[CA] [CA11] Upgrading Axiom sonar capabilities

[a7ewizard]

I am currently running an Axiom 9 with the transom mount RV-1000 transducer. I have learned this transducer operates only in the high frequency Chirp sonar.

I also read a thread on this site that said hooking the Axiom to a P66 high and low frequency transducer is an inexpensive option to obtain the low band. It went on to say that high chirp would no longer be available from the RV-1000. Downvision, 3D, and side scan would still be selectable options. Is this all correct so far?

More questions:
1) Is the Axiom capable of Low or Mid chirp sonar when coupled with the corresponding transducer? Such as B75M, B175L or TM 265LM?

2) If coupled with a Low or Med separate chirp transducer via the appropriate "Y" cable, will the RV-1000 still operate in the High chirp mode simultaneously and able to be displayed split screen? High and low chirp as an example?

3) Can you split screen to view downvision and low chirp?

4) Knowing that Axiom output is limited to 600 watts, can one expect better performance running a 1kw transducer versus a 600w transducer? I have heard this is true because of the better quality or number of elements in the 1kw transducers.

5) If Axiom is not capable of other chirp output, will it power a non-chirp Low transducer?

Sorry for all the questions but I have only operated MFDs with their included transom mount transducers. My hope is to obtain bottom readings out to 1500 feet without adding a sonar module or upgrading to the Pro version. Space is quite limited.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum a7ewizard,

Q1. Is the Axiom capable of Low or Mid chirp sonar when coupled with the corresponding transducer? Such as B75M, B175L or TM 265LM?
A1. The Axiom RV and Axiom DV MFDs do not feature internal 1kW CHIRP sonar circuitry as do the Axiom Pro RVX MFDs. The Axiom RV and Axiom DV MFDs feature internal 600W 50kHz/200kHz fishfinder circuitry in addition to RealVision or DownVision circuitry respectively. In order to add 600W / 1kW CHIRP sonar to a system featuring an Axiom DV or Axiom RV MFD, the compatible high power CHIRP fishfinder transducer would need to be interfaced to an Axiom Pro RVX MFD, RVX1000, CP470, or CP570, which in turn would be interfaced to the Axiom MFD.

Q2. If coupled with a Low or Med separate chirp transducer via the appropriate "Y" cable, will the RV-1000 still operate in the High chirp mode simultaneously and able to be displayed split screen? High and low chirp as an example?
A2. See response to Q1. If a Y-Cable is interfaced to an Axiom RV MFD, then the MFD will no longer process low power / high frequency conical CHIRP sonar via the RV transducer and will instead support 50kHz/200kHz sonar via the 50kHz/200kHz transducer.

Q3. Can you split screen to view downvision and low chirp?
A3. If 600W/1kW CHIRP sonar is introduced to the system by way of the options specified in the response to Q1 (L or LM CHIRP transducer installed) and the Axiom MFD has been interfaced to a RV transducer, then the Axiom MFD may indeed display DownVision sonar and low CHIRP within separate Fishfinder application panes of a page.

Q4. Knowing that Axiom output is limited to 600 watts, can one expect better performance running a 1kw transducer versus a 600w transducer? I have heard this is true because of the better quality or number of elements in the 1kw transducers.
A4. Power is generally associated with maximum depth performance, while the quality and number of elements are determining factors the clarity of the imaging. Accordingly, a 1kW or 2kW transducer having better quality and/or number of elements will typically provide better performance than a transducer having lesser quality and/or number of elements when driven at the same power.

Q5. If Axiom is not capable of other chirp output, will it power a non-chirp Low transducer?
A5. See the response to Q1 ... an Axiom RV or Axiom DV MFD may each be interfaced to a compatible 50kHz/200kHz transducer. The operator may then elect to display the 50kHz or 200kHz sonar channel within a pane.

[a7ewizard]

Chuck,
Thank you very much for your responses. I was able to find some answers in other threads and you have further enlightened me.

Looks like my electronics will get an upgrade. I have room to mount 2 through hull transducers or a transom mount 1kw transducer. I am somewhat leery of mounting a TM265 type since it so wide. Is drag or splash from a TM265 an issue? Will it kick up at speed? Is it more affected by aeration than a flush mount? My normal cruise is around 30 mph.

I keep my boat on a lift so bottom growth is not a factor. I think I'd rather have a TM than drill a pair of large holes through my hull if transducer performance is similar. Thoughts?

[Chuck - Raymarine - Moderator]

a7ewizard,

General comment: properly installed thru-hull fishfinder transducers will typically yield maximum performance and will typically hold bottom at the greatest speed.

Q1. Is drag or splash from a TM265 an issue?
A1. Given its size, I would expect a fair amount of spray to be generated by the transducer. The quantity / characteristics of the resulting spray will vary with each hull and how deep the transducer extends beneath the bottom of the hull.

A2. Will it kick up at speed?
A2. Like other transom mounted transducer, when properly installed, I would only expect the TM265 to kick up if it strikes something.

A3. Is it more affected by aeration than a flush mount? My normal cruise is around 30 mph.
A3. Yes.

[a7ewizard]

Chuck,
I am pretty sure on my upgrade. My main goals are to differentiate bottom structure, mark bottom out to 1500 feet, show thermoclines and to meter fish and bait suspended to 300 feet.

Realistically, the vast majority of my fishing will be in water less than 150 feet. The upgrade is to try for swordfish, albacore tuna and deep bottom fish when offshore conditions permit. Consequently, I think a non-chirp option will be the most cost effective for me.

At this point, I'm pretty much set on a CP370 sonar module with a 1kw transom mount TM-258 50k/200w transducer. If Airmar's specifications are accurate (best case scenarios), this combination will satisfy my goals as stated above AND I will retain Axiom RV's high frequency chirp capability.

I think the transom mounted transducer will perform extremely well at drift and slow troll. I'll just have to wait and see how it does at cruise speed. Give me a few months. I'll be back with my observations.

Thanks again.

[a7ewizard]

Chuck,
After speaking to a certified Airmar installer, he suggested the TM-260 transducer instead. He cited improved performance over the TM-258. NOWHERE, neither on the Raymarine nor Airmar websites is this transducer listed as CP-370 compatible! I had originally called to find out the length of cable included with these transducers. I believe he said 30 feet. Again, this specification is not listed anywhere that I could find. Two major oversights.

I hooked up the CP-370 and TM-260. Connected these to my Axiom and powered up the system. The new components were not hard mounted; transducer in a bucket of water.
This was just a test to ensure it all worked.

Axiom recognized the sonar module. The LH3 operating software was pretty intuitive. I had to manually select the appropriate transducer from a displayed list. I selected a 3 sonar panels display option. Then the sonar source and desired frequency was selected for each panel. Very pleased so far. On water results to follow.

[a7ewizard]

I finished the installation and splashed the boat. In water results were a total success!
The CP-370/TM-260 showed bottom to 32 mph (I did not go any faster) in both 50 and 200k frequencies. No noise or interference of any kind; I also had the RV-100 in sonar mode.

My initial impression is the CP-370 in 200k has more distinct fish returns than Axioms high chirp. Most of my testing was in water of 30 feet or less.

I also ran a 4 panel display showing high chirp, side vision, 200k and 50k. Pretty busy on a 9 inch screen. Endless display possibilities!

[Chuck - Raymarine - Moderator]

a7ewizard,

Thanks for following up with news of your success. I too have a variant of the TM260 installed on my own boat, and find it to be an outstanding performer.