Subject: RE: [Elecraft] Amp keying circuit K2
Maybe you can key a TIP31 or 32 Power transistor from output of K2 circuit. These worked pretty well for me back in VIC20/RTTY days for keying FT101E. Paul WD8OJL The FL-2100B pulls 20v on its keying input, whilst the circuit for the K2 is only designed for 5-12v !! This is clearly written on the instructions with the circuit, which I neglected to read. Does anyone have details of a simple circuit I can build, so I can use this with my FL-2100B ?? ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: [Elecraft] Amp keying circuit K2
David, Best solution: Change the output transistor to a mosfet device which will be capable of handling the higher voltage. See the .pdf from Tom Hammond's website - http://www.n0ss.net/k2_basic_8r_line_t-r_adapter.pdf for the re-designed output device (HEXFET). It will require changing one of the resistors in the present keying circuit as well as the output device. Another solution would be to use the present amp keying circuit (and a power supply) to key a relay - use the relay contacts to key the amp. Depending on the speed of the relays, that may slow things down a bit and you will cause problems with QSK keying. 73, Don W3FPR -Original Message- Thanks for all the responses to this - much appreciated. I'm afraid it was a simple case of me not reading the instructions on the keying circuit. The FL-2100B pulls 20v on its keying input, whilst the circuit for the K2 is only designed for 5-12v !! This is clearly written on the instructions with the circuit, which I neglected to read. Does anyone have details of a simple circuit I can build, so I can use this with my FL-2100B ?? Again, many thanks for the all the replies !! David, VK2NU ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: [Elecraft] Amp keying circuit K2
I answered David and apparently did not click on Reply All. A long time ago using the Elecraft Keying Circuit, I simply replaced the 2N keying transistor with a MPSA42 which can handle max 300V (Vce) at 100 mA. It worked fine with my SB-220 which has ~110V on the key line. 73, Ken K3IU -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Don Wilhelm Sent: Tuesday, July 18, 2006 9:57 AM To: David Douglass; elecraft@mailman.qth.net Subject: RE: [Elecraft] Amp keying circuit K2 David, Best solution: Change the output transistor to a mosfet device which will be capable of handling the higher voltage. See the .pdf from Tom Hammond's website - http://www.n0ss.net/k2_basic_8r_line_t-r_adapter.pdf for the re-designed output device (HEXFET). It will require changing one of the resistors in the present keying circuit as well as the output device. Another solution would be to use the present amp keying circuit (and a power supply) to key a relay - use the relay contacts to key the amp. Depending on the speed of the relays, that may slow things down a bit and you will cause problems with QSK keying. 73, Don W3FPR -Original Message- Thanks for all the responses to this - much appreciated. I'm afraid it was a simple case of me not reading the instructions on the keying circuit. The FL-2100B pulls 20v on its keying input, whilst the circuit for the K2 is only designed for 5-12v !! This is clearly written on the instructions with the circuit, which I neglected to read. Does anyone have details of a simple circuit I can build, so I can use this with my FL-2100B ?? Again, many thanks for the all the replies !! David, VK2NU ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: Elecraft@mailman.qth.net 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] Amp keying circuit K2
Hi, Just a quick question.. I've just installed the parts in my basic K2 to externally key an amp. I've just tried to key my old FL-2100B with this, but have found that as soon as I plug the cable in, the amp keys when the radio is still in RX ?? Is there a menu setting I need to change or have I made a mistake on the circuit ?? The cable is fine as I use this on my FT1000mp to key the same amp. I've checked the resistance on the keying circuit and I get about 18ohms, when the radio is keyed, as opposed to open circuit when in the RX state ?? Thanks David, VK2NU ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: [Elecraft] Amp keying circuit K2
Hi All, Thanks for all the responses to this - much appreciated. I'm afraid it was a simple case of me not reading the instructions on the keying circuit. The FL-2100B pulls 20v on its keying input, whilst the circuit for the K2 is only designed for 5-12v !! This is clearly written on the instructions with the circuit, which I neglected to read. Does anyone have details of a simple circuit I can build, so I can use this with my FL-2100B ?? Again, many thanks for the all the replies !! David, VK2NU -Original Message- From: Don Wilhelm [mailto:[EMAIL PROTECTED] Sent: Tuesday, 18 July 2006 2:58 AM To: David Douglass; elecraft@mailman.qth.net Subject: RE: [Elecraft] Amp keying circuit K2 David, No question is quick if you need to understand what is going on G! The amp keying circuit should work unless the output transistor is being forced into conduction from whatever voltage is being applied on its open collector - it should not be if the voltages applied are within a normal range. Without the amp connected, you can check the base voltage of the 2N transistor - it should be very close 0 volts during receive and about 0.7 volts (the emitter/base junction voltage for the 2N) during transmit. If those two conditions are not true, then you have something wrong with the keying circuit wiring. During receive, the 2N should be cutoff due to the low voltage at its base and should not conduct even with voltage applied to the collector. Be certain the resistance in the emitter path is quite low - a bit of resistance there could cause the output transistor to misbehave. If your problem still is not solved, try measuring the circuit output transistor voltages (to K2 ground) with the amp connected and the K2 in receive. The emitter should be zero volts, and the base should also be very low, while the collector should measure at the voltage applied externally from the amp. Be certain you have a good low resistance connection from the amp ground (terminal E) to the K2 ground and a good connection from the amps RY terminal to the keying circuit's output collector. If you find the conditions above are OK, you likely have a bad 2N. 73, Don W3FPR -Original Message- Just a quick question.. I've just installed the parts in my basic K2 to externally key an amp. I've just tried to key my old FL-2100B with this, but have found that as soon as I plug the cable in, the amp keys when the radio is still in RX ?? Is there a menu setting I need to change or have I made a mistake on the circuit ?? The cable is fine as I use this on my FT1000mp to key the same amp. I've checked the resistance on the keying circuit and I get about 18ohms, when the radio is keyed, as opposed to open circuit when in the RX state ?? Thanks David, VK2NU -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.9.10/387 - Release Date: 12/07/2006 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
