K3 Key-down on power-up
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I've got my K3 set up for cw on Field Day with a laptop usb
port driving a usb to serial converter. Rig control and cw keying are done over the serial cable, using the K3's built-in ability to send cw from pin 4(?) of the rs-232 cable. Everything works fine, but I got quite a scare when I turned on the K3 and it came up keyed-down 120 watts into no antenna. It seems that if the laptop is not running the logging program, rs-232 pin 4 can very well be in a key-down state. I don't see any way to prevent this event from happening again, except to unplug the rs-232 cable, turn the rig on, make sure vox is off, turn off the K3, plug in the rs-232 cable, and then turn the K3 back on again. Once it happens to you, you get gunshy about turning the rig on with rs-232 connected. Maybe there could be some sort of inhibit to prevent this from happening? Or maybe someone can suggest an easier way to prevent this from happening. On my old TS-850, there was an actual switch to disable vox, and I always disabled vox before turning on the rig. My permanent setup back home uses LPT keying, so I can leave the computer key jack unplugged. Thanks. Dave Hachadorian, K6LL Big Bear Lake, CA _______________________________________________ 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 Key-down on power-up
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I've always wondered why TEST mode wasn't persistent - if I put the K3
into TEST to prevent inadvertent keying, it comes back up on next powerup in normal mode. Bob NW8L On Fri, Jun 27, 2008 at 9:57 AM, Dave Hachadorian <[hidden email]> wrote: > I've got my K3 set up for cw on Field Day with a laptop usb port driving a > usb to serial converter. Rig control and cw keying are done over the serial > cable, using the K3's built-in ability to send cw from pin 4(?) of the > rs-232 cable. > > Everything works fine, but I got quite a scare when I turned on the K3 and > it came up keyed-down 120 watts into no antenna. It seems that if the > laptop is not running the logging program, rs-232 pin 4 can very well be in > a key-down state. I don't see any way to prevent this event from happening > again, except to unplug the rs-232 cable, turn the rig on, make sure vox is > off, turn off the K3, plug in the rs-232 cable, and then turn the K3 back on > again. > > Once it happens to you, you get gunshy about turning the rig on with rs-232 > connected. Maybe there could be some sort of inhibit to prevent this from > happening? Or maybe someone can suggest an easier way to prevent this from > happening. On my old TS-850, there was an actual switch to disable vox, and > I always disabled vox before turning on the rig. > > My permanent setup back home uses LPT keying, so I can leave the computer > key jack unplugged. > > Thanks. > > Dave Hachadorian, K6LL > Big Bear Lake, CA > _______________________________________________ > 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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I would vote not to make Test mode persistent. While I find it very useful,
it can be a trap for an inexperienced K3 user, to whom it might look like the radio simply isn't working. There is no indication that the radio is in Test mode, other than the failure to transmit. 73, andy, ae6y ----- Original Message ----- From: "Bob Cunnings" <[hidden email]> To: "Elecraft Reflector" <[hidden email]> Sent: Friday, June 27, 2008 9:00 AM Subject: Re: [Elecraft] K3 Key-down on power-up > I've always wondered why TEST mode wasn't persistent - if I put the K3 > into TEST to prevent inadvertent keying, it comes back up on next > powerup in normal mode. > > Bob NW8L > > On Fri, Jun 27, 2008 at 9:57 AM, Dave Hachadorian <[hidden email]> wrote: >> I've got my K3 set up for cw on Field Day with a laptop usb port driving >> a >> usb to serial converter. Rig control and cw keying are done over the >> serial >> cable, using the K3's built-in ability to send cw from pin 4(?) of the >> rs-232 cable. >> >> Everything works fine, but I got quite a scare when I turned on the K3 >> and >> it came up keyed-down 120 watts into no antenna. It seems that if the >> laptop is not running the logging program, rs-232 pin 4 can very well be >> in >> a key-down state. I don't see any way to prevent this event from >> happening >> again, except to unplug the rs-232 cable, turn the rig on, make sure vox >> is >> off, turn off the K3, plug in the rs-232 cable, and then turn the K3 back >> on >> again. >> >> Once it happens to you, you get gunshy about turning the rig on with >> rs-232 >> connected. Maybe there could be some sort of inhibit to prevent this from >> happening? Or maybe someone can suggest an easier way to prevent this >> from >> happening. On my old TS-850, there was an actual switch to disable vox, >> and >> I always disabled vox before turning on the rig. >> >> My permanent setup back home uses LPT keying, so I can leave the computer >> key jack unplugged. >> >> Thanks. >> >> Dave Hachadorian, K6LL >> Big Bear Lake, CA >> _______________________________________________ >> 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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> I would vote not to make Test mode persistent. While I find
> it very useful, it can be a trap for an inexperienced K3 > user, to whom it might look like the radio simply isn't > working. There is no indication that the radio is in Test > mode, other than the failure to transmit. Actually, there is a (subtle) indication ... the TX icon blinks when in TX TEST mode. 73, Ed - W0YK _______________________________________________ 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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I don't think this would help. You'd still have to remember to put it into TEST mode before switching it off. There is perhaps a case for having an option for the radio to come up in TEST mode and stay in that mode until it received a valid command over the RS-232. This could be useful for those who rarely if ever use the radio *without* a computer connected. Even if you don't have a serial port that asserts key down when no logger is active, many PCs do toggle the serial port control lines during the power-on tests at boot-up, causing the rig to transmit a series of dashes. I've had this happen a few times, when I switched on the radio before the computer. Partly because I'm also developing software and prone to accidentally transmitting test messages, I have got into the habit of always switching to TEST whenever I turn on the radio. Except when I forget to, of course.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by Dave Hachadorian
> I've got my K3 set up for cw on Field Day with a laptop usb port driving
> a usb to serial converter. Rig control and cw keying are done over the > serial cable... > Once it happens to you, you get gunshy about turning the rig on with > rs-232 connected. Maybe there could be some sort of inhibit to prevent > this from happening? If you have configured the K3 to look at RTS or DTR to activate the Transmitter, then it will do so. It can't know that your computer is attached but turned off. Two suggestions that might help: 1) change the CONFIG menu item if you are going to leave an unpowered RS232 device attached to the radio, or 2) run the USB-to-RS232 device through a USB HUB that has an external power supply which is powered whenever the K3 is powered. 73, Lyle KK7P _______________________________________________ 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 Andrew Faber
There IS an indication that one is in the "Test" mode.
The letters "TX" between the "A" and "B" VFO indicators on the right side of the display BLINK on and off when in the "Test" mode - when NOT in the "Test" mode, the "TX" is steady. Admittedly, it is easy to miss! -- '73 es gud dxing -- Don N4HH K3 #83 -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Andrew Faber Sent: Friday, June 27, 2008 12:13 PM To: Bob Cunnings; Elecraft Reflector Subject: Re: [Elecraft] K3 Key-down on power-up <SNIP> There is no indication that the radio is in Test mode, other than the failure to transmit. 73, andy, ae6y <SNIP> _______________________________________________ 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 Dave Hachadorian
Dave and folks,
That behavior is a natural consequence of an unpowered RS-232 signal line. The voltage on the RTS (or DTR) input to the K3 will be zero or close to it when the computer is not powered. If you check the R-232 signal levels you will find that the region around zero volts (+3v to -3v) is "undefined" - the system is designed that way to include noise immunity - the RS-232 receiver output might be either ON or OFF when its input is at zero volts - it is not predictable and the real state depends on the behavior of the particular LT1039ACN driver/receiver chip in the K3. Couple that with the fact that the RS-232 'no signal' or 'Space' state must be between +3 and +15 volts to assure an OFF condition at the output of the RS-232 receiver - there is just no way to avoid the 'problem'. As a result, if your K3 is set for PTT-KEY from the RTS or DTR lines, it would be prudent to power the computer on before the K3 so these input signals are at a defined state (hopefully 'space'). Even unplugging the cable will not help because that will also result in zero volts at the input. 73, Don W3FPR Dave Hachadorian wrote: > I've got my K3 set up for cw on Field Day with a laptop usb port driving > a usb to serial converter. Rig control and cw keying are done over the > serial cable, using the K3's built-in ability to send cw from pin 4(?) > of the rs-232 cable. > > Everything works fine, but I got quite a scare when I turned on the K3 > and it came up keyed-down 120 watts into no antenna. It seems that if > the laptop is not running the logging program, rs-232 pin 4 can very > well be in a key-down state. I don't see any way to prevent this event > from happening again, except to unplug the rs-232 cable, turn the rig > on, make sure vox is off, turn off the K3, plug in the rs-232 cable, and > then turn the K3 back on again. > > Once it happens to you, you get gunshy about turning the rig on with > rs-232 connected. Maybe there could be some sort of inhibit to prevent > this from happening? Or maybe someone can suggest an easier way to > prevent this from happening. On my old TS-850, there was an actual > switch to disable vox, and I always disabled vox before turning on the rig. > > My permanent setup back home uses LPT keying, so I can leave the > computer key jack unplugged. > > Thanks. > > Dave Hachadorian, K6LL > Big Bear Lake, CA > _______________________________________________ > 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: 8.0.101 / Virus Database: 270.4.1/1522 - Release Date: 6/27/2008 8:27 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 |
Re: K3 Key-down on power-up
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Don Wilhelm wrote:
> > close to it when the computer is not powered. If you check the R-232 > signal levels you will find that the region around zero volts (+3v to > -3v) is "undefined" - the system is designed that way to include noise Actually, for some modem control lines, it is well defined, and, if you use standard line receivers, it is well defined for all inputs. Zero volts is required to read as OFF. E.g the Fairchild 1489A is guaranteed to be OFF for any input less than +750mV. > immunity - the RS-232 receiver output might be either ON or OFF when its The plus and minus three volts are driver specifications. Typical receivers have a rather narrow transition region, but with a rather wider hysterisis band, which is still only about 150mV (1489A), or less. > input is at zero volts - it is not predictable and the real state > depends on the behavior of the particular LT1039ACN driver/receiver chip It should not, the positive going threshold should be definitely greater than zero volts. > in the K3. Couple that with the fact that the RS-232 'no signal' or > 'Space' state must be between +3 and +15 volts to assure an OFF RS232 uses positive logic for control signals and negative logic for data, so +3 volts is *ON* and SPACE, when using normal line receivers. This is on the line side. Typical drivers, and receivers, are inverting, so the TTL side has negative logic controls and positive logic data. > condition at the output of the RS-232 receiver - there is just no way to > avoid the 'problem'. > > As a result, if your K3 is set for PTT-KEY from the RTS or DTR lines, it > would be prudent to power the computer on before the K3 so these input > signals are at a defined state (hopefully 'space'). Even unplugging the The zero voltage state is MARK, not space, but I suspect that you may actually be referring to the CW MARK state and actually representing it by an RS232 SPACE state. If you actually have RS232 MARK set to CW mark, you will get problems from unpowered drivers. > cable will not help because that will also result in zero volts at the > input. -- David Woolley "The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio" List Guidelines <http://www.elecraft.com/elecraft_list_guidelines.htm> _______________________________________________ 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 Ed Muns, W0YK
Personally I would like the TX icon to blink at a faster rate than it does. Don't know much about peripheral perception etc but I find it easy to miss the 'blink' and sometimes start calling someone when in TEST mode. (I normally have the computer monitor in front and K3 to one side....) A minor point but on the other hand something that would presumably be easy enough to change if others felt similar..? 73, Stewart Rolfe, GW0ETF (K3 145) |
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