Sirius listening on vintage radio

[darklife]

Originally Posted by fifties

I still don't believe that you can hear an FM station -or any carrier at the FM frequency of 88-108 Megacycles- on an AM radio receiver that -at it's best moment- won't tune above 1.7 Megacycles, and can only reproduce modulation varied by amplitude rather than by a frequency.

Aside from that, however, the unit does what it's supposed to; it provides good usable signal for a distance of about 75 feet or so, using the eight foot wire that comes with it for an antenna.

I'm not talking about FM as in the broadcast band 88-108MHz. You are confusing the term FM with the broadcast band that happens to use frequency modulation.
FM and AM are modes of modulation and nothing more.
Just like the aircraft band is from 118-136MHz but they use the AM modulation mode, or some utility shortwave stations use FM for example.
What I am saying is that any change in carrier frequency from an audio source is labeled as Frequency Modulation. Any change in carrier amplitude from an audio source is Amplitude Modulation.

Yes all stations on the regular broadcast band from 520-1710KHz are suppose to be in AM mode. However a poorly designed transmitter will sometimes have a tiny bit of frequency modulation on its carrier signal, or in other words it's frequency will vary slightly with the audio program material especially on bass notes or high peaks of modulation. It's only a few tens to hundreds of hertz but that is enough to become a wobbly whining sound when demodulated by your radio.
That's the best I can do to describe this

[fifties]

Originally Posted by darklife

I'm not talking about FM as in the broadcast band 88-108MHz. You are confusing the term FM with the broadcast band that happens to use frequency modulation.
FM and AM are modes of modulation and nothing more.
Just like the aircraft band is from 118-136MHz but they use the AM modulation mode, or some utility shortwave stations use FM for example.
What I am saying is that any change in carrier frequency from an audio source is labeled as Frequency Modulation. Any change in carrier amplitude from an audio source is Amplitude Modulation.

Yes all stations on the regular broadcast band from 520-1710KHz are suppose to be in AM mode. However a poorly designed transmitter will sometimes have a tiny bit of frequency modulation on its carrier signal, or in other words it's frequency will vary slightly with the audio program material especially on bass notes or high peaks of modulation. It's only a few tens to hundreds of hertz but that is enough to become a wobbly whining sound when demodulated by your radio.
That's the best I can do to describe this

OK, thx for the clarification of your point.

I have not found the symptom you are describing, however, with any of the AM sets I have used to receive transmissions from the Talking House Transmitter.

Remember, it was designed for a commercial real estate application, so it has to display at least adequate performance, and by my results, does that very well.

[wa2ise]

Originally Posted by darklife

... However a poorly designed transmitter will sometimes have a tiny bit of frequency modulation on its carrier signal, or in other words it's frequency will vary slightly with the audio program material especially on bass notes or high peaks of modulation. It's only a few tens to hundreds of hertz but that is enough to become a wobbly whining sound when demodulated by your radio.

If that transmitter was being fed by Sirius or an MP3 player, some of that wobbly whiney wishy washy sound may be due to overly compressed digital audio. I had a rental car with Sirius satellite radio, and though Howard Stern sounded fine, all music channels on Sirius sounded like crap. It was a Ford Focus, so maybe it was a crappy decoder. But if all possible decoders sound that way, I won't subscribe to Sirius. XM didn't seem to have this problem in another rental car I had years ago.

[fifties]

Originally Posted by wa2ise

If that transmitter was being fed by Sirius or an MP3 player, some of that wobbly whiney wishy washy sound may be due to overly compressed digital audio. I had a rental car with Sirius satellite radio, and though Howard Stern sounded fine, all music channels on Sirius sounded like crap. It was a Ford Focus, so maybe it was a crappy decoder. But if all possible decoders sound that way, I won't subscribe to Sirius. XM didn't seem to have this problem in another rental car I had years ago.

Given that they are now one company, you won't be able to differentiate, lol.

Actually, I've never really had a problem with the audio quality on any of my Sirius receivers. Could be there was an audio problem with the sound system of that rental car you hired...

[AUdubon5425]

I have a basic Sirius "In-V" receiver/decoder and always thought most of the audio sounded heavily compressed.

[sidbartos]

Both Sirius and XM both use heavy compression. This is a huge complaint over at the xmfan.com forums. Most agree that XM/Sirius sound quality is worse than FM. (I find this to be true). I think they forbid sound quality complaint threads on the forum because it was getting so out of hand. The worst part is that they carry a few clearchannel channels (through some bs legal deal years ago) and they have the best audio quality out of any stations. The purposely give the talk channels lower quality and quality can vary between the music channels. Even with the less than perfect sound quality, I would rather have a huge music selection and no commercials than listen to FM during my commute every day.
That Ramsey unit doesn't look like a bad deal for $30. I used to listen to my XM receiver through FM on my German set but it would be nice to use it for my AM only Zenith.

[darklife]

Originally Posted by sidbartos

Both Sirius and XM both use heavy compression.

In a way this can be a good thing though when rebroadcasting it around the house on AM since it would push the little transmitter to full modulation allowing it to be received much farther away. As with large AM radio stations they want to compress their audio to sound "louder" and it does help their range a bit.
Also you won't have to worry about the audio clipping and distorting on the tiny AM transmitter because Sirius already does the job of compression and peak limiting for you
On the other hand there is a lot to be said for audio dynamics. Something that seems to be a lost art today

[jr_tech]

Originally Posted by AUdubon5425

I have a basic Sirius "In-V" receiver/decoder and always thought most of the audio sounded heavily compressed.

Are you talking about audio compression (reduced dynamic range) or bit rate reduction (watery sounds like a low bit-rate MP3) , or both effects?

jr