[TenTec] Yamaha CM500 Headset

[Jim Brown K9YC]

On Sat, 21 Nov 2009 14:14:15 -0500, Richards wrote:

>Did those Yamaha headsets come with a dynamic or an electret 
>condenser mic element?   I have received conflicting information about them 
>from vendors, and from the packaging at the local music store, it looks like 
>they have gone to an electret type, whereas they used to supply a dynamic 
>type.

YES, it is an ELECTRET CONDENSER mic. The only doc I can find from Yamaha 
says that it's a dynamic. The package includes a battery holder and adapter 
to provide power for the condenser just in case the thing you plug it into 
doesn't provide bias for the impedance converter (a FET built into the mic 
element). Most ham rigs DO provide that bias voltage, but you need to wire it 
to the connector. 

Further input after 22 hours using/wearing a headset for SSB SS. I LOVE this 
headset!  It is a HUGE bargain (about $40), very comfortable, decent 
isolation from room sound, the phones sound very good, and the mic sounds 
very good (MUCH better than the Heils I've heard). The mic is optimized for 
communications, which means that it cuts through QRM and noise very well 
without EQ. I got several unsolicited reports complimenting me on the TX 
audio. 

As I may have noted in a previous post, this mic has very high output, so you 
will need to take care not to overload whatever it's plugged into. When I 
plugged it into my ancient IBM Thinkpad, I had to turn OFF the mic preamp and 
reduce the gain to minimum. When I plugged it into the K3 to operate, I set 
the rig to the low gain setting and the mic gain to about 3 (on a scale of 
100). 

The ONLY downside of this mic is that it's sensitive to breath noise and pop, 
so low-cut is a very good idea (but that's true of ANY ham mic). It is also 
important to keep the mic away from your mouth. During SS, I alternated 
between two positions -- one below my mouth a few inches, and the other above 
and to the side. Both worked very well, but the low position sometimes caused 
the mic to touch my shirt and make noise that keyed the VOX.

Bottom line -- this headset is a WINNER, strongly recommended. It should work 
quite well with all Ten Tec rigs with the simple precautions noted. This mic 
is so good, the headset is so comfortable, and the price is so low, that I am 
retiring the EV RE16 that I've used exclusively for the past five years!  BTW 
-- EV was started by Al Kahn, K4FW and Lou Burroughs back in the '30s. When 
they sold EV in the late '60s, Al took his share and started Ten Tec. 

73,

Jim K9YC