Welcome Guest - Sign Up today
Welcome Guest - Sign Up today

Announcement

Collapse

Private Messages

We are aware of a current issue where your messages screen does not properly load and we are working on a fix.

In the interim, you can access you messages by navigating to this link: https://forums.iboats.com/privatemessage/notification

Apologies for the inconvenience.
See more
See less

Hummingbird Pirahnamax 4 - teach me how to use it

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Hummingbird Pirahnamax 4 - teach me how to use it

    Hello All,

    I have a Pirahnamax 4 fish finder that I'd like to get the most out of until I upgrade next season.

    I primarily fish two lakes - one is relatively deep and clear, while the other is shallow and not as clear.

    The deep lake is as deep as 180 ft. The visibility is approximately 30 feet or so. I usually fish from 70 - 90 feet.

    The shallow lake is about 60 feet at deepest, but I fish in 20-30 feet of water. Visibility is considerably less.

    So far, I've been keeping the unit on the 200 khz mode for both lakes, with the sensitivity turned up about 6/10 for the clear, deep water, and about 7 or 8/10 for the shallow, murkier water.

    Would you do it any differently? A I using this thing correctly?

    Is there an instance where I should be using the 455 khz setting? There's not much structure in either lake. Both are man-made reservoirs that were pretty thoroughly cleared before filling 50+ years ago.

    Last, I get a lot of interference while I'm running from one part of the lake to the other. I've been sure to follow the advice of making sure the transducer is away from the prop, at the correct height, and away from the strakes and rivet lines. I'm only running a 9.9 on my boat, and not moving very quickly at all. But I still get a ton of interference, and would like to see if there's a way to optimize the sonar while traveling around the lake.

    Thanks for any advice you can give.

  • #2
    I can't help you running the Bird, check You Tube or Humminbird website. As for interference when running I bet your transducer cable is too close to other electrical lines in the boat. If it is where it has to be insulating the transducer cable should solve the problem.
    Experience is a lifetime of mistakes, wisdom is not making them again.

    Comment


    • #3
      Clarity of the water has no effect on performance.

      Use gain to compensate for large changes in depth

      As far as the interference is concerned... If you don’t have the problem revving the engine out of gear it’s not electrical.

      Less than ideal transducer location, mounting height, angle of tilt off plane, etc.

      Transducer should be level with the surface of the water on plane.

      Transom mount transducers can be tuff to get right
      Last edited by dingbat; June 14th, 2018, 05:38 PM.
      ....

      Comment


      • #4
        Get someone to observe your boat when she is on plane and estimate what angle it is at if it concerns you that much. Set the transducer to that angle but then it's not accurate when the boat is level, like when trolling. I have found it best to just level the boat and set the transducer to level. It is close enough for me. I don't care if it shows 90 feet or 95 WOT, I need to know if it is 4 feet or 2 feet in shallow water that's where it counts not going wide out.
        Experience is a lifetime of mistakes, wisdom is not making them again.

        Comment


        • #5
          Originally posted by Old Ironmaker View Post
          Set the transducer to that angle but then it's not accurate when the boat is level, like when trolling. I have found it best to just level the boat and set the transducer to level. It is close enough for me. I don't care if it shows 90 feet or 95 WOT, I need to know if it is 4 feet or 2 feet in shallow.
          Bottom composition can have a huge effect on the reported depth.

          In 4ft. of water the error introduced (mathematically) by the angle is well within the error introduced by the bottom composition

          Heck, “false bottoms” are highly anticipated phenomenons in the fall. Your in 70-80’ of water and all of a sudden your 3’ shallow water alarm goes off, wtf? Zing......Fish on...lol
          ....

          Comment


          • #6
            Yes for sure dingbat, plus or minus the degree of error may be the difference of a busted prop or not. In shallow water a ducer shooting at an angle may show 10 feet not 4 feet (a guess .I'm math challenged) I like my unit shooting straight down 90 degrees from the waters surface. Most transoms are offset. The shallow alarm has gone off in 12 feet of water, the boat is over a dense weed bed that shows on the screen. I have my shallow alarm set for 5 feet. I crawl in shallow water, less than 5 feet..Shallow on Erie is 15 feet. Many limestone shoals where we fish and boat. There is a good chance a busted up vessel sits on those shoals that gather up debris like Velcro. Last year I found the mast of an old sail boat sticking up 6" out of the water on a shoal right out front of our cottage. I tied a Javex bottle on it a week later the mast and Javex bottle were no where to be seen. There are a few spots here that go from 40' to 5', one is called Johnny Hump here on Erie. That fish on was a hump not a fish. I thought I had a personal best on for 5 minutes, embarrassing. Same situation on a buddy's lake up in Northern Ontario. 30 feet to 9 feet. Tell my 61 year old kid brother "Aw I'm snagged on a rock," then he says "That rocks moving brother." 22 pound Northern Pike. That's also called Johnny's Rock.
            Last edited by Old Ironmaker; June 15th, 2018, 08:46 AM.
            Experience is a lifetime of mistakes, wisdom is not making them again.

            Comment


            • #7
              Originally posted by Old Ironmaker View Post
              Get someone to observe your boat when she is on plane
              This made me laugh....

              I have a 16 foot aluminum Starcraft, fully loaded with a 3/4" thick floor, two batteries and a fuel tank, a 75 Lb. 9 year old, my 200 Lb. frame, and all my gear on the boat.

              I run a 9.9 HP Yamaha.

              My boat is NEVER on plane.

              Comment


              • #8
                Thanks for all the replies, Gentlemen.

                But am I using it correctly? Would you keep it on 200 kHz all the time in my situation?

                When would you change to 455 kHz?

                Would you fiddle with the sensitivity more?

                Thanks for the tip on the electrical interference. I never thought of that. Will check by revving the engine out of gear.

                So, I'm a bit confused with regard to the mounting. Everything I've ever read, and everything I've ever seen, has the transducer mounted level with the bottom of the boat. dingbat says the transducer should be level with the top of the water when on plane. I've never seen a boat whose stern doesn't sit at least a few inches into the water. Who fishes on plane? What fish swims that fast?

                Typically, my stern is sitting pretty low in the water, with the transducer 4-5" below the waterline. Are you telling me it shouldn't be submerged at all?

                Thanks for the clarification.

                Comment


                • #9
                  All my transducers,3 of them, sit with bottom 1/2 in the water. Easy to do on our boats as there is always a skunge line on the white transom because we launch or have it in the slips on a skungy creek. I check all 3 and all 3 read the same depth. We longline troll as slow as 1.5 MPH up to 4MPH 90% or more of the time. I have always set them up like that since my first sonar in the 80's. Like I said I want my ducer set at 90 degrees to the water line, straight down. Never totally submerged in the water. I can't help you with what setting sorry. I am always playing with the gain on my main sonar. I want to see the lead core line in the water as well as a cannon ball downrigging. If I can see line in the water I know she is good to go. That enables me to actually see the thermocline in the water. Where warm and cold water meet. I know ice fishing guys that can see there jigs/bait 30 plus feet below the transducer, that is being dialed in. The quality of the unit comes into play there I would think.
                  Last edited by Old Ironmaker; June 15th, 2018, 09:03 AM.
                  Experience is a lifetime of mistakes, wisdom is not making them again.

                  Comment


                  • #10
                    [QUOTE=The quality of the unit comes into play there I would think.[/QUOTE]

                    I assume that has a lot to do with it too. Unfortunately, the $100 unit I bought at Walmart probably doesn't do an optimal job.

                    I'll have to check the placement of the transducer while the boat is in the water. I have a feeling it's totally submerged. I still mark fish pretty well, though, so I wonder how much it really matters.

                    Really, I'm trying to find out when I should use the 455 kHz. setting. What is it used for and when?

                    Comment


                    • #11
                      Sign up today
                      [QUOTE=Monmouth00;n10591855]Thanks for all the replies, Gentlemen.

                      But am I using it correctly? Would you keep it on 200 kHz all the time in my situation?

                      When would you change to 455 kHz?
                      depends on water depth and the cone angle of the transducer. Generally speaking, the higher the frequency the smaller the cone angle. Might be looking at an area the size of a postage stamp IDK


                      So, I'm a bit confused with regard to the mounting. Everything I've ever read, and everything I've ever seen, has the transducer mounted level with the bottom of the boat.
                      There is a reason transom mounted transducers are commonly referred to as "skimmers"

                      Every transom mount transducer I've ever mounted calls for the transducer to be mounted such that it extends half way below and half above where it intersects with the transom. On plane, the top of my transom mount transducer is completely out of the water.

                      My thru hull transducer is of course is always under water....unless the boat become airborne....lol

                      I've never seen a boat whose stern doesn't sit at least a few inches into the water.
                      They may "sit" but they don't plane below it, unless your stern has a hook, then you have bigger problems

                      Who fishes on plane?
                      I don't fish on plane (often troll at 8-9 miles per hour) but it's nice to know that I just ran over a school of fish on the way to somewhere else.

                      What fish swims that fast?
                      Lot of fish swim in excess of planing speeds. The top speed of a Sailfish is 68 mph. The tuna we fish have been clocked pushing 50 mph

                      Testing on the Water of transducer

                      1. Become familiar with your echosounder’s performance at a speed of 4 kn (5 MPH).

                      2. Gradually increase the boat speed and observe the gradual decline in performance due to turbulent water flowing under the transducer’s face.

                      3. If the decline in performance is sudden (not gradual), identify the boat speed at which the onset occurred. Return the boat to this speed, then gradually increase speed while making moderate turns in both directions.

                      4. If the performance improves while turning to the side on which the sensor is installed, the transducer’s position probably needs adjustment. It is probably in aerated water.

                      To improve performance, try the following one at a time in the order given


                      a. Increase the sensor’s angle, so the back of the sensor is deeper in the water (see Figure 11, 12° - 18° and review
                      “Checking the Sensor Angle & Projection”).

                      b. Move the sensor deeper into the water in increments of 3mm (1/8") (Figure 12).

                      c. Move the sensor closer to the centerline of the boat. Fill unused screw holes with marine sealant.

                      NOTE: High-speed operation [above 35 kn (40 MPH)] may require less projection in the water to improve performance and
                      reduce the chance that water pressure will cause the bracket to release

                      http://www.airmartechnology.com/uplo.../17-247-03.pdf
                      ....

                      Comment

                      Working...
                      X