160M Dead on my K2
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Hi Gang,
I couldn't wait to attack the 160 test with my K2. I switched to top band at the appointed time and heard..... nothing! So here's the deal. My K2 is QRP, SN543 with all modules less the DSP. The 160 did work when I last used it 3 years ago. The RX antenna likewise does nothing. I pulled the board to look for problems and it looks FB. I tried transmitting to a dummy load and the display reads LoP. Everything else in the radio functions to spec. The 80/160 BP filters are tuned up nicely for 80M. When I change bands from 80 - 160, I don't feel or hear any operation from relay K1 on the 160 module. Ideas?? 73, Mark K2QO/R and QRP _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Mark,
Well, if relay K1 does not switch, you will not have any output on 160 meters - but you also said that it does not receive on the Rx antenna either - so relay K2 must not be working either. That combination would point to something wrong in the relay coil circuits. Check all the soldering on pins 3, 4, and 16 of J1 and check the soldering on the header as well (that will likely require removing the heat sink from the K2. Also check pin 1 of the header and J1 (that is the signal path for the RX antenna). Check the soldering on the K160RX board at the relay pins too. You are probably looking for an unsoldered connection, or one that was not adequately heated. These connections can often work initially but develop enough oxidation to give trouble after a year or so. 73, Don W3FPR > -----Original Message----- > > I couldn't wait to attack the 160 test with my K2. I switched to top > band at the appointed time and heard..... nothing! So here's the deal. > > > My K2 is QRP, SN543 with all modules less the DSP. The 160 did work > when I last used it 3 years ago. The RX antenna likewise does nothing. > I pulled the board to look for problems and it looks FB. I tried > transmitting to a dummy load and the display reads LoP. Everything else > in the radio functions to spec. The 80/160 BP filters are tuned up > nicely for 80M. When I change bands from 80 - 160, I don't feel or hear > any operation from relay K1 on the 160 module. Ideas?? > > 73, > Mark K2QO/R and QRP > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.430 / Virus Database: 268.15.6/565 - Release Date: 12/2/2006 9:39 PM _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Don,
The suggestions did not fix my issue. All solder joints were redone and I checked everything with a magnifier light. Relay K2 works fine. I checked it on 80m where the RX is fine. I checked the bottom of the main board and all is well there too. When I switch bands to and from 160, I can see a small blip on my old analog VM from pin 16 to GND. I see a similar blip when I turn off/on the RX antenna using pins 3 and GND. Any further thoughts? 73, Mark K2QO Quoting Don Wilhelm <[hidden email]>: > Mark, > > Well, if relay K1 does not switch, you will not have any output on > 160 > meters - but you also said that it does not receive on the Rx > antenna > either - so relay K2 must not be working either. That combination > would > point to something wrong in the relay coil circuits. Check all the > soldering on pins 3, 4, and 16 of J1 and check the soldering on the > header > as well (that will likely require removing the heat sink from the K2. > Also > check pin 1 of the header and J1 (that is the signal path for the RX > antenna). Check the soldering on the K160RX board at the relay pins > too. > > You are probably looking for an unsoldered connection, or one that > was not > adequately heated. These connections can often work initially but > develop > enough oxidation to give trouble after a year or so. Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Mark,
If you see the blips, then the relays should be getting voltage to the coils. Since the RANT works on 80 meters, your problem may be in the 160/80 meter bandpass filter rather than the k160XV board itself (it may also be in the VFO range select area too). Check the VFO range select first - just because it is easy. Set the K2 to 1800 kHz and measure the frequency at TP1 (counter probe in TP1 and menu to CAL FCTR) - it should be very close to 6715 kHz, if it is not, then check capacitor C75 for proper value 470 pf (471) and good soldering. Then check the bandpass filter additions C13 and C14 (1200 pf [122]). If these are in place and relay K3 is working properly, you should have good 160 meter receive. Once you have 160 meter receive through the RX ANT jack, then you can move on to transmit. If it still does not work after successfully passing all the above tests, look for the problem in the toroid leads on the K160RX board. That is all I can think of at the moment. 73, Don W3FPR > -----Original Message----- > > Don, > > The suggestions did not fix my issue. All solder joints were redone > and I checked everything with a magnifier light. Relay K2 works fine. I > checked it on 80m where the RX is fine. I checked the bottom of the > main board and all is well there too. > > When I switch bands to and from 160, I can see a small blip on my old > analog VM from pin 16 to GND. I see a similar blip when I turn off/on > the RX antenna using pins 3 and GND. > > Any further thoughts? > > 73, > Mark K2QO > No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.430 / Virus Database: 268.15.6/567 - Release Date: 12/4/2006 7:18 AM _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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