Re: [Elecraft] Front end RF overload
Dale Farnsworth (call sign unknown) posted on Monday that the Mouser part number for the more robust version is 771-BAP64-04-T/R . Maybe you missed it. Mouser has over 4000 in stock at a price of $0.38, or 10 for $3.10. Glad you found the problem. It's a relatively easy fix. Dave Hachadorian Big Bear Lake, CA On 7/20/2021 9:51 PM, Connie Marshall wrote: Dave... thanks so much. The sensitivity returned when I did the J66 jumper test. So looks like PIN diode D5 needs to be replaced. Looks like I can order from Mouser. Will do some digging and see if I can find the "more robust version". 73, Connie / K5CM On 7/19/2021 12:08 AM, David Hachadorian wrote: Try this: https://marc.info/?l=elecraft=145323127930319=2 Unfortunately, the link near the bottom for the more robust replacement part doesn't work anymore, but maybe someone can come up with the part number. I've got a bunch of them at home, but I'm on vacation. The robust replacement is slightly larger in size, but it will still fit on the solder pads if you are careful. Dave Hachadorian, K6LL Big Bear Lake, CA On 7/18/2021 9:34 PM, Connie Marshall wrote: While operating SO2R the 'HIGH RF" warning flashed on the K3 display. Before I could react and stop the transmission on the other radio the front end got zapped. The radio is down about 50 db on RX. I checked Ant 2 and RX antenna and the same problem so probably not the surge protectors on each of these inputs. Any ideas on what part goes out when this happens. The TX radio was on 20 meters and the RX radio was on 15 meters. Connie / K5CM __ 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 Message delivered to k6ll.d...@gmail.com -- Dave Hachadorian, K6LL Yuma, AZ -- Dave Hachadorian, K6LL Yuma, AZ __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] Front end RF overload
Dave... thanks so much. The sensitivity returned when I did the J66 jumper test. So looks like PIN diode D5 needs to be replaced. Looks like I can order from Mouser. Will do some digging and see if I can find the "more robust version". 73, Connie / K5CM On 7/19/2021 12:08 AM, David Hachadorian wrote: Try this: https://marc.info/?l=elecraft=145323127930319=2 Unfortunately, the link near the bottom for the more robust replacement part doesn't work anymore, but maybe someone can come up with the part number. I've got a bunch of them at home, but I'm on vacation. The robust replacement is slightly larger in size, but it will still fit on the solder pads if you are careful. Dave Hachadorian, K6LL Big Bear Lake, CA On 7/18/2021 9:34 PM, Connie Marshall wrote: While operating SO2R the 'HIGH RF" warning flashed on the K3 display. Before I could react and stop the transmission on the other radio the front end got zapped. The radio is down about 50 db on RX. I checked Ant 2 and RX antenna and the same problem so probably not the surge protectors on each of these inputs. Any ideas on what part goes out when this happens. The TX radio was on 20 meters and the RX radio was on 15 meters. Connie / K5CM __ 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 Message delivered to k6ll.d...@gmail.com -- Dave Hachadorian, K6LL Yuma, AZ __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] Front end RF overload
John, KK9A is absolutely correct: without external bandpass filters, the replacement of PIN diodes in the T/R switches, even with more robust replacement devices, may not prevent the burnout from re-occurring. The K3/K3s lowpass filter for 15/17 meters would offer virtually no attenuation of a high level 20 meter signal before it hits the T/R switch diodes. If external bandpass filters were in use, you will want to measure the low side attenuation of your 15 meter bandpass filter - it may not be sufficient to prevent a high power 20 meter signal from impinging on those T/R switch diodes. Mike, K8CN __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] Front end RF overload
You should also fix the cause of the high level of RF. Did you use band pass filters? John KK9A Connie Marshall k5cm wrote: While operating SO2R the 'HIGH RF" warning flashed on the K3 display. Before I could react and stop the transmission on the other radio the front end got zapped. The radio is down about 50 db on RX. I checked Ant 2 and RX antenna and the same problem so probably not the surge protectors on each of these inputs. Any ideas on what part goes out when this happens. The TX radio was on 20 meters and the RX radio was on 15 meters. Connie / K5CM __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] Front end RF overload
Try this: https://marc.info/?l=elecraft=145323127930319=2 Unfortunately, the link near the bottom for the more robust replacement part doesn't work anymore, but maybe someone can come up with the part number. I've got a bunch of them at home, but I'm on vacation. The robust replacement is slightly larger in size, but it will still fit on the solder pads if you are careful. Dave Hachadorian, K6LL Big Bear Lake, CA On 7/18/2021 9:34 PM, Connie Marshall wrote: While operating SO2R the 'HIGH RF" warning flashed on the K3 display. Before I could react and stop the transmission on the other radio the front end got zapped. The radio is down about 50 db on RX. I checked Ant 2 and RX antenna and the same problem so probably not the surge protectors on each of these inputs. Any ideas on what part goes out when this happens. The TX radio was on 20 meters and the RX radio was on 15 meters. Connie / K5CM __ 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 Message delivered to k6ll.d...@gmail.com -- Dave Hachadorian, K6LL Yuma, AZ __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] Front end RF overload
While operating SO2R the 'HIGH RF" warning flashed on the K3 display. Before I could react and stop the transmission on the other radio the front end got zapped. The radio is down about 50 db on RX. I checked Ant 2 and RX antenna and the same problem so probably not the surge protectors on each of these inputs. Any ideas on what part goes out when this happens. The TX radio was on 20 meters and the RX radio was on 15 meters. Connie / K5CM __ 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 Message delivered to arch...@mail-archive.com
