[ARC5] My mil phones - solved.

[Dennis Monticelli]

Ken,

They are probably HC -43B/U which were made for Geiger counters.  These are
darn good phones if you take care to match impedances for max power
transfer.  1mVrms is plainly audible and that equates to 50 pico watts.  I
use my pair for crystal sets where the impedances are naturally high and
sensitivity paramount.

BTW, the datecode on the sealed package that my NOS phones came in was 1990.

Dennis AE6C



On Fri, Jan 2, 2015 at 2:59 PM, Kenneth G. Gordon <kgordon2006 at frontier.com>
wrote:

> On 2 Jan 2015 at 17:12, Mike Hanz wrote:
>
> > On 1/2/2015 2:21 PM, Kenneth G. Gordon wrote:
> > > OK. So they are HS-23s with a 4K impedance.
> >
> > Then you're in luck.  The ones in the ebay offering appear to be
> > NAF-48490-1, which do fit USAAF HS-23 or HS-33 headsets with ANB-H1 or
> > H1A elements.  The notches allow headbands that engage either pair out
> > of the four pivot points on the element.  They also work fine for Navy
> > aircraft headphones (duh...NAF = Naval Air Facility)
>
> Great. I just bought three sets. I believe I have at least one more set of
> these
> HS-23/33s around here, also without pads.
>
> > > According to what I have found so far, I don't understand why they
> have a
> > > PL-354 on them though...
> >
> > Nor do I.  The red PL-354 was used to identify a low impedance HS-33
> > headset during the period when both HS-23 and HS-33 headsets were in use.
>
> That's what I gathered from your webpage on this. Hmmm....well, mysteries
> never cease with this stuff. A lot of the white paint is missing from the
> PL-354
> lettering, but it can still be read. After going to your website, I
> checked to
> make sure it read PL-354 and it does.
>
> I'll be mighty glad to get the pads, though.
>
> I'm going to go through my stash of "junque" to see if I have any other
> decent
> headphones.
>
> I also have at least six of those extensions which fit the PL-54/354 on one
> end and terminate in a standard phone plug on the other.
>
> I do have a set of military phones which are wired with a cable
> terminating in
> a BNC connector. Supposedly, they are 20K ohm @ X-frequency phones.
> They have integral soft rubber pads, and the shells are made of aluminum. I
> have not been impressed with these, however... They sound weak with
> everything I've tried them with, and that BNC connector is a PITA.
>
> As I remember it, someone here told me these were originally for some sort
> of mine-detector.
>
> Ken W7EKB
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>