On Thu, 27 May 2010 18:18:41 -0400, "Michael A. Terrell"
wrote:

Jeff Liebermann wrote:

On Wed, 26 May 2010 14:17:56 -0700, David Nebenzahl
wrote:

In my youngah days, I could sometimes hear the high-pitched whine of
television receivers (horizontal scan, right? ~15kHz?). Not any more.

15.734 KHz or something like that. When I was about 12, I built a
Heathkit FM stereo multiplex adapter. I could hear the 19 Khz pilot
tone out of the tweeter. I couldn't figure out why nobody else could.

It didn't have a 19 KHz filter in the output?

Yes, it did. However, I still could hear a tone, which only appeared
on stereo stations. My guess(tm) is that either:
1. I goofed in the assembly or wiring.
2. The filter was mistuned by me (highly likely as I recall tuning by
ear and breaking a few hex ferrite slugs).
3. The design had problems.
4. All the above.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558