How "Hi-Fi" are FM transmitters ?

[AuroraB]

Ooooh - a wideband transmitter... not looking good for spectral purity... or at the very least - very far from simple...

 

[Andrew Eckhardt]

Not even with some really nice linear transmitting circuits?

 

[Pano]

JBLRF, thanks for the heads up on the C.Crane transmitter. Looks like a handy device.
The small FM transmitters I've bought for car and truck use tend to have a lot of background noise. Not so bad that the road and engine noise of a big truck doesn't cover it, tho...

 

[Huberto75]

Hi there.
Just wonder how the digital tv vs analog got involved into quality of fm transmitters for audio ?
It's like comparing the apples and oranges
FM tuners are great, except the fact, that radiostations are playing MP3 files, most of the time. The vinyl hour is great from my local station.
Please keep FM radio going

 

[AndrewT]

the technical decisions to move from analogue TV to digital TV are probably very similar to the decisions that will be made to move from analogue radio to digital radio.

 

[DF96]

Would it be easier to align for phase matching if the two carriers were several hundred MHz and only hundred's of kHz apart?

No. The issue is identicality of IF channel filters and FM detectors, not the RF front-end.

 

[Huberto75]

the technical decisions to move from analogue TV to digital TV are probably very similar to the decisions that will be made to move from analogue radio to digital radio.

I understand the "technical decisions" part, but the eye is much easier to trick than the ear. 25 Hz sampling rate is good enough to do it . Different story with hearing, analog rules . Time for and some LP's . Cheeers

 

[cliffforrest]

" ... the eye is much easier to trick than the ear."

The evidence for this? Interesting to ponder how this could be measured!

 

[Pano]

If there is evidence, it doesn't belong here. Let's try to stay on topic.

 

[AndrewT]

Monitors do not work effectively with a 25Hz refresh rate.
Most offer refresh rates from 60Hz to 100Hz.
Televisions have been advertising their ability to refresh at 120Hz for many years.

I put this forward as "evidence" that

the eye is much easier to trick than the ear. 25 Hz sampling rate is good enough to do it

is clearly untrue.

 

[AuroraB]

Yes - but 24 fps was once selected as sufficient for 'moving picures'...
25Hz, or rather 50 Hz interlaced half frames, was because of locking to 50Hz mains....

 

[Bigun]

The part number of this chip is Si4712/13-B30...

This is what has been being used in their latest version of this transmitter.

which models use this part - hopefully not just the expensive ones

and how good/bad are there other units ?