Topic: 987si ducer

[mulliemark]

I have a couple of questions , can i use the hdsi 180t ducer with this unit and  if I can would i see a sharper image? I know the 800 cycle wont work
also are these units really that hard to see in sunlight ? would a person need one of those visors to shade it? and any general opinions as to how the picture stacks up against the 997




thnx
mark

[Rickard]

Hi Mark,
 
I suppose you have a 987? I have a 981 that has the same sonar capacity and have used the SI 160 and the HDSI 180 transducers alot. The image gets a little bit better at 455 kHz with the HDSI 180, but you will miss the 262 kHz SI frequency. I think the SI 160 is a better choice for the 987/981 models. If you want to have dramatically better results you should build your own transducer system with a LSS-2 transducer... but this is close to treason..  You can read about how this is done in the thread Interfacing a HB with the L... LSS-2 in the section on Towfish construction.
 
Rickard

[mulliemark]

rk where would the 262 freg be useful? and is it hard to see in the daylight, I have a 798 with a hd ducer  which takes perty sharp pics and a 797c with the stock ducer  that has an acceptable pic I would hate to lose more detail than i currently have with the 797 , what good is bigger if you cant tell what something is


mark

[Rickard]

The 262 kHz is useful in long distance scanning. It has much better range than 455 kHz. Resolution is worse, but it can be good enought when one only needs an overview. Most units are unable to display the full resolution in the transducer system. One must review recordings with a computer to see all details and then the difference between different transducers becomes very evident.
 
I don't know if the display in the 798 needs shading in sunlight. I don't use any such means with my 981, though.
 
Rickard