KPA500 Problems
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Hi:
I hope nobody gets offended as I have also posted a message on the Elecraft K3 Group, but I need some help in resolving this issue. I have searched thru the 2 groups both here and also on Yahoo and can eliminate a few things. - Digout1 is off. - The top cover interlock for the KPA500 is in place and working. - KPAK3AUX cable is working with the KPA500 and KAT500 as far as tuning the KAT500 and communications between the KPA500 and the K3. - I have recycled the KPA500 off and on as well numerous band changes and still nothing. - I have re-seated all the DB15 cables as still nothing I am having problems to key the KPA500 from the K3. The KAT500 keys (Completes the tune cycle if required) but can't key the KPA500. I have taken the KPAK3AUX cable from the K3 and placed it directly to the KPA500 and still won't key. I have moved it back to the KAT500 and the KAT500 keys up fine. I have placed the KPA500 - KAT500 cable back back on the KAT500 and KPA500 and still nothing. On the KPA500 display, the HV is at 75.1 and when I key the K3, that voltage doesn't change as well when I attempt to key the amp, I get a current reading of 0. At no time during my testing did I ever get a fault. The K3 and the KPA500 are talking to each other, I can do band changes from the KPA500, and the K3 displays the KPA500 Status ie Operate or Standby All my tests have been done into a dummy load and when I have the K3 set at 25 watts output, I get the far left green led on the KPA500 power and swr bar graphs being illuminated I have even taken the KPAK3AUX cable off the KPA500 and tried putting a phono cable on the PA Key jack and shorting out the connector still doesn't key the KPA500. I am quite sure others have had this problem before. But I'm at a loss. The K3 can talk to both the KAT and KPA and the KPA can talk to the K3. I think (???) I can rule out the KPAK3AUX Cable at this point as it seems to work just fine. I am thinking something inside the KPA500 like a bad relay since the AUX Cable and a Phono cable hooked up to the PA Key jack both have no effect. This is the same for all the bands. The amp was just at Elecraft and was given a clean bill of health, it had TR Circuit updates, ALC and QSK Mods completed. Any help would be greatly appreciated. 73 De Mike VE3YF http://www.ve3yf.com ______________________________________________________________ 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 Message delivered to [hidden email] |
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Hi Mike,
When you transmit from the K3 what do you see on the left side of the KPA500 display. Obviously it's not an asterisk. Are you seeing an Underscore. You may have accidentally programmed INHIB IN to ENABLE? See page 20 of the KPA500 manual. You will want it to be in DISABLE. ENABLE allows the amplifier operation to be inhibited (won’t amplify) when a logic low is applied to pin 11 of the AUX Connector (see pg 26). When amplification is inhibited, an underscore instead of the asterisk appears on the left end of the LCD display. 73, Mike K2MK
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In reply to this post by Mike VE3YF
Hi Mike:
Tnx for the speedy reply. I see nothing on the left side fo the display. At the moment the display has what looks to be 2 balnk spots fallowed by 14.0 MHZ. I checked and the INHIB IN is set on DISABLE. The wiring diagram is exactly as mine is which is a copy right out of the manual Tnx Mike 73 De Mike VE3YF http://www.ve3yf.com Hi Mike, When you transmit from the K3 what do you see on the left side of the KPA500 display. Obviously it's not an asterisk. Are you seeing an Underscore. You may have accidentally programmed INHIB IN to ENABLE? See page 20 of the KPA500 manual. You will want it to be in DISABLE. /ENABLE allows the amplifier operation to be inhibited (won't amplify) when a logic low is applied to pin 11 of the AUX Connector (see pg 26). When amplification is inhibited, an underscore instead of the asterisk appears on the left end of the LCD display./ 73, Mike K2MK ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Mike VE3YF
This is the right place to ask questions like this, since this is where we are listening. It is one of the major reasons the lists exists.
I see from your second email that the asterisk is not being shown when the K3 keys. This indicates that the KPA500 is not getting the PTT signal. The KAT500 does not listen to the PTT signal, it only disconnects it when it is doing a tune cycle. So you really cannot rule out a bad cable. Take a good look at the AUXI/O cable to make sure none of the pins are bent.also, ohm out the cable to make sure all the pins that are supposed to be connected actually are. If the PTT pin is not touching, then that would be the problem. The fact that using a Phono-Phono cable from the K3 to the KPA is a bit troubling, make sure that cable is good also. Next check the KPA500’s menu settings to make sure that the INHIBIT signal is disabled. Shorting that input with the signal enabled in the KPA would also cause the KPA to not go into amplify mode. While you are investigating, make sure the K3 is actually asserting the PTT signal. If you don’t find the problem up to here, open the KPA’s top and check the 40 pin ribbon cable on the left side to make sure it is properly seated on both ends (IO board and Front Panel board. It could have worked its way loose during shipment, but if it had you would be seeing lots of other problems. If you don’t find anything with all of these checks, give me a shout back and we will look at more diagnosis. 73, Jack Brindle, W6FB Elecraft Engineering > On Sep 19, 2015, at 10:04 AM, Mike VE3YF <[hidden email]> wrote: > > Hi: > > I hope nobody gets offended as I have also posted a message on the Elecraft K3 Group, but I need some help in resolving this issue. I have searched thru the 2 groups both > here and also on Yahoo and can eliminate a few things. > > - Digout1 is off. > - The top cover interlock for the KPA500 is in place and working. > - KPAK3AUX cable is working with the KPA500 and KAT500 as far as tuning the KAT500 and communications between the KPA500 and the K3. > - I have recycled the KPA500 off and on as well numerous band changes and still nothing. > - I have re-seated all the DB15 cables as still nothing > > I am having problems to key the KPA500 from the K3. The KAT500 keys (Completes the tune cycle if required) but can't key the KPA500. > > I have taken the KPAK3AUX cable from the K3 and placed it directly to the KPA500 and still won't key. I have moved it back to the KAT500 and the KAT500 keys up fine. I > have placed the KPA500 - KAT500 cable back back on the KAT500 and KPA500 and still nothing. > > On the KPA500 display, the HV is at 75.1 and when I key the K3, that voltage doesn't change as well when I attempt to key the amp, I get a current reading of 0. > > At no time during my testing did I ever get a fault. > > The K3 and the KPA500 are talking to each other, I can do band changes from the KPA500, and the K3 displays the KPA500 Status ie Operate or Standby > > All my tests have been done into a dummy load and when I have the K3 set at 25 watts output, I get the far left green led on the KPA500 power and swr bar graphs being > illuminated > > I have even taken the KPAK3AUX cable off the KPA500 and tried putting a phono cable on the PA Key jack and shorting out the connector still doesn't key the KPA500. > > I am quite sure others have had this problem before. But I'm at a loss. The K3 can talk to both the KAT and KPA and the KPA can talk to the K3. > > I think (???) I can rule out the KPAK3AUX Cable at this point as it seems to work just fine. I am thinking something inside the KPA500 like a bad relay since the AUX Cable > and a Phono cable hooked up to the PA Key jack both have no effect. This is the same for all the bands. > > The amp was just at Elecraft and was given a clean bill of health, it had TR Circuit updates, ALC and QSK Mods completed. > > Any help would be greatly appreciated. > > > > > 73 De Mike > VE3YF > > http://www.ve3yf.com > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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