Hi Rich,

Congrats on the CM-500! They are excellent headphones and do not give you ‘wet ears’ if you use them for hours in a contest.

With the K3, you do not have to use the battery box! My CM-500 is plugged into the rear of my K3. Then on the K3, select MENU and go to MIC SEL and set that for rP.L BIAS. If you tap ‘1’, you can select either high or low gain; if you tap ‘2’, that turns on the bias for the CM-500.

While the CM-500’s are excellent headsets, they are somewhat fragile, especially the headband; I bought a spare for ‘just in case’, hih.

Merry Christmas and 73,

Tom – W4BQF

From: secc-bounces@contesting.com [mailto:secc-bounces@contesting.com] On Behalf Of Rich Arland
Sent: Tuesday, December 06, 2011 12:06 AM
To: North Georgia QRP Group; SECC; South East DX Club
Subject: [SECC] Yahama C-500 phones/mic

I just received my C-500s. Got them working with the K3. Had to use the little battery box, since I am thinking that the mic on the headset was an electret and requires some DC voltage to work.

The headset is very comfortable and according to W6LAB whom I worked on 20M phone this evening I had a great audio signal. Best $45 I ever spent!! Thanks to all who provided input.



73 
Rich Arland, K7SZ
Bent Dipole Ranch, Dacula, GA
"Cogito Ergo CQ" ("I think therefore I HAM")
Author: "The ARRL's Low Power Communications, the Art and Science of QRP" (all 3 editions)
Editor: "QRP POWER", QST Magazine (Jan 2000 to Dec 2003)
Editor: "The Learning Curve", CQ Magazine