RFI

[camperpaul]

Most of the members have read some of the posts about RFI generated by various systems in our homes, RVs and tow vehicles.

A lot of you laugh it off, thinking, "It doesn't apply to me."

Well, guess again and read this article from the Wall Street Journal.

[mlts22]

Ham radio operators are the people who will keep vital communications going when something happens to the Internet. I consider them to be providing a very valuable service, especially in case of a disaster.

Like above, they are a special breed of humanity.

[MEXICOWANDERER]

I regard HAM operators as being generally in another universe when it comes to understanding and troubleshooting RF interference. Their knowledge and database networking is awesome. It is a special breed of humanity IMHO.

[wa8yxm]

That is true SCVJeff. Not to mention many a stranded/crashed/whatever has been tracked over the years by hams with direction finding ability doing a "Fox Hunt", the difference is in a Ham Radio Fox Hunt the prize is generally something like a hot dog lunch.

In these tracks the prize was the victim of a disaster saying Thank You.

And frankly.. there is not much that beats that prize.

[SCVJeff]

There's nothing more fun than a good T-Hunt. But it's the knowledge and experience from these games that really pays off when it's time to find a problem

[camperpaul]

Led 67 wrote:
Radio hobbyist Tom Thompson of Boulder, Colo., last year tracked a signal using a homemade contraption.

The best "contraptions" for radio direction finding are home-brew and the Hams know how to use them.

The worst kind of RFI is that which is conducted over the power mains and little if any is radiated. Sometimes it can do more than cause interference; it can make certain electronic devices totally unusable.

A few years ago there was a camper who had a defective device in his camper; it was feeding enough garbage back on to the power line to cause tripping of GFCIs. As soon as that camper was unplugged from the mains, everyone else could then use their radios, TV sets, etc.

[wa8yxm]

If you have an RFI problem,, Something that has plagued Ham radio operators for many decades... You might find the following link interesting.

ARRL RFI Book 3rd Edition

You see, Ham radio operators get hit two ways,, Since we run anywhere from a few watts to around 2,000 peak envelope power, compared to many times that for Radio and Television stations.. And instead of covering perhaps a fifty to 100 mile circle, we are trying to cover the world.. We have very sensitive receivers. These are very good at picking up interference, so we need to know how to get rid of it when we hear it...

And we often are accused of causing it, even when nothing we own is turned on. So we need to keep our stations clean (I can watch here while talking on my 100 watt radio).

Thus the ARRL has put this book to 3rd edition. I think I used to have a 1st edition.

[tvman44]

Just yesterday my cousin was telling me he replaced a ballast in a kitchen florescent fixture with a new electronic ballast and it interferes with his X-10 system in the house. 🙂

[RoyB]

Thanks Paul - FCC gets away it by their disclaimer in the manual stating "This device may casue interference to other systems" haha

I most certainly had interference to my own system from the regulated type LED LIGHTS.

I am still amazed you was able to solder these very small strip capacitors on the connectors of your LED lights to eliminate some of your LED Interference problems..


nice report...
Roy Ken

[MNtundraRet]

If some RV manufacturer's continue to install RFI emitting LED lighting sets that interfere with television signals, and they don't resolve the problem before the RV is sold to someone who then complains.

Maybe complaining to the F.C.C. will be the only way to get the manufacturer to comply. The problem may be small now, but will increase as more RV manufactures jump on the band-wagon for supplying LED lighting (inside and out).

I suppose there are many people camping out there now that have not figured out yet that their signal interference may have an RFI problem, rather than a poor signal.

[Chris_Bryant]

Winegard had a run of Sensar heads which were defective- IIRC, a short jumper inside was not completely shielded , causing an oscillating feedback look in the amp.

[edatlanta]

Don't forget lighting dimmers. My dimmers, OEM, cause a buzzing in my sound system. I just don't use the sound system with the dimmable lights on. I don't know how far away from me the interference reaches.

[Led_67]

Very interesting article however I find these three paragraphs of particular interest

Private signal sleuths, too, hunt down errant emissions. Jay Jacobsmeyer, president of wireless-engineering consultants Pericle Communications Co., investigates interference at 150 to 200 cell sites a year, mostly for wireless clients. His team last November faced a puzzling signal in San Diego that would pop up, disappear for weeks, then resume.

Using directional equipment, it identified a cordless phone on a yacht that occasionally visited, Mr. Jacobsmeyer says. The skipper agreed not to use the system in port.

Radio hobbyist Tom Thompson of Boulder, Colo., last year tracked a signal using a homemade contraption. After knocking on the suspect's door, he traced it to ballasts on marijuana grow-room lights. He says he built a filter that the grower agreed to use.

Man oh Man what some people will do

[wa8yxm]

A key segment of that article....

article wrote:
The FCC had warned Brookfield in May, asking for progress reports, but it received none, the new letter said. It warned of fines and possible equipment seizure or jail time.

You will notice the FCC first warned, and ask for progress (Compliance) reports. and when Brookfield basically ignored them,< THEN it got a letter with stronger wording, Likewise the hair salon They took two warnings, but paid no fine,, GE fixed the problem no charge (as well they should).

Some of the earliest Winegard antenna amps were offenders.

Many devices in motor homes are potential offenders. INCLUDING but not limited to refrigerators, fuel and water pumps, Florescent and LED lights. and MSW inverters.

In nearly all cases the majority of those items are operating within certified limits and are 100% legal, but there is at least one model of Fridge for example which has that problem (The manufacturer WILL replace the control board if you have one). and the ballast for a 12 volt Florescent is really an MSW inverter.

But I stress.. ONLY SOME are offenders.. not by any means all. May be as low as 1 in 100 or less..

[SCVJeff]

GREAT article.. Thanks Paul!

These issues are everywhere, but the FCC is so underfunded its not even funny.