[Elecraft] telex head set

[Roger Steyaert, K7RXV]

This headset is designed for aircraft use. The microphone has an 
amplifier designed to simulate a carbon mike. Carbon mike were the 
standard for all aircraft use until the late 60's. At that time they 
were replaced with dynamic elements and amplifiers that worked with the 
old carbon mike circuits including their high bias current. The standard 
  impedance used in aircraft is 500-600 ohms. The amplifiers in aircraft 
are designed to drive this impedance.

Part of my working life was designing these system in general aviation 
aircraft.

Roger Steyaert K7RXV


Don Wilhelm wrote:
> RC,
> 
> Telex made headsets for a wide variety of applications.  A Google search 
> show it to be an aviation type headset and alsoseems to indicate that 
> the microphone is a dynamic type and the phones have a 500 to 600 ohm 
> impedance.
> The microphone should work fine with the K3, but the relatively high 
> impedance phones may not work as well.  Try it and see if you like it.
> 
> 73,
> Don W3FPR
> 
> Robert 'RC' Conley wrote:
>> I have been given a TELEX head set.
>> I wish to know more about it.
>> Impedance? Microphone type?
>> Can it be used with my K3?
>>  MRB 2400
>> WT. .94 LBS
>> MPLS. MINN
>> FAA TSO C57 & C58
>> CAT.-B
>> RC kc5wa
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