Topic: 798SI definitely generating noise in VHF!

[lolar3288]

I posted earlier that I had a problem with the 798 generating RF (EMI) noise in my VHF.  Now I have had more time to run down the problem.  It particularly occurs when I change views or access menus.  Even holding my hand on the right side of the unit will cause it.

I have ordered some ferrites to put on the VHF power lead but does anyone else have this problem?

Larry

[RGecy]

No, I have the opposite.  My Radio causes issues with my 997 when I key the mic.

Once I put the HB on a seperate battery, it went away. 

Robert

[lolar3288]

Well I've played with this a bit more.  I added addition ferrites to the power lines of the the Humminbird and the radio.  It seems slightly better (maybe just me).

If I set the radio squelch, then reach for the Humminbird keyboard the radio will go crazy.  Press "menu" or "view" it continues for a bit, then may stop.  If I just leave my hand on the key button side of the Humminbird it will come and go.

It is very definitive......move hand on....radio acts up......move it away and it stops..........It is sort of like there is a oscillator on the board and I'm acting like the antenna!

Out side of bringing a scope up to the flybridge...I really don't know where to go next!  Maybe rap foil around the whole unit and see if it still does it.

Is it the unit that has a problem or the radio?

[Wingnutt]

I know if you're determined, you could identify & isolate the source but in all honesty, if it were me, I would just remount one of the two units to put some distance in between each other and the wires as far apart as I could get them.  I know it's not the “way it should be”, but I've learned over the years that sometimes you have to deal with “what is” more than “what should be”. Just my .02c.

[lolar3288]

Well the boat is 12 feet wide and the radio is on the opposite side of the flybridge to the Humminbird, same for the antenna for that radio.

I may just have to live with it.

The radio is a standard horizon GX1500 which I installed this spring to replace my old Icom that failed.  I'm not the least bit happy with it and will be taking it in as a warranty complaint because the squelch opens up even without a legible signal.  The transmitter is great but the receiver is very poor.  I was beside another boat that could receive a transmission clearly that I could not.  I don't expect much satisfaction as these sorts of warranty issues usually fall on deft ears.   I may just deep 6 the radio and buy a new Icom.

[ITGEEK]

I don't know if you've done this or not, but if not, run all wires
as far away from each other (sonar, and vhf) as possible
Make sure they are not both hooked to the same battery.

[lolar3288]

The wires are very separate......many feet apart but not running on the same battery (or system) is not possible as the both the radio and the fish finder are on the flybridge of a 32 foot cruiser.  It would be a major job to bring up another feed and the wiring would be side to side in the main conduit anyway.  I have installed several ferrites on various power wires.

I'm not entirely sure the interference is coming through the power line.  It almost seems like it is being radiated.

Larry

[Roddy]

Lolar; Sounds like a unshielded VHF ANT plug, if you can try a differant VHF ANT and Radio.

I have SH2100 ASI,Icom HF,Radar,Interphase twin scope FLS,Interphase Hoz als,HB 947,987,and a 1198 with twin xducer ( one is a Tow Fish),Cell phone,SAT phone within 3 feet of space the only thing that did mess up was the ANT plug on the SH2100 ASI I covered the Ant plug with sheet lead.
It worked! Roddy

[lolar3288]

I will give it a try. 

I did replace the antenna and the PL connector on the radio (actually did the connector twice because I didn't like the quality of the first one).

I am kind of surprised that you could get certification for a piece of electronics that could effect radio transmissions.

Thanks for the suggestion.

Larry

[ITGEEK]

Larry,
It seems to me that your going through a lot of investigation and
expense to mask/muffle an obvious problem.  Having multiple devices hooked
to the same battery is going to cause interference amongst
the devices.
These interference masking devices you're using will probably negatively affect
the sensitivity of your sonar.

All you need to do is get a small battery for your sonar and mount it under your console
close to the sonar.  You don't need any additional feeds.  Just attach the positive and
negative wires from the sonar to the battery.  Then, make an effort to keep the sonar wires away from other wires.
Also, remember to use a 3amp fuse.

[lolar3288]

Well not to get stubborn, but installing a battery just to power a unit like the sonar is not a solution to anything. 

Firstly, it shouldn’t be radiating RF.  Next I’m not convinced it’s down the DC lines.  Trapping RF (EMI) in a dc line is pretty simple and this is not a small boat with small wiring and small batteries.  The main system is 500 AH (4 golf cart batteries).  It does have rf filters installed in various areas.

Certainly, has a test, I could stick a small gel cell on the sonar and may  do that.  It’s a good suggestion.

I have built systems on research boats with dozens of instruments, include some pretty sensitive ones, all on a single power system supplied by batteries and charging systems without a problem.  One boat had 3 sonars and some wireless telemetry and a few UHF and VHF radios.  Add on radar to boot.  Never had a problem like this.

I suspect the radio is the real problem with a lousy receiver and poor filtering but the fact that someone touching the sonar increases the radiation is intriguing!  It infers that the sonar is radiating and the person is either acting as an antenna or acting as a capacitor and changing the radiated frequency…..   It’s the sort of a problem that grabs a technical guy’s interest!

[ITGEEK]

Who knows.
Every boat is built, configured, and wired differently.
Different brands and types of wires are used.
Also, different brands of wire connectors and devices.
Different equipment is put on board containing different types of metals.
Put that all together, and some boats just have bad electronic interference issues
and some don't.

I've always heard that it's best to have the sonar on a separate battery.
It will most likely solve your problem.

[SC_Sonar_Kid]

I noticed this noise last week and thought the signal was traveling through the power system, so brought out my handheld VHF which work fine but it too had a strong signal.  There is no electrical connection and I moved it all around my 25' Grady, but it could not be squelched at the furthest point.  There was a fellow on the internet that sent his back and Humminbird added a filter.  I really like the 798c, but I cannot monitor my radios while its operating.  I've got a request into Humminbird, so I hope they've seen this and they have a fix or its and installation issue.  You guys may want to try a handheld VHF radio around your systems to see if you are getting the same interference.  Humminbird better fix it or they'll get turned into the FCC and then it will get real expensive especially if someone cannot make an emergency call.  Try the external radio test.

[lolar3288]

Thanks for the reply....seems I need to contact Humminbird!

Larry

[gt]

Did you ever find a fix for this?  I have a small boat (20'), with a 798ci on the console.  I only have a handheld vhf, Icom M72.  If the radio is within 3' of the 798, I get feedback on the radio.  I want to install a gimble mount radio, probably an Icom, but have been holding off, until I could find out if I would have an issue with it.  Sounds like I will..

Gary

[lolar3288]

Yes I did get a fix.  I sent my Humminbird to the Ontario Distributer and they did a modification, free of charge under warranty.

As the boat is away for the winter I haven't had a chance to check it but I assume it's fixed!

Larry

[SC_Sonar_Kid]

I sent my unit back into Humminbird thinking it would cost me $160 because I was past warranty, but it appears they fixed it free of charge.  Because I didn't get a recall letter or email, they apparently don't want the expense.  Maybe its only a few units or only effects boaters that need our radios, but its not a good way to treat the customer.  Anyways, I turned on my 798SI and pulled out my emergency handheld VHF radio, then set the squelch to 0 (no squelch).  No interference, so they did appear to fix it.  Hope this helps others.

[Murf]

well well well so by this thread it appears to be a Humminbird problem

my 778CX HD and 788CXI HD COMBO will upset boats VHF around me even over an 8meter radius not to mention what it does to my VHF,

Humminbird upgraded my 778CX and 755cx as well as bases to the above due to program upgrade problems trying to fix the interference to VHF

Humminbird Australia told me they have never heard of such a problem and must be the way the VHF is installed but if it affects other boats as well?

this thread has covered everything that I have in the way of problems except that if I touch the screen on my Humminbirds the interference gets less but not great. tried wrapping the screens with foil with no success unless I hold my hand on the screen area.

when the Humminbirds are generating the noise in the VHF the VHF is not working at all (yes big safety issue), the boat 8 meters away even with the interference from my Birds can receive a incoming signal but who knows at what diminished level?

been playing with ferrites and foil with no success at all

3 diff species of radio
diff power supplies
diff antenna plugs on coax cable
separate wiring on other side of boat
new antennas (same brand GME though)

fiberglass 1/2 cab boat only 5m long

one day I will get to the bottom of this problem (I hope)

cheers Murf

or maybe I should bin the Birds and get Lowrance

[lolar3288]

Well I can tell you Humminbird back their stuff way better than Lowrance just from my experience.

This is a known acknowledged problem that North American Humminbird has addressed well.  No reason why they should not fix it......and by the way.....in Canada...if your product generates RFI and effects radio bands the Government will get involved and very nasty!

[Murf]

cheers for the info

the Lowrance comment was a poor joke on my behalf 

its Monday morning and I will be talking to the Humminbird Tech's here again thismorning

cheers Murf

[PaulB]

Has Humminbird sorted out everybody with this problem?  I've had my unit since last February and initially thought the problem was with my handheld VHF which was a few years old so I bought another one...problem persisted.  Fixed VHF is the same.  I can't go anywhere on my 20ft boat and use a VHF with the fishfinder on.  I've resolved to getting it sorted before spring.  Just now to rule out everything else I've connected the 798 to a AA battery powered home PC kit and tried several VHF units around the house, long story short, the screen on the 798 definitely interferes to the point where the VHF is usless within 8-10 meters of the unit, it's like an on/off switch for VHF interference especially when there is lots of white on the screen.

No local reps so I've written to their web support hoping to get some sort of an answer so fingers crossed.

[Murf]

not fixed yet BLA replaced the units again and same problem

the BLA tech in Brisbane Australia had never heard of the problem before??? he has sent to the USA for info and is now waiting on some ferites to arrive from USA that go inside of the units to see if that works
been a couple of months wait again

waiting waiting waiting

cheers Murf

[PaulB]

Three weeks later and not so much as a response from Humminbirds online support.  With no local reps that leaves me stuffed.  I've tried once more but if I don't hear anything then this unit will have been my first and last from Humminbird, it'll be getting ripped out and replaced with a Lowrance before the spring. 

Here's a video of the problem:-

Humminbird Screen Interferes With VHF Radio

[Humminbird_Greg]

PaulB,
If you do not get a response after a few days it could be due to your message getting automatically blocked by our spam filters.  I have to go through my blocked messages every day to pull out the ones that really should have gone through.  I don’t know that is what is happening or not but I can give you a direct e-mail address to someone here versus the one that dumps into the CRC inbox.  You could just send me your message in a direct e-mail and I will make sure it gets forwarded to someone here.

What is the exact model name of your 798 unit?

[Jim Jack]

I have my 998 pretty close to my standard horizon gx1150 with just a 3' db antenna no more than 6' from the water line and have received and transmitted to base station 10NM away that had 8' 6db antenna mounted 12' from the ground with crystal clear reception both ways. I'm going to try channel 12 now and see what happens.

[Jim Jack]

Not able to replicate this with 998, that's for sure.

[PaulB]

Greg, sent you an e-mail, cheers.  It's a 798 CXI HD SI Combo

Although the video only shows channel 12 it actually interferes across the whole range, whenever there's any sort of display change on the screen (page change, scrolling, menu etc) it starts and then won't shut up for more than a second or 2 until you turn the fishfinder off again.  Dimming helps a tiny bit, as does using the black bachground instead of white.  Either way not exactly ideal for coming into a tidal harbour where you need radio permission.

Jim Jack, wanna swap?

[Humminbird_Greg]

Got it and a confirmation that someone should be contacting you today via the email address you sent it from.

[Jim Jack]

No way Paul .

I hope they get you sorted out. If you are anything like me I depend on VHF for safety. I often fish 12 -20 miles out in 16 ft boat, that I have never needed to use vhf for emergency is more surprising then if I had.

[PaulB]

Jim, 90% safety, 5% getting in and out of port and 5% listening in on the commercial lads to see if anybody is catching anything interesting

Thanks Greg for getting things moving, seems it's a well known problem, but it looks like you're not really geared up for UK customers.  The nearest service center to where I live (according to your support) is Italy, which makes the postage an absolute no go, if I'm going to be spending that sort of money I might as well fork out for a new unit as chuck it at the post office.  If I had even the faintest idea that there was no UK support for Humminbird products I would never have bought one in the first place!  Shame, but you live and learn.

[PaulB]

Just a quicky.  Eventually got told the right place to send the unit (UK Distributer) and a couple of weeks later I have a fully working 798 unit back with no interference. 

Still not impressed with being told 3 different things from 3 different people at HB support but these things happen and once I was given the right info everything went very smooth.  Faith restored I've got a decision to make now because I've just bought another boat that is crying out for a bit of SI technology 

[wpda]

AS FAR AS I UNDERSTAND UNITS THAT GENERATE NOISE IN THE VHF RADIO REQUIRE SOME FERRITE FILTERS TO BE FITTED UNDER THE DISPLAY
HUMMINBIRD SERVICE AUSTRALIA ARE ABLE TO RECTIFY THIS FAULT/ HAD MINE FIXED IN NO TIME

[Murf]

I will have to ring BLA Australia again as they never reply to their secretary's messages

on a very upsetting note I hit a coral reef some 65km off shore at 1770 Queensland and destroyed my gearbox, the fix was $5800 here in Australia, now this would not have happened if the Humminbirds didn't interfere with the VHF as I had the VHF off to watch the sounder coming into Fitzroy reef, I had two friends boats a few hundred meters away trying to tell me of the reef/Bombora on the VHF to no avail as I can't have both running at once

the Garmins are looking real good atm

anyone want a couple of hardly used Humminbirds cheap?

a very dissapointed and dissalusioned Murf

[PaulB]

Oh man what a bummer!  That was always my biggest worry with this problem, I operate out of a harbour with a fairly extreme tidal range where you also need radio permission.  So coming in on a falling tide where I was switching from sounder/plotter to VHF and back was an accident waiting to happen and things got a little dodgy more than once last year.  With that sort of a bill I don't think I could be as polite as what you are.

If these are being sold for marine purposes then there should have been a recall on them, without the fix they're not fit for use at sea.  I spoke to my dealer/engineer a couple of weeks ago  when I was in booking a service and he had no idea of these problems and was still "happily" selling the units, he was genuinely upset about not having any clue and having to find out from a customer.

[Murf]

an update for those interested

did I say my name is Murphy and Murphy's law is in full swing now

Well the BLA service department never did ring up when the ferrites arrived for a problem that they have never heard of before even though I was promised they would ring as soon as they arrived from the states So I ring them yet again and it seems that my ferrites had arrived but were installed to fix another sounder and one was damaged in transport (they have never heard of this problem hey)
So back to waiting for more to arrive from the states and you guessed it no phone call send units back for the ferrites to be installed, pick up units on way to a two week Fraser Island (extreme boating area in a 5m boat) fishing adventure.

wow units almost work I can now at least use radio on some channels but not all, I can talk ship to ship a couple of miles but that is it

ring up BLA when I get back from a great fishing trip to find out, "didn't they tell you we didn't have the correct ferrites so we put in some smaller ones meant for another unit " NO no mention on paperwork or told that on pick up on way to Fraser Island yes down to the last minute trying to get units back before major trips. Well apparently new ferrites ordered from states and they will ring as soon as they arrive, Bahahahaha year right

so I ring them and yes the ferrites are in we will send a courier around to pick up the units, next day comes and goes, then another, third day I call where is the courier? we ordered it so ok then a few more days I ring again and said come on give me the numbers and I will chase it up, courier had no paper work for pick up so a week and a half later I get courier to pick up units. By now I am stressed as I am going on a 3.5week fishing holiday starting of with a 1050km drive to the Tight lines comp in Yeppoon

Pick up units on way to the Tight lines comp knowing I am going to have to set up the units to my liking again

Well guess what they nearly work I get a bit more squelch and can now use  most channels but 16 and a few others I can only use half the squelch before the humminbirds wipe it out

Ohh well lets fish so go 80km offshore get some nice fish noticing that the voltages are reading different on both units whilst setting them up.
Then as dusk comes I go to anchor up for the night and notice the temp readings on the fish finder unit are all over the place going down to -16 deg Celsius (in tropical QLD Australia on a cold 23deg C evening)
Then the combo unit has a melt down, looses all my track/distance info and wont pick up external aerial, just freezes as soon as you try to use the chart plotter screen well @#$$#@%%^ me out of sight of land and want my chart and marks to fish for the comp

so get back to shore and on Monday morning first thing ring BLA and all they can offer is post them back to us and we will look into it, no I cant get a unit to keep me going in the mean time from the local dealer even though this could take weeks for turn around to get units back and I am only 4 days into my holidays. NOT HAPPY

So the decision has been made that i am now researching another brand to buy to get back on the water again and will get rid of the Humminbirds to some poor unsuspecting person

Seriously do you think I have the right to be a little pissed off by now??

a very unhappy Murf

[Murf]

wooohoooo its fixed  no more problems at all

I put Raymarine Dragonfly units in and not a problem at all

Humminbird have sent a new 700 combo unit for the cooked one after putting the ferrites in and have taken the ferrites out of the fish finder unit but when they arrive in the mail anybody knows?

anyone want to buy a Humminbird? going cheap 

cheers Murf

[PaulB]

No thanks!  I took a £850 hit on selling mine on, that's some depreciation over 12 months!

The Lowrance has proven to be flawless so far as well, the only thing I miss is Humviewer which is a great piece of software compared to the Lowrance effort.