Batboard

Anybody been successful at disabling the RX Mute when PTT on a Astro Spectra +?

Do you mean you still want to receive audio when you have the PTT pressed?

Jason

That is correct.

We are talking two way radios here. A radio with a single receiver and a single transmitter will never receive and transmit at the same time. Motorola radios are not full-duplex, they are half-duplex. I don't know of any motorola two-way radio that is full duplex.

Jason

I am sure this is what Jason meant, but a transciever has less than a single receiver and a single transmitter. What it has is a collection of modules that, in one alignment (finger off the key) work as a receiver and in another alignment (finger on the key) work as a transmitter. Only one at a time. This isn't a software or programming limitation. Stations capable of simultaneous transmit and receive have separate and independent transmitters and receivers, and, nowadays, will only be found in base stations.

Folks,

I am not asking for a software hack, or model number hack. I needed to know if the process for muting the rx audio upon PTT was an analog circuit, or a digital process. If it is an analog circuit, then it can be made to RX during TX.

Before this comes up, I understand what will happen when RX does not mute during TX. What I ultimately need to happen is for the TX audio to be heard through the headset when the pilot talks. This radio has been adjusted for aviation and unlike all the other radios, the pilot hears no audio on PTT for this radio. Again, I understand what I'm asking for. I need solutions to make this happen.

Nozzle 75,

I think I understand what you are asking for is TX "sidetone" in the headset. In other words, you want to be able to hear your own TX audio in the headset earpiece when you are in TX mode.

If this is correct, the first point to understand, as has been described above, is that the radio receiver itself is inherently incapable of operating when the radio is in TX mode so it is not a case of "unmuting" the receiver. So what you are looking for is an analog circuit that will feed the pilots headset TX audio to his headset earpiece (and possibly the headsets of other crew members) when he talks.

If this is correct, it is not a capability that I am aware of in the radio but it could be accomplished by the headset connected through an external audio intercom type module to the radio. I believe such systems are used in aircraft but I am not familiar with any specific devices for this purpose.

I hope this helps resolve the confusion and someone may know of an appropriate audio accessory to do what you want.

Yes, you are correct. I thought the NAT panel would support it, but for whatever reason, the sidetone audio is not being passed back into the headset. The only option was to modify the radio.

Thanks!

Most aircraft Spectra configurations the Sidetone is provided by the aircraft intercomm pannel.

The Spectra does not have a Sidetone on transmit ( for Tx mic audio).

What aircraft interface are you using?

I can't remember the exact model # (Will look tomorrow), but I know it's a NAT

Just a guess, but see if you can find information about the telephone handset option for Spectras. The handset option for some radios includes the sidetone function.

On a remote mount Astro Spectra you can do this:

On the command board, remove JU519 and add JU528. This will put mic audio on Pin 9 of J0006. I don't know what kind of level or impedence it is, but it'll be there. I found this out by accident when I was interfacing a Pac/Rt with an AS.

If you have a dash mount Astro Spectra, I don't really know where the output would be.

Regards,

Robert