[Elecraft] KRX3 input protection
Hi all, My KRX3 is on the truck and due tuesday. Quick question: I will be running the main receiver on a receive only antenna fed via the KXV3A and the subrx via its bnc aux. These antennas are quite close to the xmit antennas. Should I use any sort of attenuation and/or external TR switch on either of these receiver inputs? I eventually will be running a KPA500 full power... tia, Steve AD0ES __ 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
Re: [Elecraft] KRX3 input protection
Steve, the subRX of the K3 has its protection (an rf triggered relay if the power coming into the rx is too high). I've used the K3-KPA500 on a beam and I had a diversity vertical connected to the subrx quite next to it. No problem at all. It all depends on the coupling of the antennas. Try and see how you go at your QTH; the subRX is protected. 73 Arie PA3A AD0ES schreef op 3-1-2014 15:23: Hi all, My KRX3 is on the truck and due tuesday. Quick question: I will be running the main receiver on a receive only antenna fed via the KXV3A and the subrx via its bnc aux. These antennas are quite close to the xmit antennas. Should I use any sort of attenuation and/or external TR switch on either of these receiver inputs? I eventually will be running a KPA500 full power... tia, Steve AD0ES __ 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
Re: [Elecraft] KRX3 input protection
Steve - I have a similar setup as Arie - an 80 meter Inverted L at 40 feet for my transmitting antenna and a Hustler 5BTV vertical ground mounted about 10 feet from being directly under the vertical. Works fine. If I crank up my KPA500, the relays in the K3 quickly isolate the subrx from too much RF. Jim / W6JHB On Jan 3, 2014, at 8:12 AM, Arie Kleingeld PA3A wrote: Steve, the subRX of the K3 has its protection (an rf triggered relay if the power coming into the rx is too high). I've used the K3-KPA500 on a beam and I had a diversity vertical connected to the subrx quite next to it. No problem at all. It all depends on the coupling of the antennas. Try and see how you go at your QTH; the subRX is protected. 73 Arie PA3A AD0ES schreef op 3-1-2014 15:23: Hi all, My KRX3 is on the truck and due tuesday. Quick question: I will be running the main receiver on a receive only antenna fed via the KXV3A and the subrx via its bnc aux. These antennas are quite close to the xmit antennas. Should I use any sort of attenuation and/or external TR switch on either of these receiver inputs? I eventually will be running a KPA500 full power... tia, Steve AD0ES __ 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
Re: [Elecraft] KRX3 input protection
Jim and Steve, While the COR will do its job, I recommend that you not abuse it. If you hear the COR operating during transmit, it would be wise to provide some external switching (relay) to remove the RX antenna while transmitting or insert an attenuator. Of course, the best solution is to locate the RX antenna away from the TX antenna, but that is not always a practical solution. 73, Don W3FPR On 1/3/2014 11:38 AM, Jim Bennett wrote: Steve - I have a similar setup as Arie - an 80 meter Inverted L at 40 feet for my transmitting antenna and a Hustler 5BTV vertical ground mounted about 10 feet from being directly under the vertical. Works fine. If I crank up my KPA500, the relays in the K3 quickly isolate the subrx from too much RF. Jim / W6JHB On Jan 3, 2014, at 8:12 AM, Arie Kleingeld PA3A wrote: Steve, the subRX of the K3 has its protection (an rf triggered relay if the power coming into the rx is too high). I've used the K3-KPA500 on a beam and I had a diversity vertical connected to the subrx quite next to it. No problem at all. It all depends on the coupling of the antennas. Try and see how you go at your QTH; the subRX is protected. __ 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
Re: [Elecraft] KRX3 input protection
I saw a suggestion somewhere for using a small grain-of-wheat bulb across the 2nd antenna's lead as you gradually increase transmit power. If I remember correctly, the bulb I used was a 5 V @ 50 mA lamp, typical of those used as LCD screen illuminators. I tried that with a 600 ' Beverage that is at least 75 feet from any transmit antenna and was very surprised to see the bulb glowing brightly on a couple bands with only 50 watts into the LPDA up at 55'. The Beverage is fed with a 9:1 transformer and is about 8 feet off the ground, running away from any active antennas. Try it, it's quite an eye opener. 73, Charlie k3ICH - Original Message - From: Arie Kleingeld PA3A p...@xs4all.nl To: elecraft@mailman.qth.net Sent: Friday, January 03, 2014 11:12 AM Subject: Re: [Elecraft] KRX3 input protection Steve, the subRX of the K3 has its protection (an rf triggered relay if the power coming into the rx is too high). I've used the K3-KPA500 on a beam and I had a diversity vertical connected to the subrx quite next to it. No problem at all. It all depends on the coupling of the antennas. Try and see how you go at your QTH; the subRX is protected. 73 Arie PA3A AD0ES schreef op 3-1-2014 15:23: Hi all, My KRX3 is on the truck and due tuesday. Quick question: I will be running the main receiver on a receive only antenna fed via the KXV3A and the subrx via its bnc aux. These antennas are quite close to the xmit antennas. Should I use any sort of attenuation and/or external TR switch on either of these receiver inputs? I eventually will be running a KPA500 full power... tia, Steve AD0ES __ 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
