On Sun, 4 Aug 2019 12:17:58 -0700, Mike Easter 
declaimed the following:

>NY wrote:
>> I never knew that early ultrasonic remotes were mechanical whistles
>> operated by the buttons.
>
>Another US strategy was 'banging' an aluminum rod which emitted the US tone.
>
>I don't know, but that might've been how mine worked.  I never
>disassembled it, but the clunk seemed/ felt/ sounded/ more like a hammer
>blow than an 'accordion'.

 The bellows style felt like squeezing a small balloon until it popped
-- ie: increasing back-pressure with a sudden release.


--
 Wulfraed                 Dennis Lee Bieber         AF6VN
 wlfraed@ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

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