Any help with this interference?

[schmave]

I am having increasing interference problems with the AM radio in my 2013 Ford Fiesta. It's the original radio that came with the car. The interference is much worse on the lower half of the dial, mostly notably on frequencies from around 700 to 900, and it's a bigger problem during the summer than the winter.
If you watch these two video links, you will hear what I'm talking about.
For reference's sake, I live in Pickerington, Ohio, an eastern suburb of Columbus. Affected stations are the ones I hear clearly on other radios I own and in other automobiles in the same area, so it has to be something with my car.
Some of you will be very familiar with the stations I cite, and know how they should be heard in my area.
Any help is appreciated!

Recorded at about 10:20 a.m. today in Reynoldsburg, Ohio, away from overhead wires:
https://www.youtube.com/watch?v=d11mJ9ezRcw

Recorded a few minutes later about 1 1/2-2 miles south, with no overhead wires. You will hear the difference between when the engine is on and when it's turned off. Apologies for the fact that the the video is sideways:
https://www.youtube.com/watch?v=us0bqtjiI0Q

(Mods: If this needs moved to another area of the site, I understand.)

 

[rbrucecarter5]

I watched your videos, and it is pretty obvious that you have engine noise leaking into the AM section. But it may be more complicated than that. What I was hearing was multiple harmonics on top of the modulation, not just static.

Some "nasties" with later model cars. Someone decided whip antennas didn't look "cool" so they now put antennas in shark fins, nubs, downsized whips, windshields, etc. All as in ALL of these ideas work fine for satellite may be marginally adequate for local FM, but they are a disaster for AM. Unqualified disaster. AM is considered "antique modulation" / only listened to by people over 55 / irrelevant - take your pick. Even in my own car, with a 31 inch whip, some "genius" decided to put the whip mount on the side, not the top of the fender. There is no ground termination at the fender, so AM is plagued by alternator noise. It could be worse. I could be stuck without a whip at all. At least FM still works on deep fringe, which translates to translator and LPFM stations up to 30 miles away.

I think you have some basis for taking the car to the dealer and getting the radio changed out. If they don't laugh you out of the dealership for being an AM listener, or tell you in a huff that the radio isn't designed for out of town stations, you have a shot. They know they can rip it out in 5 minutes and swap with another, then sell it to the next sucker who will probably never use the AM dial.

The other thing you might consider is aftermarket. I have a top of the line Pioneer Supertuner 3D in my car, mainly for those "deep fringe" LPFM and translators that do a better job of serving me than the "normal" FM stations. Except for the static - I have good AM. I am 250 miles from WBAP, if it were 90 I would never hear a trace of static. It looks to me like your radio isn't tied to GPS, backup camera, and all the other stuff that makes aftermarket impossible in most cars today. So you could get a decent radio with professional looking mounting kit and wiring harness for under 300 that would do a much better job than the stock radio. Just an idea.

As for combatting whatever is going on - I'm not a big fan of bandaids, but you could try one of those large electrolytic capacitors. DON'T buy at the car stereo place, they will rip you off. I got a very good 1 Farad from a local electronics hobbyist store for about $15 (used). It worked for the problem I had at the time. What may help you more is a large inductor in series with the power - all that you need is the primary of just about any transformer, it will give you a few Henries of inductance (if you are lucky) which will stop anything being conducted on the 12V line. Don't forget that line that keeps the radio memory / clock, it can be where stuff is conducted in, too. So if I were going to throw the kitchen sink at the problem, I'd get two caps and two inductors. Ground EVERYTHING back to the battery. Your radio has one ground, and that is the negative terminal of the battery. Everything else is a return. I have some heavy duty strap I use for the job. Just make sure it doesn't get caught on anything that moves.

Once you are sure the conducted stuff is taken care of, then you have the radiated stuff. In the early 70's, automakers tried the first round of getting rid of whips. My 74 Nova had the blasted wires in the windshield, and corresponding horrible AM reception. I pulled the fender, drilled it for a whip, and I had performance similar to the Delcos of the late 60's. A lot of hams put whips on their car, bottom loaded to simulate enough electrical length that the whip becomes an efficient antenna at AM frequencies. They report up to 600 mile reception on 50 kW clears during the day, and I have good reason to believe them because even a 60 inch whip can get 450 mile reception (WBAP from Roswell, NM on multiple occasions). By the way, a 60 inch whip is MUCH better for FM as well, forget trying to make a quarter wave - anybody in the know will tell you 5/8 wavelength is better from transmitting and reception.

Wish I was nearby to meet you and make it work - good luck!

 

[frankberry]

It's pretty obvious that the computer in your car is causing the interference.
Something is not grounded properly. I would start with the computer module(s).
Ask the dealer to re-seat all of the connectors.
If the interference is audible while at the dealership, turn the problem over to them and ask them to resolve the issue.

 

[schmave]

Guys, I appreciate the input (and welcome more from others, too). Some of it is technical stuff that's above my know-how, but I want to get it fixed. I enjoy AM radio too much to not have a top-notch unit in my car. I am heading in for my 35K checkup soon, so I will mention it to the dealership.
My parents also have a Ford, albeit an Escape, and their radio is much, much better than mine.
I will add that my FM radio works very well. Great reception on distant stations. I would trade that in a second for the same sort of reception on the AM side.

 

[Schroedingers Cat]

My spouse insists on controlling the sound system in her Buick when she is driving. We've had the car six months and I just found out that it has HD radio. Apparently, to get that to work, especially AM IBOC, with the shark fin antenna, you have to have DSP, which I had already figured out that it must have, plus work out any of the other grounding and computer chip radiation issues. It actually works fairly well on AM IBOC, I am forced to admit. And oddly enough, WSCR, WGN, and WBBM will stop the scan DURING THE DAYTIME in the coldest part of Winter in FRANKENMUTH, MI! When there's a will there's a way. Not that I'm sold on IBOC adjacent channel interference and the sound of the low bitrate digital. But they seem to have found a solution, at least when the car is new.

One of the other reasons I didn't know it had HD/IBOC is that it has to be enabled in a menu screen. Driving to The Bavarian Inn is one of the few times I have had complete control of the radio.

 

[cyberdad]

I had a VW Passat rental car that I drove for a month a year ago January. Drove it mostly around St. Pete and was very impressed with how well it performed on AM....even with a "stump" for an antenna. You really had to listen carefully to distinguish between AM iboc HD and standard FM. Standard AM was good too with a couple of Cubans tripping the scan button. The only problem with the radio was the HD. Basically, it worked fine most of the time, but when you'd hit a weak spot on (for example) an HD-2 signal, the radio would flip to HD-3 etc.

Back to the original post (sort of). As a guy who's driven a slew of rental cars in all my years of travel, I'm always amazed at the variance from model to model and even wihin models....from the same manufacturer! This year in St. Pete, I had a new Chevy Malibu with only about a thousand miles. The standard base radio was decent, but a Malibu I drove about six months previous came wih the same radio...which was a significantly better performer. FWIW, I've found that Toyotas seem to consistently have the best radios for DX.

 

[Schroedingers Cat]

The radio in the Buick is the one I got WFLF 540 on for the first time last Fall and Winter. It's pretty good. I've had strange things happen though, the station spontaneously changing to the next frequency on AM, doors unlocking spontaneously, trunk found open, etc., which I attribute to On Star.

 

[rbrucecarter5]

I've driven a fair number of rentals myself - never found one with HD in it. Almost all of them have satellite. Believe me I look for HD - a lot of my travel is Orlando and Z-88's HD channels are top notch, but their over the air signals for them are low power and limited range. All are decent on local, some pretty good on Tampa Bay and Melbourne - but NOTHING like my own car with a 31 inch whip and Pioneer Supertuner 3D. From what I remember in Central Florida, it brought all Tampa Bay in like locals from Orlando, and Jacksonville was like local from Daytona Beach, a little weak around Orlando. Melbourne / Palm Bay had all Orlando like local, very good on Tampa Bay, fair on West Palm. That was, to the best of my knowledge, the normal non-skip conditions. With ocean fronts many nights, the band comes alive at night. I've had Jacksonville like local at night in Miami, and vice versa. Orlando - sometimes 90 frequencies with something on them. Under skip conditions, nubs, shark fins, and other cr@p antennas still bring in the stations.

AM in rental cars is fairly easy to categorize. My benchmark is WSB. Orlando is about on the southern edge of intelligibility for WSB with a decent AM radio and whip. None of the rental cars can do it. Closer things like the Miami stations are a decent test in Orlando, a couple of the high power Jacksonville AM stations. I'm finding most have alternator noise if you can get them at all. I have not had a rental car with shark fin, nub or other bad antennas that come close to the quality AM a whip brings. And I've had quite a few different models - traveling at the last minute like I do I sometimes have little choice in model and end up overpaying for top of the line cars sometimes.

Toyotas do have good stock radios. I haven't tested one of their HD versions yet, but in the 80's I remember WFAA from Dallas, a 5 kW regional, was in perfect C-Quam stereo until well past Huntsville, when heterodyne from KLVI finally made listening unpleasant. That radio had a bit of a wide IF, so selectivity was poor. After moving from the area, I was stuck in mid-Michigan and needed a Pioneer to separate out CKLW 93.9 next to a local 94.1, and the Chicago clears had switched to talk, so I sacrificed C-Quam to get a Pioneer in the dash. CKLW was amazing from Jackson, almost no crosstalk. And Canadian stations with their equalization sounded amazing. There was a classic rock in Windsor that came in great from Jackson on the Pioneer - I couldn't get either on the Toyota stock radio.

Later Toyotas I have had - I have a 2000 and its radio is very good. Not on the level of a Pioneer Supertuner 3D, but a great DX unit. Also good sounding. I was very disappointed with the radio in my 2005 Toyota, too much alternator noise on AM - but I traced that to a lack of ground on the fender at the whip. Sensitivity on AM with the engine off is great with the whip, FM a little wanting in sensitivity.

I freely admit I am very critical - probably from years of having to do extreme DX just to get the music I want. In these days of satellite and yes - HD - I have things a bit easier. HD has its own set of technical problems - just got local oscillator jammed this morning on full class C KRBE less than 20 miles away by a car that kept meeting me at lights. I turned my radio down - and yep - they had 93.7 pumping out bass from their radio. UGH - I hate the format change on that station, now it is more popular and jams KRBE HD often in traffic.

 

[cyberdad]

Interesting report, Bruce. Thanks for posting. I've had HD radios in rental cars three times. Two were Pasats. IIRC correctly, the other one was a Chrysler 500 (upgrade) loaded with all sorts of bells and whistles. What I do recall is that all of them performed about the same on both AM and FM HD.

One of my Pasats was a car I rented locally. The guy who runs the local Avis franchise is someone I've known for a long time (his cousin used to work for my wife, and I used to work with her husband). He knows what I like, and part of the deal is a good electronic entertainment system. So when he gave me the Pasat with the HD I was able to discover that our town is pretty much on the outer fringe of reliable HD for the Chicago FM signals....about 44 miles away. I also learned that the Chicago 50kw AM blowtorches (WBBM and WSCR) have reliable HD to just north of Milwaukee. A little less than 100 miles in that direction, which has quite good ground conductivity.