Hi Eric, you are right about getting stuff delivered, it's a real nightmare these days and real bad being way down here in New Zealand. my flycom was a new ga helmet but i have got to thinking that it may have the wrong mic installed like you. Not to sure how to do a reading on the mic so if any one knows that would be very help full.
Mark if you can take a pic of your current Flycom helmet mike and post it on this forum I will identify it for you and give you its details and where to purchase one at a reasonable price if required. These inserts occasionally fail. Also if you can tell me if you have a Pax with their helmet plugged into your system and what type of helmet they are using on your intercom/radio system. Your PM1200 manual is not specific about the type of microphone required (they only specify the headset impedances).
1.5 Specifications Input power: 13.8 - 27.5 Volts DC Current Drain: < 250 mA (Externally fused at 1 Amp) Output 120 mW into 150@ 27.5 VDC 70 mW @ 13.75 VDC
Headphone Impedance: 150-1000 ohms typical Aircraft Radio Impedance: 500- 1000 typical 3 dB Music Frequency Response: 200 Hz to 15 kHz Unit weight: 12 Ounces (0.342 kg) Dimensions:1.25" H x 3.00" W x 5.80" D (3.2 x 7.6 x 14.7 cm) Temperature -20ºC to +55ºC Altitude 50,000 ft.
Mark I have remained silent on your subject awaiting something constructive from "Bobby" critising my comments regarding squelch. Nothing.
In the PM 1200 manual there is the option of switching between PTT and VOX modes for your microphone and this may well be where your issue is hiding. If you have the mic function switching in and out then precluding a wiring fault this will be a function of the electronics. You are essentially dealing with 2 squelch systems in series, one in your PM1200 as a microphone VOX and the second in your Icom 200 as a sidetone squelch. Investigate this further but remember this needs to be set up in the air with all of the wind and engine noise present.
IntelliVox® The PM1200 has both automatic VOX (IntelliVox® and PTT-ICS. For open cockpit aircraft and the majority of warbirds, using the PM1200 in PTT-ICS (Push-To-Talk Intercom Mode) is required. Turning either IntelliVox® or PTT-ICS function on and off you simply depress the Copilot Volume control knob. In one mode it will work with the Voice Operated Relay (VOX) automatically. Pressing the knob again will place the intercom into the PIT-ICS mode. While in IntelliVox® mode, there must be some background noise so that the circuits that makes the automatic VOX work knows what noise is so then it can determine when a voice is present.
Regards.......Chook. (Western Australia) We have to look after our mates across the Ditch.
