Portable fish finder system

Just wanted to share this.

A while back when the new yak was on the way I really wanted to make the FF portable so I could use it across the small group of yaks building up in the garage. I'd come up w/ a few ideas but nothing that really fit all my needs. So when in doubt, go to the OG's for advice. Thanks SCWA and ChuckE of NCKA!

First, SCWA got me going w/ the KISS battery rig made by GWKC. It's a brilliant rig in that it's completely sealed and waterproof so that you don't need a drybag or box for it. It also has a waterproof wire connector so all you need to do is connect it and throw it in the hull. I then glued the foam transducer puck to the hull to make that semi-permanent. Lastly, I used the RAM mast mount for the FF and tucked the wires under the hatch.

I've taken it on the water and really happy how it turned out.

Z

That's a nice clean set-up!

I was wondering how/where you ran your cables till you mentioned the hatch.

Question:  Why doesn't anybody shorten the transducer cable?

That's a nice clean set-up!

I was wondering how/where you ran your cables till you mentioned the hatch.

Question:  Why doesn't anybody shorten the transducer cable?

The head unit it tuned to the length of the cable I believe.

-Allen

Well, I'll chalk my installation up to a rookie mistake with a healthy dose of beginers luck.

When I installed mine I removed most of the slack so as to avoid snags and tangles with the gear I store below.  To my surprise (and the previous owner's surprise) the unit works great.

I'll have to search for some technical data on co-ax length and its impact on signal quality.

That's a nice clean set-up!

I was wondering how/where you ran your cables till you mentioned the hatch.

Question:  Why doesn't anybody shorten the transducer cable?

The head unit it tuned to the length of the cable I believe.

-Allen

Yep, it is. My buddy ralph called lowrance to see if he get his shortened and they said they don't do it. I think some electronical wizard could do it, maybe..

well you could start learning here;

http://www.circuitsage.com/matching.html

http://en.wikipedia.org/wiki/Impedance_mismatch

http://hyperphysics.phy-astr.gsu.edu/hbase/audio/imped.html

http://www.maxim-ic.com/appnotes.cfm/appnote_number/742/

http://purefixion.com/2006/04/impedance-matching.html

just web search " impedance [(impedence?) one of these is the british spelling] matching"  but be ready for some heavy duty math..

i think it can be done easily... know who i'd look for to help?? old guys who used to run CB shops, or HAM radio oldsters who built or installed antenna systems for a living..

That does look simple Z,  so simple in fact that I think you forgot the kayak.   Actually I saw this on Z's new Hobie on Sunday and it does look pretty sweet.

Brian

All I gotta say is thanks to whomever came up with the foam puck trans. system. Just brilliant! Without that I would have had to buy multiple ones and goop 'em all down on each yak.

Z

hey all i gotta say is if your gonna go off trying to shorten cables and match impedances. i hope you have a few spare cables laying around lol...it could be done but it probably won't be done the first time

what i was wondering about and i am sure it is insignificant in this case but what does all that coiling of the coax induce into the system? just a thought

thanx for bringing up the increased impedence caused by coiling cables like that.

from on the job experience dealing every day with mil satcom, multi band and freq voice and gps installations, i might be able to shed a little light.

when coiling any cable that is used to send or receive data path signals, do not allow the coils to be smaller than 8-9 inches in diameter, and not more than 7-10 loops lay on top of each other. this is because any coil smaller than that diameter starts to become a resistor instead of a conductor. same goes for the amount you have stacked on top of itself. any more and you start creating not only pathway resistance, but an electromagnetic field that can cause major issues downstream. [ think TOASTER or old school 1960's electric space heater]

if you have to, make several sets of coils no closer than 6-8 inches apart along the cable route. i know this is asking a lot on the inside of a SOT but with a lot of patience, a bag of cable tie anchors you can pick up at radio shack or home despot, etc. and a bit of hot glue or epoxy, it can be done. 

btw, saw the real deal portable system in z's hands this morning, and thot it looked a lot like a skeleton of some poor deceased electronic animal.. 

seriously tho, having a fully portable unit like this would make a lot of sense for someone with multiple boats.. didnt appear to take much time to drop it into Z's new hobie...

btw, saw the real deal portable system in z's hands this morning, and thot it looked a lot like a skeleton of some poor deceased electronic animal.. 

seriously tho, having a fully portable unit like this would make a lot of sense for someone with multiple boats.. didnt appear to take much time to drop it into Z's new hobie...

Yeah, it looks funny, like a pile of electronic guts. And yeah it's unbelievably simple to install. Attach the FF to the RAM mount, attach the battery, and put the trans in the puck and you're done.

As to the problem w/ coiling the wire, I've personally never heard of anyone having trouble because of it. It's pretty standard practice in the yakfish community. Here's another pic of someone w/ the same ff as mine.



Although I have heard of people w/ trouble using Lowrance FF's. If the antenna is to close to the display unit there's probs. Could be just different engineering.

Z