Re: [Elecraft] Check Your Buttons [switch current is _not_ too low]
David G3UNA, wrote: A quick look at the circuit diagram shows that buttons are taken from a potential divider to CD74HC4051M inputs. These switches (unless I've misread the diagram) will therefore take the input current of the multiplexer which is typically 1uA. I don't know the spec for the Elecraft switch but a similar one requires a minimum current of 10uA. This should be checked more rigorously, but it might indicate a potential problem. David, The K3's front panel switches do not have a minimum required current. I just verified this again with the manufacturer. They have gold- plated contacts on the PC board and should be extremely reliable. Regarding the switch test function in the menu: A small amount of digit flicker is perfectly normal. The A to D converter has an ambiguity of +/- one count, and the firmware algorithm reading the switch has no hysteresis, therefore +/- count of flicker is also to be expected. In firmware, we read the switch voltage several times, average them, and look for the proper switch code based on bins that have a large amount of excess margin. So the operator should not be concerned in the least about a deviation of even several counts in their own switch read voltages. If you're experiencing any type of switch-read error that isn't a hard failure, it is probably something that I can improve in firmware. I'll be happy to work with you on this -- please give me a detailed example. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Check Your Buttons [switch current is _not_ too low]
I remember having this problem with an old Advantest Drift-o-matic spectrum analyser at Uni. The buttons stopped working because the plastic let out some oils and this coated the gold and stopped the contacts working. I am not saying this is what has happened to Elecraft, I am sure that problem from 20 years ago if fixed now. My fairly recent Anritsu spectrum analyser has diffficult buttons too - as apparently does this laptop so it is a common problem. My K3 has sometimes had problems with switches too, but only rarely. My K2 is much worse in this respect. Have we found any user applications for the connector on the bottom of the panel yet? -- View this message in context: http://n2.nabble.com/Re-Check-Your-Buttons-switch-current-is-not-too-low-tp3707851p3708135.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Check Your Buttons [switch current is _not_ too low]
AD6XY wrote: My K3 has sometimes had problems with switches too, but only rarely. My K2 is much worse in this respect. Have we found any user applications for the connector on the bottom of the panel yet? At least on the K2 with it's bouncing switches it is not only a known problem, especially with the A/B and A=B switches, but you can fairly easily replace them - I changes out about 20 of them on my two K2s. And you get some physical feedback on the K2. On the K3 that is not true. -- View this message in context: http://n2.nabble.com/Re-Check-Your-Buttons-switch-current-is-not-too-low-tp3707851p3709272.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Check Your Buttons [switch current is _not_ too low]
At 06:54 PM 9/24/2009, .k8dd. wrote... At least on the K2 with it's bouncing switches it is not only a known problem, especially with the A/B and A=B switches, but you can fairly easily replace them - I changes out about 20 of them on my two K2s. K2 switches are readily available from Mouser and Digikey (Elecraft, too, obviously). E-switch TL1100F160Q. I mention this because it's an easy thing to add on to an order, and it's handy to keep some spares. A couple of other common parts: Potentiometers, 9mm snap in - Alpha 9mm (mouser 317-2080F-5K, 317-2090F-5K) Headphone jack - Kobiconn 161-3503-EX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
