Re: resonant speakers


From: Jim Francoeur KC1FB (
Date: Sun Oct 11 1998 - 11:53:33 EDT

I tried the tumbler, but it was always tuned too high for my rigs, so I
looked for something that would have the right volume to tune lower and
found that an 18oz plastic peanut butter jar (Skippy in my case) was just
about perfect. Cut a circle in the top to mount a 2" speaker salvaged from
an old PC and it peaks at about 650-700 Hz.

Jim Francoeur KC1FB QRP-L #29, QRP-ARCI#6281
-----Original Message-----
From: Steven Weber <>
To: Low Power Amateur Radio Discussion <qrp-l@Lehigh.EDU>
Date: Saturday, October 10, 1998 7:24 PM
Subject: resonant speakers

>>all you'll need. Some folks on this list have reportedly used small
>>plastic drinking cups as the resonant chamber and had good results.
>I would be the one of them...
>I found I could push a 2" dia speaker almost all the way to the bottom of a
>plastic 10 oz drinking tumbler. Leave the bottom sealed. It actually
>resonates a little high, about 1000 Hz, and isn't real peaky, but makes an
>amazing difference.
>Steve, KD1JV....In the White Mountains of New Hampshire
>"Melt Solder"

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