K3 Two amplifiers 1 key line
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K3 Two amplifiers 1 key line
 
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I have a HF amp on ANT1 and (soon to be) 6M amp on ANT2. ANT2 is
dedicated 6M antenna. Has anyone come up with a way to PTT each amp when on desired band? Is it possible to just hook both AMPS to the same PTT key line so both amps Key at the same time but the RF path would then take over? Thanks, Lee WW2DX K3 #464 _______________________________________________ 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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Lee
Something like the KRC2 band decoder could be used to steer the PTT line as you change bands. 73, Bob N6WG ----- Original Message ----- From: "Lee (WW2DX)" <[hidden email]> To: "Elecraft Reflector" <[hidden email]> Sent: Thursday, July 03, 2008 10:21 AM Subject: [Elecraft] K3 Two amplifiers 1 key line > I have a HF amp on ANT1 and (soon to be) 6M amp on ANT2. ANT2 is > dedicated 6M antenna. > > Has anyone come up with a way to PTT each amp when on desired band? Is > it possible to just hook both AMPS to the same PTT key line so both > amps Key at the same time but the RF path would then take over? > > Thanks, > > Lee > WW2DX > K3 #464 > > > _______________________________________________ > 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 |
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In reply to this post by Lee J. Imber (WW2DX)
There's always the old school way - you could put a DPDT switch in the
keying line, and switch between the amps manually. Given that that's only one motion, and we have to push the BAND switch repeatedly to move between bands, that's not such a big deal. :-) 73, Steve > Has anyone come up with a way to PTT each amp when on desired band? Is it > possible to just hook both AMPS to the same PTT key line so both amps Key > at the same time but the RF path would then take over? > _______________________________________________ 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: K3 Two amplifiers 1 key line
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In reply to this post by Lee J. Imber (WW2DX)
Lee,
You should be able to provide control lines for HexFETs or some other kind of switch with just a little bit of logic and the signals from the ACC connector. Look at the Band Data outputs - the only time *both* Band3 and Band1 are at a high impedance state is on 6 meters. A NAND gate (with pullup resistors on the inputs) will give you a LOW output on 6 meters and HIGH on all other bands - call this 'partial band decode'. Now add an inverter to the KEYOUT-LP signal (another pullup resistor is needed at its input) and feed its output to one input each of 2 more NAND gates - the 'partial band decode' NAND gate output feeds the remaining input of one of these NAND gates and that one will have a low output when HF is selected *and* Keyout is active. Invert the output of the 'partial band decode' and feed the inverted output to the input of the other NAND gate that you connected the inverted Keyout signal to - that NAND will have a LOW output when 6 meters is selected *and* keyout is active. I don't know how much voltage and current your amps PTT inputs require, so I leave the final keying of the amps up to you. A pair of the K2 Amp Keying Circuit on the Elecraft website or one of Tom Hammond's K2 Amp Keying kits can be driven by the circuit I described and be used to key your amplifiers. A 74AC00 dip and a 74AC04 will do this task with one NAND gate and 4 inverters to spare - it takes longer to describe in words than to draw it. To be safe, I would not consider letting the RF path determine which amp transmits - if you ever find the ANT1/ANT2 selection changed (by an inadvertent button tap), you could send RF to the wrong amp. You may not be able to simply run the KEYOUT to both amplifiers - that will only work if both amplifiers have the same voltage on their PTT IN lines (measure with your DMM with the amplifier on and nothing connected to the PTT IN jack). 73, Don W3FPR Lee (WW2DX) wrote: > I have a HF amp on ANT1 and (soon to be) 6M amp on ANT2. ANT2 is > dedicated 6M antenna. > > Has anyone come up with a way to PTT each amp when on desired band? Is > it possible to just hook both AMPS to the same PTT key line so both > amps Key at the same time but the RF path would then take over? > _______________________________________________ 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: K3 Two amplifiers 1 key line
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All the work has already been done by Paul, WD7D. See "Improved Amplifier Interfacing for the Yaesu Mark V FT-1000MP" QST, September 2004, page 51. The only change necessary to Paul's circuit is to add a pair of pull-up resistors ... he even has (had?) circuit boards for the project. The circuit will switch PTT and Inhibit lines between HF and six meter amplifiers based on partial decoding of the Band data lines. Note: partial decoding will not work if you have any transverters on the K3 and are using the band data outputs for switching them. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Don Wilhelm > Sent: Thursday, July 03, 2008 5:48 PM > To: Lee (WW2DX) > Cc: Elecraft Reflector > Subject: Re: [Elecraft] K3 Two amplifiers 1 key line > > > Lee, > > You should be able to provide control lines for HexFETs or some other > kind of switch with just a little bit of logic and the > signals from the > ACC connector. > > Look at the Band Data outputs - the only time *both* Band3 > and Band1 are > at a high impedance state is on 6 meters. A NAND gate (with pullup > resistors on the inputs) will give you a LOW output on 6 > meters and HIGH > on all other bands - call this 'partial band decode'. > Now add an inverter to the KEYOUT-LP signal (another pullup > resistor is > needed at its input) and feed its output to one input each of 2 more > NAND gates - the 'partial band decode' NAND gate output feeds the > remaining input of one of these NAND gates and that one will > have a low > output when HF is selected *and* Keyout is active. > Invert the output of the 'partial band decode' and feed the inverted > output to the input of the other NAND gate that you connected the > inverted Keyout signal to - that NAND will have a LOW output when 6 > meters is selected *and* keyout is active. > I don't know how much voltage and current your amps PTT > inputs require, > so I leave the final keying of the amps up to you. A pair of > the K2 Amp > Keying Circuit on the Elecraft website or one of Tom Hammond's K2 Amp > Keying kits can be driven by the circuit I described and be > used to key > your amplifiers. A 74AC00 dip and a 74AC04 will do this task > with one > NAND gate and 4 inverters to spare - it takes longer to describe in > words than to draw it. > > To be safe, I would not consider letting the RF path > determine which amp > transmits - if you ever find the ANT1/ANT2 selection changed (by an > inadvertent button tap), you could send RF to the wrong amp. You may > not be able to simply run the KEYOUT to both amplifiers - > that will only > work if both amplifiers have the same voltage on their PTT IN lines > (measure with your DMM with the amplifier on and nothing connected to > the PTT IN jack). > > 73, > Don W3FPR > > Lee (WW2DX) wrote: > > I have a HF amp on ANT1 and (soon to be) 6M amp on ANT2. ANT2 is > > dedicated 6M antenna. > > > > Has anyone come up with a way to PTT each amp when on > desired band? Is > > it possible to just hook both AMPS to the same PTT key line so both > > amps Key at the same time but the RF path would then take over? > > > _______________________________________________ > 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 |
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In reply to this post by Lee J. Imber (WW2DX)
I see several suggestions already, mostly involving building circuits. That is fine if you wish but you could also just connect together the key lines, using diodes to isolate them from one another, and making sure you respect the current and voltage ratings of the key line. Both amps will of course key but most amplifiers have an off switch or standby facility and unless you are using 6m and HF at the same time it is probably easier just to disable the unused amplifier.
Mike
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RE: K3 Two amplifiers 1 key line
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In reply to this post by Joe Subich, W4TV-3
Correction ... Paul's call is WD7S (that's what I get for writing e-mail after 10 hours of working on manuals). 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Joe > Subich, W4TV > Sent: Friday, July 04, 2008 3:26 AM > To: [hidden email]; 'Lee (WW2DX)' > Cc: 'Elecraft Reflector' > Subject: RE: [Elecraft] K3 Two amplifiers 1 key line > > > > All the work has already been done by Paul, WD7D. See "Improved > Amplifier Interfacing for the Yaesu Mark V FT-1000MP" QST, > September 2004, page 51. The only change necessary to Paul's > circuit is to add a pair of pull-up resistors ... he even has > (had?) circuit boards for the project. > > The circuit will switch PTT and Inhibit lines between HF and > six meter amplifiers based on partial decoding of the Band > data lines. > > Note: partial decoding will not work if you have any transverters > on the K3 and are using the band data outputs for switching them. > > 73, > > ... Joe, W4TV > > > > > > > -----Original Message----- > > From: [hidden email] > > [mailto:[hidden email]] On Behalf Of Don Wilhelm > > Sent: Thursday, July 03, 2008 5:48 PM > > To: Lee (WW2DX) > > Cc: Elecraft Reflector > > Subject: Re: [Elecraft] K3 Two amplifiers 1 key line > > > > > > Lee, > > > > You should be able to provide control lines for HexFETs or > some other > > kind of switch with just a little bit of logic and the > > signals from the > > ACC connector. > > > > Look at the Band Data outputs - the only time *both* Band3 > > and Band1 are > > at a high impedance state is on 6 meters. A NAND gate (with pullup > > resistors on the inputs) will give you a LOW output on 6 > > meters and HIGH > > on all other bands - call this 'partial band decode'. > > Now add an inverter to the KEYOUT-LP signal (another pullup > > resistor is > > needed at its input) and feed its output to one input each > of 2 more > > NAND gates - the 'partial band decode' NAND gate output feeds the > > remaining input of one of these NAND gates and that one will > > have a low > > output when HF is selected *and* Keyout is active. > > Invert the output of the 'partial band decode' and feed the > inverted > > output to the input of the other NAND gate that you connected the > > inverted Keyout signal to - that NAND will have a LOW output when 6 > > meters is selected *and* keyout is active. > > I don't know how much voltage and current your amps PTT > > inputs require, > > so I leave the final keying of the amps up to you. A pair of > > the K2 Amp > > Keying Circuit on the Elecraft website or one of Tom > Hammond's K2 Amp > > Keying kits can be driven by the circuit I described and be > > used to key > > your amplifiers. A 74AC00 dip and a 74AC04 will do this task > > with one > > NAND gate and 4 inverters to spare - it takes longer to describe in > > words than to draw it. > > > > To be safe, I would not consider letting the RF path > > determine which amp > > transmits - if you ever find the ANT1/ANT2 selection changed (by an > > inadvertent button tap), you could send RF to the wrong > amp. You may > > not be able to simply run the KEYOUT to both amplifiers - > > that will only > > work if both amplifiers have the same voltage on their PTT IN lines > > (measure with your DMM with the amplifier on and nothing > connected to > > the PTT IN jack). > > > > 73, > > Don W3FPR > > > > Lee (WW2DX) wrote: > > > I have a HF amp on ANT1 and (soon to be) 6M amp on ANT2. ANT2 is > > > dedicated 6M antenna. > > > > > > Has anyone come up with a way to PTT each amp when on > > desired band? Is > > > it possible to just hook both AMPS to the same PTT key > line so both > > > amps Key at the same time but the RF path would then take over? > > > > > _______________________________________________ > > 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 |
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