How do I utilize best bottom imaging from factory Garmins?

[Jersey Jim]

About to pull the trigger next week on a 2120 SC, before the 2017 price increases. In addition to several useful options, such as 2nd helm station, free fall windlass, 200 hp, etc., the navigation/sonar package is particularly important to me as a diver needing the best image detail of wrecks and structure on the bottom. I have decided to upgrade from the 741XS to the Garmin 840XS. They both seem to have the same capabilities such as "DownVue" & "SideVue". I don't pretend to know a lot about those features, but need to know if the factory installed transducer will need to be upgraded to take advantage of these enhanced imaging capabilities. My last boat had the Garmin 741 but I only used a basic Airmar transducer, and only experienced basic FF/Depth performance and did not get the imaging that I will be needing. I have always liked Garmin products, and I know there is much better out there, but the factory choices are limited. Please explain to me the enhanced performance of the Garmin units, and what it takes to utilize them. The available factory options for the 2120 SC seem to be Garmin GPS MAP 741XS, 840XS, and 7608XSV, all with a B60 thru-hull transducer. Will the factory install any transducer I need to utilize the optional features? Do they have factory experts that know what to recommend? And how difficult is it to change a TH transducer if delivered without the optimum model? Are they epoxied in place, etc.

Sorry for so many questions, but only have a week to get it right and don't want to make mistakes.

Regards, Jim

 

[warthog5]

all with a B60 thru-hull transducer.

That's a 600watt unit. It's a good unit, I've installed many of them. I've also installed many 1000 watt units.

It's my contention that what your looking at is a little over entry level stuff.

Ya gotta spend more money to get more power and bigger screen. More Power equals more detail.

Your diving, so I'd guess your staying in the 100ft mark for depth?

Why do you want a "factory" option?

Installing a thru hull is a no brainer for some....and a nightmare for others. I have no problem boring a 3 3/4in hole thru the bottom of your new boat..... But I've fixed'em where a dealer screwed one up big time before. Had to fix the hole and put another hole in the boat in the proper place to make the unit work correctly.


If I had to pick a "Factory" unit...... It would be the 7608XSV. Still a little small.

But that is a Chirp unit.. It needs a 1000watt Chirp X-ducer. Ideally you would have a low & high X-ducer..... But with you diving and the depths your looking at, you want the high one.
http://www.airmar.com/productdescription.html?id=46

That X-ducer is $850 to $1000 depending on where you buy it + install.

 

[Jersey Jim]

Thank you for all the good info, and taking the time to address my concerns. I did learn this morning, that the 7608XSV Garmin unit "does" have 2 independent transducer ports. I upgraded to this 7608, and am allowing Parker to do the standard Thru-hull B60 ducer, and also will be adding a Garmin GT30-TM transom-mount torpedo style transducer for side-vue and Down-vue features. Ducer was only $199. Touch screen can toggle between the 2 sonar inputs. Local marine electronics guy says this is what I need. Hope so, cuz starting to put things in motion.
Thank you for all your input. Was hoping to do everything "thru-hull", but still want the option to trailer without all the deeply protruding torpedo-shaped transducers. Hope I got it right. :shock:

Jim

 

[warthog5]

The X-ducer is Key.... By not going full tilt with the 1000watt unit , your handicapping yourself.

Will it work? Sure....but it Will be better with the 1000watt unit.

Also......That is a Garmin CHIRP unit. You do not want a B-60. A B60 is set for 200Hz. high freq and 50Hz Low freq.

Your going to want a B75H

http://www.airmar.com/productdescription.html?id=52

It's the same physical size as a B-60, but it's designed for broad spectrum CHIRP.

You need to Read and understand what your buying , by getting into the manual now.

Specifically page 17 on the Pantpoix view.... That takes a special X-ducer.... I have never messed with them yet.

http://static.garmin.com/pumac/GPSMAP_7 ... _EN-US.pdf

But on page 21

2
Select an option:
• If you have a 200/77 kHz, dual-beam transducer, select
Dual Beam (200/77 kHz)
.
• If you have a 200/50 kHz, dual-frequency transducer,
select
Dual Frequency (200/50 kHz)
.
• If you have another type of transducer, select it from the
list.

So the B-60 will work, but again your handicapping your unit, as a B-60 is not CHIRP.

Read up on CHIRP to understand that.

And YOU thought this was going to be Easy...... LOL

 

[Jersey Jim]

Warthog5, thanks again for valuable insight. Decided to upgrade again to 7610xsv, since it's my understanding that both the 7608xsv & 7610xsv both have dual transducer input ports. Please specify which transducer you are referring to when advising me to bump up a notch. The vital transducer in my opinion is the GT30-TM for side-vue & down-vue. I figured the stock supplied B60 thru-hull would just be good for depth reading at full speed, and a back-up in the event the transom mount side-scan crapped out. Maybe you can answer this for me... in addition to good imaging, will the GT30-TM function for depth too... just not good for higher speeds? Question #2, if Parker agrees to install a B75TH, will it be same amount of connector pins? Question 3: how many pins are 7610xsv transducer sockets? the side/bottom scan xducer is a 12-pin, & not sure how many pins B60/75 is. Things are moving fast, and have already had dealer contact factory twice with additional upgrades since placing order Tuesday, mostly in the area of electronics. BTW, factory will not install the GT30 transom-mount xducer, so will have that done locally.
Oh, and lastly, which B75? They have B75L, B75M, B75H. of course this would have to be their 20 degree xducers, as the 2120 SC has 21 degree deadrise.

thanks, Jim

 

[warthog5]

I don't know all those pin deals without studying the Manual.

I suggest above the B-75H. It's physically that same size as the B-60.

Here is the list of thruhulls for that unit.

https://buy.garmin.com/en-US/US/prod169208.html

Here's the list of transom mounts.

https://buy.garmin.com/en-US/US/prod169208.html

I'm pretty sure the unit does NOT have 2 inputs for X-ducers.

There is only one pix I can find of the back of it and it's fuzzy when you zoom in.
It does NOT show that back panel in any of the manuals that I have looked at, which is weird.

Those 2 ports you see that are the same and look like a RJ45 connector are for Networking.... Not for 2 X-ducers.

 

[Jersey Jim]

Here is a better pic.This is a rear connector pic of the units when they first came out 4 years or so ago. The yellow (12-pin) and blue (8-pin) are the 2 direct connect transducer inputs. I saw other similar models with the connectors rearranged slightly, but transducer connector colors were same.

 

[warthog5]

10-4 I bet the 8 pin is for the B-60 and the 12 pin is for the CHIRP X-ducers.

After that....I don't have any knowledge.... But "IF" they are operated at the same time....on the same freq....there will be interference.

I'm betting you select 1 or the other.....and can't select both.

 

[Jersey Jim]

.... But "IF" they are operated at the same time....on the same freq....there will be interference.

I'm betting you select 1 or the other.....and can't select both.

That makes sense. OK, Here's where I'm at so far after reviewing more of the airmar & Garmin links you posted....
I've decided to have the factory leave out the thru-hull, since I'm forced to use the transom-mount specialized transducer for side-scan anyway. I need to pick your brain a little more.
1: On the 3-in-1, or "all-in-one" transom transducers that can utilize the CHIRP, Downview & Sideview features, how many options of this style are there for me to choose? I will be using this sonar for shallow 30-120' bottom imaging, if that helps in selecting a transducer.
2: I am waiting to hear back from dealer/Parker on whether or not they will install a 7610xsv on my 2120SC with new style slanted helm. Looks like more than enough room. My question #2 is, have you heard of or seen any 2120s with a 7610 flush-mounted? The factory only list 741xs, 840xs & 7608xsv options.
3: Do you think the factory will leave out the thru-hull for my local marine electronics guy to choose the correct one, if I even decide to add one some day? They refuse to install the B75H or anything different than the B60TH.

These sonar features are the most practical on a boat in my opinion, and at almost 10% of the boat's total cost, I want to get things right the first time.

thanks again for all of your help,
Jim

 

[warthog5]

They refuse to install the B75H or anything different than the B60TH.

That's because they are uneducated. This is why if your happy with what they offer...Then fine, but I wouldn't be.

Click this link and then click accessories, then X-ducers.... Then start reading.
https://buy.garmin.com/en-US/US/prod169208.html

On #1 The one they picked is a good one to go with, but this is what I'd choose if it was mine.

https://buy.garmin.com/en-US/US/prod169208.html

I've never even seen the model boat you have let alone a electronics install in one.

The 741XS in my opinion is 1] to small and is just above entry level electronics... It's not bad, but I wouldn't want it.

Now on the other hand this unit your looking at, has Sooooo much on it that I dought you will ever come close to using it all.


Your kinda now getting a education as to why you don't have the factory or the dealer install electronics and you use a professional electronics's installer or someone like me that eats this stuff up and is anal in his work.

If the manufacture or dealer installs it... You can group it in the purchase price.... Going to someone like me..... Bring CASH!

The downside is Manufacture and dealer do not keep abreast of the latest things and educate themselves.

 

[Jersey Jim]

Warthog5, the model you suggested in your last link is the model I was inquiring about in my question #2 of my last post, and is my first choice.
However, the factory informed my dealer that they were unsure if it would fit & that the 7608xsv is the biggest they will install.
Knowing my type of boating depths, (30-120' FSW), would you be able to suggest an "all-in-one" transom mount that has good CHIRP performance, angles, etc., in addition to the sidevue/Downvue scanning functions?

Before omitting the factory thru-hull installation, I was leaning toward the side-scan transom-mount GT30-TM by Garmin. Now I am looking for all 3 functions in one transom-mount, since I am forced to live with that type of transom transducer.
That is my only question for this post. Hopefully I will be winding down on my "learning curve" soon.

 

[warthog5]

Your asking about a transom mount and the GT30-TM is a transom mount that makes that unit full function.....

What am I missing?

 

[Jersey Jim]

Your asking about a transom mount and the GT30-TM is a transom mount that makes that unit full function.....

What am I missing?

Missing the fact that I mentioned "Before omitting the factory thru-hull "traditional" B60, I was leaning toward the GT30-TM.

According to the selection guide, GT30-TM leaves out "traditional mode", but does only both side & bottom scan, but at least in CHIRP mode. If I must use a transom-mount in order to trailer the boat on occasion, I may as well eliminate the useless "non-CHIRP" thru-hull for traditional FF mode, from the factory.

Upon closer study, it looks like the "All-in-One" transom series that uses CHIRP for all 3 modes, narrows down the choices to the GT50 & GT51 series. It is now just a matter of narrowing down which frequency range to go with. From what I'm learning in this crash course, is that the higher frequency models in those 2 series will give me the best detail, especially at the shallow depths I use (<100 FSW). I almost have this pinned down. Please keep the good info & tips coming. Jim

 

[warthog5]

If I must use a transom-mount in order to trailer the boat on occasion,

Trailing a boat has no bearing on having or not having a thruhull X-ducer.

Here's the thing about CHIRP.....It scans a broader freq in the water to get a better resolution than just a single freq.

So while the single freq's have been used a long time, CHIRP makes them "kinda" obsolete.....Notice I said "Kinda" More like redundant and not necessary.

As a example......You would use the high freq. for the depths your interested in to give you the best resolution. That would be 200Hz freq. in traditional.

But the CHIRP looks @ a wider freq....say 210 to 160 for high freq.

Now your not going to see that in your selection of transom mounts that are offered there.

For what YOU want to do.....The GT40TM is what I would pick.

The 50 is a plastic version of the 51....Note that that is a med freq on the down Vue.....Not a High freq.

I do not understand what you are saying as having

for all 3 modes,

?

They has 2 modes.....Down Vue & Side Vue.......Whats the 3rd?

 

[Jersey Jim]

.....Down Vue & Side Vue.......Whats the 3rd?

Thanks for input again. The 3rd mode I mentioned that I need in CHIRP also, is traditional mode. The GT40-TM only does CHIRP on the DownVu & SideVu modes. It's traditional mode utilizes 2 selectable FIXED frequencies of 77/200 khz.

On the other hand, the GT50M-TM does SideVU, DownVu & traditional, all 3 sweep frequencies in CHIRP mode. I'm just trying to decide on the GT50 or GT51. The two I just mentioned have the same sweep in traditional (80-160 kHz), but the GT50M-TM has selectable 455/800 KHz CHIRP ranges for scanning, where the GT51M-TM has 260/455 KHz Chirp ranges for scanning.

I cant find definitive info on what "shallow depth" is considered in the high frequency chirp 800 kHz (790-850) side/down mode. I'm thinking the GT50M-TM is more optimized for the 100 feet and shallower performance I will need.

Can anyone chime in who uses side & down scan with 800 khz? It yields clearer images at the shallower depths than the 455 kHz (425-485) & 260 kHz (245-275), I just don't know how shallow that is. Could always switch down to the 455 kHz range if 100 feet is too deep for the 800. Would love to hear first hand user feedback.

Tnx