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Does anyone else like FM?

Come to think of it, didn't the good old modems (that -- ahem -- some of us grew up with) use frequency modulation of a carrier to encode digital data (bits)?

1737472024253.jpeg

(random internet image of a 2400 baud modem; we had one of these RACAL/Vadic modems in the lab when I was in grad school)

The soundtrack of my young adulthood. :)

In full disclosure, my first modem experiences were at 300 baud, with acoustic coupling. I am old. :cool:

1737472308442.jpeg

(random internet image)
 
Here is a waveform representing one second of music voltage:

View attachment 422725

The FM carrier wave for "98 Rock" would oscillate around 98 million times in that second.

As the audio voltage increases, the FM carrier frequency increases.

As the audio voltage decreases, the FM carrier frequency decreases.

The change in carrier frequency represents the change in the audio voltage. That's all.

(No way I can draw that)
So, this is utterly unvetted (i.e., it's the first YT video that popped up on google:facepalm:), but it looked OK at a quick glance, and it might be helpful for those asking about how a frequency modulated carrier contains both frequency and amplitude information. :)

View attachment 422777
By Berserkerus - Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=5071748
Makes sense, I understand. Demodulation, in concept s a reversal of modulation. In real time as the carrier frequency increases, audio signal amplitude/voltage increases, and as carrier frequency signal decreases audio amplitude/voltage decrease recreating the audio signal loudness. The rate at which the carrier signal varies recreates the audio signal frequency/pitch.

Now I don't really understand how the circuitry of the demodulator produces an output voltage in response to frequency, such as with a phased locked loop demodulator, but that's a different matter https://www.allaboutcircuits.com/te...emodulation/how-to-demodulate-an-fm-waveform/.
 
I think someone mentioned SDR (software defined radio) earlier in this thread. For those of us who are cheap (or just voyeurs) there are even easier ways to sample SDR, such as:

Sorry that the latter two have some issues with http(s): security -- there are others; google a bit! :)

The next best thing to sitting in front of a boat anchor in the middle of a long, dark, cold winter night, DXing. :cool:

1737551514612.png
 
I think someone mentioned SDR (software defined radio) earlier in this thread. For those of us who are cheap (or just voyeurs) there are even easier ways to sample SDR, such as:

Sorry that the latter two have some issues with http(s): security -- there are others; google a bit! :)

The next best thing to sitting in front of a boat anchor in the middle of a long, dark, cold winter night, DXing. :cool:

View attachment 423024
I'm still too preoccupied with how HD Radio might be affecting my FM to think about software defined radio and SDR seems kind of complicated :p .

I think I need a better antenna for better FM reception. Some parts of the day I pick up some noise and lose stereo reception. I'm still using the wire antenna my receiver came with. I'm going to update with a simple dipole antenna. I thought about using a TV antenna, but figure FM horizontal dipole you can mount high near the ceiling would work better https://www.amazon.com/dp/B09J29KNT...ZEZPNM5T&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it. Anyone have any antenna suggestions?
 
@Mark1, remember that the entire "commercial" FM radio spectrum (i.e., 88 to 108 MHz in most of the world) lies in between the old, analog (US) TV channels 6 and 7! I mention this for two reasons -- 1) even an old-time broadband directional VHF TV antenna is not really optimized for FM radio reception and 2) today's (US) digital OTA TV frequency assignments are above the good ol' FM radio band. In other words, there really are few if any TV antenna "solutions", old or new, that will help much.

I don't pay close attention to the topic, but my impression is that commercially available options for high gain, directional FM radio antennas (Yagis, typically) have become much more limited in recent years. I picked up an inexpensive FM directional from Parts-Express some years back -- but it's still sitting in it box in the basement!

Altitude and directionality can be your best friends, of course, for a really good FM antenna situation -- but that won't help with IBOC HD interference problems (if you have them). Plus, if you go with a directional antenna, you'll have to add a rotator unless the only FM station(s) you want to listen to lie in one direction from your location.

A DIY antenna might be a very attractive option! Remember that even a simple 300 ohm center fed (T) dipole can be a very good antenna, particularly if 1) it's "tuned" (i.e., cut to length) for optimal reception of a favorite station and/or 2) if it is way up high! Recall also that a T-dipole has a figure-8 shaped reception pattern, so it is somewhat directional. The so-called J-pole (which I believe is omnidirectional) is a good DIY-able option. You can find designs aplenty, although biased towards designs for 2 meter (144 MHz-ish) ham use. They can be re-dimensioned for broadcast FM.

There are simple, inexpensive commercial outdoor (or attic mount) omnidirectional FM antenna options, too -- perhaps the most commonly available one is the "turnstile" design. Of course, if you mount an antenna outdoors, proper lightning protection is essential -- for the safety of your house and for the downlead connected to your radio or tuner. :eek:

Hope this is helpful -- or at least interesting.
 
Oh, @Mark1 , are you in the US someplace? I don't remember. :p
I will say that if you are, and depending on where you are, I may be able to "enable" you to some extent with antenna options. ;)
I have a bunch of interesting stuff lurking in the basement that, realistically, I'll probably never use. :facepalm:
 
@Mark1, remember that the entire "commercial" FM radio spectrum (i.e., 88 to 108 MHz in most of the world) lies in between the old, analog (US) TV channels 6 and 7! I mention this for two reasons -- 1) even an old-time broadband directional VHF TV antenna is not really optimized for FM radio reception and 2) today's (US) digital OTA TV frequency assignments are above the good ol' FM radio band. In other words, there really are few if any TV antenna "solutions", old or new, that will help much.

I don't pay close attention to the topic, but my impression is that commercially available options for high gain, directional FM radio antennas (Yagis, typically) have become much more limited in recent years. I picked up an inexpensive FM directional from Parts-Express some years back -- but it's still sitting in it box in the basement!

Altitude and directionality can be your best friends, of course, for a really good FM antenna situation -- but that won't help with IBOC HD interference problems (if you have them). Plus, if you go with a directional antenna, you'll have to add a rotator unless the only FM station(s) you want to listen to lie in one direction from your location.

A DIY antenna might be a very attractive option! Remember that even a simple 300 ohm center fed (T) dipole can be a very good antenna, particularly if 1) it's "tuned" (i.e., cut to length) for optimal reception of a favorite station and/or 2) if it is way up high! Recall also that a T-dipole has a figure-8 shaped reception pattern, so it is somewhat directional. The so-called J-pole (which I believe is omnidirectional) is a good DIY-able option. You can find designs aplenty, although biased towards designs for 2 meter (144 MHz-ish) ham use. They can be re-dimensioned for broadcast FM.

There are simple, inexpensive commercial outdoor (or attic mount) omnidirectional FM antenna options, too -- perhaps the most commonly available one is the "turnstile" design. Of course, if you mount an antenna outdoors, proper lightning protection is essential -- for the safety of your house and for the downlead connected to your radio or tuner. :eek:

Hope this is helpful -- or at least interesting.
Interesting info. I know I tried some old Terk passive tv antenna I had that is geared toward HD tv and it worked worse than my wire FM antenna. I figured maybe there's something wrong with it, but good to know going with a dedicated FM antenna over a traditional tv antenna was the better choice.
 
Oh, @Mark1 , are you in the US someplace? I don't remember. :p
I will say that if you are, and depending on where you are, I may be able to "enable" you to some extent with antenna options. ;)
I have a bunch of interesting stuff lurking in the basement that, realistically, I'll probably never use. :facepalm:
Yes I m in the US :) . I sold my house and moved into a rental so I'm not looking to go the attic or exterior antenna route. I'd be interested in trying out an indoor option and reporting if I get better reception than that dipole I have coming. I appreciate the nice offer and no pressure to go through the trouble of sending it :).

I remember as a youngster my family's house had a tall free standing tower with a tv antenna I think the previous owner had left. I imagine it would've been good for FM too.
 
Anyone have any antenna suggestions?
Hey, for less that 6.99 if you get free shipping is worth t just for the adaptors :) And if it gives you better reception,that a bonus!!!
You have probably already done this, but are you receiving more stations/better in your driveway in the car or with the tuner inside the house ?
 
Hey, for less that 6.99 if you get free shipping is worth t just for the adaptors :) And if it gives you better reception,that a bonus!!!
You have probably already done this, but are you receiving more stations/better in your driveway in the car or with the tuner inside the house ?
I know right I probably couldn't buy some 300 ohm wire or whatever and connector any cheaper to make the antenna myself :) .
 
Does anyone else think FM sounds better than free digital streaming music
Not as far as the CONTENT, no. Well, here in L.A., KKJZ jazz and KUSC Classical excepted. Otherwise even the once-mighty KROQ "Alternative" has become an oldies station.
- FM sound is not necessarily better-it depends so much on your reception/antenna/tuner. Hard to get FM antennas any more.
- SiriusXM over the air is super squeezed, way too many channels for the bandwidth. Much better on the streaming app.
- Some streaming sites sound good, some are still way too compressed. I'll agree that for me 160k is where it starts to sound stale, and 128k I'm done, not exactly but maybe
 
I'm still too preoccupied with how HD Radio might be affecting my FM to think about software defined radio and SDR seems kind of complicated :p .

I think I need a better antenna for better FM reception. Some parts of the day I pick up some noise and lose stereo reception. I'm still using the wire antenna my receiver came with. I'm going to update with a simple dipole antenna. I thought about using a TV antenna, but figure FM horizontal dipole you can mount high near the ceiling would work better https://www.amazon.com/dp/B09J29KNT...ZEZPNM5T&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it. Anyone have any antenna suggestions?
I use TV "rabbit ears" antennae can easily be repositioned as needed. These things turn up in thrift stores from time to time, and if you can find one which incorporates an antenna tuner, even better.
 
Interesting info. I know I tried some old Terk passive tv antenna I had that is geared toward HD tv and it worked worse than my wire FM antenna. I figured maybe there's something wrong with it, but good to know going with a dedicated FM antenna over a traditional tv antenna was the better choice.
As best I understand/recall, all US HDTV channels are above the FM band. Most are UHF, although I think some may be in the analog "VHF-High" band. I tried to confirm my recollection via google., but it turned out to be harder than I expected! :eek:

I use TV "rabbit ears" antennae can easily be repositioned as needed. These things turn up in thrift stores from time to time, and if you can find one which incorporates an antenna tuner, even better.
Excellent point! The old TV rabbit ears are a tuneable (!) center-fed dipole and do indeed make nice FM antennas (if a bit ungainly, no pun intended). :)
 
Not as far as the CONTENT, no. Well, here in L.A., KKJZ jazz and KUSC Classical excepted. Otherwise even the once-mighty KROQ "Alternative" has become an oldies station.
- FM sound is not necessarily better-it depends so much on your reception/antenna/tuner. Hard to get FM antennas any more.
- SiriusXM over the air is super squeezed, way too many channels for the bandwidth. Much better on the streaming app.
- Some streaming sites sound good, some are still way too compressed. I'll agree that for me 160k is where it starts to sound stale, and 128k I'm done, not exactly but maybe
Agree on all points. With content since I listen to mostly 70s-80s rock and pop and there are about 8 local FM stations that are geared to that, I get okay content. But even then SXM within about 8 channels of similar does better with content.
 
I use TV "rabbit ears" antennae can easily be repositioned as needed. These things turn up in thrift stores from time to time, and if you can find one which incorporates an antenna tuner, even better.
I was considering going with the tv antenna like this one https://www.amazon.com/dp/B07BLNWZH...ZEZPNM5T&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it for reasons you mentioned. But my old "HD tv" antenna works so poorly I'm reluctant.

What does the antenna tuning knob do, make the antenna ears act as if they are shorter/longer?
 
As best I understand/recall, all US HDTV channels are above the FM band. Most are UHF, although I think some may be in the analog "VHF-High" band. I tried to confirm my recollection via google., but it turned out to be harder than I expected! :eek:


Excellent point! The old TV rabbit ears are a tuneable (!) center-fed dipole and do indeed make nice FM antennas (if a bit ungainly, no pun intended). :)
I seem to recall reading FM reaching just below channel 6 VHF but may not be the case anymore with HDTV. My old HDTV antenna had adjustable rabbit ears, no tuner, but instead of a UHF loop it had big flat metal blades. I read that some newer tv antennas have something blocking FM.

I saw one new pricier TV antenna with the tuner https://www.amazon.com/dp/B07BLNWZH...ZEZPNM5T&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it. I wasn't sure what the tuner did, make the dipoles seem shorter/longer? I remember back in the day turning the tuner knob when my tv reception was bad and it usually didn't seem to do much :D .
 
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