The small generators from the old hand crank telephones are most effective on catfish- namely flatheads. You can bust off the crank and hook a cordless drill to it to spin it fast. Make two leads, one coming off each terminal. Throw one off the bow and one off the stern and then let'er rip. If you are in a river with flatheads, grab a big net. I know of only one drainage where this is legal, though. There's a river system in NC where flatheads have been introduced and they are decimating the native fish community. It is legal to electrofish and remove all of the flatheads you want. At least it was back in 2004, but I assume its still fair game.
Dr. Willis, do you more commonly trip your generator breaker or overload your control box? What type of control box do you use (brand and model)? I know that guys successfully electrofish with SR 9.0 in estuaries. I've spent most of my time and efforts trying to get successful samples on the other end of the spectrum- really low conductivities, even though I rarely encounter them. I've done this because this is where most have problems. We've gotten some great results with manipulating our annode configurations, spacing, and diameters. I'd like to try our new box in higher conductivities. The box I used at Bruce's was an old design by an electrical engineer named AL Lewis. He's been dead for a while but his son made me one a few years back. I cannot adjust frequency or duty cycle with it, though. The boxes we are using on customers' boats are being custom built to our specifications, and they've even named a model after our company, which I thought was pretty cool. Our configuration is based on the wiring schematic for fishing with AC, which is not really a big deal.
On the DC side, the boxes have a standard peak DC output of 45 amps or can now be upgraded to handle as much 72 amps, which will likely never be used but at least the components can handle it. To use the 72 amps means you would have to be using less than 65 volts or you would overlaod the box. But it is equipped this way for the high conductivities, but we don't know how high. I've been told that 2000uS can be fished easily, but I just don't have those kinds of waters around me to see for myself. I would like to test one on Bruce's pond, but I just can't take a client's boat on a field trip except for a local lake where we test. I wish I had a large grant and a few years to play (I mean experiment) around with this stuff to really fine tune one boat with one control box to successfully sample a large range of conductivities. It would be pretty cool to sample the condcutivity, account for temperature and then exactly where to set all parameters including the diameters of the annodes. We have been making an interchangeable annode system just for this kind of "down the road" tweaking. For now, I can do well between 50 and 1500 uS (that's about the range I have around here but mainly between 200-600), which is where most biologists across the nation seem to need. Over the past 20 years, Miranda's about the only one I've found in the literature that has added to our knowledge base.
On another note, we delivered a boat to VA about a month ago and did a field trial on the James River which was pretty awesome. I wish it was during the summer because they are growing some HUGE blue cats out there. Blues are hard to get but I've shocked them on the Missouri River before. We rolled one that reminded me of a Volkswagen Beetle....must have been 90-100 lbs.
I better get back to tax preparation. I wish JHAP lived in my office, he could do my taxes and make me laugh all day.
