Northwest Fishing Reports

I think I messed up. I hooked up and used the new fish finder I talked about in another post today. After getting home I thought I would get rid of about 15 ft of extra cable on both the speed/temp wire and the transducer wire. I figured that just like anything else electrical you could cut and just match up the color coded wires. Well, I did that and haven't been able to test it yet but I'm a little worried a made a big mistake. Anybody have experience with this? What to do if it doesn't work correctly? And yes I know, I should have researched BEFORE I cut the wires. Thanks

well, it's too late now, but you should be fine as long as it didnt have power at the time of the cutting. To prevent shorts.

the speed and temp seem to be working fine, and I don't know what a fish finder will read when it's not in the water but the depth blinks 0.0 ft Is that normal?

Call the manufacturer or a service center in your area. In all the units I have had they clearly stated DO NOT SHORTEN THE TRANSDUCER CABLE. My layman's guess would be that shortening it may have an effect on the signal going to the transducer and returning to the unit. It may change the resistance of the cable. Worst case scenario, you will have to buy a new transducer.

After reading the post, out of curiosity, I did some digging around on the boating forums, and found this discussion in The Hull Truth Boating Forum. The post was, "Cutting A Transducer Cable"........


Default Cutting transducer cable
I was a professional marine electronics tech and spliced many cables that were cut by inexperienced installers(read: boat owners).
It can be done IF the integrety of the shielding is maintained, and the person has good soldering skills.
A properly tuned VHF antenna is 50 ohms, and if the cable is good, the radio sees a 50 ohm load, regardless of lenght, however, dont shorten it below 7 feet (2 wavelenghts).
the transducer cable, is a tuned circuit with the element and cable working together.
Some shortening and lenghtening can be done but within reason. For instance, if its 25 feet, I would not cut it past 15 or lenghten it past 40.
Now, if you have to cut a plug off to run the wires, Make sure that all shielded wires stay that way, not even unshielded for an inch. Does 2 bad things: 1. Screws up the impedance match. 2. can admit stray interference to the unit.
The impedance matching thing is somewhat like having a hose with water flowing thru it. If the hose is proper, the water flows smooth and with little resistance. having the shielding damaged is like a kink in the hose. Some water gets thru, but it is not right.
As said above, if you cut the depth cable, have someone who can solder handy.
My sounder came with 30' of transducer wire and there is 15' coiled up and taped. tell you something?
Captharv

I was an electronics tech in the USAF and made many an RF cable that was tuned to electrical length, so critical it amounted to trimming as little as 1/16" to get the desired wavelength. Pilots don't like instrument landing systems put them anywhere other than the runway!

Anyway, I did the same as the guy in the section Marc posted, my extra 'ducer cable is in a neat coil hidden under the gunwale too. I know of no sounder mfr that says it's ok to cut the cable, but if you follow the specific guidelines in the quote, you might luck out. Worst case scenario you'll have to get a new 'ducer.

As a former radio and navigation tech in the USMC, I have to second what Hewsfisher mentioned. A tuned RF circuit is not something that you want to tamper with in any way. The shielding is also very important if you have any other wiring running next to your transducer cable as it acts as a noise shield as well. If it does work, I'd still keep an eye out for a replacement cable as unless the splices are soldered and the integrity of the connections are protected from any type of moisture, you'll eventually run into issues.

fishinator,
I've been looking (unsuccesfully) for some used cables for a Humminbird that I have and ran across this last week on the Seattle CL. At the bottom of the ad he says he has an old Eagle power cable and transducer. In case you're interested. If so, make sure it would match your unit. FYI.

craigslist ad

ok that was really stupid...Anyone now where I can get a new transducer for this thing? I responded to the craigslist ad and heard nothing back. Anyone else have any ideas?

Also this thing is pretty old anyway. What's the best fish finder I can get for $250 or less if I can't find a new transducer?

Thank you

Check at the White Elephant on North Division. He has some real good prices on fish finders. I bought all three of mine there. Besides, it keeps the money in our community.

Fishinator,
give the folks at Portland Marine and Electronics a call
503-922-3259
They may be able to help you out.

Fishinator - You may be OK, don't know until you try it. I don't think the sonar units use RF frequencies where the impedance matching is much more critical. I think the signals are lower frequency. (I could be all wrong, I'm just an elelctrical engineer who loves to fish.)

When you cut the cable, was there a shield around the wires- either a braided wire mesh or copper tape or a aluminum/mylar tape? If so, make sure you replace the shield and solder the two ends back together to make a continuous shield. There may be a seperate shiled on teh temperture sensor wires and on the sonar transducer wires. I recommend insulating the whole splice with heat shrink tubing. Check at radio shack for some shileding and the heat shrink.

Good luck. Don't panic!

I just had to buy a new transducer for wide side and have an extra transducer that works great . What kind of fish finder is it? The one I have is for a humminbird 700 series. On the box it dose say not to cut the cable to the transducer.

Not sure if they are still there but check out Fred's appliance on division.
They spliced a co-ax cable for me one time.

it's an old EAgle Magna II plus

Check the Lowrance home page and see if they support this unit. Might get one from them.