The Plantronics headset is normally inserted in the cord between the telephone and its handset, which does use all 4 wires, like this:
http://en.wikipedia.org/wiki/File:RJ9_Handset_diagram.svg Don't know about impedance/level-matching with the K3.... 73, ~iain / N6ML On Wed, Mar 5, 2014 at 5:13 AM, Don Wilhelm <w3...@embarqmail.com> wrote: > The complexity may involve sorting out the headphone connection from the mic > while keeping feedback away. Telephone uses only a single pair wire in all > installations I am familiar with. Yes, there are 4 wires in the typical > phone jack and cable, but that will handle 2 lines. > > 73, > Don W3FPR > > > On 3/4/2014 10:37 PM, N5AG wrote: >> >> Thanks Don. I probably am worried about nothing. I know some others >> using this setup on Kenwood and Flex. Their's seemed a little more complex. >> That is the reason for the question. >> >> Allen Griffith >> >> >> >> On Tuesday, March 4, 2014 7:33 PM, Don Wilhelm-4 [via Elecraft] >> <ml-node+s365791n7585134...@n2.nabble.com> wrote: >> Allen, >> >> Most modern audio output stages are low impedance sources, and there is >> no need to "match impedances". >> Do you think about matching impedances when you plug something into a >> power mains wall receptacle? Likely not, because the AC mains is a low >> impedance source and will deliver whatever the device needs. Your >> headphones are similar - with a low source impedance driver, you don't >> have to worry about it, just adjust the AF gain to a comfortable level. >> More power will be delivered to a low impedance device, but headphones >> do not require much power. >> >> The microphone is similar. It is a relatively low impedance source, and >> it is operating into a relatively high impedance device (1k to 10k for >> modern transceivers) and the voltage produced is the important >> parameter. Yes, high impedance microphones may not give the proper >> frequency response curve, but other than that, no impedance matching is >> normally required. Modern microphones are in the range of 200 to 600 >> ohms driving impedance. I suspect yours is also in that range. >> >> 73, >> Don W3FPR >> >> On 3/4/2014 7:12 PM, N5AG wrote: >> >>> Has anyone wired up a Plantronics CS50 Telephone headset system to the >>> K3? >>> The Plantronics CS50 system is composed of a base unit that transmits and >>> receives in full duplex to a small headset that is worn and gives the >>> capability to transmit and receive up to 300 feet. The system uses 900 >>> mhz >>> to communicate between the base and the headset. >>> >>> The base unit normally would plug in to a land line base telephone using >>> the >>> standard four wire (two pair) found in most home telephone installs. I >>> need >>> recommendations on wiring the Plantronics CS50 base unit to the back >>> panel >>> mic and phone connections with the standard four wire line from the >>> Plantronics base. >>> >>> Does the K3 have the ability via menu selection to match impedances for >>> the >>> mic and audio hook up stated above or must the matching be done in the >>> interface between the Plantronics base and the K3? >>> >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> ________________________________ >> If you reply to this email, your message will be added to the discussion >> below:http://elecraft.365791.n2.nabble.com/Mic-and-headphone-tp7585125p7585134.html >> To unsubscribe from Mic and headphone, click here. >> NAML >> >> >> >> -- >> View this message in context: >> http://elecraft.365791.n2.nabble.com/Mic-and-headphone-tp7585125p7585139.html >> Sent from the Elecraft mailing list archive at Nabble.com. >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
