Guests - If You want access to member only forums on HSO. You will gain access only when you sign-in or Sign-Up on HotSpotOutdoors.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
92python

Transducer frequency and cone angle ?

4 posts in this topic

I have a technical question I hope someone can help me with.
I have a 17.7 foot tiller boat with a Fishmark 320 in the back. My bow mount graph need replacement. I just got the Spring Cabelas catalog and they are showing all the new electronics. Now I know why stores are selling the Fishmark 320s for $169, they added new models and upgraded the pixel counts again.

My questions are: If I buy another Graph with a 200 kHz frequency and a 20 degree transducer, how deep will I be able to fish without getting interference between both units when they are on. Does the interference start when the cone angles overlap or is there some other factor that causes the interference?

I busted out the protractor and assuming the transducers are about 16 feet apart, it seems that the cone angles won't overlap until I start fishing water deeper that I normally fish while using the bow mount trolling motor.

Thanks for any feedback.

Share this post


Link to post
Share on other sites

In 60 ft. of water the diameter of the cone in ft. equals the degrees. Each time you halve the depth you halve the diameter of the cone. 30 ft. water=10 ft. cone. 15 ft. water=5 ft. cone.
In theory you will not overlap in anything less than about 40 ft of water. However in real life you will be dealing with uneven bottom conditions which will reflect the signal at odd angles. grin.gif

Share this post


Link to post
Share on other sites

Say you have a 20 degree cone angle. In 20 feet of water the cone angle will cover 7 ft on the bottom. The return echo will however will bounce all over. So the question would be what sounders are compatibly with the Fishmark 320. I don't have one so i couldn't tell you. I can tell you I've run different brand sounders with same 200 kHz frequency and had no interference what so ever.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  
Followers 0



  • Posts

    • Trump already signalling willingness to work with Democrats in order to bypass House conservatives....     http://www.nbcbayarea.com/news/national-international/Trump-Attacks-Conservative-Lawmakers-Over-Health-Bill-417117223.html?_osource=SocialFlowTwt_BAYBrand   So now we have a supposedly extreme right-leaning Republican president cozying up to Democrats?   What would Uncle Ben think?....            
    • In order to determine which direction to go with healthcare, one fundamental question must be answered.  If an American walks in to a hospital with a sick child or with some sickness themselves and has a treatable medical condition, should a provider have a right to refuse service to that person or their child based on ability to pay?  We cannot have a true free market system unless we are truly callous enough to turn poor people away at the door.  I'm not there.
    • Ice is good in some areas of main lake but bad in areas with moving water / springs. All resort / outfitter access's are closed to vehicles but some are open to four-wheelers. side by sides, and snowmobiles including Morris Point, Long Point, Dales's and Arnesen's, which still has fish houses available as well.  As always, use a resort or outfitter road for safety as they are monitored daily.  Walleye bite has been good with many keepers among smaller fish. Fish are aggressive and having a flasher is helpful.  Jigging spoon tipped with minnow head or tail and a dead stick with a plain hook or small ice jig and minnow are doing good.  Key depth  17-33 ft.  Best colors glow pink/red and gold. Tip up fishing for pike on fire.  Many flags of northern pike in back bays and reefs.
      Rainy River spring fishing is ON!  The Rainy River is open all the way to Wheeler's Point. Birchdale, Frontier, Vidas, and Timbermill landings are open to all boats. Wheeler's Point will be open in a day or so.  Walleye fishing has been excellent. Many eater walleyes so far with a few monsters. Right now a 1/2 - 3/4 ounce jig is enough to get to the bottom while tipped with 1 or 2 frozen shiners. Pink, orange and gold are hot colors. Many sturgeon being boated as well.     Up at the NW Angle, ice conditions are unstable as current areas are opening up quickly.  Travel with caution. Many resorts using airboats at this point.  Fish houses on LOW can stay on ice through March, walleyes/saugers through April 14th.  Pike and crappies open all year for LOW MN.  
    • I loved BBs post game the other nite after the canucks game,  he nailed it.  Guys got to step it up and play, outside of granny and staal, the rest look like they just started playing.  Lack luster for sure.  Im still hoping they come out and play like I know they are capable of but not looking good
    • This is what I have so far and I think I'll be changing A. Hackney B. KVD C. Ehrler D. Howell E. Lucas   I don't feel confidence about any of them except KVD haha Well I already made a switched and put Dafoe in bucket A for Hackney.
    •   I asked the same thing about a Month ago...must be a contract/money issue...we don't spend money foolishly 
    • Live Target for me. Tried a Lunkerhunt and it kept sinking and holding water.
    • Oh, the hat?  Correct, I was using clone stamp to build the hat.  Of all the problems with my photoshopped images, your issue is with the hat?  I thought the crude cutting and pasting was bad enough that nobody would notice the hat.      Still, you're a massive tool and I have accepted your challenge to do it better.    
  • Our Sponsors