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Re: [TenTec] Fwd: Model 715 question / Yamaha CM500 bias

To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Subject: Re: [TenTec] Fwd: Model 715 question / Yamaha CM500 bias
From: Richards <jruing@ameritech.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 26 May 2011 20:58:40 -0400
List-post: <mailto:tentec@contesting.com>

Since you mentioned the Yamaha CM500 - I can tell you that it will not take
the 10 volts - wont hurt it but it does not like it -

                TRY USING AN IN-LINE ATTENUATOR LIKE THIS:

        http://andreaelectronics.com/Buy/ProductDesc/S100.htm

        OR THIS...

        http://www.fullcompass.com/product/399621.html

        OR....

        I recall RadioShack used to carry an in-line headphone
        attenuator,  and also an inline audio line-level-to-mic-level
        attenuator cable, which should also work to knock down
        high signal level coming from the Yamaha set.

        I was a big hero at the contest station (my rookie season)
        because I was able to tame this problem on the Omni VII
        and Orion II they have there.  All the rigs were either K3s
        or TenTec Omni VI, VII or Orion II radios.  It's very cool...


.I just kept adding more resistance from the ten volts to the mic
element until it sounded OK. BUT its still way too much output - mic gain
has to be set very low - one of these days I am going to mke a voltage
divider up inside the connector shell .


                The attenuators do not reduce the voltage on the
                electret capsule, but they do reduce the resulting
                output signal level.   Maybe this will make it for you.


The little battery voltage inserter that comes with the CM500 applies  the
voltage from two AAA cells in series (abt 3 volts) through 2200 ohms in
series.  So  it would appear Yamaha would like to have a 3 volt supply to
that mic.


                Agreed.    Those sets, like most computer type sets,
                prefer a voltage between 2.5 and 5 volts, typically.
                

The Orion works OK with that - I just have not gotten around to
re-doing my mike  8 pin to 1/8 inch adapter .  SSB not very high on my
priority list right now.


                Maybe that attenuator would help.   I could mail you
                one to try if you like... that would cost you no more
                than the postage to return it if it does not work out
                as expected.


Happy days y'all.

=========================  James - K8JHR  ====================

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