Author Topic: Adding a 2nd temp sensor to measure subsurface temp (Read 26227 times)

ajelstein · « **on:** February 07, 2012, 03:40:39 PM »

Is it possible for me to add a temperature probe (Humminbird item TG-W) to my 898c (in addition to the temp sensor in the transducer)? I intend to weight the temp probe and drop it overboard to various depths to get the subsurface temp. I wouldn't need to keep the second sensor connected all the time. Is there another item made for this purpose?

Thanks in advance for any info or suggestions offered.

sonar2000 · « **Reply #1 on:** February 07, 2012, 03:50:49 PM »

You could certainly do that.
Grab a temp probe sensor and connect to your unit in the temp/speed connector....
It comes with a 20' cable I think...
Chuck

ajelstein · « **Reply #2 on:** February 07, 2012, 04:00:53 PM »

Thanks Chuck, Do you know if the unit be able to display the output from both temp sensors concurrently on the same screen or is there some way for me to select between the two?

sonar2000 · « **Reply #3 on:** February 07, 2012, 04:06:27 PM »

AJ, let me check on that...
Chuck

sonar2000 · « **Reply #4 on:** February 07, 2012, 04:11:26 PM »

AJ, go into your advanced mode and select readout. you can have the temp, the one on the transducer and the aux temp, the probe you want to purchase and hook up......
Remember you can only have 5 readouts at a time on the screen.
Do you have the manual for the 898.
This is on the readout page..
Chuck

ajelstein · « **Reply #5 on:** February 07, 2012, 04:36:52 PM »

I know how to change the readouts but I was not aware of the Aux temp field. Thanks allot for all your help on this.

Regards,

Andy

xSilmarilSx · « **Reply #6 on:** February 08, 2012, 03:02:35 AM »

It works, I have one on the 778C.

Very useful. But for 2012, I will extend the temp sensor cable to 50ft-70ft.
Since you have only 15ft of usable depth with the supplied cable.

I have a small weight on the end of the cable and you can track the depth with
the sonar in real time. Only drawback, you need to be almost still speed wise or
the sensor will be too far behind for the sonar to track it's depth.

ajelstein · « **Reply #7 on:** February 08, 2012, 01:14:23 PM »

xS, Thanks for the confirmation. I was thinking of lengthening the wire myself...do you know if there are any special tricks to splicing in an extension?

Should it be done in the middle or at one of the ends? What is the maximum length that can be achieved before signal is too weak (assuming quality splices)?

Thanks,

Andy

xSilmarilSx · « **Reply #8 on:** February 08, 2012, 01:20:14 PM »

Since a temp sensor is only a variable resistor, the only thing to watch, is to use a quality marine cable and to be sure that your connection is waterproof. Any change in the resistance of the cable will change the value. But a great thing, is even if the lengthening of the cable change the temperature value, you can recalibrate the temp sensor with the offset in the unit.

You just put your transducer and your aux temp sensor near each other, with a standard thermometer and verify each for accuracy and make the change necessary.

For splicing, I will do it around 2 feet after the main unit. And will put a connector there because my kit is portable, and not always practical to lug around 50ft+ of cable when I will not use the aux temp.

xSilmarilSx · « **Reply #9 on:** February 08, 2012, 01:22:48 PM »

For maximum length possible, the bigger the cable, the longer you can go.

I would venture to say that a good 18/2 Marine cable should extend your temp sensor to 300 ft without any problems..

sonar2000 · « **Reply #10 on:** February 08, 2012, 01:25:14 PM »

http://forums.sideimagingsoft.com/index.php?topic=711.msg3241#msg3241

Andy, here is a link in the forum that Jolly Roger did awhile back and shows soldering and splicing.
Maybe this will help also..

Chuck

Bob B · « **Reply #11 on:** February 08, 2012, 05:21:42 PM »

Quote from: xSilmarilSx on February 08, 2012, 01:20:14 PM

Since a temp sensor is only a variable resistor, the only thing to watch, is to use a quality marine cable and to be sure that your connection is waterproof. Any change in the resistance of the cable will change the value. But a great thing, is even if the lengthening of the cable change the temperature value, you can recalibrate the temp sensor with the offset in the unit.

You just put your transducer and your aux temp sensor near each other, with a standard thermometer and verify each for accuracy and make the change necessary.

For splicing, I will do it around 2 feet after the main unit. And will put a connector there because my kit is portable, and not always practical to lug around 50ft+ of cable when I will not use the aux temp.

Great info.
Increasing the wire length will cause the temperature to read higher. How much it increases depends on what type RTD sensor it is....but the ability to calibrate will correct this induced error.
Greg, do you know what type sensor this is....PT1000, thermocouple, etc.

FuzzyGrub · « **Reply #12 on:** February 08, 2012, 06:18:54 PM »

On my 798 I thought I lost Aux Temp when I loaded the S/W version that had the first ethernet update. I think it was the release just prior to 5.840, which I haven't loaded yet. I thought they dropped support for it when they changed the connector? I would be happy to hear that its back.

Roddy · « **Reply #13 on:** February 08, 2012, 10:34:16 PM »

AJ, I use a 1198 setup on one of my rov's with 511 feet of CAT8 cable this works well. Finding the thermocline/inversion layer is helpfull in SI/DI and SS use and fishing.

Roddy

xSilmarilSx · « **Reply #14 on:** February 09, 2012, 02:47:54 AM »

From what I could find on the net, the new 798cSI HD can't have the TG W option since the connector is now used by the Ethernet.

sonar2000 · « **Reply #15 on:** February 09, 2012, 07:45:45 AM »

Now that would not be nice...Unless they come up with an ethernet probe. $:-\$
How in the world are we supposed to keep up with all these background changes...

Chuck

ajelstein · « **Reply #16 on:** February 09, 2012, 10:54:55 AM »

Thanks allot for all the info guys, you have all been very generous with your time and knowledge.

Best regards,

Andy

xSilmarilSx · « **Reply #17 on:** February 09, 2012, 12:29:20 PM »

I suppose HB prefer the Ethernet option than the TG W, which not many people might be using it.
It's one of these minor things that bother me since I'm looking toward a 798.

FuzzyGrub · « **Reply #18 on:** February 09, 2012, 05:32:07 PM »

Yea, but the paddlewheel speed, which is on the same connector, still works. I am hoping it was just a legacy product over-look on the S/W release.

xSilmarilSx · « **Reply #19 on:** February 10, 2012, 03:18:11 AM »

The paddle wheel and the temp sensor work with the 1st gen 798c SI

Not with the 2nd gen 798c SI HD.

The ethernet connector is not the same.
I asked Greg last year about it.. It said that maybe they will provide an adapter, but as of today, you can't plug the TG W into the Ethernet port.

FuzzyGrub · « **Reply #20 on:** February 10, 2012, 05:53:36 AM »

Just to be clear, I have a 1st gen 798 that use to work fine with aux temp and paddlewheel. Once I installed a version of the s/w that included the ethernet code, I lost the aux temp.

sonar2000 · « **Reply #21 on:** February 10, 2012, 08:18:11 AM »

Hmmmm, Left hand and Right hand not talking to each other..
Must be two different departments making decisions..
Wonder why no caution was issued for the older units on the upgrade.
Chuck

Humminbird_Greg · « **Reply #22 on:** February 10, 2012, 08:44:49 AM »

Quote from: FuzzyGrub on February 10, 2012, 05:53:36 AM

Just to be clear, I have a 1st gen 798 that use to work fine with aux temp and paddlewheel. Once I installed a version of the s/w that included the ethernet code, I lost the aux temp.

Fuzzy,
I’m a little confused here… How did you install the Ethernet software into your 1st Gen 798 unit?
Check your unit again. The Auxiliary Temp was not removed from the 798 units (any of them). Try resetting the unit back to its factory defaults and see if that helps.

Humminbird_Greg · « **Reply #23 on:** February 10, 2012, 08:50:51 AM »

Guys,
We have accessories for using temperature or a paddlewheel with the 700 series units that have the Ethernet connector (700E series):

The AS-SW-Y cable is used on the 700E units if you want to use a paddlewheel.

The AS-T-Y cable is used on 700E units if you want temperature or temperature and paddlewheel speed.

I really appreciate the faith and support that some of you demonstrate for Humminbird…

sonar2000 · « **Reply #24 on:** February 10, 2012, 08:55:03 AM »

Greg, we have faith in HB but get confused on changes.
Question, did the temp/wheel connector on the older units change for the new units and now we need an adapter cable...
Depending on whether we want ethernet or temp?
Just trying to get the picture in my head..

Chuck

Humminbird_Greg · « **Reply #25 on:** February 10, 2012, 09:19:52 AM »

Yes Chuck. See my post above.

Here are a few drawings of the new cables.

sonar2000 · « **Reply #26 on:** February 10, 2012, 09:31:19 AM »

This is good...
Thanks for the pictures. They are great....
Should we add this to the gallery section.....
Or maybe in the FAQ's....
Pictures are great..

Thanks, Chuck

xSilmarilSx · « **Reply #27 on:** February 10, 2012, 12:17:55 PM »

With the AS-T-Y cable, is the temp sensor bypass the transducer sensor, or we still have 2 values to play with in the unit?

sonar2000 · « **Reply #28 on:** February 10, 2012, 01:10:22 PM »

Another question:
Are there two manuals for the 798?
One pre ethernet and one post ethernet?

?
Chuck

Humminbird_Greg · « **Reply #29 on:** February 10, 2012, 04:42:34 PM »

The AS-T-Y cable will add auxiliary temp to the 700E series units.

There are two different manuals for the 798: one for the non-Ethernet models and one for the Ethernet models. The one off of the 798ci HD Si product page is for the Ethernet version. I did not check the manual download page on the Humminbird web site to see if they had the other version available but I do know it is available through the downloads section of this web site as I saw it earlier today.

sonar2000 · « **Reply #30 on:** February 10, 2012, 06:15:59 PM »

OK, thanks,
chuck

FuzzyGrub · « **Reply #31 on:** February 10, 2012, 07:59:25 PM »

Quote from: Humminbird_Greg on February 10, 2012, 08:44:49 AM

Fuzzy,
I’m a little confused here… How did you install the Ethernet software into your 1st Gen 798 unit?
Check your unit again. The Auxiliary Temp was not removed from the 798 units (any of them). Try resetting the unit back to its factory defaults and see if that helps.

Greg,

Here is where I reported having the problem: http://forums.sideimagingsoft.com/index.php?topic=2431.msg13474#msg13474

It is too cold to check on the boat, but hooked up a temp/speed to my portable. Plugged in the 798, powered on and went to the main 2D screen. Main temp was displayed. No aux temp. Went to the "connected" screen, and both temp and aux temp showed connected. Spun paddlewheel and it was detected. Went back to the 2D screen, main temp and paddlewheel speed showing. Still no aux temp. Went to the set-up menu to confirm display. Aux temp was set for display right under main temp, at position "2". Went and changed position "2" to something else, and then back to aux temp. Went to main 2D display, and now it is working??

I tried a number of variations of powering on and off, with and without the connector for the speed/temp. Since I swap my head unit between a number of different mounts, with and without aux temp, I thought that might be triggering it. Well, for tonights testing (after above) tThe aux temp goes away when not connected, and comes back when it is. Seems to be working now. Not sure why, but happy it is, and hope it stays this way.

As far as the release, this was 1st noticed when the new 798 s/w that "I thought" included the ethernet change. This was the 1st release after that s/w. I assumed it has the same code, just not used in the old 798. I didn't know the 798E has a sepertate and unique load.

Humminbird_Greg · « **Reply #32 on:** February 13, 2012, 03:53:41 PM »

Well I’m glad that it is now working as well but would really like to understand why it wasn’t before…

xSilmarilSx · « **Reply #33 on:** February 20, 2012, 01:09:56 PM »

I just done my temp sensor extension with a plug to disconnect the 70 ft temp sensor when not in use. ( Since I use a portable setup for my 778c)

Didn't have to compensate the temp for the cable length. I was amazed that HB used a shielded coaxial cable for the temp sensor.. Me, I used a 2 conductor, shielded, tinned cable, soldered and protected by 3 layers of heat-shrink with glue.

Just need to figure what weight I will put on the end of the cable.

Humminbird_Greg · « **Reply #34 on:** February 24, 2012, 02:22:23 PM »

"Just need to figure what weight I will put on the end of the cable."

Hopefully nothing that a fish might mistake for food!

sonar2000 · « **Reply #35 on:** February 24, 2012, 02:27:44 PM »

I think fish are smarter than that.....

Chuck

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