---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Thu 09/10/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:19 AM - Re: Headphone jack wiring (D L Josephson) 2. 09:19 AM - Re: Headphone jack wiring (D L Josephson) ________________________________ Message 1 _____________________________________ Time: 09:19:08 AM PST US Subject: Avionics-List: Re: Headphone jack wiring From: D L Josephson On 9/9/15 11:59 PM, Avionics-List Digest Server wrote: > From: Detlef Heun > Subject: Avionics-List: Headphone Jack Wiring Mono to Stereo Icom A-210 > > > I bought a Icom A-210. Unfortunately it has only a Mono output. > Can I wire the Mono output to the Left and Right tab of a Stereo > Headphone Jack? > Thanks You can, the problem is that if you then plug a mono headphone into the stereo jack, the sleeve (ground terminal) will connect to the right channel (ring contact of the tip-ring-sleeve jack) and short the output to ground. A solution commonly used in broadcast stations where this problem also occurs is to connect the mono output of the radio through ~300 ohm resistors to the left and right tabs of the jack. If you use a stereo headphone, the level is reduced somewhat because each channel has a resistor in series with it. If you use a mono headphone, the output sees another 300 ohms to ground rather than a dead short. It's a good compromise if the radio has enough volume to drive the headphones you're using even with the additional loss of the resistors. David Josephson ________________________________ Message 2 _____________________________________ Time: 09:19:08 AM PST US Subject: Avionics-List: Re: Headphone jack wiring From: D L Josephson On 9/9/15 11:59 PM, Avionics-List Digest Server wrote: > From: Detlef Heun > Subject: Avionics-List: Headphone Jack Wiring Mono to Stereo Icom A-210 > > > I bought a Icom A-210. Unfortunately it has only a Mono output. > Can I wire the Mono output to the Left and Right tab of a Stereo > Headphone Jack? > Thanks You can, the problem is that if you then plug a mono headphone into the stereo jack, the sleeve (ground terminal) will connect to the right channel (ring contact of the tip-ring-sleeve jack) and short the output to ground. A solution commonly used in broadcast stations where this problem also occurs is to connect the mono output of the radio through ~300 ohm resistors to the left and right tabs of the jack. If you use a stereo headphone, the level is reduced somewhat because each channel has a resistor in series with it. If you use a mono headphone, the output sees another 300 ohms to ground rather than a dead short. It's a good compromise if the radio has enough volume to drive the headphones you're using even with the additional loss of the resistors. David Josephson ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message avionics-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Avionics-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/avionics-list Browse Digests http://www.matronics.com/digest/avionics-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.