What is an "External KP"??

[Atomck1]

From the DFF1-UHD manual:
"2.2 Transducer Cable, Cable for External KP (option)
If the external KP is not to be connected, do only the applicable procedures in section 2.2.1 and 2.2.2. "

Can someone please enlighten me, what is an "External KP".

 

[Johnny Electron]

KP stands for Key Pulse. It is used when you might have two sounders both operating at the same time. It allows the sounders to coordinate transmissions so they don't interfere with each other.

 

[Atomck1]

Thank you Johnny! I couldn't find that info, anywhere I looked.

 

[Moonzy1]

I will be running a DFF3, DFF3D, and DFF1-UHD
IF I network these together via Ext KP, will that prevent them from overlapping matching frequency transmission and prevent interference?

At least in the case of the chirp signal.

Thanks

 

[Snips]

Moonzy1,
Key Pulsing is not a network function, addition wiring will be needed to link the sounder modules together. Sounder interference is caused when one sounder is transmitting while another one is listening. Key Pulsing is a way have all the sounder modules transmit at the same time. It doesn't change their TX frequency just when they transmit.

Hope this help.

Snips

 

[Moonzy1]

ah I see
what is the advantage of synchronizing the pulses?
Thank you

 

[Snips]

As long as the sounders are set to similar ranges you will see less interference.

Snips

 

[Moonzy1]

ok if I understand this correctly then this is something I should do?

If I am running a chirp and a fixed frequency transducer at the same time, Ext KP should be able to keep them from creating interference.

Correct?

 

[Snips]

Moonzy1,
Key Pulsing will help reduce the interference, so will turning on the sounders IR filters. Personally I can't see that using all three sounders at the same time will be a benefit. If you use the KP you can always disable it in the menu.

Snips

 

[Moonzy1]

Agreed
It wouldn't be all three
Just the Chirp and one of the other 2.

 

[Hemlock_SF]

I will be running a 165t- b54 Dff3d and a b265lh at the same time once I get it installed. Will I need the KP cable?

 

[Deep Blue]

Hemlock_SF,

What is the unit that will be connected to your B265LH..?

- Deep Blue :think

 

[Magnetron]

I will be running a 165t- b54 Dff3d and a b265lh at the same time once I get it installed. Will I need the KP cable?

Hemlock_SF,

Thanks for posting in the Furuno Forum, I see that you replied to a very old posting (nearly two years old!). Sometimes the context of these posts get lost, unless this is exactly the same problem you have (not knowing what one is). So if possible, post a new post for better assistance.

In general, a KP cable is not required when using a B265 with a 165T transducer. The concern, if there was one, is when transmitting the 165T at 165kHz at the same time the B265LH is sweeping between 130 kHz - 210 kHz CHIRP, at one point they both will be transmitting 165kHz and that'll show up as a streak or line in the fish finder. If that streak line bothers you WITH interference rejection turned on than you should get the KP Cable. Otherwise, they both function normally.

We make one for the network sounders and one for the TZ Touch MFDs.

Hope this clarifies, :sail

- Maggy

 

[Hemlock_SF]

Thank you Maggy, they will be hooked up to 2 - Tzt3 16 and would probably be easier to put them on the MFD

 

[Quitsa]

Thank you Maggy, they will be hooked up to 2 - Tzt3 16 and would probably be easier to put them on the MFD

There is definitely interference visible when you run the DFF-3D and high frequency CHIRP at the same time. It is a series of vertical lines and affects both the DFF-3D display and the HF CHIRP display.

If you set the interference filter to "high" on both, the vertical lines will go away completely. In my experience playing around with the settings, only "high" will eliminate the interference.

I have not noticed any visible impact on the performance of either sounder from using the filter to get rid of the vertical lines so I decided not to get the key pulse cable. It would be a pretty big job to install in my case because access to open up my DFF-3D to connect the cable.

Assuming you have easy access to your DFF-3D and the ports on the back of one of your TZT3 MFDs, I would wait to install a KP cable until after you try out just using the filters to manage the interference.

Probably it would have been good if Furuno had anticipated this issue and either suppressed the 165Hz transmissions from the HF CHIRP or had a filter of some sort built in since it is very common to use the DFF-3D with a HF CHIRP sounder in water less than 500-600 feet.

 

[Magnetron]

Thank you Maggy, they will be hooked up to 2 - Tzt3 16 and would probably be easier to put them on the MFD

So to your original question, you do not need the KP cable.

- Maggy