Hello group
Was wondering if anyone had the same experience as I have. Got a Vibroplex Classic a few months ago and took quite awhile to get the adjustments right and it is sounding very decent on the K3. No secondary dit chirp, contacts clean and all is good. I then put it on the K2 and all those chirpy dits like an intermittent show up and really sound like a lid on the air. Tried the K1 also with same results. go back to the K3 and all is normal. All I can figure is the keying circuit must need more time/better contact than the K3? Hate to adjust the bug for fear it will be whacked out and take me hours to get it set to the K3 again. Not a show stopper but a ponder. Thanks 73es Werner N8BB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
--- On Sun, 8/23/09, Denise&Werner <[hidden email]> wrote: From: Denise&Werner <[hidden email]> Subject: [Elecraft] Vibroplex Bug To: "Elecraft List" <[hidden email]> Date: Sunday, August 23, 2009, 5:15 PM Hello group Was wondering if anyone had the same experience as I have. Got a Vibroplex Classic a few months ago and took quite awhile to get the adjustments right and it is sounding very decent on the K3. No secondary dit chirp, contacts clean and all is good. I then put it on the K2 and all those chirpy dits like an intermittent show up and really sound like a lid on the air. Tried the K1 also with same results. ------------------------------------------------------------------------------------ Werner, I have similar results between the K3 and K2, although not quite as severe as yours sounds. K3 keying is crisp and clean, K2 often seems to throw in some dits that don't sound complete. I am going to try to make some adjustments and modifications to my bug (1941 Original) as suggested at http://extendadot.com and see if I can improve the K2 bug keying. When using the bug on the K2 I have the key input set to HAND. 73, Sam, N4SAM ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by Denise&Werner
I guess the K3 just likes your bug!
First, make sure the contacts are mating squarely. Then measure the continuity when the dot contacts are resting closed. It should be a dead short. If there is any resistance find out where and correct it. Assuming that is okay, how many dits does the bug generate when you thumb the dot paddle? Try adjusting the dot contact spacing so that you don't get more than about 15 maximum. (No, you do not want 20 or 30 or more dits before the contacts finally come to a close.) You can also try wedging a piece of cotton or felt in the "U" of the dot spring. 73, Drew AF2Z On Sun, 23 Aug 2009 13:15:13 -0400, Werner N8BB wrote: >Hello group > >Was wondering if anyone had the same experience as I have. >Got a Vibroplex Classic a few months ago and took quite awhile to get the >adjustments right and it is sounding very decent on the K3. No secondary dit >chirp, contacts clean and all is good. >I then put it on the K2 and all those chirpy dits like an intermittent show >up and really sound like a lid on the air. Tried the K1 also with same >results. >go back to the K3 and all is normal. >All I can figure is the keying circuit must need more time/better contact >than the K3? >Hate to adjust the bug for fear it will be whacked out and take me hours to >get it set to the K3 again. >Not a show stopper but a ponder. > >Thanks > >73es > >Werner N8BB >______________________________________________________________ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by Denise&Werner
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Ron D'Eau Claire wrote:
> I suspect you're experiencing "scratchy" or intermittent dits, not chirp. > ("Chirp" is when your frequency shifts up or down during the initial > milliseconds after the key closes) > > As others pointed out, a good low resistance contact is *required* by modern > rigs that key a low voltage/low current line, which is a problem with > mechanical contacts, especially contacts that just "bump" with little > pressure like the dit contacts on a bug. Deoxit helps, as Ron says. Also intermittent cleaning with a business card. But the real solution for bug keying of modern rigs -- even the K3, which *is* better than the K2 at this -- is a simple circuit composed of a reed relay with a capacitor across the coil to soak up the contact bounce. Here is a description and schematic. You will need to use a fixed-width font to see it properly: Get a radio shack 12 volt SPST reed relay (275-233) or similar. One side of the relay coil goes to the positive terminal of a 9v battery and the other side goes to your bug's ungrounded contacts. In parallel with the coil put a 4.7 to 10uf 25v electrolytic capacitor (also from Radio Shack) and any silicon diode. Orient the capactitor so that the positive side goes to the coil terminal that is connected to the battery. The diode is reverse-connected; its CATHODE goes to the coil terminal that is connected to the battery. Finally, connect the negative side of the battery to the bug's grounded side. If you want to run the circuit from a 12v supply instead of a battery, put an 820 ohm 1/4w resistor in series with the 12v. coil |------------+@@@@@@@+--------> to bug | | | - + +--| (--+ 4.7 to 10 uf capacitor --- - 9v | | | +--|<---+ diode |------------------------------> /// Here's a photo of such a circuit attached to a bug: <http://www.qsl.net/k2vco/Bug640.jpg> The value of the capacitor should be the smallest necessary clean up the bounce. The large it is, the more it will stretch the dots and you will have to adjust the dwell time of the dot contact on your bug to compensate. Yes, I have tried various electronic debouncing circuits, and none of them proved as satisfactory to me as this simple one. The relay is almost silent (the slight tick is drowned out by the noise of the bug). -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by Denise&Werner
Have you tried a bit of foam tucked into the "U" shape of the dit
contact spring? Bob NW8L On Sun, Aug 23, 2009 at 11:15 AM, Denise&Werner<[hidden email]> wrote: > Hello group > > Was wondering if anyone had the same experience as I have. > Got a Vibroplex Classic a few months ago and took quite awhile to get the > adjustments right and it is sounding very decent on the K3. No secondary dit > chirp, contacts clean and all is good. > I then put it on the K2 and all those chirpy dits like an intermittent show > up and really sound like a lid on the air. Tried the K1 also with same > results. > go back to the K3 and all is normal. > All I can figure is the keying circuit must need more time/better contact > than the K3? > Hate to adjust the bug for fear it will be whacked out and take me hours to > get it set to the K3 again. > Not a show stopper but a ponder. > > Thanks > > 73es > > Werner N8BB > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by Vic K2VCO
> Deoxit helps, as Ron says. Also intermittent cleaning with a business
> card. But the real > solution for bug keying of modern rigs -- even the K3, which *is* better > than the K2 at > this -- is a simple circuit composed of a reed relay with a capacitor > across the coil to > soak up the contact bounce. Another solution is to create a solid-state buffer between the bug key line and the rig. In the past, I've used a Schottky-input gate, driving a 2N7000 transistor to the key line. An off-the-shelf solution, might consist of the microHam PIC-based debouncer, developed by K1EL. It was designed primarily for iambic paddles with dissimilar metal contacts, but it may be possible to adapt it for bug use. W4TV would know for sure. http://www.microham-usa.com/Products/Begali.html Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by Vic K2VCO
All you need is a 1uf capacitor across the bug contacts. Radio Shack has
some that are small enough to fit in an RCA plug! Actually .5 UF is enough so I have 2 ea. 1UF in series. These eliminate the mushy and double dit symptom. Cleaning doesn't always work. Some modern rigs such as the K3 and Omni 7 are overly sensitive to switch noise and the cap will clear it up. Radio Shack PN is: 272-1434 Steve N4LQ [hidden email] ----- Original Message ----- From: "Vic K2VCO" <[hidden email]> To: "'Elecraft List'" <[hidden email]> Sent: Sunday, August 23, 2009 3:19 PM Subject: Re: [Elecraft] Vibroplex Bug > Ron D'Eau Claire wrote: >> I suspect you're experiencing "scratchy" or intermittent dits, not chirp. >> ("Chirp" is when your frequency shifts up or down during the initial >> milliseconds after the key closes) >> >> As others pointed out, a good low resistance contact is *required* by >> modern >> rigs that key a low voltage/low current line, which is a problem with >> mechanical contacts, especially contacts that just "bump" with little >> pressure like the dit contacts on a bug. > > Deoxit helps, as Ron says. Also intermittent cleaning with a business > card. But the real > solution for bug keying of modern rigs -- even the K3, which *is* better > than the K2 at > this -- is a simple circuit composed of a reed relay with a capacitor > across the coil to > soak up the contact bounce. > > Here is a description and schematic. You will need to use a fixed-width > font to see it > properly: > > Get a radio shack 12 volt SPST reed relay (275-233) or similar. One side > of the relay coil > goes to the positive terminal of a 9v battery and the other side goes to > your bug's > ungrounded contacts. In parallel with the coil put a 4.7 to 10uf 25v > electrolytic > capacitor (also from Radio Shack) and any silicon diode. Orient the > capactitor so that > the positive side goes to the coil terminal that is connected to the > battery. The diode > is reverse-connected; its CATHODE goes to the coil terminal that is > connected to the > battery. Finally, connect the negative side of the battery to the bug's > grounded side. > If you want to run the circuit from a 12v supply instead of a battery, put > an 820 ohm 1/4w > resistor in series with the 12v. > > coil > |------------+@@@@@@@+--------> to bug > | | | > - + +--| (--+ 4.7 to 10 uf capacitor > --- - 9v | | > | +--|<---+ diode > |------------------------------> > /// > > Here's a photo of such a circuit attached to a bug: > <http://www.qsl.net/k2vco/Bug640.jpg> > > The value of the capacitor should be the smallest necessary clean up the > bounce. The large > it is, the more it will stretch the dots and you will have to adjust the > dwell time of the > dot contact on your bug to compensate. > > Yes, I have tried various electronic debouncing circuits, and none of them > proved as > satisfactory to me as this simple one. The relay is almost silent (the > slight tick is > drowned out by the noise of the bug). > -- > 73, > Vic, K2VCO > Fresno CA > http://www.qsl.net/k2vco > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Need to remember that in the days when bugs were king, the typical
voltage being keyed was between a cathode(s) and ground (often a couple hundred volts at several hundred ma) or bias voltage (75, 105, 150 volts). Turn off the lights and key the bug keying an 807 rig, and you could see the sparks. Stuff of the time was never designed for 12 volts at 7 ma or the like. Even with the higher voltages and currents had problems with contact bounce and resistance. That was why when keyers started showing up, the sealed mercury-wetted relays surplus from somewhere in the Bell System were all the rage. No contact bounce or contact resistance problems. One could really get tossed across the room by touching the "hot' parts of the key. 73, Guy. On Sun, Aug 23, 2009 at 7:10 PM, Ron D'Eau Claire<[hidden email]> wrote: > The problem I dealt with is not contact bounce, but contacts that do not > make a low enough resistance connection to trigger the logic properly. It > sounded like that was Werner's problem too. > > It's easy to see the contact resistance issue using a scope on the key line. > The key voltage simply isn't being pulled down far enough to reliably key > the rig unless the contacts are *very* clean, and without adequate current > flowing through them to maintain a self-cleaning action, they quickly > oxidize again without help - or some other way to key the rig like Vic's ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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