AM Apparatus

Hello and thanks for your interest.
There are basically two reasons to use AM or some other type of modulation:
1. For the ease of information transmission over the air.
2. For multiplexing.

My project revolves around the second one (I would not use AM for air transmission).

With that in mind I am in a great need of some equipment that will simply have an input for audio and will output an AM signal with a frequency selector.
Any ideas of such product?

PS. I could build one, I mean I have but do not have a good quality sound

You can find some simple test gear. An RF oscillator with a modulation input.
That is your easiest way to dial up the frequency you want and have an audio signal modulated upon it.

If you're building your own oscillator, then directly modulating the output transistor is the simplest method.
Is there a particular frequency you wish to use ?

I recommend this one:

HP 8656A

here is an example:
**broken link removed**