Hello Frogger, i think you would like to use FH to validate blowback by chart value vs. FH reading. I think its a good idea to find how accurate your chart calculations. But as Jonson mentioned dont run it near the bottom if you dont want to lose it. Also use Jonson recommended method - tilt one of transducers up so it will detect your weight (for better reflection you can wrap your weight in aluminium paper), and attached aslo FH. In this scenario you will be able to determine delta reading from your sonar vs FH. Try this method on different depths so you can created your own chart.
Check URL below. They may help. This official Cannon info fo filter it
Pages 57 to 59 speak to bottom tracking and specifically pages 59 and 60 shows the sensitivity and offset adjusting.
Depth cycling (if interested)
Hi 58Johnson, thank you very much for super-detailed response. I feel much better now. Have another question - can I adjust sonar transducer signal emission cone electronically? I know from my past experience you can adjust signal cone by making metal cone and experimenting with shape :). My dilemma - should I buy Cannon dedicated transducer and tilt a bit to view my rigger weight position or should I seel my Helix 7 and buy Helix 8 compatible with Cannon. My concerns about having 2 transducers next to each other about 1 yard. Most likely "main" signal will be an issue but signal harmonics could be strong enough to interfere the second transducer signal spectrum. What is your opinion?
Hello folks, I would like to share with you information I discovered (this is some sort of hidden by Cannon) regarding the Bottom Tracking feature. A few Cannon-sponsored videos on YouTube is just like video manuals provide no real value. The guys shows how it works on anchored boats, the most important cavity is the fact that it is not automatic. This info hidden by Cannon and cannon's advertisers in purpose to mislead people on functionality. Ironically no one in cannon support know much about bottom tracking except how to turn this future on and set it up. a. Let me disclose Cannon Bottom tracking feature Myth and Reality. let's start from cannon nicely wrapped Myth about convenience of Bottom Tracking. I am sure that everyone watched nice animation on Cannon site about how the bottom fishing works. Looks very promising and simple - you install Cannon transducer (or use Humminbird Helix instead off), turn ON bottom tracking on downrigger, set distance from the bottom, set Offset Distance value and vuala - you done. Isn't sounds simple ? Yes. Not sure if you know this already but Offset Distance means your weight blowback factor (push back while your boat in motion caused by hydrodynamic resistance of water column to the weight you're dragging through the water). Therefore you need manually to calculate this value using provided blowback chart table. Because of blowback value heavily depends on your trolling speed, underwater flows, and wind you will endup with 30-35 percent error in your calculation. This error is sufficient to either keep your weight too high, above desired distance for the bottom (best case scenario), or too low - cause your weight drop on the bottom. When its on the bottom, it will stuck instantly in junks or rocks. If you are lucky, you will take back your line and hook up one more weight before you will lose it again; if you are not lucky you will damage your downrigger boom and some other parts. Be aware that Cannon sonar will not track you weight position, including blowback and automatically adjust it to selected distance from the bottom. It wood be too nice to have it. Probably Cannon left this to the next release to force us to spend another couple of thousands on a new toy.
Hello folks here. I think I can de-mystify cannon problem. I purchased recently Cannon downrigger and spent a lot of time learning this technology. I agree with all of you - Cannon support is very useless. They can tell you what button to press and what in theory should happened. Ok, let move to the subject - reading your posts I think you should first turn off (power off) your fishfinders. if problem resolved, learn on what frequency operate your fish finder. Fishfinder frequency suppose to be at least 20kHz off the Cannon transducer frequency. Also try reposition transducers if possible to increase distance between transducers. As a last resort you may try to install Cannon transducers a bit by angle , 5-7 degree should be OK. Hope it will help.