Problems using a QRO amp with the K3
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Problems using a QRO amp with the K3
 
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Anyone out there using a QRO with the K3? I can't seem to get the amp working with the K3. I have previously used the amp with the 480HX, 1000MP and 706 MIIG. I am using the key out circuit on the back which does activate the relay in the amp but when I release the ptt, the amp stays in transmit and will not release. Before I did use the ALC circuit with the amp but I have been told I do not need to use an ALC circuit with the K3. Do I need a separate t/r relay between the radio and the amp? Is there some other menu item I have overlooked? Any help will be appreciated.
73, Richard N4WDU |
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I have a QRO Technologies HF-2000 amp. I am keying it with a K3 thru the amp's
"+15V Key Xmit" input port, but I have a homebrew transistor circuit between the K3 and the amp to supply +12V to this input. The other amp keying port is called "Key Xmit". It needs only a contact closure able to handle 80ma. However the open circuit voltage measured at this port is about 150V. When I had a different transceiver, I was concerned about the high open circuit voltage. I built the interface to allow use the "+15V Key Xmit" port and avoid any damage to the transceiver relay. Maybe this high open circuit voltage is the cause of the problem with the K3 trying to key the amp? 73, Paul K5ESW > > Anyone out there using a QRO with the K3? I can't seem to get the amp > working with the K3. I have previously used the amp with the 480HX, 1000MP and > 706 MIIG. I am using the key out circuit on the back which does activate the > relay in the amp but when I release the ptt, the amp stays in transmit and will > not release. Before I did use the ALC circuit with the amp but I have been told > I do not need to use an ALC circuit with the K3. Do I need a separate t/r relay > between the radio and the amp? Is there some other menu item I have overlooked? > Any help will be appreciated. > > 73, Richard > N4WDU > -- > View this message in context: > http://n2.nabble.com/Problems-using-a-QRO-amp-with-the-K3-tp524929p524929.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > 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 _______________________________________________ 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 |
Re: Problems using a QRO amp with the K3
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In reply to this post by Richard Robbins
Richard
While I don't use it often, my K3 works just fine with my Acom 1000 Amplifier. The Acom has low Voltage/current keying and I just use a straight phono to phono cable between the two. No, ALC or loop-back connection. 73 Dave, G4AON K3/100 #80 ---------------- Anyone out there using a QRO with the K3? I can't seem to get the amp working with the K3. I have previously used the amp with the 480HX, 1000MP and 706 MIIG. I am using the key out circuit on the back which does activate the relay in the amp but when I release the ptt, the amp stays in transmit and will not release. Before I did use the ALC circuit with the amp but I have been told I do not need to use an ALC circuit with the K3. Do I need a separate t/r relay between the radio and the amp? Is there some other menu item I have overlooked? Any help will be appreciated. 73, Richard N4WDU _______________________________________________ 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 |
Re: Problems using a QRO amp with the K3
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In reply to this post by Richard Robbins
Richard.....
What happens if you turn down the drive on the K3 to zero? Does it key normally if there is no drive applied to the amp? Is your station grounded? Lee - K0WA In our day and age it seems that Common Sense is in short supply. If you don't have any Common Sense - get some Common Sense and use it. If you can't find any Common Sense, ask for help from somebody who has some Common Sense. Is Common Sense divine? _______________________________________________ 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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In reply to this post by Richard Robbins
I have used my K3 with the QRO 2500 with no problems just using the key out
on the K3 to the amp. No need for a keying relay. If you look at the schematic on the 2500 you can see there is a keying buffer and I measured the current drain at around 100 mils at 12V. I am assuming you have a 2500 not a 2000 since you only said QRO. At the present time you cannot use ALC with the K3 since the QRO puts out a negative voltage and the K3 only accepts positive until the final ALC mods are released. Just keep the drive down to around 25watts and you should have full legal output. Don't know why it would lock up. Mike WA8EBM ----- Original Message ----- From: "Richard Robbins" <[hidden email]> To: <[hidden email]> Sent: Sunday, July 13, 2008 2:06 PM Subject: [Elecraft] Problems using a QRO amp with the K3 > > Anyone out there using a QRO with the K3? I can't seem to get the amp > working with the K3. I have previously used the amp with the 480HX, > 1000MP > and 706 MIIG. I am using the key out circuit on the back which does > activate the relay in the amp but when I release the ptt, the amp stays in > transmit and will not release. Before I did use the ALC circuit with the > amp but I have been told I do not need to use an ALC circuit with the K3. > Do I need a separate t/r relay between the radio and the amp? Is there > some > other menu item I have overlooked? Any help will be appreciated. > > 73, Richard > N4WDU > -- > View this message in context: > http://n2.nabble.com/Problems-using-a-QRO-amp-with-the-K3-tp524929p524929.html > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > 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 > _______________________________________________ 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 |
RE: Problems using a QRO amp with the K3
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Do you have any other devices that you are keying with key out line?
-----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Mike Penkas Sent: Sunday, July 13, 2008 5:24 PM To: Richard Robbins; [hidden email] Subject: Re: [Elecraft] Problems using a QRO amp with the K3 I have used my K3 with the QRO 2500 with no problems just using the key out on the K3 to the amp. No need for a keying relay. If you look at the schematic on the 2500 you can see there is a keying buffer and I measured the current drain at around 100 mils at 12V. I am assuming you have a 2500 not a 2000 since you only said QRO. At the present time you cannot use ALC with the K3 since the QRO puts out a negative voltage and the K3 only accepts positive until the final ALC mods are released. Just keep the drive down to around 25watts and you should have full legal output. Don't know why it would lock up. Mike WA8EBM ----- Original Message ----- From: "Richard Robbins" <[hidden email]> To: <[hidden email]> Sent: Sunday, July 13, 2008 2:06 PM Subject: [Elecraft] Problems using a QRO amp with the K3 > > Anyone out there using a QRO with the K3? I can't seem to get the amp > working with the K3. I have previously used the amp with the 480HX, > 1000MP > and 706 MIIG. I am using the key out circuit on the back which does > activate the relay in the amp but when I release the ptt, the amp stays in > transmit and will not release. Before I did use the ALC circuit with the > amp but I have been told I do not need to use an ALC circuit with the K3. > Do I need a separate t/r relay between the radio and the amp? Is there > some > other menu item I have overlooked? Any help will be appreciated. > > 73, Richard > N4WDU > -- > View this message in context: > ml > Sent from the Elecraft mailing list archive at Nabble.com. > > _______________________________________________ > 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 > _______________________________________________ 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 _______________________________________________ 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 |
Re: Problems using a QRO amp with the K3
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In reply to this post by Richard Robbins
After I tried another radio and rechecked all connections, everything is now working fine. It may be simply a case of operator error on my part. Several of you great Elecraft guys responded to my query with things to look at. Thank you one and all. It is wonderful to have a forum like this available when a person needs help. All the responses have confirmed that I made the correct choice in choosing the K3 which by the way is my first Elecraft product. 73, Richard N4WDU |
RE: Problems using a QRO amp with the K3
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In reply to this post by Richard Robbins
My old Alpha 78 works just fine with full breakin on the K3. I just key the
amp with the K3 and did not have to worry about time delays, etc. I have NEVER used ALC with any rig. Jerry AI6L -----Original Message----- From: Richard Robbins [mailto:[hidden email]] Sent: Sunday, July 13, 2008 11:06 AM To: [hidden email] Subject: [Elecraft] Problems using a QRO amp with the K3 Anyone out there using a QRO with the K3? I can't seem to get the amp working with the K3. I have previously used the amp with the 480HX, 1000MP and 706 MIIG. I am using the key out circuit on the back which does activate the relay in the amp but when I release the ptt, the amp stays in transmit and will not release. Before I did use the ALC circuit with the amp but I have been told I do not need to use an ALC circuit with the K3. Do I need a separate t/r relay between the radio and the amp? Is there some other menu item I have overlooked? Any help will be appreciated. 73, Richard N4WDU -- View this message in context: http://n2.nabble.com/Problems-using-a-QRO-amp-with-the-K3-tp524929p524929.ht ml Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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 |
Re: Problems using a QRO amp with the K3
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Jerry,
Good that you never use ALC with an amplifier. Driving an amplifier into the region where it develops ALC voltage is a sure recipe for creating non-linearity and the accompanying distortion and splatter. More folks should follow your lead. 73, Don W3FPR Jerry T. Dowell wrote: > My old Alpha 78 works just fine with full breakin on the K3. I just key the > amp with the K3 and did not have to worry about time delays, etc. I have > NEVER used ALC with any rig. > > Jerry AI6L > > _______________________________________________ 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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That may be true for some amplifiers that generate ALC voltage from grid current, however it is not true of an amplifier that generates ALC based on detecting the RF. Such an amplifier could still be very linear at the ALC threshold. ALC might be being used to protect something else, like a dissipation issue, or to protect the antenna tuner, or to ensure the local licence limits are not exceeded. Operators make mistakes. It is a very good idea to connect the ALC. Then by all means adjust the power to prevent ALC acting, one day the radio will almost inevitably become mis-configured to apply full drive to the amplifier. Mike |
RE: Problems using a QRO amp with the K3
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In reply to this post by Jerry T. Dowell
I use a Commander HF 2500 with vox operation and the K3 and amp work fine
here. I also don't use ALC but I watch to be sure I don't over drive the amp so as to exceed the permissible grid current. Bruce-W8FU -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Jerry T. Dowell Sent: Sunday, July 13, 2008 8:23 PM To: 'Richard Robbins'; [hidden email] Subject: RE: [Elecraft] Problems using a QRO amp with the K3 My old Alpha 78 works just fine with full breakin on the K3. I just key the amp with the K3 and did not have to worry about time delays, etc. I have NEVER used ALC with any rig. Jerry AI6L -----Original Message----- From: Richard Robbins [mailto:[hidden email]] Sent: Sunday, July 13, 2008 11:06 AM To: [hidden email] Subject: [Elecraft] Problems using a QRO amp with the K3 Anyone out there using a QRO with the K3? I can't seem to get the amp working with the K3. I have previously used the amp with the 480HX, 1000MP and 706 MIIG. I am using the key out circuit on the back which does activate the relay in the amp but when I release the ptt, the amp stays in transmit and will not release. Before I did use the ALC circuit with the amp but I have been told I do not need to use an ALC circuit with the K3. Do I need a separate t/r relay between the radio and the amp? Is there some other menu item I have overlooked? Any help will be appreciated. 73, Richard N4WDU -- View this message in context: http://n2.nabble.com/Problems-using-a-QRO-amp-with-the-K3-tp524929p524929.ht ml Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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 No virus found in this incoming message. Checked by AVG. Version: 8.0.136 / Virus Database: 270.4.7/1546 - Release Date: 7/11/2008 6:47 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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