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Old 09-09-2014, 11:26 PM
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This is another quote straight from Navico,

Our standard 83/200 kHz (HST-WSBL) and HDI Skimmer 83/200 455/800 kHz will Chirp; medium (approx. 83 – 130kHz) and high (approx. 130 – 200kHz)



Our deep water 50/200 kHz (HST-DFSBL) and HDI Skimmer 50/200 455/800 kHz will Chirp; low (approx. 50 – 75kHz) and high (approx. 130 – 200kHz)

" *Yes, Custom Chirp is still Chirping. When using Custom Chirp, you are selecting one frequency to Chirp (ex. 180kHz) instead of a range of frequencies."

Again, quotes straight from Navico.

Last edited by Team Old School; 09-10-2014 at 05:47 AM.
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Old 09-10-2014, 02:26 AM
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Originally Posted by Team Old School View Post
Ok guys. I got some great info from the Chirp engineer at Navico.
There are a lot of posts on which chirp transducer to get, hope this helps.

A Traditional or Broadband Transducer CAN BE USED WITH NAVICO CHIRP SONAR.
Even though it may be listed as a single or dual frequency, it can still sweep frequencies, and it can do it well, especially in most shallow water capacities depending on transducer model. 50khz will do better in deep water than 200khz.

A chirp transducer will outperform a broadband transducer of the SAME power.


Since the 150TM is 300watts and most 50/200 83/200, etc. Are at least 600watts, the 150TM will not do as well as most broadband transducers.

The TM150 gives medium chirp only. 83 kHz broadband ,Or custom single chirp frequencies.

I personally have a 150TM chirp 300 watt it does well, but struggles on plane. I also have a thru-hull B164 50/200 1kw. It outperforms the 150 EVERYWHERE, especially on plane. It gives me High Chirp- Low Chirp- Custom Chirp- 200broadband- 50broadband. It outperforms the 150 because it is 1000watts (and thru-hull). It doesn't have Medium Chirp, but the 50/83/200 transducers will have high, low, and medium chirp choices.

The transducers and their respective chirp frequencies are as follows per Navico;

Our standard 83/200 kHz (HST-WSBL) and HDI Skimmer 83/200 455/800 kHz will Chirp; medium (approx. 83 – 130kHz) and high (approx. 130 – 200kHz)

Our deep water 50/200 kHz (HST-DFSBL) and HDI Skimmer 50/200 455/800 kHz will Chirp; low (approx. 50 – 75kHz) and high (approx. 130 – 200kHz)

Also, Custom single Frequency is INDEED STILL CHIRP.

I received all of this info straight from the Chirp Engineer.
It is very reliable. I was waiting to hear back on all points before posting.
I personally will use my thru-hull B164 1kw for most applications, but will use the TM150chirp300watt for any Medium Chirp needs.

Hope this makes sense!!!

Mike Smedley
Simrad Pro.
Team Old School.
I have never seen a post at this forum with such an amount of misinformation before. The person you have been communicating with is obviously not a CHIRP engineer, I doubt he can be an engineer at all.

Transducer power rating is not a very important factor in deciding transducer performance especially not for a CHIRP transducer. Transducer sensitivity is what's most important parameter, but for a CHIRP transducer lower peak power can be compensated by longer pulses without sacrificing resolution. The sensitivity difference between transducer models can be a factor of several hundredths, the difference in peak power is max a factor 10 (300W to 3kW), but is usually 2 or 3.3. The max continuous power rating is the specification setting the max amount of energy which can be transmitted into the water. Transducers with identical transducer elements and max transmit power may have major differences in max continuous power due to different thermal conducting properties of the housing.

Another very important factor deciding transducer performance is the Q-factor. This is telling how flat the passband of the transducer is which is setting the resolution in CHIRP mode and how long the transducer will continue to oscillate (ring) after the drive signal is removed, this together with pulse length is setting the resolution in fixed frequency mode. Airmar CHIRP transducers have a Q-factor of about 2 which give excellent resolution both in CHIRP and fixed frequency mode. Conventional transducers have typically a Q-factor of 30 or more which is severely reducing the CHIRP bandwidth and resolution and also hurts in fixed frequency mode. Then we have Airmar Broadband transducers which are in between, they typically have a Q-factor of about 8 which is improving fixed frequency performance substantially but which is not sufficient for good CHIRP resolution. TM260 is a typical example of a Broadband transducer with Q-factor of 8 for both 50 and 200kHz, B164 is only Broadband for 200kHz, for 50kHz the Q-factor is 17.

Navico CHIRP bandwidths for non XID equipped transducers:

Low: 40-60kHz
Medium: 66-100kHz
High: 160-240kHz

For Airmar CHIRP transducers with XID the frequencies are adapted to fit the different transducers.

A custom single frequency is not CHIRP, a single frequency is a single fixed frequency, CHIRP is frequency sweeping. I think the reason why you have totally misunderstood this is because you see much better performance from TM150M in fixed frequency mode than you are used to with conventional transducer, the reason for this is the low Q-factor of Airmar CHIRP transducers.

In my experience CHIRPing a traditional transducer in shallow water doesn't bring much if any improvement in resolution, but doing the same in deep waters can give dramatical improvements in resolution (I've had excellent results with HST-WSBL in a medium CHIRP when trolling at 400m)

I will end this post by showing what NSS9 Evo2 with TM150M is capable of in deep waters.

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Last edited by abbor; 09-10-2014 at 06:31 AM. Reason: Inserted quoute of the original post I responded to
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Old 09-10-2014, 05:01 AM
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Originally Posted by abbor View Post
I have never seen a post at this forum with such an amount of misinformation before. The person you have been communicating with is obviously not a CHIRP engineer, I doubt he can be an engineer at all.

Transducer power rating is not a very important factor in deciding transducer performance especially not for a CHIRP transducer. Transducer sensitivity is what's most important parameter, but for a CHIRP transducer lower peak power can be compensated by longer pulses without sacrificing resolution. The sensitivity difference between transducer models can be a factor of several hundredths, the difference in peak power is max a factor 10 (300W to 3kW), but is usually 2 or 3.3. The max continuous power rating is the specification setting the max amount of energy which can be transmitted into the water. Transducers with identical transducer elements and max transmit power may have major differences in max continuous power due to different thermal conducting properties of the housing.

Another very important factor deciding transducer performance is the Q-factor. This is telling how flat the passband of the transducer is which is setting the resolution in CHIRP mode and how long the transducer will continue to oscillate (ring) after the drive signal is removed, this together with pulse length is setting the resolution in fixed frequency mode. Airmar CHIRP transducers have a Q-factor of about 2 which give excellent resolution both in CHIRP and fixed frequency mode. Conventional transducers have typically a Q-factor of 30 or more which is severely reducing the CHIRP bandwidth and resolution and also hurts in fixed frequency mode. Then we have Airmar Broadband transducers which are in between, they typically have a Q-factor of about 8 which is improving fixed frequency performance substantially but which is not sufficient for good CHIRP resolution. TM260 is a typical example of a Broadband transducer with Q-factor of 8 for both 50 and 200kHz, B164 is only Broadband for 200kHz, for 50kHz the Q-factor is 17.

Navico CHIRP bandwidths for non XID equipped transducers:

Low: 40-60kHz
Medium: 66-100kHz
High: 160-240kHz

For Airmar CHIRP transducers with XID the frequencies are adapted to fit the different transducers.

A custom single frequency is not CHIRP, a single frequency is a single fixed frequency, CHIRP is frequency sweeping. I think the reason why you have totally misunderstood this is because you see much better performance from TM150M in fixed frequency mode than you are used to with conventional transducer, the reason for this is the low Q-factor of Airmar CHIRP transducers.

In my experience CHIRPing a traditional transducer in shallow water doesn't bring much if any improvement in resolution, but doing the same in deep waters can give dramatical improvements in resolution (I've had excellent results with HST-WSBL in a medium CHIRP when trolling at 400m)

I will end this post by showing what NSS9 Evo2 with TM150M is capable of in deep waters.

I don't know what to tell you Abbor. I actually copied and pasted the numbers I got STRAIGHT FROM THE NAVICO CHIRP ENGINEER. I don't see how I could have misunderstood "copy and paste".

I have been discussing this with him (thru email) in detail over the last 5 days, I have also been talking with a dozen or so guys struggling to hold bottom with the 150 in very shallow water when on plane.

I only added what my personal results on the two transducers I have been using.

Thanks.
Mike.

Last edited by Team Old School; 09-10-2014 at 05:28 AM.
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Old 09-10-2014, 05:07 AM
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Abbor. My TM 150 looks great too, until I hit 25 mph, then it degrades rapidly. Do you have any screen shots of your 150 while on plane? Somewhere between 25-40 mph? I can mark even small stripers at these speeds beautifully at full throttle sometimes with my 50/200 on chirp.

Last edited by Team Old School; 09-10-2014 at 05:48 AM.
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Old 09-10-2014, 05:14 AM
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WTF is a "CHIRP" Engineer? Where does one go to get an engineering degree in CHIRP?

IMHO there is quite a bit of intelligent and useful information on THT as well as unbiased personal experiences. These are usually not coming from factory "Pro Staff" though.
No offense meant, but we all know it is part of "deep discount" plan.
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Old 09-10-2014, 05:17 AM
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Originally Posted by cravenMH View Post
WTF is a "CHIRP" Engineer? Where does one go to get an engineering degree in CHIRP?

IMHO there is quite a bit of intelligent and useful information on THT as well as unbiased personal experiences. These are usually not coming from factory "Pro Staff" though.
No offense meant, but we all know it is part of "deep discount" plan.
I'm Actually a beta tester.

Here is the quote Straight from Navico.


" *Yes, Custom Chirp is still Chirping. When using Custom Chirp, you are selecting one frequency to Chirp (ex. 180kHz) instead of a range of frequencies."


I'm not selling transducers or anything, just passing on the info. I thought people would be happy to know they won't have to shell out big bucks for a CHIRP transducer.



Just an FYI.

Mike.
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Old 09-10-2014, 06:06 AM
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Originally Posted by Team Old School View Post
I'm Actually a beta tester.

Here is the quote Straight from Navico.

" *Yes, Custom Chirp is still Chirping. When using Custom Chirp, you are selecting one frequency to Chirp (ex. 180kHz) instead of a range of frequencies."

I'm not selling transducers or anything, just passing on the info. I thought people would be happy to know they won't have to shell out big bucks for a CHIRP transducer.

Just an FYI.

Mike.
Ok, not trying to insult anyone here, so please don't get offended :D

I am an engineer, Abbor is an engineer, and lets assume whoever at Navico you are talking with is an engineer. Stereotypical engineers (all engineers are stereotypical, except those guys that are just good at school, they aren't real engineers :D) understand things like this at a low level on how they work. I do, Abbor does (better than me), and let's assume this Navico person does. Frequently as an engineer if I want to talk with a fisherman about sonar, I get to a point where his eyes glass over and I realize he doesn't know WTF I am talking about anymore. Keep in mind, he might very well be able to run circles around me at USING a sonar, but knowing how it works is another matter. At this point I have lost him, and I need to stop talking with techno mumbo jumbo and get him to understand the concepts of what I am saying.

So what I would presume is happening is this Navico person is used to talking with people who don't know as much about how sonar works as (s)he does. So in order to convey the concepts they want, they are oversimplifying things, and even in some cases saying things that are incorrect to make the point they want. Like CHIRPing at a single frequency is probably just to make you understand that you can't do single frequency and structure scan at the same time. This is because the CHIRP, Structure Scan, and Custom Frequency mode all use the same sonar circuit. 50 kHz, 83 kHz, and 200 kHz use a different sonar circuit.

A CHIRP sonar at a single frequency would be "THE WORST SONAR EVER." Resolution of a fixed frequency sonar boils down to simple math. Resolution = (Speed of Sound in Water * Pulse Length) / 2. So what this means is that as your Pulse Length gets smaller your Resolution gets smaller, you can see smaller things. Resolution of a CHIRP sonar also boils down to simple math. Resolution = Speed of Sound in Water / (2 * Bandwidth). Where Bandwidth is the High Frequency - Low Frequency. So you can see, as Bandwidth gets bigger, Resolution gets smaller, you can see smaller things. In the case of a single frequency CHIRP, Bandwidth = 180 kHz - 180 kHz which is 0. If you try and divide a number by 0, you get Infinity, basically saying your Resolution doesn't exist anymore, it would take an infinitely large object to see it on your sonar screen! This is how you can have a better pulse sonar than CHIRP if either the pulse sonar has very small pulses, or the CHIRP has narrow bandwidth.

I would presume that if you cut and paste Abbor's comments into an email, and picked out the gruff parts about it being the biggest misinformation, and sent that to your Navico contact, you would get a VERY different response than you get from the questions you ask, because the engineer at Navico would switch back to engineer mode.
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Old 09-10-2014, 06:07 AM
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PS - Where does the Navico contact you are talking with work?
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Old 09-10-2014, 06:29 AM
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Originally Posted by stiletto View Post
PS - Where does the Navico contact you are talking with work?
I have been a beta tester with them since it was Navman and Northstar.



I get 3000 views a day on my youtube channel and was getting overwhelmed with questions on what transducers to use with chirp. I asked Navico to send me the answers to those questions, and that is what I received.
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Old 09-10-2014, 06:34 AM
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Mike, I know you are a very knowledgeable sonar user so I don't question your capabilities when it comes to explaining people how to use a sonar. It's when you start to go into technical details it goes wrong,


It does not matter what someone at Navico says about about the CHIRP frequencies for transducers which are not Airmar CHIRP, because I've measured the output from NSS Evo2 and SonarHub using an oscilloscope. It's what the sounder outputs, not what it's specified to which matters

I also have the numbers verified trough two independent channels to Navico. One of them had first given wrong numbers, but corrected them after seeing the results from my measurements. The only difference is that the Navico guys specifies the Medium to 60-100kHz, while I measure 66-100kHz.

My numbers also make fully sense because a CHIRP bandwidth for a high-Q transducer will normally be symmetrically centered around the transducer frequency (50, 83 or 200kHz)
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Old 09-10-2014, 06:34 AM
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Originally Posted by Team Old School View Post
I have been a beta tester with them since it was Navman and Northstar.

I did not selectively pick sections of an email to post. I do not get paid to sell anything. The quotes I posted are in their entirety.

I get 3000 views a day on my youtube channel and was getting overwhelmed with questions on what transducers to use with chirp. I asked Navico to send me the answers to those questions, and that is what I received.
Sure, I understand. I like your videos. Nothing like seeing from an arch to boating a fish. Where is your contact from?
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Old 09-10-2014, 06:36 AM
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I thought navico told me that you could use the 50/200 Ducer with chirp. I don't remember their telling me that a single frequency was chirping. - even when using the tm150 in single frequency mode.
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Old 09-10-2014, 06:43 AM
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Yes you can CHIRP with a Lowrance 50/200kHz transducer. You have to select High/Low CHIRP in the transducer installation menu and the unit will output 40-60kHz for Low CHIRP and 160-240kHz for High CHIRP. Just don't expect the same performance as with an Airmar CHIRP transducer.
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Old 09-10-2014, 06:44 AM
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Originally Posted by stiletto View Post
Sure, I understand. I like your videos. Nothing like seeing from an arch to boating a fish. Where is your contact from?

I appreciate that.


Navico in Tulsa.
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Old 09-10-2014, 07:21 AM
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TM150M at speed:
In shallow water (less then 100 meters) it holds bottom but I have to tune up sensitivity a lot to get a good picture on my HDS. I have not tried to mess around with the installation, as my TM150M is ment as a ducer for drifting and slow trolling, and I use a P66 at a slight angle for high speed transportation. (My boat maxes out at 29 knots.) In most cases trouble while on plane with a transom mount is due to bad placement or adjustment of the ducer.

"Real" CHIRP ducers vs broadband.
Probably no surprise, but I agree totally with abbor and stiletto. I have tested my Sonarhub with 83/200/455/800-HDI and Airmar P66. The HDI ducer was pretty good while CHIRPing, but not close to TM150M. P66 was worthless in high Chirp, and pretty worthless in Low. So no doubt on my behalf that the Navico-ducers work well in CHIRP, but a "real" CHIRP-ducer is better. Keep in mind that TM150M is a cheap CHIRP-ducer after all.

I to enjoyed your videos Old School, but in this case you have recived som bad info.
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Old 09-10-2014, 07:29 AM
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Hey but what about finding birds on the dome radar, is that true or not?
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Old 09-10-2014, 11:06 AM
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I like Stiletto's point on technical vs. non technical explanations of the CHIRP theory. Read how Furuno tries to explain it:

"The DFF1-UHD uses a precise sweep pattern across 90 frequencies (50 kHz +/- 20 kHz, 200 kHz +/- 25 kHz) within a long-duration transmission. "
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Old 09-10-2014, 11:26 AM
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Originally Posted by Point Consults View Post
I like Stiletto's point on technical vs. non technical explanations of the CHIRP theory. Read how Furuno tries to explain it:

"The DFF1-UHD uses a precise sweep pattern across 90 frequencies (50 kHz +/- 20 kHz, 200 kHz +/- 25 kHz) within a long-duration transmission. "
This explanation is at a similar technical level as the first post in this thread
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Old 09-10-2014, 11:40 AM
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Anyone using a CHIRP system....especially a true swept frequency CHIRP...will get the best overall results when using a CHIRP transducer with XID that has been designed for use in their CHIRP system.
Again...very important to use a CHIRP transducer to get the full functions in a CHIRP system.


If Airmar could have found a way to use a B60 or B164 in a CHIRP system they would have done so...but instead they designed a transducers specific to CHIRP systems.

The CHIRP transducers now in use are superior in almost every every parameter of transducer design...just look at the Q.

Last edited by semperfifishing; 09-12-2014 at 10:28 AM.
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Old 09-10-2014, 11:41 AM
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What's xid?
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