[ARC5] mike current

[WA5CAB at cs.com]

FWIW, the Signal Corps had a Stock Number for replacement carbon granules.  
However, by 12/45 it had been voided because of "insufficient 
requirements"..

In a message dated 09/07/2011 08:18:45 AM Central Daylight Time, 
aaf-radio-1 at aafradio.org writes: 
> On 9/6/2011 5:43 PM, Bob Krueger wrote:
> >Any body know the carbon mike button current of the T17 mikes commonly 
> used with the arc5 equipment?
> 
> Nominally 40mA, Bob.  That's about in the middle of the usual 20-65mA 
> range for the RS-38 and T-17 mikes used with WWII sets.  More current = 
> higher output, but also higher distortion.  Tests made in 1943 showed 
> about 40% peak distortion for the T-17 while the RS-38 had a peak of 
> about 15% at the upper end of the normal voice frequency range.  
> Distortion at 1kHz was 22% for the T-17 and 5% for the RS-38.  Carbon 
> granule cementation over the years will of course affect output.
> 

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480