How can the same FM station appear at two different spots on the dial?

** It says NOTHING the sort - Wanker boy.

It says exactly that. It's amazing that someone as intelligent as you can't understand plain language.

** Garbage. With the LO at 77.4, the image is at 66.7.

Uh... that's right.

** FFS learn to read you autistic idiot.

MY post say there are NO in-band images at all - neither from high nor low side injection of the LO.

** Wot a thick head.

.... Phil

More Philshit, as always. It's a damned good thing you didn't design and build deep space telemetry equipment. Even business radios used expensive crystal filters to reduce adjacent channel interference, instead of 50 cent IF transformers. Digitally tuned FM receivers can still receive an adjacent channel, but more than a channel away it becomes quite distorted. Go back to hacking old stereos.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.

** Desperate liars resort to abuse when they have no case. ** Not one bit relevant to *wide band* FM broadcast receivers. ** Which, when used in multiples, produce sharp roll ofsf at the skirts of the pass band. ** More irrelevance, it matters not how the LO is tuned. ** Tuned FM detectors are like that.

** Go back to washing dunny floors, you pathetic ass.

.... Phil

DING! DING! DING! Whenever you have no clue you start your 'Angry Dumbass Dance', and call people a liar. All you do is prove what a fool you are.

Only if you have the I.Q. of a rusty doorknob.

Define sharp. If it is too sharp, it causes distortion in the recovered signal. Each transformer has an insertion loss in the IF stages. FM radios use just enough tuned circuits to get barely acceptable performance. Even the cheap Murata ceramic filters have a sloppy skirt. The only advantage is that they don't need aligned during manufacturing.

Cram your bullshit and look at it on a network analyzer. Oh, that's right. You have no real test equipment, just junk from a '70s TV shop. You want to talk wideband? One of the Telemetry products we manufactured had an IF range from 1 KHz to 20 MHz bandwidth at the -3 dB points. They had to be aligned on a network analyzer, or with a calibrated sweep generator to achieve the proper skirt.

Sigh. More of your stupidity. Digital has no AFC, so it can't be pulled off of center.

Whatever the hell that crap means, but I guess that you've heard it all your life from people around you. Read a damned book on receiver design. Analog IF bandwidth is specified at the -3 dB points. That wouldn't be possible without a skirt. Brick wall requires a FIR filter or another digital filter that processes a digitized input. The design I worked on digitized to 50 to 890 MHz range for a 70 MHz IF. That was followed by a pair of FIR filters for the IF and another pair for the output bandwidth.

--
Anyone wanting to run for any political office in the US should have to 
have a DD214, and a honorable discharge.

Cheap consumer radios are using pretty exotic methods to reduce the mass and the current draw these days. Any oscillators are deep into the chipset.

The fcc.info link I sent lets you search the FCC database in a friendly gui fashion

I have a Denon tuner where the narrow ceramic filters were not narrow enough to weed out the station I wanted to eliminate. I bought narrower filters from Digikey which resolved my problem. Chuck

** It's worth pointing out that there is only ONE carrier for an FM broadcast signal. At any instant in time, there is only one frequency to deal with and one signal voltage coming from the detector.

With FM stereo, the detector's output includes supersonic signals up to 50 KHz or so. The supersonic stuff provides the L-R difference signal.

** Crystal filters are a tad expensive for an FM radio - so designers make do with tuned transformers and Ceramic filters in the 10.7MHz amplifier stages.

Even a budget FM tuner will have at least one or two of each along with a tuned RF stage to provide good out of band and nearby signal rejection for normal use. FM DXing is NOT normal use.

** There are never two, strong FM signals separated by 200KHz - authorities govern frequency allocations on the band so as to prevent this. ** Only mad FM DXers have that issue.

** Yep - mad FM DXers sometimes do that.

** Sure - an antenna rotator with a high gain Yagi on top is what every home needs. Pure bollocks.

The most common FM antenna is the TV antenna on the roof or maybe a dipole parked inside the roof cavity.

... Phil

I can't stand C-span though they have some good programming. The problem i s that fake synthesized brass keyboard they use for the theme music. How h ard would it have been to buy a CD of a real brass ensemble playing it? Th at piece has been recorded many times.