Flying on the Cheap - VOX

VOX - - Voice-Operated Xmitter (ie, transmitter) - - is often favored
among those who dangle under the wings they fly.

The Maxon PTT/VOX model CA-1482A, which is known to work with most Icom
and Yaesu HT's, is presently being offered for $3.50 as new-surplus
by All Electronics (www.allelectronics.com) Their catalog # is VOX-2.

The Maxon CA-1482A is a well designed unit that uses a combination of
SMT and traditional components. It is powered by an internal,
rechargeable NiCad cell that is recharged in a novel manner. The
standard Maxon wall-wart, their CA-1410D, delivers 14.5vdc @ 60mA via a
2.5mm phone plug, designed to recharge the Maxon SP- and CP-5000
radios. But by plugging the wall-wart into the MICROPHONE jack of the
CP-1482A, the 14.5vdc is fed through a series of diodes and dropping
resisters so that the NiCad cell sees a suitable voltage for recharging
- - which takes about 12 hours, assuming the battery is dead, which it
will be when you receive the unit from All Electronics. Just plug it
in and leave it over-night before trying to use it. Once charged, the
VOX is good for about ten days of normal use.

If you don't have the standard Maxon charger (ie, their CA-1410D),
All Electronics carries a suitable replacement, their catalog #
DCTX-1211 @ $3.00.

I originally purchased the VOX module only for the molded dual-plug
connector. (!!) At $3.50 the cost of the VOX was less than the price
of individual mini-phone plugs and wiring. And while the VOX units
I've purchased (four, so far) all worked perfectly well, their
primary purpose is to provide an inexpensive source of parts for
fabricating aviation head-sets for a gang of youngsters.

-R.S.Hoover (KA6HZF)

Thank you again VW'er,

Unfortunately, all talks of electronics fly right over my head.

Off on a slight tangent, I purchased two old military headsets that
have helicopter type plugs many years back. What do I need to get
these working (being compatible with civil radios)? Something about
the mic not being compatible was what I remembered, but I really need a
layman's term to understand. I fly choppers, so the one plug thingy
fits fine, no need to change to airplane's two plug type, just the mics
I think something with impedence?

The Monk

A simple solution would be to go to your local aircraft salvage and pic
up on the cheap a microphone and earphone speakers from a civil headset
and transplant them. The impededence of both are a problem, not just the
microphone. The microphone simply plugs in but the earphones will
require some experince with a 30 watt soldering pencil.





"Flyingmonk" wrote in message
oups.com...
Thank you again VW'er,

Unfortunately, all talks of electronics fly right over my head.

Off on a slight tangent, I purchased two old military headsets that
have helicopter type plugs many years back. What do I need to get
these working (being compatible with civil radios)? Something about
the mic not being compatible was what I remembered, but I really need
a
layman's term to understand. I fly choppers, so the one plug thingy
fits fine, no need to change to airplane's two plug type, just the
mics
I think something with impedence?

The Monk

Flyingmonk wrote:
I purchased two old military headsets that
have helicopter type plugs many years back. What do I need to get
these working (being compatible with civil radios)?

---------------------------------------------------------------------------------------------

I haven't got a clue :-)

Common sense sez the equipment has to fi together in the mechanical
sense, meaning your plugs would have to match at some point, and the
equipment has to match in the electrical sense, but since I've no idea
what the specs are on either end of the system, I've no what you would
need to 'get these working.'

Using new/surplus ear-phones and mikes to make-up headsets that will
work with the typical Icom or Yaesu is duck soup compared to getting
two antiques to talk to each other. I've seen some comm gear that
still used the PJ-068 jacks & plugs -- stuff that dates from the
1890's(*) -- being copied and fosted off on innocent airman because
"We've always done it that way' or other non-sensical reason, as if our
next flight will be in a 1937 DC-3, complete with its Detrola radio.

-R.S.Hoover

(*) -- During the early days of telephone expansion there was some
serious competition between Ma Bell and honest people. The 7/32" phone
plug came into existance during this time (I think it was introduced by
Stromberg-Carlson). Later, it was used by Collins as their microphone
plug.

Flyingmonk wrote:
Thank you again VW'er,

Unfortunately, all talks of electronics fly right over my head.

Off on a slight tangent, I purchased two old military headsets that
have helicopter type plugs many years back. What do I need to get
these working (being compatible with civil radios)? Something about
the mic not being compatible was what I remembered, but I really need a
layman's term to understand. I fly choppers, so the one plug thingy
fits fine, no need to change to airplane's two plug type, just the mics
I think something with impedence?

The Monk


Try FlightHelmets.com and get the military to civilian adapter.

Worked fine with my VietNam SPH-4 and handheld.

Richard

Worked fine with my VietNam SPH-4 and handheld.

Hey now... That's uplifting. I was hoping that I didn't waste my
money on those headsets. They looked very robust.

Thank you and all others for answering.

The Monk

In most cases if you have a David Clark headset all you have to do is
change the mic to a civilian type. The electro fet M-7A is the desired
mic but the old M1 which is bigger will also work. It will just plug
right in to the same plug at the mic. You just have to loosen two set
screws at the mic to remove the plug.. I have some friends that used
to fly ex-military OH-58's and Bell 206 helicopters also and they
tywraped a second mic to the back of the military mic and would rotate
the mic around 180 degrees on the ball and socket mic mount on their
flight helmets and swap the mic plug to the other mic to change
between military and civilian aircraft. For fixed wing aircraft you
also need a single plug U-174/U to two plug adapter Y cable. Several
places sell these DC PN 18253G-05 including Sporties for about $40.
David Clark sells a dual impedance headset H10-66 that has a switch to
change between the mil and civilian types. The addition is an
internal mic amplifier PN 18911G-01 and a switch.

The mil mic is a 4 ohm impedance dynamic (no built in amp].
The civilian mic is a dynamic mic with an internal amplifier so that
it looks like an old style carbon mic, the amp is powered by the
radio.
The earphones are about 150 to 300 ohms in either case.
John F

On 26 Feb 2006 07:33:16 -0800, "Flyingmonk" wrote:

Thank you again VW'er,

Unfortunately, all talks of electronics fly right over my head.

Off on a slight tangent, I purchased two old military headsets that
have helicopter type plugs many years back. What do I need to get
these working (being compatible with civil radios)? Something about
the mic not being compatible was what I remembered, but I really need a
layman's term to understand. I fly choppers, so the one plug thingy
fits fine, no need to change to airplane's two plug type, just the mics
I think something with impedence?

The Monk