Question about replacing Raymarine L760 with Garmin

[ZZ13]

I have 2001 state of the art electronics. It includes a Raymarine RL80C chartplotter/radar and a Raymarine L760 Fishfinder with its own dedicated sounder that gives the fishies, depth and water temp. I rarely use radar so I plan to just keep the RL80C for that and as backup chartplotting, but I want to replace the Raymarine L760 fishfinder with the largest Garmin plotter/fishfinder that will fit in 10"x10" footprint where the L760 is now. My plan is to use the Garmin for chartplotting and fishfinding.

So, can I make this easy? Here's what I am hoping I can do:

Buy the Garmin unit and associated sounder
Remove L760 and mount Garmin in its place
Connect Garmin to power and use its internal GPS antenna (no plans to put another GPS antenna on the arch for this)
Remove Raymarine sounder and install Garmin sounder in its place (I suspect this is the hard part)
Use the existing sounder wires to connect the Garmin sounder to the Garmin unit (do whatever splicing is needed)

Can I make it this easy or is the sounder replacement going to require professionals?

 

[rondds]

Bill
Kinda like what I did. I didn't replace my sounder though. I will stick with the TriData b/c I'd have to replace the transducer for the Garmin. The new transducer (if you go that route) will become part of the NMEA2000 network. Very easy to set up.

Not sure what it entails to set up the new transducer. Can you remove the old and put in the new? Not sure. Just arbitrarily drilling a hole somewhere in the bottom is a bad idea b/c your boat has a cored bottom. SR glasses in some sort of reinforcement pieces around all through-hulls.

Here's the boring story of my setup...
http://clubsearay.com/showthread.ph...splay-with-Engine-Data-to-the-helm?highlight=

 

[ZZ13]

Thanks. I actually have a l760 sounder separate from the tridata transducer. The l760 sounder is mounted in a solid spot in the hull just below the starboard transmission. The tridata transducer is forward up in the forward sump area. My hope is to pull out the L760 sounder and put the Garmin sounder in its place. I just have no idea how/if this would be done.

 

[rondds]

I'd be curious to know how that works out for you. If it's a direct replacement that would be great... but that would be WAYYY too easy. You might also be able to get the tridata to talk to the new Garmin display. TriData is either SeaTalk or NMEA 0183 and your new Garmin should have a port for 0183. Not sure if that would give you fishfinder capabilities. Best bet is a new transducer for sure.

 

[ZZ13]

How's the 740 screen size working out?

Guess I'll give BOE Marine a call about my sounder question. I am hoping for a miracle that they all use a standard thread size and I can screw out the old and screw in the new.

I have a Garmin 441s on the 175 Sport and love it, so that's why I am set on a larger screen version of it to put on the 400DB

 

[rondds]

I haven't really even used it yet so I can't comment on whether I love it or hate it yet. Only ran the boat from the sling to the slip. It's definitely not as versatile as larger screens would be. Limited # of fields to populate with engine data but I'll manage. I had a Garmin 492 on my previous boat and loved it. Intuitive and easy to use. And no proprietary SeaTalk stuff - if it's NMEA2000 compatible, you can connect it to the Garmin.

 

[kaz911]

Double splicing old transducer cable is a bad idea sorry. And for modern transducers you need 6-8 wires dependent on the transducer you select. Airmar does sell "Splicing boxes" but does say maximum 1 splice on a cable as rule of thumb.

Garmin 740 (or better the 741xs) can only be used with internal GPS antenna - or GPS antenna "Puck". They wont listen to NMEA 2000 GPS senders. Dependent on where you want to place it - that might be a consideration.

Which transducer is your old one? It is not too bad to remove the old one and then put in a new. Even if you need a larger hole that is also possible to do.

But lets reverse a bit

What depths are you fishfinding in? So what depths are your targets? That has a huge impact on the transducer selection. From you old L system until now - the world has changed a few times. So from your system (Old style analogue) -> Digital -> Broadband Digital -> Now Chirp.

Chirp is the latests most efficient transducers available. The Garmin 741xs has a "baby chirp" built in. Baby-Chirp usually means a Chirp limited to "one" frequency band. (So no longer 50/200 kHz - but either around 30-60 kHz or around 155-235 kHz dependent on the Chirp transducer). The Garmin 741xs also has normal "Digital Broadband'ish" 50/200 sounder built in. The modern transducers also have a ID chip inside - which then requires more wires in the cable. But takes the guesswork out of transducer settings as the transducer tells the sounder who it is.

So the higher the frequency - the smaller the depth range - but the better the resolution A bit like comparing a VGA screen with a WXGA screen.

And regarding your old "Triducer" - find the part number so we can find out what is needed to put it on a NEW MFD.. And if it was me - I would convert it to NMEA 2000 with a Actisense NGW-1 - and start building on your NMEA 2000 network to get rid of the 1:1 ish NMEA 0183 network.

 

[rondds]

Good info Kaz. Not sure if you were addresing me, or Bill, or both. But for me...

I don't fish and could care less about finding fish or the topography of the bottom. If I replace my TriData transducer it will render the TriData display useless. I'd rather leave things as they are. The depth shows on the big old RL80c off to the left and on the TriData display,which is right in front of my face. For me, it's not necessary to have depth appear onthe Garmin, esp since I'd rather use that the extra data box for engine data.

If my RL80c takes a dump, I'm in big trouble. I'd have to replace the array AND stick something in that humongous hole in the dash!

 

[ZZ13]

Yes, thanks Kaz.

I am perfectly fine with the internal GPS antenna. That is what I prefer.

I have no need for an NMEA2000 setup. My engines are pure mechanical. So I would never put engine data on it. And I only need one NMEA0183 output to feed the GPS for DSC. My desire is for this unit/sounder combo to be completely standalone.

I think my sounder that I want to replace is the B744V, but not sure how to verify that.

My tridata is useless to me. It only provides me with depth. It's temp sensor isn't accurate and speed always reads 0. I get depth and water from the L760 and it's sounder. And I use SOG from the chart plotter.

 

[ZZ13]

Good info Kaz. Not sure if you were addresing me, or Bill, or both. But for me...

I don't fish and could care less about finding fish or the topography of the bottom. If I replace my TriData transducer it will render the TriData display useless. I'd rather leave things as they are. The depth shows on the big old RL80c off to the left and on the TriData display,which is right in front of my face. For me, it's not necessary to have depth appear onthe Garmin, esp since I'd rather use that the extra data box for engine data.

If my RL80c takes a dump, I'm in big trouble. I'd have to replace the array AND stick something in that humongous hole in the dash!

Unfortunately I don't have the PLUS system with the faster processor. So my RL80 redraws kinda slow and doesn't do radar overlay. If I had the PLUS, like I did on my 300DA, I would happily use this system until it broke down. I priced a few used PLUS systems to just do a drop on replace of the RL80, but the bundled the radar unit and all want outrageous prices for 10-12 year old worn down units.

 

[rondds]

Do you have Raytheon stuff (before they sold off the marine division)? That's what I have. Yeah it is SLOWWW to pan and to redraw. The boat icon practically runs off the end of the earth before you get a new screen. I have to keep hitting "FIND SHIP." But for a zoomed out view it's fine. I'll keep the Garmin zoomed in for greater detail and the Ray zoomed out to 3nm.

As for RADAR/Plotter overlay, I'd rather have two different displays for that. Just personal preference, though I understand the allure of overlay.

 

[kaz911]

Yes, thanks Kaz.

I am perfectly fine with the internal GPS antenna. That is what I prefer.

I have no need for an NMEA2000 setup. My engines are pure mechanical. So I would never put engine data on it. And I only need one NMEA0183 output to feed the GPS for DSC. My desire is for this unit/sounder combo to be completely standalone.

I think my sounder that I want to replace is the B744V, but not sure how to verify that.

My tridata is useless to me. It only provides me with depth. It's temp sensor isn't accurate and speed always reads 0. I get depth and water from the L760 and it's sounder. And I use SOG from the chart plotter.

The B744V is also a tri-data transducer. It kind of a B60 (600w 50/200 kHz) with paddle wheel. Main hole is 2" and there are quite a few transducers with 2" holes.

But you might want to stay with a transducer with Fairing - since on bigger boats - transducer might have to stick out more than 2" to escape the boundary layer at higher speeds else you might loose bottom reading.

 

[ZZ13]

I checked the boat thoroughly. I have three in-hull transducers. The first two have one wire each coming out of them and are in the forward bilge area. One provides depth to the ST-60 Tridata unit. The other single wire in-hull is the paddle wheel for the ST-60 Tridata unit and is supposed to provide temp as well. It doesn't appear to be working. The third in-hull has two wires coming out of it and provides depth/fish data and sea temp to the L760 fish finder. According to the manual it is a B44-TH and is supposed to also have a paddle wheel on it

 

[kaz911]

I checked the boat thoroughly. I have three in-hull transducers. The first two have one wire each coming out of them and are in the forward bilge area. One provides depth to the ST-60 Tridata unit. The other single wire in-hull is the paddle wheel for the ST-60 Tridata unit and is supposed to provide temp as well. It doesn't appear to be working. The third in-hull has two wires coming out of it and provides depth/fish data and sea temp to the L760 fish finder. According to the manual it is a B44-TH and is supposed to also have a paddle wheel on it

Ok B44-TH is the "prior" version of the B744l

You can get "updated" replacement sensors for it (maybe) - might also find some for your ST-60 instruments...

http://faq.airmar.com/index.php?action=artikel&cat=1&id=177&artlang=en

But since the B44-TH is Raymarine - I think it will not like your Garmin.... as Raymarine usually are slightly "on their own" with Transducer cabling. (They use different impedance than everybody else)

But if it was me I would consider what to do with all the holes in my boat. The paddle wheels are not very efficient on big boats due to the boundary layers (only works reasonable at low speed or with 2"+ fairing) - and the tri-data stuff is old.

And if the Tri-Data depth sensor is running 200 kHz which many of the older depth sensors do - it will interfere with your fish finder that ALSO runs on 200 kHz (and 50 kHz) - so maybe just put blanking plugs in your tridata things and disconnect them.

But you have so many choices so better you tell us how your dream system works *G* - but the only thing that is certain - get a transducer with fairing for the Garmin. The easy way out is to get new B744L...

 

[ZZ13]

That's great advice Kaz. Thank you very much.

 

[ZZ13]

But you have so many choices so better you tell us how your dream system works *G* - but the only thing that is certain - get a transducer with fairing for the Garmin. The easy way out is to get new B744L...

To be honest Kaz, I really like the L760. It works great. My real preference is to rip out the RayNav300 GPS unit/passive antenna and the ST-60 Tridata. Then add a modern 8" Chartplotter (Garmin 740 or Simrad
NSS8) to provide faster and more detailed chartplotting, and use it to feed GPS data to the RL80C via Nmea0183. I could easily do this wiring at the helm myself and I am not then messing with transducers. Then, in the future I'd replace the Rl80 and radar transmitter with a larger screen MFD and transmitter from the same manufacturer as the 8" plotter I'd buy now.

Since you asked, that's really my preference. I didn't put that in my original post because I just thought it out. Ha!

 

[magstang1]

For what it's worth, I replaced all my old Raytheon stuff with a Garmin 740s and GMI 10 and I was able to reuse my old transducer. Airmar has all the schematics on their website. I did have to repin the connector but it works just fine.

 

[kaz911]

To be honest Kaz, I really like the L760. It works great. My real preference is to rip out the RayNav300 GPS unit/passive antenna and the ST-60 Tridata. Then add a modern 8" Chartplotter (Garmin 740 or Simrad
NSS8) to provide faster and more detailed chartplotting, and use it to feed GPS data to the RL80C via Nmea0183. I could easily do this wiring at the helm myself and I am not then messing with transducers. Then, in the future I'd replace the Rl80 and radar transmitter with a larger screen MFD and transmitter from the same manufacturer as the 8" plotter I'd buy now.

Since you asked, that's really my preference. I didn't put that in my original post because I just thought it out. Ha!

Okay - so "RESET" button pressed.

My favourite is Simrad NSS. But check the new NSS Evo2 9". Simrad is better than Garmin for Radar (for the future)

You get one box with everything embedded (Normal Sounder, Chirp Sounder, Structure Scan - and soon Forward Scan so you can check depths in front of you) - and fabulous speed - much faster then the Garmin 740/741. I have 2 NSS Evo2 12" on order. as they won't hit the market for another month or so. The 7" and 9" NSS Evo2's are shipping now.

But in reality - Garmin and Simrad are rather equal in quality and performance. Garmin uses Garmin maps - Simrad uses their own, Navionics and CMAP and a few more. So I would let the charts help you decide which way you go. I prefer Simrad - but do have both a Garmin 8008 and 741xs for tests