Transducer(s) connection to a Raymarine DSM300

[MapisM]

At the moment, I've got an in-hull Airmar (OEM Raymarine, afaik) transducer connected to the DSM300, which feeds via seatalk all the connected MFDs, hence allowing the sounder window to be selected on any of them.

Now, the next time the boat will be lifted, I was thinking to fit a second through-hull transducer, also because the original VDO wheel speedo for STW doesn't work anymore, and I could use its hole without drilling another.
But while looking at the manuals, I realized that the DSM300 only has one transducer connection, so I am wondering if and how it is possible to connect the new transducer in parallel to the existing one.

I understand that I could leave the in-hull transducer plug disconnected and use it just as a backup, reconnecting it whenever the "new" through hull transducer should fail, but it seems odd that there's no way to leave both permanently connected (hence hot-swappable).

Any thoughts? TIA!

 

[Hurricane]

Interesting idea.
I've been having trouble with my depth system.
Initially, Princess fitted a simple depth sounder to the ST60 instruments.
When we took delivery, we refitted everything with a glass bridge system and as part of that installed a DSM 300 with its associated transducer.
This year, I have been getting some strange symptoms and the depth has been intermittent.
Also all video displays through the boat have been experiencing interference whenever the DSM 300 was powered up.
Interference was in the form of a vertical banding pattern.
It was fine earlier this year but it happened just before our late season cruise.
A friend squirted some WD40 over the transducer just before we left and it started to work - the interference went away completely.
I can't explain that so I put it down to "just a coincidence"
During the cruise, the depth worked most of the time (especially in shallower water).
I think there might have been some moisture/condensation somewhere in the system causing a bad connection to fail.

That said, it is on my winter list of "things to do".
I had thought of getting a spare transducer and replacing the old one but maybe a completely new one like you say which could be plugged in/out as required.

The old Princess ST60 is still in place but it is not compatible with the DSM 300.
Just before our cruise, I tried separating it from all the other instruments and it doesn't work either so that one isn't a suitable backup anyway.

I might get a spare transducer for the DSM 300.
Can anyone on here say if a new one would work "jury rigged" temporally to see if the fault is the old transducer or the DSM itself.
My transducer is an Airmar B117 which has worked over the last 10 years but I'm not sure that it is the correct transducer.
I need to more research.

 

[MapisM]

Initially, Princess fitted a simple depth sounder to the ST60 instruments.
When we took delivery, we refitted everything with a glass bridge system and as part of that installed a DSM 300 with its associated transducer.
...
The old Princess ST60 is still in place but it is not compatible with the DSM 300.
...
My transducer is an Airmar B117 which has worked over the last 10 years but I'm not sure that it is the correct transducer.

Hi, M. your comments above reminded me that I should have posted another question.

But before that, when you mention your old "ST60" transducer, is the Airmar P79 that you are referring to, maybe?
I'm asking because that is my current in-hull transducer, and I've seen it advertised also as "ST60 transducer", but obviously ST60 is the series of instruments, rather than the transducer itself.
Anyway, if that's what Princess fitted, and if that's what I also have got (in fact, I'm not 100% positive about it, because I can only judge from the look of the thing, which indeed appears to be a P79 - see pic below), I don't understand why it didn't work with your DSM300, because it does with mine.

Regardless, here's my question: what is the better through hull transducer to mate with the DSM300?
I've yet to buy anything, so any suggestion is welcome also in this respect.
As I understand, your B117 did work well so far, even if you aren't sure that it's the correct model?

PS: in the above pic, forget the orange tube.
That's a custom installation meant to fit the thing exactly along the center keel, btw against Airmar recommendation to install it on a side, using the angled tube which they supply with the transducer.
It works just fine anyhow, so who am I to argue...?

 

[petem]

Mike, have you tried refilling the transducer fluid?

P, have you tried a new paddle wheel for your existing unit?

 

[Hurricane]

Just for the record.
I only tested the old ST60 transducer by connecting it to an ST60 depth instrument.
I'm reasonably sure that it won't work attached to the DSM 300.

Is yours a combined depth/log transducer?

My Raymarine G Series system allows me to access the DSM 300 and set up the type of transducer that is connected.
It is a shame, I didn't record the options on the screen when I last looked.
There were about 4 different transducers that are compatible with mys system.
I think I will be buying another B117 because it has worked in the past.

 

[MapisM]

My Raymarine G Series system allows me to access the DSM 300 and set up the type of transducer that is connected.

Now, that's interesting.
I never checked on my displays (HSB2 series), but maybe they also have a similar setup page.
Will play a bit with the thing asap, I must go out in a minute.

Anyhow, nope, the in-hull transducer in the previous pic ain't a combined depth/log (are there log capable in-hull transducers?), just a sounder.
Log and temp are in a separate thing - I'll explain also this asap, also in reply to petem...

 

[Hurricane]

Anyhow, nope, the in-hull transducer in the previous pic ain't a combined depth/log (are there log capable in-hull transducers?), just a sounder.
Log and temp are in a separate thing - I'll explain also this asap, also in reply to petem...

Just interest.
I have separate units but I cleaned my log wheel about 9 years ago and left it hanging up in the engine room.
We never use it and I don't think we ever will.
Long has gone the day is which we would ever manually plot positions or even get a paper chart out (I will run for cover now - I bet there are people out there that still plot using paper and pencil).
There are so may revuntant backups to nave these days, you don't need paper.
My goodness - paper - gosh that could get wet or blow away!!!

 

[Hurricane]

Mike, have you tried refilling the transducer fluid?

Interesting - is that something I should do?
If so how?

 

[petem]

Unscrew transducer (rotate 30 degrees or so anticlockwise). Lift out. Mop up old fluid with some kitchen roll. Refill with 71ml of Propylene glycol. eBay is your friend for a 50ml syringe and 100ml of Propylene glycol.

 

[MapisM]

I have separate units but I cleaned my log wheel about 9 years ago and left it hanging up in the engine room.
We never use it and I don't think we ever will.

Agreed, STW in the Med is as useful as a chocolate teapot.

That said, not only I have (as you do) separate units for depth and speed+temp, but the VDO paddlewheel unit that I mentioned in my OP, meant to feed the analogue speed/log gauge, is actually redundant, because there is another paddlewheel+temp Raymarine unit, which is still working fine.
Btw, I neither know the exact model of this unit, nor how it is connected to the seatalk network.
Anyway, useless as it is, STW is indeed available on all instruments (as long as the paddlewheel is kept clean enough to spin freely).
The pic below shows the VDO sensor on the left and the Raymarine one on the right.

I guess this makes it even more understandable my wish to get rid of the VDO sensor and replace it with a thru-hull depth transducer...

 

[Hurricane]

Unscrew transducer (rotate 30 degrees or so anticlockwise). Lift out. Mop up old fluid with some kitchen roll. Refill with 71ml of Propylene glycol. eBay is your friend for a 50ml syringe and 100ml of Propylene glycol.

Never heard this before.
Makes sense though - would explain some of the circumstances.

Does this work with all Airmar transducers?
If so, maybe thats why both my transducers are faulty.

Obvious question - can the boat be in the water?

EDIT
Both my transducers are proper "through hull" units.
Are you sure your refill notes are for "through hull" and not for transducers fitted "in hull" where oil is used.

 

[petem]

Apologies Mike, my description referred to in hull not thru hull.

 

[petem]

This sounds similar to your issue Mike...

https://www.thehulltruth.com/marine-electronics-forum/371328-transducer-problems.html

 

[Hurricane]

This sounds similar to your issue Mike...

https://www.thehulltruth.com/marine-electronics-forum/371328-transducer-problems.html

Thanks Pete.
I suspect it is a bad connection somewhere.
It seems to work better when warmed up (particularly when the engines are warm).
Unfortunately, the transducer has a sealed wire connection so I can't check that end.

 

[petem]

Never heard this before.
Makes sense though - would explain some of the circumstances.

Does this work with all Airmar transducers?
If so, maybe thats why both my transducers are faulty.

Obvious question - can the boat be in the water?

EDIT
Both my transducers are proper "through hull" units.
Are you sure your refill notes are for "through hull" and not for transducers fitted "in hull" where oil is used.

Mike, are you sue the ST60 one was thru hull?

 

[petem]

Incidentally, does this look like the ST60 paddle wheel fitted to your boat P?

http://www.cactusnav.com/raymarine-st60-triducer-paddle-wheel-b744v-b744vl-ss544v-p-148.html

I understand them to be extremely sensitive to corrosion in the axle so they might appear to be spinning freely they don't actually work. Whilst I agree that STW is irrelevant in the Med, I don't believe I can display SOG on my tridata so would like to get this fixed as it currently reads perhaps 10% of actual speed.

 

[MapisM]

My Raymarine G Series system allows me to access the DSM 300 and set up the type of transducer that is connected.

I just checked my HSB2 displays (L1260 sounder/chartplotter and RL80C radar, fwiw - though I don't think this matters a lot), and I couldn't find any page related to the DSM300 and/or to the transducer.
Do you possibly remember the logic sequence used in the G series instruments?
I guess it's different from HSB2 systems anyway, but just to get some ideas...

Regardless, the original question about the possibility to have two transducers simultaneously connected to an HSB2 vintage network still stands.
For all I know, it might as well not be feasible, but I'd be surprised if nobody else at least checked this possibility before!

 

[MapisM]

Incidentally, does this look like the ST60 paddle wheel fitted to your boat P?

Yes, it does look similar.
But actually, that's the one (right side of the pic of post #10) which is still working fine, on my boat.
It gets stuck due to u/w growth occasionally, but so far after brushing it a bit while snorkeling, it always came back to life nicely.
I believe it's also possible to clean the wheel after pulling the transducer from inside the boat (hence the plug visible in the pic, which is meant to seal the hole after pulling out the transducer), but I've yet to try that.
And I don't think I ever will, actually: in summertime, it's easier and quicker to brush the wheel while swimming, and I'm happy to live without STW anyway...

The paddlewheel sensor which isn't working anymore in my boat is the one on the left side of the pic, and it's dedicated to the analogue VDO speedo/log which used to be part of the analogue engines instrumentation.
Btw, as I was told, that's a bit of kit which is known to never last more than a very few years - and it was pretty much useless anyhow, to start with.
Hence my train of thought of replacing it with a proper thru-hull depth transducer, to be connected in parallel with the existing in-hull one (pic in post #3) if possible.

 

[Hurricane]

I just checked my HSB2 displays (L1260 sounder/chartplotter and RL80C radar, fwiw - though I don't think this matters a lot), and I couldn't find any page related to the DSM300 and/or to the transducer.
Do you possibly remember the logic sequence used in the G series instruments?
I guess it's different from HSB2 systems anyway, but just to get some ideas...

Regardless, the original question about the possibility to have two transducers simultaneously connected to an HSB2 vintage network still stands.
For all I know, it might as well not be feasible, but I'd be surprised if nobody else at least checked this possibility before!

Two answers here.

To get to the DSM settings on my G Series system, I had to first switch to the DSM (Depth) display (i.e. press Page until you get to depth).
Then press Menu and then I get a menu item for the DSM
Maybe that helps.

Two tranducers.
The ST60 depth instrument has an option in its settings to run as a Master or as a Slave.
Unfortunately, this option is overridden - when it sees depth data on the same network it automatically switches to Slave and doesn't sent or display its own depth data.
So, in my case, it really isn't an option as a backup depth device.
I would need to separate my Seatalk 1 system from my other networks (Seatalk NG etc) and then the Autopilot (on the old Seatalk 1) wouldn't connect to the rest of the G series.
So, for me, maybe a good backup would be to replace the ST60 transducer with a new DSM transducer and wire it back to the DSM so that the transducers can be swapped as required by unplugging and replugging.
Anyone on here ever removed/replaced an in hull transducer.

 

[MapisM]

To get to the DSM settings on my G Series system, I had to first switch to the DSM (Depth) display (i.e. press Page until you get to depth).
Then press Menu and then I get a menu item for the DSM

Grrr... That's exactly what I'm missing.
Maybe there's some way to enable an extended set of options, by entering an "administrator mode" or something like that.
I remember to have followed a weird sequence of buttons for a similar purpose on the a/p display, for checking the s/w version of the course computer.
Time to re-check the manuals, methink!

PS: ref 2 transducers, yep, of course the "unplug/replug" option would be the easier solution.
Btw, accessing the rear of the instruments panel is no big deal, on my boat.
But keeping both connected and somehow "hot-swappable" would obviously be much better, if feasible...