Questions for anyone familiar with Schmid and Frequentis voice switches.
 

1. Can these systems accept any type and impedance of microphone without adjustment ? Or are they built to function with just one type ?

2. What is the pin-out for the 8-pole Lemo headset connectors ? Is there more than one ? I would expect one pair for the microphone, one pair each for the earphones and the last pair for the PTT switch.

Be assured my questions are nothing to be alarmed about. I have a genuine technical interest in ATC equipment, as well as the industry as a whole.

Thankyou.

My alarm is you thinking that ATCOs have a scooby do what you are talking about!

Where's an engineer when you need one.......?

There's no way I would expect your every day controller to understand the question. I am hoping there is a Tels Engineer out there who does !

Ask Nick or Simon.

Aren't they in the pension queue with you fella??? ;-)

Anyone ? I have an enquiring mind !

To your first. No their are specifics and both systems will support electret and dynamic microphones elements. The electret microphone requires an Amplifier usually housed in the PTT switch assembly. On the earphone side they will work from 150 to 600 ohms headsets.

The Pinouts should be the same
1 and 2 are earphone
3 and 4 are PTT
7 and 8 are mic audio + DC (12v)

The maybe is that the gain levels at the position are set for a specific microphone type and amplifier. Frequentis uses pins 9 and 10 and each headset type has a specific resistor value so it can automatically detect and adjust the gains. I think Schmid has a similar system. This way when you plug in a dynamic handmike, or a headset, or handset it recognizes the device and adjust the gain.

You might want to contact a headset supplier like Plantronics, Imtradex, or Sennheiser -- they know the specifics of each VCCS supplier as they supply direct to end user and the OEMs.

There are lots of variations of systems throughout the world -- some use PJ7 (USA) and there are 8 pin lemo variants.

Thank you for your reply Radarman. I have sent you a Private Message.