Interesting local FM reception anomaly

[gar hi]

I should have done this earlier but I started listening to our local FM station that I think has the best variety among our classic rock stations.

It's called 'Thunder' and it's a revival of the old classic Rock station that was on 105.5 in the 90's and then 103.5 until 2005 when the station turned country.

But now, it broadcasts with 250 watts on three different frequencies to cover the area - 105.9 Tampa, 94.5 St. Pete, and 99.1 New Port Richey. It actually came on the air a couple years ago but I only recently decided to really check it out.

So from my location in Tampa on my Sangean PR-D5, the one on 105.9 has the best signal, pretty much like all the other higher power locals and it always turns on the RDS function.

The one on 94.5 from St. Pete is not nearly as strong and is compromised by the station from Daytona Beach when we have tropo enhancement.

I decided to preset one of the buttons on my car radio to Thunder and I assumed that the one on 105.9 would be the obvious best choice.

Not so at all. The FM reception my car radio is noticeably better than my PR-D5 or any other radio I have but on my car radio the one on 94.5 actually comes in a lot better than the one on 105.9 which has a very weak signal.

So what may account for the big difference in reception between two radios from the exact same location?

 

[Schroedingers Cat]

My impression is that the antenna on the two radios has substantially different polarization, one is probably vertical and the other horizontally polarized. Either that or one has poor RITOIE rejection. I was near Lansing, MI today, near where there are many very strong signals. I was waiting for my spouse at her friend's condo while they did some errands. I turned on the under counter Sony radio, thinking it would be half way decent. All I could get was the strong local signals, blanketing three or four adjacent channels, RITOIE (intermodulation 2A-B and 2B-A third order products) and almost no weak signals could be received. On the car radio (a Buick with DSP, HD as I discovered, etc.) there is no problem getting numerous weak signals.

So what might be the best signal on one of the 250 watters might be adjacent to a strong signal or under a RITOIE product on the radio with poor rejection of these. Or it could be the antenna polarization.

 

[gar hi]

Thank you.

Both the 94.5 and 105.9 stations are 4 frequencies down the dial from high power locals.

WDUV 105.5 is closer to my location than WLLD 94.1

 

[purpledevil]

Here's one that has baffled me since I purchased it several weeks ago. I bought a pocket FM transmitter from Fry's Electronics. Nothing fancy, you know, one of those $40 jobs. I plug it into the truck, set the frequency to a fairly open channel, and it has static underneath the audio. This is within just a couple of feet from the fender that the external antenna is mounted on. The peculiar part is that if the transmitter is plugged into the truck, and the truck is sitting in our driveway (some 100 feet from my living room receiver), I get a clear, uninterrupted signal from the house receiver. Could not get the same results from the pocket unit I had previously. The only difference between this transmitter and the one it replaced, is that the new one plugs directly into the cigarette lighter, as opposed to using a pair of triple A's. Either way, it is a DC current feeding the thing, so I'm at a loss.

I was going to return it, thinking that if I'm going to hear static in the truck, while listening to my phone, I'd probably better go the next step up in quality, however, I wonder if there's not some way to back the transmitter up, since it's apparently overshooting the intended target receiver. The truck has the OEM Infinity unit, which has no problems picking up even the more distanced translators farther south of me.

Any ideas?

 

[rbrucecarter5]

Here's one that has baffled me since I purchased it several weeks ago. I bought a pocket FM transmitter from Fry's Electronics. Nothing fancy, you know, one of those $40 jobs. I plug it into the truck, set the frequency to a fairly open channel, and it has static underneath the audio. This is within just a couple of feet from the fender that the external antenna is mounted on. The peculiar part is that if the transmitter is plugged into the truck, and the truck is sitting in our driveway (some 100 feet from my living room receiver), I get a clear, uninterrupted signal from the house receiver. Could not get the same results from the pocket unit I had previously. The only difference between this transmitter and the one it replaced, is that the new one plugs directly into the cigarette lighter, as opposed to using a pair of triple A's. Either way, it is a DC current feeding the thing, so I'm at a loss.

I was going to return it, thinking that if I'm going to hear static in the truck, while listening to my phone, I'd probably better go the next step up in quality, however, I wonder if there's not some way to back the transmitter up, since it's apparently overshooting the intended target receiver. The truck has the OEM Infinity unit, which has no problems picking up even the more distanced translators farther south of me.

Any ideas?

The FCC forced the power output of those things way down a few years ago. You could go on eBay and see if you can find one of those old Belkin units from before the FCC mandate. The other option is to open it up and tap into the antenna connection. I did that with mine, and got a robust signal over 100 feet away on a portable. Of course your vehicle makes a pretty good Faraday cage, so anything you can do to improve the broadcast antenna will reap benefits with the radio.

 

[austingrace]

Here in Brandon 105.9 seems drivable for the most part. I was in the Tampa area near university and it seemed like 105.9 was dropping out a bit. This was on a jvc car radio. Not sure on the model number. It's rare that wocl takes over that channel but I have heard it happen before. I wished 98.7 had a better signal here as well. So I'm new to this area and cannot drive. I have yet to find a radio nerd like myself here in Brandon. So is 97x really not that drivable here? Also what is on 790 and 640 here? I have tried from my apt but have not heard anything. I may have to get my cc 2e shipped to me from Altamonte. hahaha I knew I should have brought that one with me. I only bought the skywave. another thing, 107.3 was fading a bit near lithia springs. This was on an acura mdx from 2007 with the factory radio. also for some reason I thought the 91.5 joy fm would do a lot worse here than what it does. So how is 98.3 on a car radio here? I really like that station as well. Same with 98.7.