Getting to the bottom of Chirp Technology

Learning the difference between CHIRP vs. NON-CHIRP transducers 

AIRMAR’s CHIRP-ready transducer product line 

Getting the answers to your CHIRP questions

Fishing Package Info and Prices

What is CHIRP? 

• CHIRP has been used by the military, geologists and oceanographers since the 1950’s

• This is the first time the technology has been available to the recreational, sport fishing and light commercial industry… and at an affordable price 

Fish Imaging at Different Frequencies

CHIRP Starts with the Transducer 

• AIRMAR transducers are the enabling technology for manufacturers designing CHIRP sounders.

• Only echosounders using AIRMAR CHIRP transducers can operate as a CHIRP system. – Furuno’s DFF1-UHD – Garmin’s GSD 26 – Simrad’s BSM-2 – Raymarine’s ClearPulse 450C

AIRMAR’s new CHIRP transducers are engineered with ceramics designed to operate over a broad range of frequencies (28kHz – 210kHz) with no sensitivity loss.

How Does CHIRP Work?

• CHIRP sounders transmit a long pulse across a wide frequency band – Traditional sounders operate at 50kHz and 200kHz. This limits what targets can be detected in the water column. – Any object(s) below the boat that are detected in the frequency band, will be seen on the display                                                         TVR Next- Generation  

CHIRP vs NON-CHIRP: What’s the difference?

• Non-CHIRP fishfinders operate at discrete frequencies of 50kHz and 200kHz 

• Transmit pulse is only at a discrete frequency • Typical Non-CHIRP fishfinders operate with a maximum duty cycle of 1% - meaning they transmit a voltage to the transducer no more than 1% of the time 

• Consequently the transmit pulse can be high power but very short duration, limiting the total energy that is transmitted into the water column CHIRP vs NON-CHIRP Fishfinders 

• CHIRP sounders use a precise sweep pattern of many frequencies (28kHz – 210kHz) within a long-duration transmit pulse, sent to a CHIRP transducer. 

• The equivalent sound energy transmitted into the water is 10 to 1,000 times greater than a conventional marine fishfinder. Resulting in more energy on target.

• Results are 5x greater resolution and depth capability than current fishfinders due to the advanced signal processing of the return echo! 

• Key to the signal processing is knowing what they CHIRP signal looked like. “Pattern Matching” CHIRP vs NON-CHIRP Fishfinders 

• ONE transducer offers over 117 kHz of bandwidth, eliminating the purchase and installation of multiple transducers.

• Mix and match nomenclature: – 

B265LH/B265LM Thru-Hull: 42-65 kHz(L), 85-135 kHz (M), 130-210 kHz (H) 

– M265LH/M265LM In-Hull: 42-65 kHz(L), 85-135 kHz (M), 130-210 kHz (H) 

– TM265LH/TM265LM Transom-Mount: 42-65 kHz(L), 85-135 kHz (M), 130-210 kHz (H) 

– CM265LH/CM265LM Tank-Mount: 42-65 kHz(L), 85-135 kHz (M), 130-210 kHz (H) 

– PM265LH/PM265LM Pocket Mount: 42-65 kHz(L), 85-135 kHz (M), 130-210 kHz (H) 

– R509LH/R509LM Thru-Hull: 28-60 kHz(L), 80-130 kHz (M), 130-210 kHz (H) 

– R599LH/R599LM In-Hull: 28-60 kHz(L), 80-130 kHz (M), 130-210 kHz (H) 

– CM599LH/CM599LM Tank-Mount: 28-60 kHz(L), 80-130 kHz (M), 130-210 kHz (H) 

Understanding “Q”

• A transducer’s quality factor that describes the amount of bandwidth and the ringing of the ceramic element, or elements undergo when voltage is applied to the transducer. – Q is reported from a range of 1 to 35 – The lower the Q, the better the performance. – A low Q transducer has more bandwidth. – Most competitors transducers have a Q ranging between 25-35. – AIRMAR transducers have a Q value ranging from 2 to 30. – All of the transducers designed for use with CHIRP sounders have a Q or 3 or less. 

Real Data Echo Waveforms 

Transducer: P319 Frequency: 200 kHz Q=31 Cycles: 35 

Transducer: B260 Frequency: 200 kHz Q=8 Cycles: 10 

Transducer: R509LH Frequency: 200 kHz Q=2 Cycles: 10 

Understanding “Q” 

• A high Q means the transmitted acoustic pulse is extensively elongated • A low Q means the acoustic pulse has minimal elongation, and closely resembles the drive waveform 

• Q values range from 2 to 35 • With a high Q transducer, two close targets will blend together, and will not be displayed as individual targets Understanding “Q” (Con’t.) • With a low Q transducer, two close targets can be distinguished, and each target will be resolved on the display • Transducers that are termed “Broadband” have Q’s of 2 or 3, and can also be used for CHIRP 

Fishfinders with Low and High Q Transducers

Fish 6” above the bottom blend into the bottom echo by long ring from high Q Echoes from fish 6" and less above the bottom blend in with echoes from bottom Individual fish may be detected as close as 1” above the bottom Fish 6” above the bottom can be distinguished by short pulse from low Q Individual fish blend together Individual fish are separated High Q - Long Ring CHIRP Q = 2, 5° beam Non CHIRP Q = 25, 5° beam Low Q - Short Ring Minimal ring-down Increased ring-down 

Major Benefits of CHIRP Technology 

 10 to 1,000 times more energy on targets 

• 5 to 10 times greater detail and resolution • Accuracy down to 3,000 m (10,000’) 

• Precise separation between bait fish and game fish 

• Ability to pull targets from within the noise floor – better signal to noise ratio 

• Improved bottom tracking at high boat speeds 

• Low Q improve shallow water performance 

Unique Transducer ID®

• All of AIRMAR’s CHIRP transducers include a unique, patented Transducer ID® – measures and stores the operating parameters for each transducer Unique Transducer ID® 

• All of AIRMAR’s CHIRP transducers include a unique, patented Transducer ID® – measures and stores the operating parameters for each transducer – enables the fishfinder to automatically configure itself to the transducer being used – minimal set up or customization is needed – transmitting across the bandwidth is done automatically by the sounder 

• Stored data also assists with troubleshooting, warranty or required information about the transducer 

Example Screenshots: Courtesy of Furuno, Garmin, Raymarine & Simrad  

Individual target separation Fish detached from the main bottom signal return Incredibly sharp fish targets with separation even in the dense shoals Baitfish detached from the main bottom signal return Minimal ring-down resulting from a low Q

Individual target separation

Minimal ring-down resulting from a low Q 

Impressive resolution of swordfish going after baitfish at the bottom Excellent resolution in deep waters

The CHIRP Product Line 

• CHIRP is available to ANY angler with ANY size boat 

• Twenty-four (24) CHIRP transducers available in seven (7) different mounting options The Complete CHIRP Product Line CORE In hull, transom mount, tank mount, pocket and keel mount versions available.

LH model provides 103 kHz of bandwidth LM model provides 73 kHz of bandwidth 

HARD CORE 

In-hull and Keel/Pocket Mount options also are available LH model provides 117 kHz of bandwidth LM model provides 83 kHz of bandwidth 

ELITE In-hull and Keel/Pocket Mount options also are available LH Model provides 112 kHz of bandwidth LM model provides 83 kHz of bandwidth

Core Products – Tilted Element Price point Broadband

Advantages of the Middle Frequency Variations in Beamwidth

CHIRP transmits across a wide frequency band

The combination of a CHIRP sounder, a broadband transducer and the fishfinder’s DSP can transmit over 10x’s more energy in the water– Able to detect bottom >3000 meters and fish or objects in the water column in more difficult conditions that ever before

Dramatically better signal to noise ratios resulting in better performance in noisy environments and tracking at high speeds

One transducer covers all the popular fishing frequencies

Transducer ID feature optimizes the system

Single vs Dual Transmission Line

One transducer covers all the popular fishing frequencies

Transducer ID feature optimizes the system

A single transmission line sounder has one transceiver for both the high and low frequency signal–ie: BSM1, DSM300, GSD24, FCV585

A dual transmission line sounder has two transceivers–ie: DSM400, FCV1100, FCV295

Why do they Cost More?

Entire system is much more sophisticated

New Transducer ID features

Addition of heat sinks for thermal dissipation

Common impedance requires transformers and inductors

Diplexers

Allows the ability to use transducers with separate elements for each frequency with a single transmission line echo sounder.

Non-diplexed transducers have separate pairs of conductors for the high and low frequency. (Furuno’s FCV sounders, DSM400)

It is not possible to use a diplexed transducer with a dual transmission line sounder

Dual vs. Single Transmission Line Transducers

Most CHIRP Transducers have NO

connector and use 4 wires for depth

2 wires for High Frequency

2 wires for Low Frequency

Most echosounders currently available use a single transmission line and require an internal diplexer

These transducers use 2 wires for depth

The HF and LF transmissions share these 2 wires

B260 Wiring with Diplexer

B265LH Wiring Diagram

Transom Mount Flow Noise

If experiencing interference with a transom mounted transducer you must test drive the vessel to determine what speed the image is lost at.

Move the transducer to it’s lowest position and retest.

If screen image is improved repeat until you are satisfied with results.

If screen image gets worse, move transducer up and re-test until improvement is seen.

Perform a slow but constant turn to the side of the hull that the transom transducer is mounted. Gradually increase rate of turn. If screen image improves the transducer needs to be mounted lower in the water.

If screen image is worse when turning to the same side as the transducer try turning the opposite direction. This would indicate the transducer needs to be mounted higher in the water