Problems with newly installed Garmin 93SV on Trolling Motor- vibration or interferenc

[sfw1960]

Excellent tips! Makes me wonder what the Humminbird ones are made of.

They should be very similar to a Fair Rite 31 Mix Larry.

http://www.fair-rite.com/product/rou...es-2631803802/

I just got 4 of these in today, I am hoping to get them on & do some OTW testing soon, but it's been miserably windy, cold, wet and sloppy here lately.

These are considerable larger that the ones from HB (so I can get more turns wound) and are not sealed or coated with anything yet.

I think I saw them on Amazon for about $15 a pop TYD and there are a lot of sources online.

I don't think I would use the ones cactus flyer was linking myself, since the sonar operates in those frequency ranges and may raise impedance high enough to possibly cause damage to the final output stage of the unit's transmitter.

Data sheet:
http://www.fair-rite.com/wp-content/....php?pid=19348





Ferrite_9096rsd.jpg

[Larry3215]

Wouldnt you be putting these on the power leads rather than the transducer leads? As close to the trolling motor as possible is how its usually done. That keeps the signal from getting out of the trolling motor.

The impedance change should hurt anything in that case.

I agree, putting one on the transducer cable might cause more problems than it fixes.

[DonnieG]

I tried 43mix, 77mix & 75mix. Had better luck with 75mix.

[cactusflyr]

31 material shows 1mhz to 500mhz.....1mhz=1000khz. What frequency you using? And yes....put on power cable.

[sfw1960]

Wouldnt you be putting these on the power leads rather than the transducer leads? As close to the trolling motor as possible is how its usually done. That keeps the signal from getting out of the trolling motor.

The impedance change should hurt anything in that case.

I agree, putting one on the transducer cable might cause more problems than it fixes.

I am installing them on the XDCR cable, as per recommended by HB when they ship you the Steward Ferrite Toroids.

EMI/RFI usually enters the units thru 2 different ways.

Either direct coupling to a conductor or by inductance and the second method is most always the biggest pain to remedy, since it's so hard to find where the noise is "hopping on" and riding.

Spurious emissions are random and harmonic emissions are multiples of the desirable frequencies - both we want to keep out of the units receiver circuitry.

31 material shows 1mhz to 500mhz.....1mhz=1000khz. What frequency you using? And yes....put on power cable.

I want to band pass below 1MHz not above.

Right now, I am using the typical 200/83/455/800KHz many units use, for a XDCR cable the Ferrite Toroids I am using are suitable - and for wiring to/from a TM the Amidon ones listed previously are going to be good for DC wiring.

I didn't wish to start a debate or try to argue about what chokes were best for what usage, as I used to deal with RFI questions & answers for many amateur radio operators a long time ago ~ I was only speaking to Larry's question about the ones HB usually sends people when they get RFI on their units.

I am pretty sure the TMC-1 (not sent out for free AFAIK) is a completely different mix similar to the Amidon Toroids cactusflyr was recommending.

The bottom line is whether you are trying to stop RFI from radiating or coupling, the choke types used will need to be different.



HTH clarify,
RAS

[Larry3215]

Sorry if it came out wrong - Im not trying to argue, just understand. Im going to bow to your expertise. Its been decades since my active amateur radio days.

So, basically, your recommending use of two different chokes on the power and xdcr cables?

It never occurred to me to put one on the xdcr cable - for the exact reason you mentioned.

Let me see if I understand this - and please correct me if I have anything backwards.

It seems to me any choke you use on the xdcr cable will have to be as you say, a low pass type as far as the sonar frequencies. They will need to pass anything below 800 khz or you could have the hi impedance issues you mentioned, which could lead to issues for the MFD or loss of the sonar signal itself. So that would mean the chokes you put on the xdcr cable will only block upper harmonics.

For the direct in-band noise, you still need chokes on the power leads.

The trick is going to be knowing which one you have or if you have both. Very few of us are going to have access to the equipment needed to analyze the noise to see what frequencies are causing problems. I would expect any noise from the brushes would be broad band and the PWM stuff could have harmonics all over the place.

These are not that expensive, so doing both makes sense to me.

[sfw1960]

I hope Al's not cross with this statement Larry...


"You hit that one DEAD NUTz man!"





Let the lower frequencies pass on the XDCR cables and block, crush, kill and destroy ANYTHING that's not pure DC coming up or down the DC wiring.

[Larry3215]

Thanks to you and cactusflyr for pointing out that there are differences between the various ferrites and where to use them!

This is excellent info from both of you that I have not seen before.

[sfw1960]

Thanks to you and cactusflyr for pointing out that there are differences between the various ferrites and where to use them!

This is excellent info from both of you that I have not seen before.

Well, regardless of brand preference and knowledge level, I'd like to think that we can all learn from each other Larry.

I haven't goofed with ham gear in 20+ years, but some stuff seems to get to be an ink stain on your brain that won't go away...

Some stuff is easily recalled if you use it and some stays around, for only God knows why!

I still recall the (old 468/f) simple formula for a 1/2 wave dipole and I haven't ran a radio on eons... !

I don't get in here often, maybe to check on Len or Donnie once in a while - but like Wayne, I like to tinker and read too.



RAS

[LWINCHESTER2]

Robert and cactusflyr. I appreciate the posts and information. A bit over my head though-obviously. My solution was to buy a different trolling motor.

[Larry3215]

I quit messing with it when transistors took over and you could no longer get tubes at the local electronics supply store! That was long before Radio Shack came along and there actually were local electronic supply stores. We had three military surplus outlets selling electronics and two different retail stores in my small town. It was heaven for a gizmo head kid. Turns out I was more interested in building gear than in using it for its intended purpose :)

Well, regardless of brand preference and knowledge level, I'd like to think that we can all learn from each other Larry.

I haven't goofed with ham gear in 20+ years, but some stuff seems to get to be an ink stain on your brain that won't go away...

Some stuff is easily recalled if you use it and some stays around, for only God knows why!

I still recall the (old 468/f) simple formula for a 1/2 wave dipole and I haven't ran a radio on eons... !

I don't get in here often, maybe to check on Len or Donnie once in a while - but like Wayne, I like to tinker and read too.



RAS

[cactusflyr]

I tried 43mix, 77mix & 75mix. Had better luck with 75mix.

where did you put your blocks......power or transducer cables? Might try and clear up the last bit...wondering about a 75 on the transducer cable....specifically the ps21 cable.

[DonnieG]

where did you put your blocks......power or transducer cables? Might try and clear up the last bit...wondering about a 75 on the transducer cable....specifically the ps21 cable.

Both power & transducer

[cactusflyr]

You remember what you had in your ps21? Have the w material on the power cable, gt22 is clean now. Ps21 is good, but not perfect.

[DonnieG]

You remember what you had in your ps21? Have the w material on the power cable, gt22 is clean now. Ps21 is good, but not perfect.

I don't...I gave them to a friend to try...

[cactusflyr]

What frequency does the ps21 use....so I know what to not put on it....anyone?

[LWINCHESTER2]

417 kHz

[sfw1960]

https://buy.garmin.com/en-US/US/p/548982#specs

Dang Len you beat me!