echo sounder transducer cable - what plugs?

[Burnham Bob]

I may have to replace my echo sounder but the main unit is at the nav styation with repeater on the cockpit binnacle. If I can reuse the old transponder (it's 150 khz frequency which I think is standard) the cable probably won't reach - can i join it with a nortmal coax lead and connectors? Any idea without me taking the boat apart what plugs transducers come with?

 

[sailorman]

I may have to replace my echo sounder but the main unit is at the nav styation with repeater on the cockpit binnacle. If I can reuse the old transponder (it's 150 khz frequency which I think is standard) the cable probably won't reach - can i join it with a nortmal coax lead and connectors? Any idea without me taking the boat apart what plugs transducers come with?

yes co-ax ok

 

[hightech]

150 kHz is not a standard frequency, pretty much all manufacturers now use 200 khz with some using 235 kHz for the newer "smart" transducers.

Not changing the transducer is not really on.

 

[Burnham Bob]

the nasa replacment transducer for their clipper, target and stingray ranges is 150kz, so presumably i'm limited to them.....

still interested to know what plugs he cable uses.....anyone know? the normal maplin coax plugs are cheap and easily used - will they fir the exiwsting cable? it saves me disconnecting everything to look

 

[NorthUp]

NASA told me to use ordinary TV co-ax cable and plugs a few years ago, to extend an echosounder (Clipper) transducer cable- 75 ohm impedance?
edit- there are male and female type plugs in Maplin- buy both types to be sure!

 

[William_H]

Connectors for depth sounder transducer

Ones I have seen recently (NASA) had an ordinary (to Oz) TV plug. i think we used to call them Belling-Lee but that was 40 years ago. The outside shell 8mm in diameter with a 2mm diameter pin in the middle the plug being just push fit. Yes certainly plug and female plug are easily available here in Oz so I feel sure so in UK. Get an extension cable as provided for video recorders ie M and F they are usually about 1 metre long which may not be long enough for you.So you may have to make it up to length.
It is worth trying your transducer on the new set. Potential problems are the added capacitance of the cable causing detuning and hence less performance at extreme range. Likewise the transducer may not be designed for the correct frequency...again poor performance. No harm in trying olewill

 

[electrosys]

Can't comment on later units, but with the Seafarer range the cable used is standard 50 ohm coax with TV-type plugs.

What many may not be aware of is that the length of cable is critical to accuracy as it forms part of a tuned circuit, and should be kept at the same length as when initially manufactured. If you have extended or modified the cable in any way and have run into problems then the set will need to be re-tuned. I have diags and re-tuning procedures for the Seafarer 3 if anyone needs.

 

[rob2]

All the above is correct, I think. Worth noting that 150 used to be the standard frequency. You can check the frequency of current manufacturers' products by visiting the Airmar website, they make the transducers for the majority of sounders. Nasa still use 150 but, for example, many Raymarine units use 200.

Possibly more difficult in most applications is finding a transducer which suits the installation, if you have to change it. We fitted a new Nasa unit on my mate's boat, which had the transducer builkt into the centreline forward of the keel, faired into the hull's lines. changin it would have been a haul out and a fair bit of glassfibre work! On my own boat, there is not enough room beneath the sole to mount ther so the unit is in a far less suitable position alongside the keel, requiring a special transducer for the 20 deg deadrise.

Best of luck, Rob.