jts

its nothing to do with avoiding spending money and in this case the exact freq is not relevant as I just wanted to turn off the mute which I have successfully done by introducing a tone.

Its interesting to note that the human ear can hear tones up to around 20 kHz but when I inject a 32kHz tone into the transmitter I can hear an audible tone on the JTS receiver along with the audio which I am feeding in, maybe the tone I can hear is a harmonic frequency. The mute is turned off with a tone added between 25 kHz and 28 kHz and again around 52 kHz give or take 3 or 4 kHz again some harmonics at work here. No audible tone is heard on the receiver at 52 kHz.

I figured it out, I injected a 26 KHz sign wave at the input of the transmitter using a signal generator and the mute was turned off on the JTS receiver but with a beeping noise!. I upped the tone to 52 kHz and the mute was turned off again and all was fine. :) The sound is not fantastic though as maybe the bandwidth is not matched. or as you mention companding. Im guessing a JTS or similar transmitter has a wider bandwidth than the 1 MHz transmitter I am using. or perhaps less bandwidth, more like broadcast fm which is 200khz Thanks for pointing me in the right direction with the tone.

Thanks for the info Sandall, Actually its transmitting on 863.5MHz , I just rounded it off for the post. its not a mic, its a headphone transmitter which feeds audio from a radio or whatever is plugged in to it. which so happens works on the same freqs as the JTS. there is no mute option, only a switch to switch between the frequencies 863MHz and 865.MHz Thanks for the info Bruce, Yes its a random transmitter. do you happen to know what exactly the pilot tone is? does it stay on or is the tone sent briefly to turn the mute off and again to turn it on? perhaps I could generate the tone if I knew the tone frequency, I am guessing it just sits aside the audio as a carrier? as I don't have a JTS transmitter I cant analyse the spectrum to see the tone. Would be an interesting project to create the tone to unmute the JTS. Thanks

Hello, I am using a wireless headphone transmitter to transmit audio to another room on 850mhz, but when I try to receive the audio using my JST US100D true diversity receiver plugged in to an amplifier via the AF out unbalanced socket there is no audio at all, the signal strength is 90% and on the JTS US-1000D screen it says mute, what exactly does mute mean and can it be turned off on the receiver? or is that option only available using JTS transmitters or similar? I also have a JTS US-9001D which also will not receive audio and says mute on the screen. Am I missing something obvious? perhaps the bandwidth the JTS is trying to receive is much wider than the transmission? I can hear the audio fine on my SDR, (the bandwidth is 1mhz) Thanks