Why does my radio fail at night?

[Shdwdrgn]

I've been having this issue since I got the truck in 2009, but this week I finally realized something... I've always noticed that the radio has *terrible* reception in the Winter months but seems to do fine when it's warm. I live and work about 30-40 miles from Denver, the local radio stations all have their antennas up on the side of a mountain, and I have direct line-of-sight to that mountain during much of my daily drive. However there are times even when I am driving straight into Denver (the highway is significantly higher than the city so going in to town we're actually level with or higher than the skyscrapers) that I still can't get any stations to come in without a lot of static.

Yesterday I realized... DST time change, radio was working great last week, but this week when leaving work the sun has now set. Yesterday was also sunny with clear skies so no extra reflection happening, but I couldn't get my station to come in clearly until I was well outside of town, and even then the hills would block it again. Which also got me to thinking... the times I have trouble with reception while driving directly into Denver, ALSO happen at night when we're going to visit friends, so it seems rather likely that this issue has something to do with the sun position.

Of course none of that even begins to explain why I'm having trouble with reception in the first place, when my old car would pick up the same stations a couple hundred miles away at any time of the day or night. I've already tried eliminating the obvious culprits over the years... first I picked up an aftermarket antenna to put on the dash or hold out the window, with an extra wire to ground it to the chassis frame. Then I grabbed another radio of the same model (the Bose 6-disc player) -- I haven't had it reprogrammed but you get about 30-60 seconds of it working before it shuts down, so I tested that with both the original and aftermarket antennas. And yeah, still no difference in anything I tried.

So... anyone have any ideas on this? Or does the radio in these vehicles just really suck for some reason? I don't really know what else could be causing this, but it might be nice to try and figure it out some day since the CD player doesn't work either.

 

[budwich]

Radio station turn down their power in the evening is one potential answer while the other might be radio design. Get a "boom box" and try it out along your route and compare.

 

[Shdwdrgn]

I'll do ya one better... it's rather annoying when the guy sitting next to me at the stoplight is blasting the station that I am desperately trying to hear over the static. I'd say for the number of times that's happened, it's a pretty clear indication that it's my radio and not the station or location. And again, there was no problem with reception last week, plus I've been driving this particular route for 14 years now and reception always craps out at about the same time of year and just as suddenly starts working again each Spring. It may also be helpful to know I get off work at 4:30, so I can't imagine they would be reducing their output power during the peak of rush hour traffic?

In a few more weeks the sun will still be down when I leave in the morning, so it'll be interesting to see if there's a certain point where I also start losing my morning reception.

 

[budwich]

OK... so its the radio design. Are you talking am or fm. Again, try a boom box and see what happens. Another guys radio doesn't tell you much as you don't know what he is running for a "radio"... he could even be using the internet radio.

Check / clean any grounds associated with the circuits involved.

My 2008 stock radio isn't the best but I don't expect much to begin with.... even the fact that the design fails on simple things like bulbs being burnt out does not give one a sense of "robust design". The other thing that you can try is an amplified antenna.

ADDED: specs on the radio's capture ratio seem to be no where ... probably for a good reason... its a car no an "audio studio"... Depending on your area, evening time might have things with "signal multipath" in terms of terrain that the radio is not handling well.

 

[Mooseman]

If AM radio, that is about the worse for reception. Of the cars in the fleet I manage, only a couple AM works. As for FM, some cars have great reception in the underground garage, some are iffy, and most get nothing and those have so-so reception in the open.

Here's something you could check. Unscrew the antenna from its base and check the resistance from it to the center pin on the antenna wire in the back of the radio. It should be very low or 0. There could be a break somewhere. The ground side of the wire is for noise shielding but also check that there is no short between the two.

I have never used any stock radio, always swapping it out to an aftermarket HU. Maybe time to try that but be forewarned that a lot of them don't have AM anymore so I use my phone with Android Auto to stream the one news channel I listen to. However, with more tech, it's also more finicky and sometimes doesn't connect to my phone.