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Re: LF: OT: Headphones

To: [email protected]
Subject: Re: LF: OT: Headphones
From: John Bruce McCreath <[email protected]>
Date: Fri, 27 Jan 2012 19:56:07 -0500
In-reply-to: <CAHAQVWP_9KdqZ1NjzmJqB3O2mrb-GfJfZBf_D7CY0Y8FAasC3Q@mail.gmail.com>
References: <CAHAQVWP_9KdqZ1NjzmJqB3O2mrb-GfJfZBf_D7CY0Y8FAasC3Q@mail.gmail.com>
Reply-to: [email protected]
Sender: [email protected]
My other hobby is building "high-tech" crystal radios.  I needed a really 
sensitive set of headphones
but didn't have the cash to lay out for a pair, so in true ham tradition, I 
made a pair to suit my needs.
I bought a high-qualty pair of ear defenders, which any safety or industrial 
equipment retailer should
have on hand, and put two earpiece elements from old rotary dial telephone sets 
into each side with
some creative cutting of the foam inserts.  The elements I used came from Bell 
500 series phones
and wired in series have an impedance of around 600 ohms.  They work really 
well, allowing me
to pull the weak ones out of the noise of the AM broadcast band.

73, J.B., VE3EAR

LowFER Beacon "EAR"
188.830 kHz. QRSS30
EN93dr







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