[CA] [CA11] Axiom Pro RVX - High / Low chirp Transducers??

[DFMott]

I currently have a CP370 connected to a B164. If I upgrade to an Axiom-pro RVX my understanding is that it comes with the functional equivalent of a CP470 built in. At least that is what I read in an older post response - "In short, the internal 1kW CHIRP sonar circuitry within an Axiom Pro RVS MFD is designed to be the functional equivalent of that found within the CP470 CHIRP Sonar Module", and in the literature - "Axiom Pro 1kW sonar offers a wide spectrum of CHIRP sonar bands for deep, mid-range and shallow water fishing." If I replace my B164 with a B175 LH pair and revert to using the built in sonar of the Axiom Pro RVX over the CP370 - would it be the equivalent of that same through a CP470/ B175 Pair and superior to the CP370/B164? What type of range will it provide me with? This option doesn't seem to be presented in any of the literature.

[Chuck - Raymarine - Moderator]

Welcome back to the Raymarine Forum DFMott,

As you have suggested in an earlier message, the RV transducers are primarily designed to support the needs of nearshore and inshore fishing. When fishing offshore waters, 1kW 50kHz/200kHz or 1kW/2kW CHIRP fishfinder sonar is typically recommended. The primary advantage of an external fishfinder sounder module is that its sole function is to process analog fishfinder transducer signals. As such external sounder modules do not have additional circuitry (ex. displays, WiFi, etc.) which can be a source of signal noise which can adversely affect fishfinder performance. Typically, external fishfinder sonar modules will provide the greatest level of fishfinding performance (depth and image quality) over a MFD's internal fishfinder circuitry. Anecdotal feedback has supported the information supplied above. How deep is the water which will be fished?

[DFMott]

The minimum is 280 feet and the maximum is about 7000 feet. I do a lot of trolling in the 280 - 1800 foot range. I am never bottom fishing. My boat is a 26 foot Scout Abaco and I just don't see how I could get 2KW transducers in it. The flush mount Airmar B series are the best fit for my hull design, Still, I am looking for the best performance and why I thought a pair of B175's would be an improvement in range and clarity over a single B164 on a CP370. The literature says full 1KW Chirp on the Axiom Pro so if I can't utilize the 2KW potential on the CP470 it would seem the B175's on the Axiom-pro would be the best match. The other choice is a B275LHW but not sure I like the idea of putting such a large fairing on my small hull. That is if they are compatible with the Axiom-pro RVX...

Would you then recommend I purchase an Axiom Pro S with a CP470 over a Axiom Pro RVX for my situation? Even if I can only have 1KW transducers? Will I have better performance with the Axiom pro / CP470 / B175 LH pair vs my current ES97 / CP370 / B164?

I would prefer a 2KW transducer but I just don't see how it will fit in my 26 Foot boat. The R111 is 17" long and 6" wide. Since I have a 20 degree dead rise I can only moun it lengthwise and it just won't fit....

[Chuck - Raymarine - Moderator]

DFMott,

Q1. I am looking for the best performance and why I thought a pair of B175's would be an improvement in range and clarity over a single B164 on a CP370.
A1. I would concur with this assessment, particularly when considering the depths to be fished. However, for the depth range specified, it would be recommended that a B175M and a B175L be installed.

Q2. Would you then recommend I purchase an Axiom Pro S with a CP470 over a Axiom Pro RVX for my situation?
A2. I favor this solution. Should there be any possibility that you may want to experiment with RealVision, SideVision, or DownVision sonar imaging in the future via a transom mounted transducer and operation as slow trolling speeds, then you may want to alternatively consider an RVX1000 fishfinder sounder module and an Axiom Pro S MFD.

[DFMott]

Someone suggested that hooking one transducer to the AXIOM and the other to the CP470 may provide better performance since unlike the CP570 the CP470 only has one channel. Your thoughts?

[Chuck - Raymarine - Moderator]

DFMott,

Unlike the CP570, which features two independent sets of CHIRP sonar transmitter/receiver circuity, the CP470, RVX1000, and Axiom Pro RVX MFDs feature a single set of CHIRP sonar transmitter/receiver circuity. When interfaced to a pair of 600W or 1kW CHIRP transducers and when pinging both CHIRP transducers, the maximum ping rate will be half that which would be possible if the two transducers had been interfaced individual transducers to the CP570's two Transducer sockets.

[DFMott]

I understand that the ping rate on the 470 is half of the 570 when 2 transducers are connected to it. However, is it possible to connect only one transducer to the 470, and only one transducer to the AXIOM-PRO? If you can, would that configuration provide the same ping rate as the 570 with 2 transducers on it since you are in essence running 2 470’s with single transducers? This configuration was suggested by someone at the NY boat show....

[Chuck - Raymarine - Moderator]

DFMott,

Q1. Is it possible to connect only one transducer to the 470, and only one transducer to the AXIOM-PRO?
A1. Yes. In fact, as you can see within the thread found here, this has indeed been previously suggested to address a similar issue.

Q2. If you can, would that configuration provide the same ping rate as the 570 with 2 transducers on it since you are in essence running 2 470’s with single transducers?
A2. Yes.

[DFMott]

I have the Raymarine B175M / B175L on order. I believe it comes with the Y cable necessary to connect both to the CP470. Do I need to purchase an additional A80328 cable for both the CP470 and the Axiom-pro if I want to connect just a single B175 to each of them?

Would you recommend the split configuration over connecting both to the CP470?

I don’t need 30 feet of cable for the transducers. Would I get better performance if their length were reduced by cutting and splicing?

[Chuck - Raymarine - Moderator]

DFMOTT,

Q1. I believe it comes with the Y cable necessary to connect both to the CP470.
A1. The T70076 B175LM (Low & Medium Frequency) 20 deg Pair 1KW Thru Hull CHIRP Transducers package does not include the Paired CHIRP Transducer Y-Cable (A102146). If connecting both transducers to the single 1kW CHIRP transducer socket of an Axiom Pro RVX MFD or CP470, then the Paired CHIRP Transducer Y-Cable (A102146) must be installed.

Q2. Do I need to purchase an additional A80328 cable for both the CP470 and the Axiom-pro if I want to connect just a single B175 to each of them?
A2. Yes. Use a Single Operation Cable (A80328) with each B175 transducer is required when these transducers will be interfaced to individual 1kW fishfinder 1kW fishfinder products.

Q3. Would you recommend the split configuration over connecting both to the CP470?
Q3. If seeking to maximize the ping rate, then the split configuration would be recommended.

Q4. I don’t need 30 feet of cable for the transducers. Would I get better performance if their length were reduced by cutting and splicing?
A4. Negative. Shortening fishfinder transducer cables not recommended and would likely void warranty. Excess transducer cable should be loosely coiled (6" minimum diameter) and secured to a bulkhead.