Strong RFI from Chinese goods?

[mmiller7]

Has anyone else had problems with RFI from cheap Chinese goods?

I'm currently having issues with an "Auto-VOX A118 B40" car dash cam which is destroying 2M ham/business bands within 20-30 feet of my car. A ferrite choke reduced noise to about S2 on all but one frequency (148.510 per my FT-8800) which is still S7 noise out about 10-15 feet from the car and causes slight interference with the ham band when operating weak-signals (local repeater fringe coverage near my office goes from choppy but copyable to unreadable). I'd really like to make this work but I'm running out of ideas of what to do.

I have a RF-Explorer spectrum analyzer and used a SMA-to-PL259 adapter as a "probe" to isolate where the noise is, that seems to suggest the noise is coming out of the camera's plastic case (even on battery power) at a low level maybe -85dbm at 1-2 inches away and then being broadcast stronger along the USB power cord reading -80dbm at 1-2 inches away peak on the graph. The ferrite choke at the camera plug helped eliminate broadband noise (3 turns thru) but didn't eliminate it.

(EDIT: I'm certain it's the camera, I can reproduce the nose starting when it's powered on and going away when it's powered off very reliably)

Any suggestions?
Is there any standard I can cite or use for acceptable RFI at a certain distance?
Has anyone ever tried to argue getting a product exchanged due to RFI when the seller argues that it appears to function as-advertised (it turns on, records and appears to operate properly, just generates what I believe is excessive harmful interference)?
Am I being unreasonable expecting no interference with an antenna <20 feet away from a device which is not supposed to be an intentional radiator?

 

[FKimble]

Just shipping it back and shipping back to you may cost more than the unit initially cost. Not sure of original cost, And the seller knows 2 way shipping will prevent a lot of returns. He could care less about US FCC certicication cause he already has your money. A unit manufactured to the level needed to prevent RFI would cost more. No real idea of how much more. With cheap Chinese goods you spends your money and you take your chances. Maybe a lot for ferrites would help.

 

[MTS2000des]

J With cheap Chinese goods you spends your money and you take your chances. .

What he said.
Brings to mind what radioTVphononut said in this video Shango066 did re: repairing some cheap Chinese POS DTV box:

https://www.youtube.com/watch?v=uI0RZhxo-No

"Cheap Chinese **it that ain't worth a tinker's damn for nothing" is responsible for raising the noise floor from HF through UHF in many places, not just your dashboard. Countless switching power supply adapters have low quality filter caps, lack chokes, and put out spurs and garbage all up and down the dial.

With the FCC not caring about part 15 levels anymore, the future is not too bright for us.

 

[mmiller7]

Alright, yes this was thru Amazon 3rd party seller so I could probably get my money back ($70) but it sounds like getting a different model or another of the same I'd likely see the same faults.

I guess I'll try the "add more ferrite chokes and new power supply" method, there's a hamfest this weekend so that gives me plenty of time to build a shopping list.

I'm also debating trying to disassemble the camera and see if I can fit some metal tape (like HVAC tape) inside but I'm not sure it will make a significant difference.

 

[N8OHU]

What he said.
Brings to mind what radioTVphononut said in this video Shango066 did re: repairing some cheap Chinese POS DTV box:

https://www.youtube.com/watch?v=uI0RZhxo-No

"Cheap Chinese **it that ain't worth a tinker's damn for nothing" is responsible for raising the noise floor from HF through UHF in many places, not just your dashboard. Countless switching power supply adapters have low quality filter caps, lack chokes, and put out spurs and garbage all up and down the dial.

With the FCC not caring about part 15 levels anymore, the future is not too bright for us.

It's not just the "Cheap Chinese stuff" that's like this, though; there are indications that many major manufacturers seeming ignore not just the US FCC Part 15, but similar regulations in other countries. I vaguely recall reading a post somewhere where a ham in the EU was being interfered with by his neighbor's TV, actually got support for his case from the relevant authorities to get said neighbors to stop using said interference source, but they refused unless someone would buy them an expensive, non-interfering replacement. Their argument? Their hobby (watching television) was more important than his (talking with people in other parts of the world for fun, emergency communications, etc.).

 

[mmiller7]

It's not just the "Cheap Chinese stuff" that's like this, though; there are indications that many major manufacturers seeming ignore not just the US FCC Part 15, but similar regulations in other countries. I vaguely recall reading a post somewhere where a ham in the EU was being interfered with by his neighbor's TV, actually got support for his case from the relevant authorities to get said neighbors to stop using said interference source, but they refused unless someone would buy them an expensive, non-interfering replacement. Their argument? Their hobby (watching television) was more important than his (talking with people in other parts of the world for fun, emergency communications, etc.).

Yeah, assuming it came from a legit reseller (WalMart, BestBuy, Amazon, etc) I can't say I'd be willing to give up an expensive TV over that, though I'd probably take it up with the manufacturer, store, or my credit card company to get a refund as "defective" rather than demand the ham replace it.

Google turned up results from "alibaba" that listed the camera as "available with any certifications required for your country, FCC, CE, or anything else" which to me sounds like they'll download the loco and put it on a sticker.