In addition to Bob's system, I usually use a DPDT relay for the antenna relay. The second set of contacts I use to ground the receiver antenna input during transmit. Probably not an issue at low power like for the DX-60 but found to be a good safety at higher power.
73, Mitch K9PNP > Date: Wed, 12 May 2010 17:09:02 +0000 > From: w6...@comcast.net > To: kf5...@arrl.net; amradio@mailman.qth.net > Subject: Re: [AMRadio] T/R Switching > > Hi Brian, > > There are several options. I use an old Dow-Key relay with my DX-60. It's > powered from the accessory socket on the back of the DX-60 (117 volts, as I > recall), and is energized when you rotate the function switch to AM or CW. > > Also, if you can't find a Dow-Key at a reasonable price you can build your > own relay box. I used two 117V relays from Radio Shack. The first relay > controls the antenna switching, and the other "unmutes" my receiver. The box > also has three female coax connectors just like the Dow-Key relay (one > connects to DX-60, one to your receiver, and one to your antenna). Check you > receiver's schematic to find out what's required to "unmute" your receiver. > If you leave the Receive/Standby switch in "Standby", your receiver's muting > and unmuting can be controlled by the second relay. Your receiver's accessory > socket should have pin-outs for that relay. In some receivers it's just a > matter of completing a ground connection to "unmute' your receiver. Be > careful, though...other receivers may require you to switch B+ voltage. > > In my set-up I use the Dow-Key to control my vintage CW station, and the > home-brew box to control the two AM stations. > > Hope this helps! > > 73, > Bob > K6GCN > > ----- Original Message ----- > From: "Brian Zwiener" <bzwie...@sbcglobal.net> > To: AMRadio@mailman.qth.net > Sent: Tuesday, May 11, 2010 2:45:31 PM GMT -08:00 US/Canada Pacific > Subject: [AMRadio] T/R Switching > > I have Purchased a gem of a Heathkit DX-60 AM Transmitter.I was wondering if > someone had a better idea that what I have for T/R switching. I need to use > the same antenna with separate transmitter and receiver, and not have the > transmitter power get in the receiver front end. If someone has an idea, > schematic, or link I would appreciate it very much. I want to get this on the > air soon and have fun. > > 73 Brian kf5...@arrl.net KF5CCN.COM NEW Ham Radio News Group > Life is much too short for QRP! > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ > Our Main Website: http://www.amfone.net > AMRadio mailing list > Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ > List Rules (must read!): http://w5ami.net/amradiofaq.html > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Post: AMRadio@mailman.qth.net > To unsubscribe, send an email to amradio-requ...@mailman.qth.net with > the word unsubscribe in the message body. > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html _________________________________________________________________ The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with Hotmail. http://www.windowslive.com/campaign/thenewbusy?tile=multicalendar&ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5 ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
