Any sub-$500 scopes with hard plastic, tactile buttons? - Page 1
Forum section: electronics / testgear

author: MatthewTx
author_rank: Newbie
timestamp: February 19, 2020, 09:13:33 pm
content: None of this soft, velvety, rubbery rubbish.I like my keys to be hard, tactile, and even clicky where possible. I know that some landline phones have the rubbery keys, while others have nice plastic ones. So it can't be too much to ask for.If my $40 Panasonic landline phone can have "the right kind" of buttons, why can't a $350 scope?Thanks in advance for any pointers in the right direction --Matthew

author: tautech
author_rank: Super Contributor
timestamp: February 19, 2020, 09:26:54 pm
content: Quote from: MatthewTx on February 19, 2020, 09:13:33 pmTactile switches don't offer the same reliability that membrane switching do, pure and simple !Why would designers want to use old outdated and less reliable technology ?In the current offerings from Siglent the buttons feel firm and hard like plastic yet are on membranes that are not overly soft so there's no need to press them hard and overturn the scope.You need get to a shop with a few brands and try them for yourself.

author: thm_w
author_rank: Super Contributor
timestamp: February 20, 2020, 12:07:18 am
content: Quote from: tautech on February 19, 2020, 09:26:54 pmWhat an absurd statement, its clearly a cost decision. If you press a tactile switch 100 times per hour, 8 hours per day, it will last over 3 years (1 mil cycle life).The cost of a LED lit SMD based tactile keypad would be ridiculously more than the equivalent rubber membrane. I would guess 5x as much.I have zero problems with their use, but you are essentially claiming rubber dome keyboards are superior, and any sort of mechanical switch based keyboard is outdated.As for OP, its not an option I am aware of.

author: tautech
author_rank: Super Contributor
timestamp: February 20, 2020, 12:13:29 am
content: Quote from: thm_w on February 20, 2020, 12:07:18 amAnd you've never apparently had to replace a tactile switch ?

author: thm_w
author_rank: Super Contributor
timestamp: February 20, 2020, 12:39:36 am
content: Quote from: tautech on February 20, 2020, 12:13:29 amI have replaced tactile switches multiple times.Manufacturers don't care about reliability to the degree that they'd "choose the switch type with the highest reliability". Cost is the main driving factor. Not to mention you can much easier make unique shapes and colors.Its a completely fair trade off, I wouldn't be willing to pay the extra for tactile switches on my low end scope. However, I am willing to pay extra for those switches in my mouse, as they are used much more often.

author: aheid
author_rank: Regular Contributor
timestamp: February 20, 2020, 12:49:00 am
content: Cherry MX Blue, because you're worth it.

author: MikeLud
author_rank: Regular Contributor
timestamp: February 20, 2020, 12:53:30 am
content: Amazon has a good price for a Siglent SDS1104X-Ehttps://www.amazon.com/Siglent-SDS1104X-oscilloscope-channels-standard/dp/B0771N1ZF9/ref=pd_ybh_a_1?_encoding=UTF8&psc=1&refRID=W84SJHZJYYB65W121N34

author: aheid
author_rank: Regular Contributor
timestamp: February 20, 2020, 01:40:11 am
content: Quote from: MikeLud on February 20, 2020, 12:53:30 amWell OP wanted hard plastic tactile clickety buttons, not the soft membrane that the SDS1104X-E has. As a programmer who got my employer to buy me a Cherry MX Brown keyboard, I can sympathize.

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2020, 02:28:10 am
content: Quote from: MikeLud on February 20, 2020, 12:53:30 am...with rubber buttons.

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2020, 02:29:03 am
content: Quote from: aheid on February 20, 2020, 01:40:11 amBrown?Ick.

author: aheid
author_rank: Regular Contributor
timestamp: February 20, 2020, 03:21:07 am
content: Quote from: Fungus on February 20, 2020, 02:29:03 amWell my gf thinks the Browns are loud enough, and I wanted the same keyboard at home and at work so compromise.

author: james_s
author_rank: Super Contributor
timestamp: February 20, 2020, 03:29:08 am
content: I haven't really had a problem with them. My preferred buttons on Instruments are the sort Tek used in the older TDS scopes, hard plastic keys that rest on a fairly generic rubber membrane that could be easily replaced or repaired if needed. Haven't had one fail yet. Can't think of any digital scopes that have actual tactile keyswitches but something might exist somewhere.

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2020, 03:50:04 am
content: Quote from: aheid on February 20, 2020, 03:21:07 amI actually just moved from a (Unicomp) Model-M to a Logitech Romer-G keyboard because I wanted nice backlighting, which Cherry aren't good for.It's similar feel to a Cherry brown, not the greatest switch-feel ever but I think I can live with it as a compromise.The Model M is on another machine and it seems far too loud now. Maybe Browns aren't so bad after all...

author: BravoV
author_rank: Super Contributor
timestamp: February 20, 2020, 04:08:06 am
content: Quote from: MatthewTx on February 19, 2020, 09:13:33 pmButtons ? Meh .. rotary dial is way cooler->Rotary Cellphone

author: tautech
author_rank: Super Contributor
timestamp: February 20, 2020, 06:54:42 am
content: Quote from: Fungus on February 20, 2020, 02:28:10 amHow could you know, have you bought one ?Really unless you have you wouldn't have the faintest clue as rubber membrane buttons don't need to have soft rubber buttons.....but you already know that......or at least you should !

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2020, 09:00:44 am
content: Quote from: tautech on February 20, 2020, 06:54:42 amThe requirement is "hard, tactile, and even clicky where possible". Do they meet that requirement?

author: tautech
author_rank: Super Contributor
timestamp: February 20, 2020, 09:16:44 am
content: Quote from: Fungus on February 20, 2020, 09:00:44 amWhat scope does ?

author: aheid
author_rank: Regular Contributor
timestamp: February 20, 2020, 09:29:46 am
content: Quote from: tautech on February 20, 2020, 09:16:44 amI recently gave away an old Tektronix from the early 80's, it had nice hard plastic clicking (almost ka-chunk) buttons

author: Fungus
author_rank: Super Contributor
timestamp: February 20, 2020, 09:39:59 am
content: Quote from: tautech on February 20, 2020, 09:16:44 amThe correct answer is therefore "no", not a Siglent advert.

author: MadTux
author_rank: Frequent Contributor
timestamp: February 20, 2020, 02:28:07 pm
content: The classic HP instruments had the best clicky buttons imaginable.Some VCRs and even remote controls in the 1980/1990s had soldered click buttons.Guess everyone cheaped out and now everything comes with rubber pad shit that gets all sticky and nasty when old.It's also what I don't like with Keithley 2000 and friends, wish they had used those soldered square mini switches instead of rubber pad.Quote from: tautech on February 20, 2020, 12:13:29 amAnd you never had a rubber key pad with eroded carbon contacts or ripped off rubber buttons.I rather do a tactile switch replacement instead of trying to repair worn unobtainium rubber pad crap.

author: wraper
author_rank: Unknown
timestamp: February 20, 2020, 02:53:53 pm
content: Quote from: MadTux on February 20, 2020, 02:28:07 pmYou only need to make a bulky boat anchor front panel. FWIW TACT switches are the worst and least reliable type of switches.QuoteIt's only a problem for remote controls. Distance is very short, a lot of buttons/openings in small space so fat from hands gets through the rubber and washes out carbon. It's not a problem for front panel switches. In any case, tact switches will die many times before rubber will get bad. And they are especially bad in harsh/ humid conditions. They go bad very fast. Not only they stop to work, they often become slightly conductive between contacts.

author: BravoV
author_rank: Super Contributor
timestamp: February 20, 2020, 03:08:51 pm
content: Quote from: wraper on February 20, 2020, 02:53:53 pmThe metal dome, that supposed to be convex / buldging, when its normal, the pressure turns it nto concave shape and bounces back, hence it clicks, but once the metal fatique creeps in, it will stay concave and wont bounce back anymore, aka shorted or both contacts are constantly shorted.

author: wraper
author_rank: Unknown
timestamp: February 20, 2020, 03:10:11 pm
content: Quote from: MadTux on February 20, 2020, 02:28:07 pmUsually you only need to remove a very thin layer of conductive rubber by fine sandpaper and resistance becomes low again. Oh and what you do when button caps break off from cap array held by thin plastic strips, and it falls out? Seen that countless times. And when you place individual button caps on TACT switches, it's even worse. They simply suck when pushed not exactly straight and there is come degree of freedom.BTW have you seen faulty car key fobs failing to register presses or not working at all? They usually fail because of those damn TACT switches.

author: wraper
author_rank: Unknown
timestamp: February 20, 2020, 03:20:14 pm
content: Quote from: BravoV on February 20, 2020, 03:08:51 pmNope, that's different failure mechanism, though failure you described is quite common. They still are OK mechanically and remain bouncy. Silver dendrites grow between contacts on surface of plastic and cause conductive path with resistance in kOhm range. Seen it under microscope several times. And it's not some outdoor equipment, in things like monitors, TVs, DVDs.

author: james_s
author_rank: Super Contributor
timestamp: February 20, 2020, 05:19:25 pm
content: Sandpaper? Jeez, I've never had to resort to that.Oil eventually leaches out of the silicone rubber keypads and the buttons stop responding. I wash the rubber with warm water and a bit of dish soap then do the same with the PCB. I've fixed dozens of remotes and other various equipment by doing that. I've never had to use any kind of abrasive or conductive goo.

author: wraper
author_rank: Unknown
timestamp: February 20, 2020, 06:11:45 pm
content: Quote from: james_s on February 20, 2020, 05:19:25 pmIt's not like I'm grinding it. Remove few microns of surface and resistance becomes low again (actual measurement was done). It's just a few light passes of fine sandpaper. But it's more for buttons which were pressed too often and too hard. Have not tried it on oily remotes.QuoteHave done it too in the past.

author: tooki
author_rank: Super Contributor
timestamp: February 21, 2020, 01:24:05 pm
content: Quote from: Fungus on February 20, 2020, 03:50:04 amHuh? Cherry makes switch versions specifically for full backlighting, aside from the regular versions that accept a single LED.

author: Berni
author_rank: Super Contributor
timestamp: February 21, 2020, 02:11:07 pm
content: I don't see why these rubber membrane switches would be a bad thing.Sure there are some TV remotes with absolutely horrendous squishy rubber buttons that don't register half of the time and you are not even sure if you pushed it in the first place because its like poking piece of jello. But when rubber membrane buttons are done properly they are perfectly fine. The button can be made reasonably solid feeling, give a nice buckling feedback so you know when you actually pushed it and they work reliably even after years of service.I have some old gear with mechanical buttons and they wear out too. Had to service plenty of old HP leaf spring switches because they didn't operate smoothly anymore (but still worked). Also have some RF gear where the soft power switch got a bit dicky, and its apparently a common failure on this old Gigatronics RF gear.

author: tooki
author_rank: Super Contributor
timestamp: February 21, 2020, 02:56:16 pm
content: Quote from: Berni on February 21, 2020, 02:11:07 pmTactility. Yes, you are correct that there are massive differences in the quality of rubber membranes and the tactility they provide, but they can never provide the positive “click” of a tactile button. (And there’s kind of a tradeoff between tactility and button travel, insofar as you can’t make a really thin membrane with good tactility, since you need a structure that can buckle. So this means you require longer travel than a tactile button, which can have a very short, but distinct, travel. This becomes relevant for quick repetition, which is a lot harder with long travel rubber membranes.)So while tactility certainly isn’t always an essential feature, it’s something a lot of people value.If you wanna look into it more, google “haptic feedback”.

author: Berni
author_rank: Super Contributor
timestamp: February 21, 2020, 05:48:15 pm
content: Quote from: tooki on February 21, 2020, 02:56:16 pmButton travel is only really a limiting factor in small portable applications(like phones). Test equipment is typically large anyway so there is plenty of space for key travel, some of my equipment has buttons with as much button travel as a standard desktop PC keyboard. In fact some of those long stroke buttons are actually one of my least favorite ones because they have no snap action at all and only really make a noise if it hits the sudden stop at the end of its travel.On the other hand i have equipment with rubber buttons with enough snap action that you could hear me press the button anywhere in the same room (As long as its a quiet room) and these are some of my favorite ones. Then there are things with the classic 4 pin short travel tactile button switches that make a very loud and positive click but to me they feel kinda meh.I am also a fan of the old HP leaf spring switches, but only when they are in correct working order. It seams those leaf springs become too resilient to buckling over time and start feeling like those cheep short travel 4 pin tactile switches, except that the button falls in quite a distance after the click. Giving the springs a bit of a bend gives them the much nicer soft buckling feeling closer to a mechanical keyboard.So yes tactile feeling is a nice thing, but there is a balance to be struck in how sharp of a click it needs. Having a click so hard that it could be used as a center punch is not a positive thing, but does need enough of a click for you to go "Yep i definitely pressed that" without the need for any supplemental feedback (Like some equipment produces short blips or clicks in the internal speaker to artificially enhance the button feedback).

author: tooki
author_rank: Super Contributor
timestamp: February 22, 2020, 12:05:47 am
content: Did you even read my post? I wasn’t advocating for long button travel. I said expressly that the short travel of tactile switches that a desirable, and something that rubber membranes cannot reproduce.This has nothing to do with keyboard switches; they have entirely different requirements and characteristics.

author: Berni
author_rank: Super Contributor
timestamp: February 22, 2020, 09:32:35 am
content: Well maybe it is just me, but i usually find these short travel clicky switches kinda meh.To me they feel like they have less of a fingertip feedback while making an unnecessarily loud clicking noise that is often made even louder by the often sparsely supported PCB holding the switch. Tho there are some nice feeling ones out there in the classical 4 pin tactile button format where they have a rubber actuator on top to dampen things a bit and have a well chosen actuation force, but i very rarely seen those used in products because they are a good bit more expensive than the usual cheap switches.One rare modern implementation of a clicky short travel switch done right is the Rigol DP832 power supply with its menu buttons along the lower edge of the screen. Maybe not the best keycap design, but the click is soft quiet and provides enough tactile feedback to know you definetly pressed it (Tho all the other frontpanel buttons are rubber membrane and are not all that good, too spongy and wobbly).

author: rsjsouza
author_rank: Super Contributor
timestamp: February 22, 2020, 02:43:05 pm
content: All this discussion is quite interesting and about an area that I am not very familiar (mechanical details and differences of buttons)However, I can't shake the amazement of how far we came to get to a time where so many choices are available for something so simple as a push button. Engineering is really awesome!

author: nctnico
author_rank: Super Contributor
timestamp: February 22, 2020, 02:54:13 pm
content: Quote from: rsjsouza on February 22, 2020, 02:43:05 pmI don't think there are many choices. Most of the equipment I have uses rubber mat pushbuttons. Even on old equipment their feel is consistent. I have one piece of equipment from Advantest with the 'clicky' tactile feedback buttons but they aren't consistent. Keys which are used often definitely feel different (less defined) compared to other keys. Back in the old days HP went completely overboard with their pushbuttons which IMHO are outright awfull to use due to their non-consistent feel. Fortunately I only have one piece of equipment with such keys and I don't use it very often.

author: tooki
author_rank: Super Contributor
timestamp: February 22, 2020, 03:50:13 pm
content: Quote from: Berni on February 22, 2020, 09:32:35 amOh, there's definitely a huge amount of personal taste in this. And it depends on the use case, too. And you're absolutely right that it depends on the switch's feel, too!For example, the tactile buttons I love on my Panasonic remote control would be atrocious as a keyboard.What I certainly can agree with everyone on is that tactile switches (or really, any mechanical keyswitch) is less reliable than the rubber membranes. I use mechanical keyboards at home, due to hand problems that demand I use a keyboard that registers a keypress without bottoming out, and I've already had to retire two due to switch failure, and I don't even type that much! (Eventually I'll get around to replacing the failed switches…)Quote from: nctnico on February 22, 2020, 02:54:13 pmUneven wear is a very good point I'd kinda overlooked until you mentioned it. From a manufacturer's point of view, rubber membrane buttons are likely the most reliable, resulting in lower warranty fulfilment costs, so it makes sense to use them wherever they can get away with it!Quote from: wraper on February 20, 2020, 03:10:11 pmWell, those are both certainly infuriating situations, but those are implementation failures, not inherent problems with tact switches. A properly designed button cap has flanges that keep it in place, with the plastic strips only there to make assembly easier. They certainly should not be the only thing holding the cap in place!!!Similarly, in quality gear, the tolerances are tight enough to ensure that things stay aligned. That, or you use button caps that actually physically attach to the stem of the tact switch, ensuring permanent alignment. (Those buttons also come with flanges, so they can't get yanked off accidentally.)I may need to take apart and document the Panasonic remote I've been raving about, because they did absolutely everything right. I was floored when I took it apart for a deep cleaning to see how well made it is. It exemplifies everything one should do in designing buttons.

author: rsjsouza
author_rank: Super Contributor
timestamp: February 22, 2020, 05:18:18 pm
content: Quote from: nctnico on February 22, 2020, 02:54:13 pmI have a HP3314 with these large buttons and, at least in my unit, they feel quite solid. However, I can imagine how wear could get them in a bad spot. But that is a much better solution when compared to the membrane keyboard of my Wavetek 275.What I am referring is the overall variety of technology developed over the years on the simple push button. I have calculators and other equipment with reed switches, chiclet, spring-on-mat , buckling spring and many others developed over the years with varying degrees of complexity, cost, etc. Just look at how many "Cherry" models of push buttons exist. It is fascinating.

author: james_s
author_rank: Super Contributor
timestamp: February 23, 2020, 07:59:50 pm
content: Quote from: rsjsouza on February 22, 2020, 05:18:18 pmI did have one issue with the keypad on a HP 33120a. It was filthy so I had the thing apart for cleaning, I was scrubbing the keys and one of them tore out of the web and fell in the sink. I just about had a heart attack when I saw that happen but fortunately I looked on ebay and there was a replacement keypad for $25 so I bought that, lesson learned.Handle with care if you have it apart because they are big long heavy keys in a thin webbing however in use I have never had one of these fail.

author: wraper
author_rank: Unknown
timestamp: February 23, 2020, 09:01:12 pm
content: Quote from: tooki on February 22, 2020, 03:50:13 pmCannot be further from the truth. They are exactly for holding button in place, in certain orientation. When cap attached onto switch plunger, it decreases switch life and may cause not registered presses. But when not mechanically attached to anything, it's a wobbly crap. If you use so called flanges as cap guides, button will feel like wobbly and scratchy crap as minimum.https://omronfs.omron.com/en_US/ecb/products/pdf/precautions_tactile.pdfQuoteAnd button will operate like crap as already mentioned. Switch plunger cannot keep button cap straight. So as minimum you will continuously scratch button cap walls against opening in panel.

author: tooki
author_rank: Super Contributor
timestamp: February 24, 2020, 04:30:52 am
content: Quote from: wraper on February 23, 2020, 09:01:12 pmYour reply indicates you have ZERO idea what I'm talking about. I assume this is a language barrier in this case.The first question was about buttons that, if the plastic strip breaks, completely fall off. That'sterribledesign. Similarly, a good design has separate keying to keep button caps from rotating. Well-designed moldings and tolerances stop them from being wobbly.What on earth makes you think that a cap attached to a switch stem will cause it to fail?!? Why would they make switches specifically made to hold caps if they weren't supposed to use them? That's just absurd. I'm not saying to ghetto-rig it, I'm talking about switches designed specifically for snap-on caps, if you want this approach.The link you share explains how you don't want a wobbly, off-center plunger pressing on a button. Duh. That doesn't contradict what I said.

author: wraper
author_rank: Unknown
timestamp: February 24, 2020, 05:16:19 am
content: Quote from: tooki on February 24, 2020, 04:30:52 amBecause of radial force applied to the switch. Metal dome does not like it.QuoteThey not necessarily exactly fall off. They may stay inside but you'll notice right away since button will no longer operate properly.QuoteNo matter how well it is designed, unless cap is attached, it will feel/work like crap.QuoteBecause not everyone will/can roll out custom molded button caps. I used them and they are not good.QuoteSimply using guides won't keep the cap exactly straight unless guide and button cap are very long which will help keeping it in correct orientation.

author: tooki
author_rank: Super Contributor
timestamp: February 24, 2020, 05:54:07 am
content: Quote from: wraper on February 24, 2020, 05:16:19 amSo you somehow think you know better than the switch manufacturers, who make switches with stems for caps, and sell the caps, too? Suuuuure...Quote from: wraper on February 24, 2020, 05:16:19 amYour original comment which spawned this discussion said "fall out". I took this to mean that the button plops out the front panel, having nothing else to hold it in place. Such designs exist, and they're a terrible idea.But other designs also exist, where the plastic serves no structural function at all, where the failure causes no malfunction whatsoever. There are also designs where the buttons do not have the plastic strips at all, with each cap being independent. Doneproperly, this works very well.Quote from: wraper on February 24, 2020, 05:16:19 amNo, it's possible to do right. Again, it's something I've seen before.Quote from: wraper on February 24, 2020, 05:16:19 amWho said anything about custom caps? You can buy tact switches with plungers designed specifically to mate to caps sold by the switch manufacturer. All off-the-shelf stuff.For example, the Omron B32 series of caps, which attaches to various switches of theirs, such as the "projected type" models in the B3F series.Quote from: wraper link topic=230664.msg2934320#msg2934320 date=1582521379Except that if done properly, they can, without being long. I've worked on enough devices to have encountered such assemblies many times.