I made a pair of these Dixie Cup resonant speakers today. Remarkably, they
have a very sharp peak at 600 Hz (my preferred center frequency). I opened up
the filter on the KX3 and found that the speakers were better than tightening
down the filter on the radio. It is the equivalent of about a 100 Hz filter,
but much better sonic quality. I am impressed! Now I have extra Dixie cups
for summer as well. (I made two because the KX3 needs “stereo” to work
“Dual Watch” mode.
One suggestion that was not shown in the YouTube video: After attaching the
speaker to the cup, place another cup underneath it, up against the bottom of
the speaker, and hot glue it in place. I found this narrows the bandwidth
considerably, and fortunately at just the right frequency (for me, anyway).
Charles - NK8O
> On May 3, 2017, at 9:22 PM, 'Sam Neal' n5af@... [4sqrp]
> I made it's el-cheapo little brother ( some old issue of Popular Electronics
> out of a Pringles potato chip can and the speaker out of an old CB radio.
> sounded very good, so I can imagine that it's big brother from QST will be
> much better.
> Sam Neal N5AF
> Celebrating 60 Years In Amateur Radio
> ------ Original Message ------
> Received: Wed, 03 May 2017 05:36:31 PM CDT