[Elecraft] Headphones

[Jessie Oberreuter]

> I like the Heil Pro Set Plus my friend has, but my Heil Pro Set from
> Elecraft are almost unusable after an hour or so. The size of the hole
> where your ear fits is quite different, and the headphones I bought from
> Elecraft make my ears hurt a lot. It's enough that I'm about to buy the
> Plus.


      I had the same experience, but then just reduced the tension by 
bending them open (ultimately, slightly "backwards") until I got the 
tension down.  Now they do pretty well.  My only criticism so far is with 
the active noise cancellation b/c the cutoff freq is just too low.  It may 
work great in an airplane or next to a freeway, but it does nothing to 
keep the sounds of other operators out.

      When operating cw, I use a pair of medium range phones from Radio 
Shack.  I just went down and tried a bunch, found the pair I liked the 
best, and replaced the plug.

      The phase reversal trick on the Heil is pretty neat!  No problem 
adding it to most headphones.  One can also achieve the same effect with a 
center-tapped isolation transformer at the input.  It should also be 
possible to do it with just capacitors, but I haven't done this yet b/c I 
want to try tailoring the values to get some kind of useful effect from 
the freq. dependent phase shift :).