I have tried everything I can think of to kill the coilless ignition noise hammering away into my IC706MKIIG.  This isn't a problem on FM (VHF/UHF), but is a big one on HF.  Even with an AMCom external DSP unit the noise into the external speaker and/or headset is extreme.

So...I am planning on pulling out the Icom and installing my TS480HX.  It is supposed to have much better noise suppression capabilities with it's NR/NB1+2, AF DSP, etc. The upside is that not only will noise be less of an issue, the HX puts out 200 smoking watts!  The downside is that I will then have to install my IC207H too for VHF & UHF.  That means two mikes, more wiring harnesses, etc.

Anyone here have any experience with the Kenwood TS480HX in their rigs?  I want to know if in real life it will be worth the effort.

Thanks in advance!

Dale WU7X

Dale, I was troubleshooting an issue like this on certain frequencies a while ago with my Kenwood. It turned out that My GPS was causing the interference. Odd but true, when i turned the gps off it went away. just an idea but have you tried seeing if you have interference with no other accessories running, and no cell phone in the vehicle?

Just a thought.

edit:  wow, 200 watts?  You could tape a burrito to the antenna and cook it while you talk!

GM Todd!

Yup, 200 watts output.  But the TS480HX does not have the autotuner that is found in my TS480SAT.  I have a Turbo Tuner that will automatically tune the Tarheel screwdriver for any frequency between 10-80 meters.  It can also do 6 meters if I take the 102" whip antenna off.

I have been using the IC706MKIIG for 7 years in my Taco.  I have had the problem from the beginning.  I have tried ferrite beads, rewiring the systems, checking all grounds, etc.  I was using it before I had either the Garmin GPS II (yes, that long ago!), or the present Garmin GPS76C installed.  Man, even before cell phones were popular.  Now I am really feeling ancient.

The problem with the Icom, I believe, is the multiple lenghts of RG8X coax; one long length for the Diamond 2m/440 mobile antenna mounted on the side of the hood, a run from the antenna to the Turbo Tuner, and a third from the Turbo Tuner to the radio. The outside shield of these coax pieces acts as an antenna, picking up the RFI from the ignition.  I have tried all kinds of RF choking devices to no avail.  I recently installed a 40 A noise supressor on the power cable, also to no avail.  I am going to be ordering several of the newer Type 31 ferrite chokes and give them a try.  If you aren't familiar with them, this new ferrite mix works all the way from 0.1 MHz to UHF frequencies.  The ones I'm ordering have a >2" diameter ID so that I can run multiple turns of the coax through them.  The impedence increases as a square of the number of turns of coax through the core.  1 turn = 1X, 2 turns = 4X, 3 turns = 9X, etc. I am going for 4-5 turns of RG8X through the center of the doughnut shaped ferrite core.  This should knock the RFI being transmitted on the outside of the shield down dramatically.  That's the plan.

If it works on the present system, I'll live the 706 in the rig.  If not, I'll go to the TS480HX.  I'm a lazy bugger, so would like to stick with the easier process of replacing the coax with pieces having the new ferrite cores installed, rather than ripping out the whole system and starting anew.

Thanks for your suggestions.  They are appreciated.  Hope this answer isn't boring you.

Dale WU7X

Well it certainly sounds like you have a handle on it. My GPS 176C was the issue. No issues on the 276C. I tried Ferrites and the whole bit. Anyway, good luck with the troubleshooting! 

Could the coax be pinched somewhere?

Todd,

I checked and rechecked the coax runs.  Even replaced the coax from the tuner to the screwdriver antenna twice.  It is an outside the cab run of cable, so try to replace those every 3-4 years, the rest every six years.  At any rate, still had the noise issue.

By the way, I was wrong about my GPS. Mmy present GPS is a Garmin is a GPSMap76S, the older, B/W screen with no SD card accessibilty version.  A freind gave it to me several years ago as he wasn't using it.  I like it primarily for the trackback features when in the mountains over here.  If it's on, I can always find my way back out. I've had it on and off with the radio running HF and no discernable differences in noise. I wouldn't trust the elevation readout for flying, but for in the field it is pretty good.

I don't know if you have ever tried HF mobile when off-roading and camping but it sure can be fun.  I have made contacts all over N. America, Hawaii, Alaska, Central America, and even a couple into S. America with 100w and a simple antenna.  VHF/UHF, as you know are superior for vehicle to vehicle communications, but are limited to line of sight when off-roading.  2 meter sigs will bounce off mountains a bit.  But I am a HF DXer at heart.  Just received QSL cards from Libya (5A7A) and St. Maarten (TO4X) this past week.  It's fun to give out rare states, counties, and grid squares while out off-roading.  Just something to add to the general pleasure of being "OUT THERE".  The Icom 706 series, the 7000 and new 7200 Icoms, along with several Yaesu rigs will give you both HF and VHF/UHF capabilities in one unit.  The TS480HX is the only HF/6 meter rig that has 200 watts output, but then, like I probably will be, you're hooked into having to install a second radio to cover the higher bands.  I have noted that several hams in this group us the Kenwood d700,d710 models which are great fro tracking (APRS?).  May have to try to find one of those used on eHam some day....

Dale WU7X

To correct an error in my last post.  The Icom 7200 is a HF+general coverage (shortwave) radio.  It does not have VHF/UHF coverage, nor does it contain an antenna tuner.  Otherwise, the reviews for it have been outstanding.  Only 100 watts output though.