Low Medium vs Low High Frequency trannys

 Interested to know more about frequencys that people are using.

might be upgrading transducer to a 1kW and would like to know thoughts about the low/med frequency transducers. Low 42-65 Med 85-135.

are there more limitations with these or are there more benefits fishing depths that range from shallow 20's through to deeper 400's ?

cheers

CC


Stevo81's picture

Posts: 1278

Date Joined: 16/04/12

What sounder are you

Thu, 2016-09-15 19:41

What sounder are you running?

Low/Med or Low/High trannys are dual band chirp transducers that sweep the frequencies in that band, so low band sweeps 42-65 kHz and shows detail across that bandwith. Some sounders will also let you select a single frequency and run like a traditional sonar at say 200 kHz. 

For deep 400's and shallow 20's work you would want L/H. Low for deep and high for the shallow stuff. 

Thats my understanding of it anyway but i know theres  couple of blokes on here that can explain it better and in more detail than me

 

____________________________________________________________________________

                                   ••••••••  Electrical Contractor NOR  ••••••••

CC106's picture

Posts: 59

Date Joined: 07/01/14

 Cheers Stevo, I've got a

Thu, 2016-09-15 19:52

 Cheers Stevo, I've got a Garmin GPSMAP 1020xs.

was interested to know how well or how bad lower frequencys work in he shallower stuff, more like 40-60mtr. Send most of my time in 60+

Tim's picture

Posts: 2497

Date Joined: 26/09/06

Low

Thu, 2016-09-15 20:14

the low or med should give you much better detail in shallow.

The low freq can be much more affected by interference and dirty water at speed though

High also tends to have a narrower beam so all depends what you are trying to do.

I have just swapped to a wide beam 200 and a narrower med freq transducers for what I do

 

CC106's picture

Posts: 59

Date Joined: 07/01/14

 Cheers Tim Im just tryin to

Fri, 2016-09-16 17:27

 Cheers Tim

 

Im just tryin to find the best transducer in the 1kW price range that is going to let read at speed the bottom and when slowed down find bait fish balls or large fish without too much interference. I want accuracy with what it is reading. I bottom bash 95% of the time and in 40-60mtrs but do sneak out to 200+ on the good days

Bryce Day's picture

Posts: 812

Date Joined: 01/06/15

id be more worried about

Fri, 2016-09-16 17:58

id be more worried about placement!

Stevo81's picture

Posts: 1278

Date Joined: 16/04/12

what boat?

Fri, 2016-09-16 21:56

Thru hull with performance fairing. 

B265LH

____________________________________________________________________________

                                   ••••••••  Electrical Contractor NOR  ••••••••

t bone's picture

Posts: 351

Date Joined: 20/04/14

Tm275LH-w

Sat, 2016-10-01 13:28

I went with the transom mount 1KW chirp tranny and don't regret anything.
The TM275LH-w does the low (42-65kHz with a 16 - 25 degree cone) and the high (150-250kHz with 25 degree cone)

I run the high chirp in water anywhere up to 60m deep. If its 30 meters of less, ill also use the downscan image at same time.

Have found heaps of new spots to peak my interest whilst cruising around 24 knots, then mark it and come back over at a slower speed.

Marineboy's picture

Posts: 837

Date Joined: 14/03/14

Transducer

Sat, 2016-10-01 15:13

 gotta love the wide beam trannys ?

____________________________________________________________________________

 My spots are so secret even the fish don't know about them !