Sounder fundamentals for the guys who wanted it

[Ronje1]

As promised.

I was unsure of what level to pitch this at initially. Then thought that the fundamentals are important 'cos everything follows from that. Forgive me if too basic for some but a little revision won't hurt.

121236

[Ronje1]

Bit meatier

I've tried to keep the technical stuff to a minimum. It won't get any more technical than this.

Need a bit of f/back if its too deep etc.

Can sure see the irony where a term (resolution) is used by the industry to describe 3 different things. No wonder it's become confusing.

121237

[Lucky_Phill]

Can't wait for the explanation of " side scan ", forward scan and 3D mapping :):) :)

[Ronje1]

Make sure that you are au fait with the 2 things that I've put up particularly with the bit about range resolution where we're dealing with a sounders ability to distinguish between targets. In the case of the usual technology we're talking about single pulse sounders.

I commented on the catch 22 situation that single pulse sounders left us with in trying to do that and spoke about new technology.

We're going to be looking at that new technology next. Its called CHIRP and haven't the manufacturers been playing fast and loose with it.

Side scan is pretty straight forward but what do you understand by "forward scan", Phill? Make sure we're on the same page.

Haven't had much to do with 3d mapping although I've used it to give a 3d diagrams of the bathymetrics of Yeppen Lagoon here on the southern outskirts of Rocky near the big bull roundabout. Lagoon on the left as you enter the southern outskirts of Rocky. That lagoon is 11 metres deep. I'll dig up the map.

[scottar]

" If you want a sounder to give you accurate reliable information, you must have high resolution in the pixel count. At least 480 or better."

Not at all. People - a lot of them commercial fisherman, have quite successfully for a lot of years, been catching a lot of fish with sounders that had pixels the size of lego blocks in comparison to todays high res screens. It all comes down to being able to drive your sounder effectively and time on the water. In at least one situation I know of, the advancement of screen technology meant the loss of a particular type of bottom echo that was relied upon by W.A. based cray fisherman to the point we had "legacy software" written by the Japanese engineers so the new units could read the same way the older ones did. Screen resolution can certainly allow a smoother, more detailed picture and if the target resolution allows it, individual fish echos to a much smaller size I agree, but to say you "must" have it is nothing more than an advertising blurb.

[Fed]

I have an auto button that draws little fish pictures. :D

[Ronje1]

to say you "must" have it is nothing more than an advertising blurb.

How do you arrive at that conclusion, scottar? Advertising what? Larger screens?

If one only wants to see the type of bottom, then screen resolution indeed doesn't matter much. Its a big target and hard to miss.

But if you want to see detailed info, then decent screen resolution is one of the 3 important features that you need.

Screen resolution is dependent on the number of pixels that the screen is capable of displaying (esp vertically considering the main measure is depth - a vertical measurement).

Insufficient pixels and the screen image will appear a bit "blocky", more pixels and the blocks are smaller showing more detail and even more pixels again yield even more detail.

The bottom line is that if you want to see as much detail as possible (which is what recreational guys want - including me), then it doesn't matter what types of processing smarts you have in the device, you must indeed have the screen resolution or you won't be able to see the detail you are expecting. Without it, you're not going to get what you want from the device and are wasting your money.

Smaller screens are a performance compromise to suit different purchaser budgets.

Its like buying a car, scottar.

What performance, luxury, safety, economy and look you are seeking is determined by your budget. You won't get the luxury out of a Hyundai, the economy out of a V8, performance out of a 2 litre engined vehicle, safety out of a small car or look from a mass-produced one. So you compromise on some features.

But there are some essential features that you need to take more note of than others.

In respect of sounders, the number of vertical pixels in the screen is one of those essential features.

Its the screen that is going to be used the most as that's what's delivering the results to your brain via your eyes (not the controls adjusting depth, width, sensitivity etc).

Prospective purchasers/users of sounders are battered from pillar to post with heaps of misinformation and flounder trying to sort things out.

They don't want to hear how complicated things are or how many or what types of exceptions exist. They simply want to get things sorted enough to get a handle on things and can then find their own way of making it work best for them. Bit like your cray fishermen, I guess Scottar. A "one-size-fits-all" approach didn't work for them so a workaround was arrived at.

People want to over-complicate things by quoting "exceptions". That's human nature, I guess.

Anyway, I think I'll stick to blurb that advertises vertical pixel count (bigger screens).

I currently use a 10 inch screen but it wasn't that long ago that I was using a 5 inch (from memory) screen on one of the first CHIRP recreational sounders available from Raymarine (to have a look at the effect of CHIRP technology ) and there is a big difference in screen resolution between 5'" and 10".

Meanwhile, those who want to, see what u can find out about the origins of this CHIRP stuff.

[Ronje1]

CHIRP is the one of the more significant relatively recent additions to sounder technology as was "broad band" terminology.

All the manufacturers were at it. Broadband this, broadband that, chirp this, chirp that. Chirp and broadband do have a connection but I'll defy anybody to explain what its all about and how it works. I've come across a couple of people who can tell me what it brings to the table but not how or why.

I just refer to it as a "jesus box" for simplicity (no disrespect intended to anybody).

If I told you that chirp was around the place in 1912, would that surprise you? As we all know, 1912 was the year that the Titanic struck an iceberg. The rest is history so to speak.

Titanic attempted to communicate by morse code to other ships but none were in range except 1. The wireless operator on that vessel had simply turned his ship's wireless off.

That morse code installation had a fault that clearly identified the ship without the need for the operator to say who it was.

Had that wireless been on, the story of the Titanic would have been a whole lot different.

Anyway, subsequent enquiries about the tragedy were centred around the identity of the ship that could have so easily assisted the Titanic had it known what was unfolding but didn't.

The key to identification of that ship in 1912 was............chirp. Yep, everything old is new again.

Have a pressing matter that's suddenly cropped up here, so will be back overnight. Sorry.

[scottar]

"How do you arrive at that conclusion, scottar? Advertising what? Larger screens?"

Besides the fact it was basically the catch cry in every advertising campaign form Humminbird and Lowrance during their head to head product development wars 15-20 years ago, a pretty successful 20 year career - selling, installing, setting up, using and servicing pretty much every major brand and quite a few minor ones.

Larger screens - or higher resolution. Take for example your 5 inch Raymarine with a vertical pixel count of 480 or a similar sized Lowrance and then compare it to a JRC FF50 with a vertical pixel count of a mere 320 - on a 6.5 inch screen. One market place - shallow water will prefer the Raymarine because of its features. In a different market place - offshore fishing, the FF50 would have arguably been the countries number one selling unit at one time because it had features that were pertinent to it's target market, it was simple to operate and it worked - even though there were higher resolution offerings available from other manufacturers. Same can be said of the FCV range of Furuno offerings from the arrival of the 625/585 variations onwards.

I get what you are saying but the bottom line - if your sounders transmitter, receiver, transducer and processing can't display what you want to see - all the pixels in the world will not help. That's the issue with approaching sounders "by the numbers". There are some pretty impressive numbers out there but unfortunately, much along the lines of a pretty famous TV commercial - "Sounders ain't sounders".


I sold the odd sounder in my career. What most wanted was a unit that was easy to use, showed them what they needed to see and was reliable. For a lot of guys, they simply don't need to be able to count how many individual fish are in a school - sure the pictures look cool but at the end of the day, by using a zoom or shift facility they got all the detail they require. Certainly for some types of fishing - shallow, calm water using the later gen sidescan units that actually have the capability to return echos that can be processed into near photographic quality images, resolution is of the utmost importance but for others the biggest things are the sounders ability to return noise free images at speed or sheer deep water capabilities.

Complicate things by quoting exceptions - every different type of fishing is to an extent an exception. One sounder no matter how high the resolution, will not suit all and some sounders with "inferior" screen resolution did / do a much better job of some applications. If two separate fisherman came to me asking for a sounder, the first question they would be asked is "for what type of fishing", the second was "on what type of boat" and the third was "at what type of budget. The recommendations were very different dependant on the response to the first question in particular.

[Ronje1]

Scottar

I'll send you a message where you can have a urinating contest (if that's what you want) without disrupting the guys who want to find out about things, maybe?

Now we know that the principle of chirp has been around for years and years.

Morse code chirp (warbling code characters) was caused by the morse code tones changing frequency (therefore what the tone sounded like) every time the transmit key was pressed. The result was that the transmission sounded like a canary warbling or chirping.

Yep, birds chirping. THAT'S the principle behind recreational chirp sounders. That's one you can use on trivia nights.

Wind forward 30 years from the Titanic to WW2 and the infancy of operational radar.

WW2 (and later) military radar researchers found that while they might be able to see a reflected signal, they didn't know if they were looking at 1 enemy aircraft or several.

They needed a way to improve resolution and found that by changing the frequency of the radar pulse as it was sent out, they could achieve that. Success but that military success was immediately classified for military use.

Like every research project that military researchers get involved in, this project had to have a name.

Radar research had more priority (and funding) than submarine research, so the radar guys got naming rights.

A name related to changing (sweeping) of frequencies in use already existed (from morse code days) for that type of thing. Chirp.

Having a name already , suitably impressive-sounding words were cobbled together starting with the the first letter of each word. Back -to- front acronym construction.

Compressed high intensity radar pulse. Compressed high intensity radiated pulse. Compressed high impact radar/radiated pulse. Take your pick of which one you think is correct as they all sound technically impressive but ALL the letters still spell CHIRP.

Only in the 50s was the breakthrough de-classified and work began on the principle for civilian use.

That's the history behind your chirp sounder.

Everything old is new again.

[Ronje1]

Back again with the next step - Chirp technology.

We all know abouit chirp by now. Don't we?

Anyway, I can't move on without talking about Lowrance.

Lowrance is a US based manufacturer who caters for the US east coast (Atlantic) and west coast (Pacific) markets. Deep water stuff.

So their chirp innovations are concentrated on deep water applications. That means lower freqs. Hence we see them them focusing on 50khz, 83 khz and the highest effective deeper water frequency 200 khz.

So that's what they did and mainly in the commercial market.

In Aus we don't normally see anything like the depths that require those frequencies.

We're basically "shallow water" uses of sounders.

Humminbird, Garmin and Raymarine (plus others) focused more on the shallow water users.

Aus is lucky that that shallow water users in the US included the "bass brigade" in dams, impoundments, rivers, creeks and other shallow environments.

So there was a fair US market for shallow water sounders.

That means standard higher frequencies like 455khz, 800 khz and 1200 khz (Mega). Raymarine had their own shallow water frequency of 360khz.

To maintain a place in that market, Lowrance advertised broadband technology, CHIRP technology etc but really only paid lip service to that by only putting CHIRP on their deep water market (50 khz, 83 khz and 200 khz).

Even their comprise to appease the US shallow water bass brigade stopped at 800 khz (last time I looked) so their sidescan stuff isn't chirp so doesn't have the ability to distinguish between targets like most of the others. Don't think that their structure scan feature uses chirp either. Happy to be corrected about that.

Then to add insult to injury they called 200khz CHIRP High Chirp. High my foot!

Anyway, here's the next edition.

121250

[scottar]

No pissing contest required. You asked how, I answered. There is no way to put experience into a quantifiable numerical answer and regardless - like I posted, numbers don't make a sounder. Don't bother with the PM.

Your Lowrance post - you may have been given a bum steer as to the companies history I'm afraid. Up until chirp came about Lowrance wouldn't have known a deep water sounder if you belted the MD of the company about the head with it. They had been chasing the Japanese and Simrad in the race for deep water performance for like - ever.
Lowrance's parent and main US market was the bass fishery - why - that's where the money was. Navico - the investment company that now owns Lowrance, killed off one of the better deep water sets when they purchased Simrad and "Lowranced" the sounder component. Compared to them back then we were a deep water fishery predominantly - at least those that bothered with sounders. They were years behind in even introducing 50KHz as a frequency and even then you only got it if you purchased a separate (and somewhat expensive transducer). All their earlier offerings were 192Khz and used cone angles that made any sort of definition beyond 50 metres near on non existent. They even manufactured a "3D" model that was a dismal flop at 192KHz using a 6 beam transducer - in a direct response to Humminbird doing it first. They also struggled in the deep water markets because as the rest of the world went to colour and the inherent echo return strength differentiation it provides, Lowrance chose to stick with LCD on the grounds of being water proof (ish).


It was well down the road - long after some of the Japanese manufacturers, that Lowrance, with the availability of cheaper Colour LCD displays, went to colour and at the same time someone in marketing made the decision to go to more traditional frequencies - probably to allow them to utilise Airmar's range of transducer options and give them transducers alongside their own, that could provide deeper range capability.

It was Airmar's chirp transducer development that has driven the sounder manufacturers push into chirp for a traditional 2D picture. For some of the manufacturers it has provided a cost effective way to finally attempt to challenge the Japanese in the deep water race.

[Ronje1]

Geez, a "negative nancy" ego that wants to argue about every bloody thing. I can't see him any more now so he's disrupting you guys only.

Got some more for ya to think about.

[Ronje1]

A screenshot from yesterday.

Note the speed across the bottom at .3kmh. That was at electric anchor.

However, speed through the water was more than that because of pretty high tidal run (about 3-4kmh). Fish were travelling WITH the run so they were going through the beams at about my normal searching mode. THAT'S why not much elongation of the image. You get elongation of image when boat still and fish moving through beams slowly therefore taking longer to pass (so they appear elongated).

If you're sitting above a school with little relative movement between boat and school, it looks like spaghetti junction.

Saw a image not so long ago of a elongated image under a guys boat at anchor. He thought it was croc but it was simply a long fish being made to appear even longer by the slow movement. You won't mistake a croc under the boat.

What I'd like to capture on a sidescan image is a Fitzroy R dolphin (special type apparently).

These 3 images are all CHIRP. You can tell that by the little frequency boxes in the bottom left hand corner.

175 - 220 , 780 - 860 and 1150 -1275 means that each image is being swept across a range of frequencies. 45khz sweep centred around approx 200khz, 80khz sweep centred around approx 800khz and 125 khz sweep centred around approx 1200 khz respectively.

Sweep frequencies mean its a CHIRP image.

Anyway, top is sidescan, bottom right is downview and bottom left is normal sonar.

Still got a bit of fiddling to do with "knob" settings since software upgrade (as you can see from the straight "sonar" view - bottom LHS).

Today's job in town reach. More king have arrived since the other day so should be plenty of targets available.


121252

[chris69]

Geez, a "negative nancy" ego that wants to argue about every bloody thing. I can't see him any more now so he's disrupting you guys only.

Got some more for ya to think about.
Your writing the stuff that's being questioned Ron if you can't hack it move on.

[shortthenlong]

Geez, a "negative nancy" ego that wants to argue about every bloody thing. I can't see him any more now so he's disrupting you guys only.

Got some more for ya to think about.


121253

I need to add ten characters.
Matt

[Funchy]

Scottar has been around these parts a long time and I value his opinions and experience. I don’t think he was trying to piss you off think he was adding to the discussion for all of us to consider.

hopefully you will both continue to provide your valuable insights

[Funchy]

Ahhhhhh I see now. This is Ron aka “Douglas” from Rocky. (You AAers should know what I’m on about)

I’m off to get the popcorn

[Barry Ehsman]

Ahhhhhh I see now. This is Ron aka “Douglas” from Rocky. (You AAers should know what I’m on about)

I’m off to get the popcorn
Fair dinkum !!!

[Funchy]

Fair dinkum !!!

would I lie to you Baz 😂

[gunna]

Yep. I warned the members about him in another Post he put up. Scottar has confused the issue by stating facts. Some people can’t handle that. Particularly those who get all their so called expert articles by copying different stuff from all over the Internet. Not saying this bloke would do that. And some people get fish pictures and sounder pictures by copying them off the internet. Just saying.

[blacklab]

I had a good read of the first stuff, for me, an interesting read, thankyou.

I hope it continues, but equally, u should unblock Scott ( i presumed that's what you mean by not being able to see him anymore), as discussion or debate, if done properly, is how we learn. You obviously have a great deal of knowledge on the fact, but I do have to point out, that in my opinion, Scott, who physically worked in this industry, or to that matter still does, offers excellent first hand knowledge, both technically and physically on the water, of which, I personally, and I'm sure many others on this site, respect both him and his opinions and advice we have all received over the years.

As I am someone that really is deficient in the "sounder fundamentals", It would be a shame to ruin, the potential benefits this topic could bring for a lot of people..

Just my view..

Col

[catshark]

great discussion from all perspectives , i for one am enjoying the read thankyou

[Volvo]

Me three :) .

[Cammmo]

Well I valued the read thanks!!!

So,

If you had a budget of 20K (ish)
And we’re building a new glass boat at 6.7m predominantly to chase Red Emperor and Rosies in the NW what would you install?

I thought I had it figured out but keep second guessing. I want to read bottom at 25knt +.
Through hull, transom mount or otherwise still has me muffed.

I looked at a furuno package as follows; still await the final $$$. But this still lacks a second screen for navigation & sounder at once. And budget 25K+ (I think)

TZT3 - 12” display
DI-FFAMP sonar module
Nav Pilot 711C
SCX-20 sat nav
DST -800 - temp sensor (any other option if avail)
82B 35R - 2kw transducer
SS175HW - 1kw transducer
1 x VHF radio
1 x fusion stereo

Worried that the manufacturers specs have temp range up to 55°. I want to flush mount and think I would exceed that temp at times here 🤔

Thoughts ???

[Ronje1]

Cammo

I'm flattered by your post, but I recommend that you seek advice from a supplier who should be able to sort out a suitable package for you. That's their living and I don't want to intrude on that.

However, I recommend that you go to a retailer who specialises in sounder servicing and marine sales (not a tackle shop or supplier where they simply sell stuff or send faulty stuff away).

What am I setting out to achieve?

Cut through as much confusion as possible by avoiding technical and industry jargon and laying it out in simple easy to understand terms with a view to helping non-technical people sort some of it out.

I've put up some little anecdotes about history involving some of the terms to give some perspective on the different subjects and also to give real life instances of why/how something is what it is.

I've also used some PDF attachments in pretty plain language that can be downloaded and printed as a reference if somebody wants to check on something.

They're simply my version of "making it simple" and meant to complement any existing sources (maybe make them a bit easier to understand). Not replace them.

For that to be successful, some "literary licence" needs to be given by people who have a better understanding about the subject than most. To understand what's trying to be accomplished.

You might have noticed that I've done the easy to understand stuff on a couple of other subjects where confusion exists 'cos I've got the background experience and quals to do it.

[Lucky_Phill]

Well I valued the read thanks!!!

So,

If you had a budget of 20K (ish)
And we’re building a new glass boat at 6.7m predominantly to chase Red Emperor and Rosies in the NW what would you install?

I thought I had it figured out but keep second guessing. I want to read bottom at 25knt +.
Through hull, transom mount or otherwise still has me muffed.

I looked at a furuno package as follows; still await the final $$$. But this still lacks a second screen for navigation & sounder at once. And budget 25K+ (I think)

TZT3 - 12” display
DI-FFAMP sonar module
Nav Pilot 711C
SCX-20 sat nav
DST -800 - temp sensor (any other option if avail)
82B 35R - 2kw transducer
SS175HW - 1kw transducer
1 x VHF radio
1 x fusion stereo

Worried that the manufacturers specs have temp range up to 55°. I want to flush mount and think I would exceed that temp at times here 樂

Thoughts ???


Sending you a PM to sort this out.

stand by

[Ronje1]

A little ready reckoner calculator to help better understand some of the fundamental terms like size of targets that you sounder is capable of seeing, the range resolution/separation of CHIRP and the range resolution of sounders without chirp. The last one is based on the length/width of the pulse in milliseconds (thousandths of a second).

Just put the detail that you have in the yellow squares and the answer appears in the pink/lavender squares.

Its protected against accidents so you can't hurt it.

.................................................. ......................

PS looks like excel isn't an acceptable file type.

My email a/d is ronje1@optusnet.com.au if you want a copy of it to use for yourself.

[seastrength]

Sending you a PM to sort this out.

stand byHi Phill and other Ausfishers
Would you mind making your recommendation public as I am considering a similar upgrade of my current sonar. I have an a128 Raymarine MFD package running Lighthouse software with separate transom mounted CP100 downvision and CP200 sidevision transducers, now 5 years old. It will only hold bottom to 40 klm/hr at depth to 30 metres. Good for Moreton Bay. Looking at best option for offshore Moreton and Straddie hunting snapper and pearlies. Cheers SS.

Sent from my LG-H815 using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[scottar]

Well ……….that escalated quickly :LMAO:

Ronnie, if you are listening, jeebers bud, if a difference of opinion and a couple of corrections is all it takes for you to throw the toys out of the cot, do yourself a favour and never open the politics part of the forum or you will probably have a stroke.

I'm all for poetic license - where it has a place. I'm also passionate about a field that I have basically spent all of my adult life involved with. As you said - there is too much bullshit out there (poetic license taken) - let's not add to it. You are doing a pretty good job with the tech stuff - better than I probably would because I stopped worrying about all the "why it works" years ago and concentrated on the "does it work" and "is it better than the other one" - that's the reality of technical retail. We didn't want to sell gear that we then had to sort out at our cost so selling the product that was best for what the client wanted in the most reliable package available is paramount. Engineers and tradies have the same "clash" in pretty much every field where they are both involved. No argument that the numbers guys are clever and know why stuff works - but it's the bloke on the coal face that sees the difference between various products and that ultimately one works better than the others for a given set of circumstances - maybe without ever fully understanding why - because in reality to him, it doesn't matter. As for the PM - it's a forum mate. Everyone is here to learn - try a bit more technical stuff - I suspect quite a few of the lads here will surprise you with their understanding - and they will call you out if they think it's bullshit - at least they do with me. If you can't cope with that, you are going to struggle round these parts.

Your chirp chit chat - pretty spot on. I will add that besides the effective pulse shortening (for each frequency - not overall), the other reason it gives such a clear picture is that they process the bejesus out of the return. For some blokes - this is great. Not everyone understands raw echo sounder data from a traditional pulse sounder to the same extent. Ultimately though, with high processing, the downside is that some raw information is lost - thus for a lot of users, chirp has it's own inherent problems. The biggest one I have noticed (in the field I spend most time in - offshore), is that in comparison to a traditional sounder the bottom discrimination is pretty average. This really comes into play when looking for variations in flat country that can hold species like pearl perch. Chirp can also be noise prone - just like a pulse unit. The receiver is open to a much wider range of frequencies and as such things like propeller noise can be just as much (if not more) of an issue.

[scottar]

Well I valued the read thanks!!!

So,

If you had a budget of 20K (ish)
And we’re building a new glass boat at 6.7m predominantly to chase Red Emperor and Rosies in the NW what would you install?

I thought I had it figured out but keep second guessing. I want to read bottom at 25knt +.
Through hull, transom mount or otherwise still has me muffed.

I looked at a furuno package as follows; still await the final $$$. But this still lacks a second screen for navigation & sounder at once. And budget 25K+ (I think)

TZT3 - 12” display
DI-FFAMP sonar module
Nav Pilot 711C
SCX-20 sat nav
DST -800 - temp sensor (any other option if avail)
82B 35R - 2kw transducer
SS175HW - 1kw transducer
1 x VHF radio
1 x fusion stereo

Worried that the manufacturers specs have temp range up to 55°. I want to flush mount and think I would exceed that temp at times here 樂

Thoughts ???

A couple of new products in that list Cammmo that haven't hit the streets - may be some teething issues - if you can live with that until the software updates arrive, I would assume that in typical Furuno fashion they will do everything you want. The new TZ3 from the U-Tube video at least has some pretty good user interfaces. The temp rating - my opinion - is probably to do with the fact that pretty much everything (all brands) that uses a bonded LCD has suffered from instances of screen delamination. https://en.wikipedia.org/wiki/Optical_bonding

The main reason in marine screens at least is fogging - it's been the bain of LCD displays in boats since their inception - doesn't hurt having less reflection either. The downside - the resins don't seem to like heat too much. From the looks of things they soften and then get bubbles around the edges. It doesn't seem to effect operation to much but it looks pretty average.

Transducers - first up the high wide. Great transducer if you want pretty fish arches everywhere...….but IMO really only has a place on two types of boat - those that chase highly mobile game fish where they will zero in on a lure from anywhere in the cone angle and those that pretty much stay in water less than 30 metres deep - places like Port Phillip Bay. Over 30 metres, a wide angle transducer is missing bottom detail due to the sheer area of the cone and any fish in the extremities are lost in the bottom echo anyway. If fish are holding tight on structure and not coming off, it's also harder to know whether you are above them or beside them. You would be far better off IMO with a 200B-8B for general bottom fishing in those depths. I'll make the assumption you intend doing a bit of deep dropping with the 82B-35R - used them myself to 500 odd metres - good transducer. If you aren't deep dropping - probably wouldn't bother - way too much money for the shallower offshore. Something like the CA-50-200-1T and a matching box is also a viable option for shallow to medium depth and will save a bucket of cash as you don't need the sounder module. There are also Airmar 1 Kw tilted element options that will drastically reduce your installation cost if you don't need the 2Kw punch.

[Ronje1]

Guys

Getting too disruptive to people who genuinely want to learn some basics.

Had a couple of other little things about sounder fundamentals (to do with transducers) that I thought might be useful for those wanting to find out a bit more.

Also a couple of the technical specification tricks to watch out for that sounder manufacturers get up to in their advertising which has also done its share of adding to the confusion.

I think the main impact of those little tricks is to further confuse any retailers who are not technically conversant with what its all about. These confused retail staff are the ones who most prospective buyers take advice from.

Anyway, I'll leave you with a little summing up of CHIRP and a screenshot of that simple little calculator.

My email a/d is there.


121286



121287

[Dignity]

Interesting views, textbook vs reality. I might have to get more popcorn.

[Lucky_Phill]

I am finding it interesting and always appreciate an alternative view or opinion.

It's a bit like the saying ": you can lead a horse to water ..." ><>

or my favourite..... a boat only rides as good as the skipper... same same for a 4 x 4.

cheers LP

[Ronje1]

Just because somebody has an engineering understanding of things doesn't mean that they stay on the textbook side, Dignity.

I'm also familiar with the "dark side" (reality). More than most. Not as much as those who make a living out of it.

Between those two extremes is the "confused zone" and that's where the problems faced by the average prospective buyer/user lie.



Its nothing like the saying " you can lead a horse to water" Phill, 'cos I'm not trying to convince anyone about anything or trying to make them do anything.

Just laying it out for people to take it or leave it as they wish. No alternative views or opinions.

More like showing a horse how to recognise water thus making it a bit easier for him to find it and get it for himself. That's the idea anyway.

Nothing to get excited about let alone reaching for the popcorn.

Got a bit more informative stuff.

[gazza2006au]

Teachers in the house she has a whip for the naughty learners 121288

Sent from my SM-G900I using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[Dignity]

Just because somebody has an engineering understanding of things doesn't mean that they stay on the textbook side, Dignity.

I'm also familiar with the "dark side" (reality). More than most. Not as much as those who make a living out of it.

Between those two extremes is the "confused zone" and that's where the problems faced by the average prospective buyer/user lie.



Its nothing like the saying " you can lead a horse to water" Phill, 'cos I'm not trying to convince anyone about anything or trying to make them do anything.

Just laying it out for people to take it or leave it as they wish. No alternative views or opinions.

More like showing a horse how to recognise water thus making it a bit easier for him to find it and get it for himself. That's the idea anyway.

Nothing to get excited about let alone reaching for the popcorn.

Got a bit more informative stuff.

I don't doubt your knowledge or abilities as I am also intetested in the subject and happy to learn something new. What is interesting is that you find others input offensive in a forum that invites participation of it's members. "No opinions or alternatives" is a very dictatorial approach and in itself quite derogatory of other members on this forum who busy as they are, take the time to help to numerous others with their knowledge and abilities.

Constructive feedback is what has been given and you should accept it and where necessary debate it not shove it in a corner.

[Ronje1]

Thanks for the observations and advice, Dignity.

No alternative views or opinions.

That's a well made point and I can see why you commented about it. It was intended to apply to me and why I was putting stuff like that on the forum and why it was in that simple format but I didn't explain that intention very well.

It was meant to indicate that I wasn't putting up any of my views or opinions (just facts).

I do however disagree with your claim that constructive feedback was given and should be accepted.

There was nothing constructive in the way that was carried out.

The first post of what you call "constructive feedback" was dismissive and ended with the sentence about " nothing more than advertising blub".

Pretty constructive stuff, eh? Derogatory?

I don't find genuine input offensive at all. Happy to debate.

I DO see that posting stuff about fundamentals of subjects which can (and do) cause confusion as my contribution towards helping people sort things out a bit.

It has to be done in simple non-technical and interesting language though and that means that to be successfully delivered and understood, a bit of "literary licence" needs to be afforded by other people who DO know a lot about the subject.

Not everybody who IS knowledgeable recognises that need though and some persist with wanting to debate (and that's fair enough at first).

The downside is that wanting to debate while others are trying to put their ideas together to resolve some of the confusion, distracts and disrupts people who want to get a better grasp of the basics and simply confuses them even more.

So I sent a simple private explanation (by pm) and asked for some indulgence while the fundamental stuff was being laid out for digestion.

His failure to respond to that request coupled with a public rejection of any flagged private message public and persisting with argument meant that things were then getting into the realm of argument for argument's sake and doing everybody who wants to learn a disservice becoming simple intentional disruption.

Publicly rejecting a flagged attempted private approach (after its been made and without making any response) means that there's also a matter of manners involved. Common courtesy suggests that one at least responds privately first.

I can assure you that I did indeed attempt to converse. I also flagged that intention publicly and carried it out seeking that indulgence (including an explanation of why) and offered to debate on a separate thread.

I can confirm that there was no private answer to any of my suggestions prior to him being blocked.

When he persisted after not responding to my private message, I simply blocked him.

Yes, it was an opportunity lost for enhanced and informative forum debate about a subject confusing to many members I'm sure.

That's the story, Dignity.

Perhaps not as cut and dried as it may have first seemed and not much in the way of entertainment (see below) involved.


P.S.

Please allow me to give some constructive feedback.

"Getting more popcorn" is synonymous with entertainment and generally flags the subject as being more of entertainment value rather than of any genuine interest to the author.

That observation is borne out by the ringside seats looking for entertainment. Some even have their own popcorn.

[Funchy]

.. .



.

[gunna]

Change your mind Luke ?

[Funchy]

Change your mind Luke ?

Yeah, dead horse and that

[scottar]

Looks like I owe an apology - we will get to that in a minute.

"I'll send you a message where you can have a urinating contest (if that's what you want) without disrupting the guys who want to find out about things, maybe?"

Seems like a perfectly adult way to initiate a private conversation without bias - coupled with the undertones of the pm pointing to academic snobbery, prompted me to simply delete the pm - right alongside the handful of other PM's I had warning me about Ron's modus operandi. It is to those lads I owe the sincere apology. Fellas, I am sorry I didn't listen. I thought I knew better and would give Ronnie the benefit of the doubt as I had no prior contact with him. It won't happen again.

Ronnie,


forum

[ˈfɔːrəm]




NOUN



a meeting or medium where ideas and views on a particular issue can be exchanged.
"we hope these pages act as a forum for debate"
synonyms:
meeting (https://www.bing.com/search?q=define+meeting&FORM=DCTRQY) · assembly (https://www.bing.com/search?q=define+assembly&FORM=DCTRQY) · gathering (https://www.bing.com/search?q=define+gathering&FORM=DCTRQY) · conference (https://www.bing.com/search?q=define+conference&FORM=DCTRQY) · seminar (https://www.bing.com/search?q=define+seminar&FORM=DCTRQY) · convention (https://www.bing.com/search?q=define+convention&FORM=DCTRQY) · [more]






a website or web page where users can post comments about a particular issue or topic and reply to other users' postings.



If you don't want other input, might I suggest an "article".

You Stay Classy San Diego.

[gunna]

Nicely said Scottar.

[BR65]

..,,,,,,.......

[gunna]

Go on Brian. You know you want to lol. We’ve seen it all before eh.

[Muzza]

I believe everyone is entitled to their opinion, my opinion is Ronje , has provided some information anyone can get on the net, but he has provided it so thanks Ronje.
I also believe people will take and make an idea of a person on what they do and say, now I have done some shit I'm not proud of, but in this case my opinion for what its worth is Ronje is not playing nicely and sticking to the topic. Of course I may be wrong as it's just my opinion from what I've seen so far. He took it to the personal level and dropped the ball.
Muz
Muz

[Noelm]

Gees, this has turned out nice.....

[Dezzer]

Yeah
Sort of like a reincarnation of Kerry/Satnav.
Like Kerry original poster seems to have an agenda.

[gunna]

And isn’t karma a bugger. He has trashed other sites but fortunately people woke up to him quickly on here.

[Noelm]

I guess some people know this guy from elsewhere? The whole thing did seem to take an abrupt turn when some relevant questions were asked or info suggested.

[Volvo]

I guess some people know this guy from elsewhere? The whole thing did seem to take an abrupt turn when some relevant questions were asked or info suggested.

Dont know enough so stay out of it Mate , alway enjoy Fishing advice and believe one is never too old to learn about most stuff so listen , say thanks and share where i can..

[gunna]

Volvo - you are one of the good ones. Always enjoy your posts mate.

[Volvo]

Volvo - you are one of the good ones. Always enjoy your posts mate.
Thanks Mate and Kindly Appreciated :) ,

[Volvo]

I guess some people know this guy from elsewhere? The whole thing did seem to take an abrupt turn when some relevant questions were asked or info suggested.

Not trying to kidnap the thread lol , but Noel how far from the lake Bridge do you live ?? , Many Moons ago when working at Lysaghts i had a Good Mate who lived adjascent to the Lake right side south of the bridge and his house yard used to back onto the lake and after Arvo Shift we used to wade waste high with scoop net and Dolphin Torch for Prawns :)..
Mind you we used to get a good feed with a few Beers wee early hours of the morning made life GOOD!!..
Theys till run and still go scooping for them ??...

[Noelm]

I live about 5 minutes at the most from the bridge, I can kind of see it from my house, very few houses on the lake now, the caravan parks are still there, but the houses were purchased, along with the old hire boat shed and converted to public park land. There hasn't been decent prawns in the lake for a few years now, ever since they "fixed" the entrance, lots of crabs though, and still good fishing for Whiting, Flathead and Blackfish. There was a real big deal recently where people were getting Cockles in the lake near the bridge, they have always been there, but it became well known and people starting getting bags and bags of them, the Fisheries Inspectors kept fining them and tossing the cockles back, but in the end, the hoards won, and now you would be lucky to get a few.

[Ronje1]

OK Phill

Almost there.

Leadup to sidescan stuff

121301

[Ronje1]

Scottar and I have now settled differences and put the episode behind us.

We'll maybe work out a way to complement each other's contributions to the benefit of site members.

regards
Ronj

[blacklab]

Scottar and I have now settled differences and put the episode behind us.

We'll maybe work out a way to complement each other's contributions to the benefit of site members.

regards
Ronj

Now where talking......

Col

[chris69]

Scottar and I have now settled differences and put the episode behind us.

We'll maybe work out a way to complement each other's contributions to the benefit of site members.

regards
Ronj


Gee Ron that was nice of you, what did we all do to deserve that ,its nice for you to allow other ausfish people to share with out getting the the negative nelly comment from you.

[Ronje1]

Chris69

Mate you're wasting your time with me 'cos I can't see anything you put up. You're only disrupting other members who DO want to look. If that's what your intention is then maybe they can sort it out with you.

I've got a bit more work to do.

Guys, I think I'll put up a simple diagram to demonstrate the effect of a sloping bottom on a sidescan sonar. A picture is worth a thousand words and it might help explain things a bit better.

[Ronje1]

The diagram.

I've used a bottom slope of 15 degrees from right to left with 2 similar targets the same height out of the bottom and equidistant from the c/l of the boat.

With the same angle from the transducer out both sides to the tops of the targets and then beyond to where they hit the bottom. Measuring gives us each shadow length on the bottom.

The shadow length on the bottom behind Target B is 43% longer than the shadow length on the bottom behind Target A.

If we put 100 targets like these 2 each side, then the LHS ones would have longer shadows than their counterparts on the RHS.

Much more black because of more shadows on the LHS (sloping to deeper water).

Scaled this diagram to about 3m of water.

As water gets deeper, the shadows get shorter. Like the sun at noon casting short shadows and at sunset casting longer shadows due to the shallower angle of sun's rays. Liken that to transducer beams.


.121326

Clear as mud?

[gazza2006au]

Dropped into bcf was a quick walk in and out but got held up by another customer as i dont look around in shops.. so went for a quick squiz at the fish finders/gps first time ever playing with one with all the gizmos was quiet interesting the lowrance hook 7 i think it was was really dark on the sides of the scan i couldnt see anything the pixals were not the greatest for modern technology

I than had a ply with a 95S or 9S something and it was like a change of world u could clearly see right out to the side, changing screens was very easy got a bit lost with the zoom tho

Always wanted a 12 inch but after seeing one today that is just massive that size is not needed i reckon i'll be happy with a 9 inch screen

Sent from my SM-G900I using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[Ronje1]

Hi Gazz.

Bit like attempting to learn a new language isn't it? Faltering steps as you learn. I think that's why a lot of people like to stay with the same brand.

The 95S or 9S was probably a Garmin.

Guys like Scottar need to be across all of these brands especially those used by people to make their living from (more sophisticated types than the consumer brands made specially for the recreational market). Scott needs that knowledge to make HIS living.

I recall a trawler guy in Bundaberg called Gollchewsky (Golly) who was a disaster with anything electronic in boat. Local marine electronics dealer/repairer used Golly as a marketing tool. He didn't have to extoll the technical virtues of anything. Most didn't understand those anyway.

He used to advertise that a piece of electronic kit was " Golly-proof". Locals then knew that it was bullet-proof and simple. Golly didn't seem to mind.

I have a 4.4m alloy boat and use a 10" screen.

Just bought a 2nd hand 360 degree transducer. The 455khz version.

Always have trouble in tidal run when finding a school of king on bottom. Can never find them quickly using the electric "anchor" button or using the waypoint function. The bloody things are never where they are supposed to be when boat stops turning in circles!

Idea is when the boat settles down, to use the 360 to pinpoint direction and distance instead of turning the boat in more circles looking for them again.

Spin the transducer instead of the boat in tidal run.

[shakey55]

Dropped into bcf was a quick walk in and out but got held up by another customer as i dont look around in shops.. so went for a quick squiz at the fish finders/gps first time ever playing with one with all the gizmos was quiet interesting the lowrance hook 7 i think it was was really dark on the sides of the scan i couldnt see anything the pixals were not the greatest for modern technology

I than had a ply with a 95S or 9S something and it was like a change of world u could clearly see right out to the side, changing screens was very easy got a bit lost with the zoom tho

Always wanted a 12 inch but after seeing one today that is just massive that size is not needed i reckon i'll be happy with a 9 inch screen

Sent from my SM-G900I using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

I hope you had gloves on. Don’t want to spread or collect any germs.

Like people shopping. They pick up a item look it all over and then place back on shelf.

Just a pet hate during these times.


Sent from my iPhone using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[gazza2006au]

I hope you had gloves on. Don’t want to spread or collect any germs.

Like people shopping. They pick up a item look it all over and then place back on shelf.

Just a pet hate during these times.


Sent from my iPhone using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)I didnt even think of that thats probably why most of the screens were turned off bugger

Sent from my SM-G900I using Ausfish mobile app (http://r.tapatalk.com/byo?rid=91595)

[Ronje1]

I don't know what sort of sponsorships this site has but maybe the organisers need to be aware of this.

I won't put anything specific up if its deemed best not to by the organisers. There's more than 1 manufacturer involved with various things.

A couple of days ago I showed you how one particular manufacturer was playing "ducks and drakes" with technical claims about their product. They were upfront it about by telling everybody but very few understood the significance of what it meant.

Anybody worked out which manufacturer?

[Lucky_Phill]

OK, you can put up stuff from any manufacturer. I like to use the term... IMO ( In My Opinion ) as that simply states, you have used this and compared it to others. Nothing wrong with that.

Personally I have used many brands, but still go back to what I know ( language etc ) as you pointed out.

I remember using my first colour sounder Koden and there were NO words, just symbols on the touch keys.... might have been back in the 80's ?

IMO......... :).......... and because I know how to use them.... Furuno sounders and Garmin GPS's for me.

I did see the WASSP system when it first came to light many years... mind blowing back then ( 20 years ago now ) https://enl.co.nz/pages/wassp

.............. continue... ><>

LP

[Ronje1]

Koden made good little navigation radars, Phill.

Popular one was 16nm version for use on yachts mounted about 15ft above the deck.

However, you could open the case and bridge 2 points on the circuit board and it opened up into a 32nm radar. That meant you could see out to 40nm on the outside of the last 8 mile range ring.

Installed one on the local ASR boat in 1985 and it gave many years faithful service. This was before the days of GPS when cumbersome old SatNav was the only thing around. There was a a 1200ft mountain with big steel towers (Mt Watalgan n/west of Bundaberg) which reflected radar signals well that we could see on radar @ 40nm. With the bearing to it (compass) and range (radar) we could work backwards for a chart position with very good accuracy.


The sounder brand doing that is Humminbird. They're still doing it.

https://www.humminbird.com/sites/humminbird_site/files/2020-humminbird-product-catalog.pdf

page 26 - 27 Look for heading Sonar capabilities on the 2 page specification sheet.

2nd line is called "Sonar coverage (LHS). The columns to the right contain the different beam angles. Note the words "@ - 10 db". It appears on the spec sheet for ALL Humminbird sounder models in the brochure.

At least they're telling everybodybut they don't want to talk about it why they do it.

[scottar]

It's something I had totally forgotten about Ron. They were doing it back in the 90's too as sounders developed. From memory the unofficial industry standard was -3db. At the time they were using large coverage angles as a primary marketing tool.

[Ronje1]

That's right, Scott. The old over-used but much vaunted "broadband" promotions. Humminbird are still doing it.

The industry convention remains at -3db.

I don't believe that H'Bird were trying to introduce a new industry "standard" for measurement of bandwidth or calculation of beam angles.

Simply a "sneaky" product marketing/promotion tool aimed at market advantage.

Should attempts to change the industry to a new "standard" have been the case, H'Bird would have used the -10db points on calculating the Q Factor of transducers as well (to be consistent).

Larger divide by numbers in the denominator formula for transducer Q would give lower Q in calculations (desirable for chirp/broadband).

Had they also used those -10db points in calculating range resolution, H'Bird would also have been able to claim much better range resolution figures than their competition.

Wonder why they didn't.

Maybe they simply didn't realise the added advantage in range resolution that they could also claim by that simple bit of specification modification (despite the real rr figure not actually changing).

About the only thing that I can say about that H'Bird practice is that they at least told people albeit in the fine print.

I use a H'bird now and am happy with it despite the practice.

Had a "run-in" with Garmin marketing and promotions staff in the US (2017 or 2018) over some technical stuff.

They're still quoting those very suspicious specs on their latest models.

At least Garmin nominates the b/width measuring points as the normal -3db.

[Ronje1]

Remember this?

The Garmin GVC20 UHD (Ultra High Definition) Black Box.

https://buy.garmin.com/en-AU/AU/p/618945#specs

Click the "SPECS" and look in the Frequencies Supported boxes.

What's in there was sufficient to raise the question in my mind "what's going on here"? The sums simply didn't add up (and there are only 2 sums there).

[Lucky_Phill]

My head hurts now................ :( :)

[Ronje1]

OK, Phill.

I not going to put up anything to create sore heads.

The bottom line is that Garmin put this stuff up in ALL of their advertising. Not just in Aus.

When challenged about it, the garmin guys in Aus simply did not understand what the problem was. So I ended up with garmin in US (the marketing/promotions guys) who were across the product equally as well as the aus guys.

The garmin engineers were talking the same language though and agreed there was a problem. They claimed that it was the marketing guys who had stuffed it up. The marketing guys said no, it wasn't them.

The question of was it simply a marketing/promotions error remained unanswered but nobody within garmin wanted to accept blame for it.

In the end garmin waited and quietly changed the advertising to what it is now.

Here's the new advertising.

Look in the same place for the new info.

Might'nt look like much of a change but it certainly was to the claimed performance etc.

https://buy.garmin.com/en-AU/AU/p/626121#specs

The moral of the story is that these were just 2 of the 4 major suppliers to the rec fishing sounder market.

The other 2 (Lowrance and Raymarine) also had their moments.

They all get away with what they are able to and couldn't care less about the confusion they create.

[Ronje1]

Here's the little interactive xl sheet I told you guys about courtesy of Lucky Phill and the IT backup guys he has working for him;D.

Its protected against accidents and you can only input data in the yellow squares.

You can download the sheet to your computer to use it yourself if you wish.

There are a couple of things to look at.

No1 is the minimum size of the targets that the well known frequencies can see. The freq 360khz may not be so well known as that was the freq that Raymarine used on their first little CHIRP sounder the DragonFly.

Note the minimum size that 1200 khz (Humminbird's Mega) can see. 1.3mm.

Holy cow, who wants to catch/see something 1.3mm in length?

Well nobody I guess unless you're in NSW or Vic ('cos that's all that's left ).::)

However, if you were looking at a target in the 60cm - 1 metre range, then you'd be able to see it in 1.3mm portions thus showing the shape of every fin on the fish to the stage of recognizing what it is. I've seen

the feelers on threadfin king with 1200khz. Basically it allows species identification in lots of instances. Turtles, dolphins, sharks, crocodiles, stingrays etc stand out.

No 2 is how CHIRP makes a dramatic improvement in being able to separate 1 fish from another so that 6-7 fish together or a fish close to the bottom don't show up as 1 single target. They show as separate targets.

Look at the range resolution that CHIRP can produce ( 94mm).

You can see separate targets even if they're only 94mm apart.

Look at the range resolution that a normal pulse sounder produces using a pulse of one thousandth of a second (commonly called 1 millisecond - 1ms). 780mm.

You can only see single targets if they're a minimum of 780mm apart.

So CHIRP has a 8 times advantage over a pulsed sounder using a 1 ms pulse in separating targets.

121508

[Ronje1]

Just when you thought that it was safe to go outside again.................................

I've got a bit more info for those who want to know about choice of freqs to use and depths of water to use 'em in.

There's a big difference between the needs of blue water use (offshore stuff) , green water (inshore stuff) and estuary stuff (dirty water).

[beergood]

I’m Brian! !!
So’s my wife

[Ronje1]

Simple and basic (I hope) explanations about sounder frequencies, power and target separation for different depth users.

121658

I don't know how to delete an attachment so I'm stuck with 2. The one below this is the one I want to delete if some kind soul can assist please.

[Ronje1]

Tall tales but true. Chapter 2.

Clear as mud or any queries?


121670

[Ronje1]

Now that we’ve all had plenty of time to think about sounder basics, it’s probably time to reflect on the most significant development to occur in fish-finding circles in many many years.

That was the introduction of CHIRP technology and what it brought to the sounder table was a truly remarkable feature.

Up until then the only way to obtain accurate deep views (1000ft +) was to use low frequency channels 50 khz, 83 khz or 200khz simply because low frequency channels travel further in water.

If we wanted to obtain more depth than 1000ft then we simply used more power. That meant making the pulse/ping longer.

We’ve all seen the submarine movie “Hunt for Red October” and how pulse/pings were used to communicate. One single ping lasted for a long time (apparently).

With fish-finding sounders, pings are actually pre-set as very, very short and are repeated continually many times per second.

The longer the pulse/ping, the more power is fed into the water and the greater the range attained.

Sounds great but the real problem associated with longer/more powerful pings is that target separation (range resolution) suffers badly. Target separation/range resolution is the ability to distinguish between targets close together. With a normal pulse sounder, that distance could easily be up to 1.65m.

So if 2 fish are 1.65metres or less apart, then they’ll show up as 1 single blob.

A fish 1.65m or less from the bottom will show up as a lump/blob attached to the bottom.

That might seem OK in 1000ft + of water but hopeless in shallow water.

CHIRP technology changed that by getting rid of the pulse/ping length as the determining factor for target separation/range resolution.

It was replaced by sweeping a frequency band across our designated “channel” and that SWEEP range then became the determining factor.

Our ability to distinguish between target separation/range resolution magically became independent of sounder power and depth and INCREASED dramatically. Suddenly we could see targets individually that were only 16mm apart. Fish near the bottom became individual fish unless they were 16mm or less from the bottom (½ inch).

From 1.65 metres to 16mm for a sweep of 50. The greater the sweep, the better the target separation/range resolution. A sweep of 100 gives us 8mm separation.

And THAT increased target separation/range resolution was independent of the channel used AND also independent of the depth of water.


121972
Conventional pulse sounder


121973
Same image CHIRP

And THAT folks is what CHIRP technology brings to the fish finder table.

So the question then changes from “ What is CHIRP and should I change?” and becomes “ Why am I NOT using CHIRP?”

[BillB]

Sent a PM to you