11/ 2014 Lowrance Chirp On November 13, 2014

Lowrance CHIRP

Lowrance uses the new CHIRP technology in the Elite HDI CHIRP models and the HDS with the SonarHub.
I just got my Elite HDI/CHIRP and SonarHub with the Airmar TM150 transducer for my HDS. My testing was minimal since the open water fishing season has ended for me. But many people have been wondering about the Lowrance CHIRP so I used the data I have collected so far to show you some of my examples.
The Elite will use the standard HDI transducer and the SonarHub will use the Airmar TM150. These are your best choices right now; it may change since electronics often change the week after I write something!
Traditional sonar is called burst sonar and the sound is sent as a burst at one frequency which is usually 50, 83 or 200.
CHIRP (Compressed High Intensity Radar Pulse) The name sounds complicated as the technology was used for radar first, but I will try to simplify it for you.
Standard sonar we have used for years sends a short burst at one frequency; CHIRP sends multiple frequencies over a longer time which can give better target discrimination. The cone is usually larger with CHIRP so bottom detail is not as good since a narrow cone is better for bottom detail.
The Elite gives you multiple choices in frequency choices.

The Custom high CHIRP gives slightly better target separation than the standard 200 kHz in this comparison. So far I can’t see much difference than the old 200 kHz standard frequency at shallow depths. I will test more next year.

Custom High

High CHIRP

One tip for Elite owners, when you select Custom High you can select a frequency between 190-210 kHz. You adjust it with the adjust feature and I think it is worth testing when you get crosstalk with 2 sonar models to see if it helps. I just put my boat away so I can’t test it this year.
The adjust starts at 200 kHz and +10 would be 210 kHz.

The above images came from Lowrance support.
The HDS and SonarHub with the TM150 transducer give 4 choices when using the TM150.
83 kHz, Medium chirp and Custom where you can pick any single frequency between 95-145.

Testing the CHIRP on my school of crappies didn’t show much difference between CHIRP and a single Custom frequency at 2 different speeds.

I think the standard Lowrance Broadband sonar at 200 is so good in the HDS and the Elite HDI that the CHIRP doesn’t improve it much at shallow depths.
My testing was minimal and I will do more next year in deeper water.