On Oct 10, 2021, at 8:26 AM, Michael Hanz <[email protected]> wrote:
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.<05.png>)
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 <[email protected]> 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
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-- Michael Hanz - KC4TOS
-- Michael Hanz - KC4TOS