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Black Box Techniques

Chapter XI. Common Black Box Questions


Does it really work?

With some species, absolutely yes. It has been well proven that certain fish are attracted to a very slight positive voltage and will swim to the source of the voltage if it is in the range that attracts them.



How can I determine how much the Black Box will improve the catch on my boat? Are some boats naturally better than others?


The impact a Black Box will have on each boat differs. Some boats may have all factors favorable. The bonding is good, there is no electrical leakage and the natural voltage is just about the ideal level. In this instance, the Black Box would add very little to the catch results. Many other boats have poor bonding, "hot spot" voltage leaks, bad zincs or natural electrolysis levels that are way too high or too low. In these instances, a boat tune-up and the Black Box would help considerably. If a boat has electrical leakage or a problem which results in a high or low charge on its downrigger wires, it will have a very difficult time catching fish. The only way to know for sure if you have a problem is to go through three steps: 1) Check the bonding, 2) Find and correct any electrical leakage and 3) Measure the natural voltage. See the Chapter on testing your boat. Another factor that enters the equation is the water. A boat that measures just the right voltage in saltwater may be a little low in some freshwater. The Black Box will properly compensate for all these variables.



The fish species I am after is not listed in the book. How can I find out if it works on these fish and what setting to use?


All fish have sensitivity to electricity but some species are particularly sensitive. Most of the commercial work with Black Boxes has been done on salmon where sensitivities are well known. Some fish are known to have special electro sensor cells the fish uses to find prey. Some of these are sharks, rays, sturgeon and catfish. There is simply no data on many species of fish. As experimental test results come in, we will publish them.



Will the Black Box work in freshwater?


It may actually be more effective in freshwater than in saltwater. Because of its high salinity, saltwater creates more natural voltage. Freshwater is much more variable in salinity and mineral content. The Black Box voltage control circuit will provide the correct voltage in freshwater regardless of salinity.



The text indicates you should have an "insulated downrigger wheel". How can I determine if my wheel is insulated?


Insulated wheel means the downrigger spool is not in electric contact with the boat hull. Most downriggers are constructed with plastic spools and are automatically insulated. An all metal downrigger mounted on an aluminum boat would not be insulated. Some electric downriggers are intentionally connected to a boat's electric system (Cannon Mag series). They use an electric circuit through the downrigger wire as a means of stopping the weight when it gets to the surface. This applied voltage spooks fish. Most electric downriggers are insulated by design.



Will the Black Box work on aluminum boats?


Yes. An aluminum boat actually has an advantage over fiberglass as long as it is properly bonded and equipped with zinc anodes. The metal hull serves as the minus side of the electrolysis circuit and your downrigger cables are the positive side. With the large aluminum hull area, a wide electric field is set up in the water below the boat. With the broader electric zone, fish are attracted from a broader area. All metal hull boats have a large negative "footprint" and can have a fishing advantage.



When using the Black Box, what is the effect of my leader length or the distance between my downrigger release and my lure? If I use long leaders will it reduce the effect of the Black Box?


The electric field that attracts fish surrounds your metal downrigger cable. The further away from this cable you get, the weaker the field. Therefore for best results, you do not want to use leaders that are too long. Fish will actually swim to the cable where they sense the electric field. Leader lengths of ten to twenty feet are best. However, you must balance the affect of the Black Box with other factors that dictate leader length. In some cases (very clear water for example) leader lengths of 50 to 100 feet are often needed to catch fish. In these instances the Black Box will be much less effective.



I have a Cannon or other electric downrigger that uses the short stop feature. Can I use this with the Black Box?


The Cannon short stop feature is a system where the electric downrigger automatically stops when the weight breaks the surface of the water. This is accomplished by using the downrigger wire as part of the electric control circuit. When the Cannon downrigger is turned on, a strong positive charge of up to 7 volts is imposed on the cable. When the weight breaks the surface, the circuit is broken and the downrigger stops. The Black Box is going to impose a steady voltage of whatever you dial onto the wire (.5 volts, .6 volts etc.). If a downrigger with a short stop is turned on with the Black Box running, the Black Box voltage control circuit will not let the voltage on the wire rise above your setting. The result is normally the short stop feature will be overridden and the weight will not stop until it jams into your downrigger pulley. If the Black Box switch is turned to natural voltage position prior to turning on the downrigger, the automatic stop will work.  Note: When voltage as high as 7 volts is imposed in the water, most fish will be repelled from the area. When commercial trollers are being bothered by hake or other trash fish continuing to hit their lures, they will "blow off" the trash fish by turning the commercial Black Box up to 2.0 volts.



How much power does the Black Box take? Will it interfere with my loran, VHF radio or fish finder?


The Black Box takes very little power. At full load it uses only one tenth of one amp (.1 amp). This is an insignificant amount of power relative to the other electrical devices on the boat. It puts out a small steady current of DC electricity and will have no effect on radios, lorans, etc.



Do I need to increase the Black Box voltage for extra deep operation?


If your boat has a base natural voltage reading in the range of .7 to .9 volts, most of the time you need not be concerned with depth up to 100 feet or so. Your Black Box will bring the entire wire into the range you set at the surface. If you are fishing more than 100 feet down, there can be a slight drop in voltage on the deep section of the cable. The Black Box voltage can be raised by .1 or .15 volts to compensate for this.



How does the Black Box actually increase or decrease the voltage all the way up and down the cable?


This answer is complex even for those with a good understanding of electricity. The Black Box is not actually adding or subtracting voltage from the wire. If it attempted to do so, the charge would be quickly dissipated by the electrical conductivity of the water. The Black Box works by altering the rate or level of natural voltage that your boat and downrigger cables generate. Because of this, the same voltage is being generated by the chemical reaction at all points along the cable. You will therefore have the same voltage 50 or 75 feet down that you read at the surface.



Can the Black Box be used on boats without a 12 volt battery?


Yes. The Model 1500 Black Box is designed to operate from a standard 9-volt battery, when installed. The Black Box installation is the same except the wire going to the 12-volt boat battery is not connected. The Black Box technology is available to all fishermen usung downriggers or the transom mount. It will work on any boat large or small; with or without an external 12-volt battery. 

Kokanee are very sensitive to an electric charge. A Black Box works very well on this species.

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