2022 Rav4 Hybrid - HF RFI

[AF1UD]

I was wondering if anyone could maybe point me in the right direction regarding an ongoing problem with my mobile install. With my pre-amp off, I have no noise floor but when I turn it on my noise floor rises to an S5, and reception isn't that good with my antenna on VHF Low Band.

I have narrowed down the a few causes of RFI:
Power Windows
Regenerative Braking
High Beams/Lights - Only for the first 10 minutes or so of starting the car.

I mounted my HF antenna on the front it's a Alpha MOTO-FMJ on a piece of bent steel and attached it to one of the screws that hold my hood in place. I have tinned copper strapping on the bottom of the antenna to the car frame, and the same on the doors.

I also attached a diagram of my wiring, maybe someone sees something I don't. I wonder if it's the inverter or if I need a line rectifier.

Any help/feedback would be greatly appreciated!

 

[RFI-EMI-GUY]

Equipment grounding should be at the vehicle chassis/body as close to radios as possible. Not at the neg terminal of the battery. Radio chassis should be bonded to vehicle chassis/body as well.

 

[AF1UD]

Sorry it's not clear there. The negative for the powerpole block is on the chasis ground not the battery terminal. Should all radio negatives be attached to the frame/bonded?

 

[mmckenna]

Sorry it's not clear there. The negative for the powerpole block is on the chasis ground not the battery terminal. Should all radio negatives be attached to the frame/bonded?

I do that.

I think what RFI was saying was that your grounds need to be as short as possible. If you are running them all the way back to the place where the battery is grounded to the body, that may be an issue. Keep the grounds as short as reasonable.

 

[AF1UD]

Thanks!

I the only other closest option is my passenger seat frame. I'll have to check the base of it.

 

[mmckenna]

Thanks!

I the only other closest option is my passenger seat frame. I'll have to check the base of it.

That would work. Make sure you get good metal to metal contact.

Other option is to use a self drilling screw, once you have positively confirmed there is nothing on the other side.
Or, stainless bolt/washer/nut.

 

[AF1UD]

Ok so instead of negative to the cars' ground point, i'll attach all negatives to the closest single point possible. Thanks guys!

 

[RFI-EMI-GUY]

Ok so instead of negative to the cars' ground point, i'll attach all negatives to the closest single point possible. Thanks guys!

While your drawing does not show a main fuse. The main fuse should be on the engine side of the firewall so that if the wire chafes or damaged in a wreck, the fuse opens and no wires burn.

 

[AF1UD]

I do have a fuse on the main power and main negative. I bought premade one rated for 45A from Amazon.

I only draw 30A through it so I figured it'd be fine.

Amazon.com

 

[RFI-EMI-GUY]

I do have a fuse on the main power and main negative. I bought premade one rated for 45A from Amazon.

I only draw 30A through it so I figured it'd be fine.

Amazon.com

FYI if a fuse on the negative is removed, your 30 amps will sink through your antenna coax and other undesired paths like microphones in grounded hang up clips or that fancy FTxyz123 TNC modem you added. Fusing the negative is not recommended . I know, all the Japanese radios have or show a fuse on the negative side.

 

[mmckenna]

I don't think I've ever seen a commercial radio with a negative fused lead.
In fact, it's not uncommon to see commercial radios with short negative leads because they want it grounded close to the radio.
Looking at the install guides for Motorola/Kenwood/Harris LMR radios will show install standards quite a bit different that what you'll find on the ham radio side. There's good reasons for that.

 

[slowmover]

Mobile Radio Wiring and Grounding

Wiring & Grounding