[MRCA] J22/ARC-5 throat mic push to talk switch question

Sun Oct 10 08:26:27 EDT 2021

Perhaps you meant this for KK5F?  I only offered a possible throttle 
switch nomenclature for consideration.  (We're both named Mike, so 
confusion is inevitable. )

Though the Navy rejected them, there had been a long ongoing attempt at 
improving the throat (more precisely the larynx) mic by the Signal 
Corps, probably out of embarrassment of perpetuating the use of a 
product they pioneered in the 1930s.  The last of the series, the 
T-30-P, Q, R, S, U, and V, were pronounced in T.O. 16-1-29 (25 April 
1945) as being "...the only throat microphones suitable for use in 
aircraft.  Their performance is far superior to that of earlier 
models."  The last sentence was probably a plaintive plea to crewmen who 
had suffered through the difficulties of the earlier throat mics and 
were leery of glowing assessments because they knew better from 
experience.   All this "improvement" came about as a result of Bell 
Laboratories having labored mightily to make them at least marginally 
acceptable, despite their documented scientific conclusion after 
exhaustive testing that a throat mic ".../would probably have been////a 
very effective instrument but for the fact that the speech signal 
available from the larynx is intrinsically unintelligible/".  These last 
gasp models had elements on both sides of the neck to enhance whatever 
phase subtleties might be gleaned from the larynx, and finishing touches 
like gold plated brass cartridges to minimize corrosion.  Making a silk 
purse out a sow's ear was eventually a bridge too far, unfortunately.  
There is more on pages 131-133 of 
https://aafradio.org/docs/NDRC_Division_17_excerpts.pdf .

I have no doubt there were examples of Navy fliers "borrowing" some of 
the T-30 throat mics...using an RS-38 was as much a diversion as using a 
T-17, and Navy aircraft didn't often need to operate at very high 
altitudes during the first half of the war, despite most of the combat 
aircraft having oxygen capabilities with the vastly superior (from an 
intelligibility standpoint) oxygen mask mic.

I much prefer the H-46-A/UR that you are planning to use 
(https://aafradio.org/flightdeck/H-46.html ).  With the chamois ear 
cushions, it is probably the most comfortable headset I've ever had.

- Mike  KC4TOS

On 10/9/2021 11:08 PM, MARK DORNEY wrote:
> There is more than a few interviews with Navy fighter pilots that 
> mention their use of throat mics.  Maybe not official by the manual 
> use - more than likely more of a use of what was available sort of 
> thing. I actually plan to connect a NAF headset with boom mic to this 
> set up.
>
> Mark D.
> WW2RDO
>
>> On Oct 9, 2021, at 7:21 AM, Michael Hanz <aaf-radio-1 at aafradio.org> 
>> wrote:
>>
>>  The AN/ARC-5 HF manual mentions NAF 1124-17 as the throttle switch, 
>> but it is probably not the only one:
>>
>> - Mike  KC4TOS
>>
>> <NAF%201124-17b.jpg>
>>
>> <NAF%201124-17a.jpg>
>>
>>
>> On 10/9/2021 2:29 AM, Mike Morrow wrote:
>>>
>>> The throttle switch is part of the top of the handle on the aircraft 
>>> throttle lever, on the port side of the cockpit.  It is part of the 
>>> aircraft.  There is likely some sort of NAF number associated with 
>>> the throttle switch, but no JAN nomenclature.  The 3-pin A.R.C. 9488 
>>> plug for the J-22/ARC-5 (or J-16) should have two wires as part of 
>>> aircraft wiring going to the permanently-installed throttle switch.  
>>> I don't know if there is typically a connector between the throttle 
>>> switch and its aircraft wiring.  The throttle switch and wiring are 
>>> separate from the mask mic and wiring until they get to the J-22 or 
>>> J-16.
>>>
>>> I find NO references to USN use of any "throat mic", which is very 
>>> different from the mask mic that's mentioned in AN/ARC-5 instruction 
>>> books.
>>>
>>> Mike / KK5F
>>>
>>> -----Original Message-----
>>> From: Captain D. <mkdorney at aol.com>
>>> Sent: Oct 8, 2021 11:08 PM
>>> To: <mrca at mailman.qth.net>
>>> Subject: [MRCA] J22/ARC-5 throat mic push to talk switch question
>>>
>>>
>>> There is a 3 lead male receptacle on the J-22/ARC-5 jack box, below 
>>> the hard wired cord that plugs into the throat/mask microphone.  
>>> Wiring diagrams say that this receptacle connect to a throat 
>>> microphone push to talk switch.  Does anybody know the nomenclature 
>>> of the switch?
>>> Thanks
>>> 73
>>> Mark D.
>>> WW2RDO
>>>
>>>
>>> ______________________________________________________________
>>> MRCA mailing list
>>> Home:http://mailman.qth.net/mailman/listinfo/mrca
>>> Help:http://mailman.qth.net/mmfaq.htm
>>> Post:mailto:MRCA at mailman.qth.net
>>>
>>> This list hosted by:http://www.qsl.net
>>> Please help support this email list:http://www.qsl.net/donate.html
>>
>> -- 
>> Michael Hanz - KC4TOS

-- 
Michael Hanz - KC4TOS
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20211010/72b4cfc3/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 05.png
Type: image/png
Size: 400 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20211010/72b4cfc3/attachment-0001.png>