30971.6

However, the published Loran-C numbers are:

TD1 = 13776.5
TD2 = 47138.7

As you can see, TD1 is very close, but TD2 is bogus (in my area, all the published TD2 numbers are 47XXX.X).

Is there a Furuno user out there that can give me a clue?

Thanks!

[Spearchucker]

Take this for what it is worth: Conversion softwares suck, they do not work, GPS's with conversion software in them do not work, do not waste your time!!!!!!!!!!!!

Buy yourself a Loran, install it on your boat. Get to the spots for the first time with a Loran, then save it as a GPS number. Slowly but surely, you will convert your numbers one by one.

[Stone]

Originally posted by Spearchucker
Take this for what it is worth: Conversion softwares suck, they do not work, GPS's with conversion software in them do not work, do not waste your time!!!!!!!!!!!!

Buy yourself a Loran, install it on your boat. Get to the spots for the first time with a Loran, then save it as a GPS number. Slowly but surely, you will convert your numbers one by one.

I hear you loud and clear.

I don't care if my Loran numbers are 1000 ft off when converted. I just want to be able to plot them on my GPS maps. Then, when I am diving my GPS numbers, I can see which converted Loran numbers are nearby.

My question is: Why is TD1 so close, and TD2 so wrong?

[Spearchucker]

S2 is picking up the wrong secondary on your GPS. Their should be a manual setting where you can lock it in on the 4XXXXX TD secondary. I have a Raytheon Loran that on auto mode keeps trying to grab the wrong secondaries.

[100days-a-year]

Stone,see if there is a GRI setting when you go to the LOP menu I believe you are still in 7980.As you go to spots switch the machine back and forth between L/C and Lat/Lon making adjustments in the offsets until your machine reads the #s as published in loran.The offsets are OK up to a coupla miles away.It's a very convoluted method,but it's what I do when the loran towers are down.EBAY is much easier,lorans run under $100 all the time.

[Stone]

Originally posted by 100days-a-year
Stone,see if there is a GRI setting when you go to the LOP menu I believe you are still in 7980.As you go to spots switch the machine back and forth between L/C and Lat/Lon making adjustments in the offsets until your machine reads the #s as published in loran.The offsets are OK up to a coupla miles away.It's a very convoluted method,but it's what I do when the loran towers are down.EBAY is much easier,lorans run under $100 all the time.

Tony,

7980 gives me a good conversion on TD1, but a bad TD2 (too bad to use an offset.

I was told on another board that my GPS is using the W and X chain when it should be using the W and Y chain. Since I can load my GPS via my computer, it would be so easy to load my LORAN numbers and information then make corrections. If I can't figure out how to tell my GPS to convert based on the W and Y chain instead of W and X, then I'll have to load all the LORAN numbers by hand and go hunting

I have a LORAN and a bunch of LORAN numbers I have never used. I'm not trying to get an accurate conversion . . . I just wanted to plot the LORAN numbers on my GPS map so I would know what was in the vicinity when diving my GPS numbers. I plan on finding the LORAN numbers with the LORAN, then marking them on the GPS.

[100days-a-year]

Stone,I'm using Andren,Ozi and Excel with an L&H voice recogition program to move everything around into areas.The offsets in the ASF file on Andren get me close.Micrologic gets me on the spot.Sounds like you've got it well under control.

[Denny]

Stone-
Your proper GRI setting is 7980 W Y. You are using a slave station that does not provide for a decent angle of crossing. Ideal angle is 90 degrees (perpendicular to each other).
If you would like, I'll copy and email the LORAN conversion setup info fFOm OFFSHORE HUNTER. You can set up your GPS for the correct stations in your navigation setup page or system setup page in your GPS.
This is also why your conversion doesn't work. I have had alot of success with my conversion program. Converting and finding middle grounds numbers tells me this.
Denny

[Stone]

Denny,

Thanks for the input. Any info you send me would be appreciated.

[Stone]

Finally got the right chain dialed in. My TD setup screen doesn't mention X, Y, and W, but there were a series of number sets that I found out I could scroll through, for example: 11-23, 11-47, 11-59. The second number set gave me the TD2 I needed.

Now it's just a matter of loading up the machine with numbers and finding all the secret honey-holes.

[100days-a-year]

Good deal,I had faith in you.Being able to load areas into your machine with a mouseclick is nice.I know you'all have a lot of stuff over there to keep track of.My next GPS will have a bigger memory so I can load in more areas.My files run around 10x10 miles before they get to big to load onto my GP35.It only holds 350.Yours should get 1000.I think Garmin has some that'll hold 3k.If I plan on fishing 2 areas I have to bring printouts.Last week I went thru almost 20 at NM before finding an unoccupied spot.