Up to 21 feet long and 1700 lbs?
Who is bringing the crane? Otherwise it is a questions of who is catching who.
(I suppose ice anchors would be needed for the fishermans harness)

Fishing at 800 to 1300ft depth? with 80-120lb test braided kevlar?
Gonna need a somewhat bigger reel
(Anybody got a range extender for the vexlar?)

Anyway, it sure makes our little crappie harvesting look tame

Comparing graph vs flasher…

Having never used graphing unit this is purely a
“mental excercise” Real world feedback would add
a lot.

As I stated in an earlier post, there is almost no
intellegence applied to successive samples on flasher
units. Each “ping” is displayed and forgotten.
With graphing unit’s the display is capable of conveying
much more information, and as such and information that
can be correlated between successive “pings” can be
presented to the operator.

This ability to accumulate information about whats going
on underwater over successive “pings” is what makes graphing
units MUCH more useful in a moving environment (such as
a boat under power). A flasher unit is pretty much
only useful as a depth sounder on a moving boat especially
one moving at any speed above a crawl. The graphing unit
will be able to identifiy objects which have moved relative
to the surrounding and identify them as fish, and provide
a visual picture of the bottom as opposed to a single point
of “depth”.

To me this means that a flasher is ideal for ice fishing
and other forms of fixed location fishing. Whereas for
mounting on a boat, some form of graphing or LCD panel
display device is better suited.

Mike

BTW, If somebody want’s to see both in action and is willing
to commute to NW Twin City Metro area, drop me a line and
we can work out a time (Unfortuantely next 3 weekends are
out)

Mike

If you have 300 to spend, save up 50 more and look
around for a lx3. They had a new one at Trails End
store on 65 south of 610 for 320$ recently. May have
been one of a kind.
I’d mortgage the cat for a few extra bucks for the
zoom capability of the FL18 or the LX3.
In my opinion it is worth waiting for.

I’ve had the Marcum out once now, so I’ll provide
some early observations:

I like the color presentation on the FL18 better.
Green/Yellow/Red on FL18 vs Yellow/Orange/Red on the LX3
Perhaps a partial color blind person (Isn’t blue/green
most common?) might find the Marcum better.

Both seem about the same as far as brightness.

The LX3 appears to be able to cram the bands closer
togeather than the Vexilar. (More display resolution)

In 45ft of water, the FL18 seemed to be able to filter
out the chaff better than the LX3. That can be good
or bad depending on the willingness of the operator to
use grey matter for filtering.

Raw facts and associated observations:

The LX3 has scales of 20ft,40ft,80ft,160ft
The FL18 has scales of 20ft,40ft,60ft,80ft,200ft
Edge here to FL18 for having the 60ft range if you
fish between 40 and 60ft.

LX3 has a two stage zoom which either zooms to a 5ft
or 10ft range on the 20 and 40 foot ranges (10ft/20ft
on the 80 and 160ft ranges) The zoom is adjustable
to anywhere on the display, however it defaults to
the top 5/10ft (Wouldn’t it be nice if it started out
zoomed to the bottom)

The FL18 has a fixed zoom on the bottom 6ft of the range.

Edge on zoom capabilities clearly to the LX3 (Those fish
bouncing between 5 and 7ft from bottom always were a pain
with the FL18.)

The FL18 has a bottom lock feature for use on “soft water”
ie attached to boat.

The FL18 has a low power option for fishing in shallow water.

The LX3 has a higher output power than the FL18.

The LX3 has a flat black finish whereas the FL18 has
glossy finish…. IMHO LX3 looks better

Both are good flashers, I wish I could combine features
of each into the ideal flasher:
FL18’s flasher color scheme.
LX3’s Zoom system
FL18’s Selectable output power.
FL18’s 60ft range
LX3’s display resolution
And a 100$ price point

Hope this helps some,
Mike

1/4 amp at 12v to produce 2000w Peak to Peak…

Well it’s possible… basically playing the same games

the old cheap amp manufacturers used to play….

The unit is drawing 3 watts of power so it must use

a duty cycle of less than 3/2000. (Think of the flash unit

for a camera)

As far as how some of the best units can operate on 15 watts

of power (peak or RMS Without knowing of the unit you

speak of, I would have to guess that they focused some on

the receiver to augment it’s sensitivity. But (just

guessing here) The majority of the additional cost is spent

on signal processing and presentation. The flasher units

are presenting the sonar data in nearly a raw format with

very little correlation between successive sonar samples

(exceptions for bottom lock on FL18).

I’m not an engineer for a fish finder manufacturer so I’m

flyin’ by the seat of my pants here. Nor do I have any

experience in the field with the units of which you speak.

However, I would seem to me that the power output of the

unit and the receiving sensitivity of the unit are a

balancing act. And barring outside factors (exploading

fish and such) higher power output is a better solution

than increased receiver sensitivity as it raises the signal

above the ambient noise floor.

For example drawing back on the stereo/audio market again;

DBX noise reduction works by compressing the audio source

then amplifying it during the recording process. Then on

playback, the normalization of attenuating the audio

as it comes off the tape prior to expansion drops the

noise floor of the tape by the percentage of the attenuation. (Kind of like hiking up your pants when

walking through a puddle. With your pants being the

music, and the puddle being the low level noise on

the tape)

That being said, if the most expensive units are using

sensitive receivers and low level transmitters… there

must be a reason, I just don’t know what it is.

Cheers,

Mike

Well the RMS power may not be as relevant in this area

as in the audio world. RMS stands for Root Mean Square

and is easily thought of as “heating power”. For example in

your wall outlets, the voltage is labeled and 120V 60hz. It

is a simple sine wave which goes up to a peak of roughly

120+ Volts and then swoops down to a negative peak of -120v.

Power in watts is Volts times Amps (Current) so if you

averaged the Volts times Amps of the electricity going into

your heater, it would average out to zero…. Obviously

not right.

RMS power is the amount of power a DC power source would

need to generate in order to produce the same Heat output

as the AC power source.

Back in the bad old days, before stereo equipment

manufacturers where required to measure output in RMS, they

would claim “Peak output power” which the amp would only

have to be able to generate for a millisecond of time under

theoretical but not realistic configurations.

I contend that peak power has more relevance in a fish

finder than RMS. It is clear

that no fish finder powered by a 12v 7Ah battery is likely

providing 40W RMS output as I’ve defined above. What they

are claiming is “while the finder is generating signal, it

is producing 40W RMS”. I’m sure you’ve all heard the clicks

from the transducer… most of the time it is not generating

signal.

So for a given RMS rating, you may have one unit with a peak

value of 600W and a signal duration of 1/10th of a second.

And another unit which has a peak value of 1200W and a

signal duration of 1/20th of a second. (yes I know the

numbers are messed up, but ya get the point).

Higher peak output will likely have better penetration and

resolution at greater depths (Return echo’s will be

correspondingly louder to the transducer).

I can’t really see any advantage to longer clicks.

As to what Derek said about the “reciever” providing the

resolution… He is partially right….

A weaker receiver can be offset by a louder transmitter.

I would expect that the signal processing (that which

takes the echoes heard by the receiver and translates

it into flashes) in all modern fish finders should be

able easily handler much more than can be displayed on

the flasher circles. (Considering what calculations GPS

receivers are able to do based on the speed of light)

The Marcum can display a 5 ft range on 1/2 the display (lx3)

and the Vexilar can display a 6ft range on 1/2 the display.

So the Marcum wins (slightly on the 20/40ft ranges).

I’ve used the Vexilar in 60ft of medium clear water and

the zoom functionality seemed somewhat crippled at that

depth (I had a hard time tracking by my bait).

I obtained an LX3 from a guy at work who is moving down

south, and look forward to trying it’s higher power under

similar circumstances.

Sorry for the rambling post.

Mike