Update: My son Louie and his industrial design friends have come up with a concept for a DSP switch lockout. Details here.
Considering recent attention to this version of the DSP (green “Sport” model, same switch mechanics as DSP Pro), I acquired a used but not abused unit, and performed a few instrumented tests.
Disclaimer: Please note that this blog post is personal opinion based on my own testing and manipulation of the Pieps DSP Sport. It’s somewhat of a review, but only regarding a few specific issues. I only tested one beacon, others could test differently, and while of good quality, my instrumentation is not calibrated. The beacon models in question here have been around for at least five years, may have undergone “inline” changes of both the beacon and the harness. Most of the issues below have been previously presented in various internet venues. I only seek to offer measurements, my ideas, and perhaps more clarity.
The object at hand, Pieps DSP Sport avalanche beacon transceiver has ceased manufacture, but remains available in retail channels. There is also a “Pro” model of this beacon, presumably with the same switch and accessories. We did not test the Pro.
If you’re not familiar with the Pieps DSP Sport, see the Black Diamond video embedded below, as well as myriad other YouTube vids. The issue we’re addressing here is the design and function of the green Pieps DSP Sport’s yellow sliding switch and its associated lock button. When the lock button is depressed, our test unit’s switch feels tight, though it slides fairly easily once I got the hang of it, (in fact it’s eerily reminiscent of working the slide on a semi-automatic Austrian machine designed to propel hunks of lead. Even the locking tab is similar in concept to the slide lock on said machine.)
Important: With our test unit lock engaged, with normal hand strength I could not force the slide switch and compromise the lock — BUT I DID FIND WAYS IT MIGHT BE DEFEATED. Read on.
The switch lock button, inked in with black for the photo. Protrudes 1.57 millimetres.
The switch lock is a tiny yellow tab, a plastic living hinge that protrudes 1.57 mm and requires depression of a third — or less — of that distance to release. This is difficult to measure, I used a set of feeler gauges as well as my digital caliper to do the best I could. In real-life language, it’s sensitive. How sensitive? Next slide please.
Force required to depress the lock button — sans holster — was difficult to measure, but after multiple tries I think I got close enough. Using my push/pull force gauge, it took 820 grams of pressure to disengage the lock, thus allowing the slider switch to move. If you’ve got a decent scale, try feeling this force yourself with a finger press, it’s about the same pressure the average person would use to give their head a firm scratching. It’s not much force.
Hmmm, it was time for dissection.
The slide switch was easy to remove, thus exposing the button and lock mechanism.
Slide switch revealed.
The lock tab is minimal.
Every WUV certified testing facility has a set of feeler gauges to go with their ANSI approved pry bars.
The lock tab protrudes about 0.6 millimetres, determined using my feeler gauges. That makes sense, as we previously determined a press of about 0.5 mm releases the slider switch.
So, in my opinion the lock button and associated tab might be somewhat sensitive to inadvertent presses. It’s not hard to imagine how this might happen in the event of an avalanche ride. But does the holster-harness help prevent that? My take is a big NO for the harness pictured here. An improved harness might be better, but in my opinion the potential for accidental button presses exceeds any solution I can envision other than duct taping the slide switch into the transmit position. Put another way, the button is perhaps a design problem.
While Pieps documentation recommends placing the beacon in the holster face-in towards body — “In order to protect the beacon’s display, carry the beacon with its display facing inwards…” — it is all too easy to place it face out, in fact doing so to me seems in some ways more logical, as it’s easy to see if it’s transmitting. But while the Pieps manual doesn’t mention it, carrying the DSP Sport face-out is probably the worst thing you can do in terms of preventing inadvertent movement of the lock and thus the slider. Check it out:
I took a few moments to cobble this little contraption. It uses a water-weight (easily adjusted) to apply pressure over the switch button in the case of the beacon facing out, while in the holster. (The steel bar and hinge may look a little complex, but their only purpose is to stabilize the weight so it presses on the buckle without tipping over.) The holster buckle is perfectly located to concentrate force on the switch button if the beacon is facing out.
It took 1,798 grams of weight on the buckle to overcome any resistance of the case and depress the lock. Also with the unit in the case, sliding the switch required 1,440 grams of force-weight (and that force was noticeably reduced when I lubricated the slider with a spritz of water). Again, not much pressure considering we’re talking about a device designed for use by an avalanche victim doing things such as hitting trees at sixty miles per hour, not to mention being buried under thousands of pounds of snow.
Beacon facing out, in transmit mode. The lock is located under a pressure point created by the buckle. More, the sliding switch is exposed to possible pressure from gear or clothing, or even the constant movement of the holster could gradually move the slider switch to the off position. Could this be a recipe for disaster? In my opinion that could be so.
What if the DSP is placed in the holster face-in (LCD towards body), as Pieps recommends? I couldn’t figure out a way to measure the button pressing force in this configuration, but by simply squeezing with my fingers I could depress the lock button and thus free the switch for possible accidental switching out of transmit mode. Again, the switch moved under about 1,440 grams of force-weight, well within what could happen if gear or rucked clothing were pressed against it during an avalanche ride and subsequent burial.
So, how about carrying the DSP Sport in a clothing pocket? Judging from the protrusion of the lock button and ease of pressing it, as well as the ease of moving the slider, I wouldn’t be totally confident of a pocket carry either.
CONCLUSIONS
When I originally tested the DSP Sport several years ago, when hand manipulated in my office the slide switch and lock strongly resisted defeat — same with the test unit used for this blog post. BUT with more attention to simulating real-world use, I find the slightly protruding lock tab, and consequently the exposed slider switch may be too easily defeated by possible vagaries of clothing or terrain pressing against it during an avalanche incident, or even during hour-to-hour use in the field.
Moreover, the locking button reportedly may crack, thus rendering it weak or entirely ineffective. I cold soaked our test unit to negative 3 degrees Fahrenheit and depressed the lock button 300 times, with no cracking. But, I did notice our test unit had previously cracked near the battery door screw, and the transmit indicator light. These cracks were present when I received the unit, they could have been from it being dropped or otherwise impacted, they’re worth noting.
Our previously used test unit had these cracks when we received it.
Is it locked in send-transmit, or is it not? In this case, it is not! This is due to the magnetic switches having a broad range of operative distance. Could this happen in the field? Who knows for sure, but while experimenting I got the nice elongated beep and the LCD display showing me the unit was in “SEND” mode, only this happened before the lock clicked in!
(Interestingly, I can place a magnet next to the switch, with switch in “off” position, and turn the DPS on. Thankfully (documenting all this weirdness is getting tedious), once the slider switch is moved to the “send” position, the magnet has no influence. My test magnet is powerful. I tried the same thing with my laptop and wall audio speakers, and nothing happened.
I’m not sure this is CE certified, but it works.
If you continue to use the DSP Sport, be sure to place it rear facing in the holster, and if it was me I’d duct tape the switch in the transmit position. If carrying in a pant or jacket pocket sans holster, again face it in, and again apply duct tape. Pieps is said to have redesigned the harness and holster, but from what I gather in my ‘net research, the pouch design shown in this post is ubiquitous — and if the DSP is carried in a pocket, there are still possible issues.
The newer models of this beacon, the Recon/Powder-BT, have a redesigned switch lock, perhaps for good reason. Thankfully, Pieps and Black Diamond (BD owns Pieps) have stepped up and will help save your duct tape, and perhaps your bacon? They’re offering some kind of upgrade, more about that here.
Lastly, to be fair, I have found that funky switches are endemic to the avalanche beacon industry. I’ve got my opinions on why this is, but won’t pile on any more words. Comments on!
40 comments
Hmmm, I’ve owned and tested dozens of beacons since my Echo 1. I don’t recall ever being mandated to face the beacon inwards in the holster to stay alive–that is pure stupidity. Most modern units seemed good to go for pocket carry but that was a bad idea for Ramers and IIRC there was a bad batch of the early Trackers.
Pieps/BD, Mammut, and Tracker all instruct the user to wear the transceiver with the display facing towards the body. It makes sense in that is the most fragile part of the beacon. Page 23: https://static.mammut.com/file/2710-00140_man_en_3-4_Barryvox_S_Extended_Reference_Guide.pdf Page 16: https://k2sports.a.bigcontent.io/v1/static/2020_Tracker_Manual_T4_T3_T-S_Final_091220%5B6461%5D
Indeed they do Mark, and I refer to the DSP manual in the blog post above. But in the case of the DSP Sport we tested, we could defeat the lock with the beacon facing in towards the torso, and at least one of our commentators found the same thing to be true. Moreover, it’s easy when you’re cold and tired to make the simple move of holstering the beacon face-out instead of face-in. I think conventional wisdom holds that either way the beacon faces, the lock button should not be prone to defeat. Lou
Really doesn’t matter what they print in their 5-language lawyer manuals. If the design permits it to be used in a dangerous manner, it’s a defective product. It’s equivalent to a gun that can fire when dropped with the safety engaged…looks safe but isn’t. Gun companies are totally liable for design defects, despite what many think.
But you make a good argument for why most avy transceivers should not have fragile screens. An unnecessary “feature” that adds cost, decreases safety, and does not really improve survival odds for victims.
The Mammut harness is designed so that the beacon must face inward.
While Instructors like to have an opionon on this and something to talk about, this concept was more of a discussion back in the Barryvox Opto3000/Orto Digital Patroller/Arva Evo days when the screen were more fragile, and companies would not offer any sort of repair for impact. There are still a few base models that have these older simple LCD screens. The other side of the coin when screen is in, is your batteries are out (and theoretically could be colder); so batteries in or out could also be a conversation. The newer designs like the Arva Neo or Evo5, Barryvox and Barryvox S have a protection layer over the LCD display so even if you smash with a hammer it acts like a windshield and you can still see the display just through a crack, a much better concept.
Hi Clyde, I always appreciate you stopping by. What do you think some of the better beacons were over the years? Lou
Interesting read. I have this beacon and I strapped it up recently with typical layer to test all of this out. I could not get mine to move with the screen facing out despite trying to push the lock directly through the case and pressing on the switch. With the screen facing in (towards the body) I could cause it to fail quite easily as you describe every time. I hope to upgrade to avoid any issues outside of course.
Perhaps it’s those protruding ribs, they push on the button (smile). Seriously, that’s really interesting you got it to fail with screen towards body!! Thanks for sharing. Yeah, if you could invoke that kind of behavior, sounds like an upgrade is mandatory. Or, duct tape? Lou
I’m curious if any other beacons have been tested for this issue. I can think of several beacons that could potentially move out of transmit.
Two things. 1) Have a buddy whose Sport button cracked and the slide could slide up and down. BD replaced. 2) These make a sound when turned on. Would be a nice and simple safety feature to also make a sound when either turned off or just out of send mode.
Scott, for starters here’s where you can access our beacon reviews, going back many years. https://www.wildsnow.com/category/avalanche-beacon-review/
And here’s one of the reviews that specifically addresses a switch issue.
https://www.wildsnow.com/25940/arva-evo5-avalanche-beacon-review/
I recall stating that we were going to pay more attention to beacon switch issues. We’ll continue with that whenever possible. Like I said in the review above, my opinion is that funky switches are endemic, if for no other reason than most moving from search back to transmit with nary a nudge, and thus causing confusion during searches.
I couldn’t stay away, did some take-apart and added a few photos.
We reached “peak tech” over 15 years ago. Since then, it’s just whizbang features and marketing hype to sell new beacons. Multi-burials, LCD screens, flagging, firmware upgrades, blah, blah, blah. I’ve read the reports, tried a lot of them and find the technology offers no real-world advantage. Just give me long range, simple interface, great battery life, durability…and a switch that doesn’t turn off by itself.
Beacons shouldn’t cost more than $250. Two or three decades ago, the argument for higher cost was valid. But these days, the high volume of sales and low manufacturing costs make $300+ beacons absurd.
Mammut is the only way to go in 2020-2021. But doesn’t the problem remain the same? People are crushing and abusing the Pieps button and yes that’s design problem. Fact is the problem remains the same in that the individual approach to learning and seriousness of the overall problem set remains weak. Granted many smart people out in the mountains and many smart people still acting like sheep or lance corporals breaking gear cause its not private proof.
Maybe. Pricey, plus it looks like an uncomfortable boxy brick to strap on and carry.
I really really liked the ergonomic rounded and bowed shaped of the original Backcountry Access Tracker 0 DTS Beacon and the simplicity of the cold proof and easy to always see LEDs. Wished that they could just keep shrinking that same shape. Also the turn knob switch on that seemed almost impossible to change accidentally. Without reading any manuals, you could pick it up and immediately see how to use it.
Very interesting, I love seeing a practical test with real data rather than conjecture. I was disappointed in BD’s VP of quality’s statement in the skimag.com article regarding standards and recall. He said (paraphrasing) that for a recall the product must pose a hazard compared to the state of the art, that most other manufacturers use a similar lock, and this lock is no more easily interfered with than others. BS. I’m currently using the Barryvox S and previously the Barryvox element. Both have send to search locks that are secure to the point of being difficult to unlock with gloves on. I can’t even imagine a scenario where either one moves spontaneously. From other examples I’ve seen in the last few days the DSP sport lock is much more easily defeated than even other BD/Pieps models. Like I said, disappointing.
My DSP Pro with the beacon facing inward toward the body, I was able to switch from send to search while exerting pretty light pressure on the outside of the case. And not in the specific spot right above the button, but with four fingers simulating ribs pressing on the case. I like that beacon. I was hoping it wouldn’t switch. Yet it did. I took it to the BD store here in Salt Lake on Wednesday and they sent me an email today (Sunday) stating they are going to replace it with a new version. Honestly, cutting a hole in the case for that button would probably solve the issue since the case material will not be able to press the button and unlock the switch. But you know… Lawsuits…
Hi all, I did a bit of editing to strengthen my recommendation about duct taping the slide switch in the transmit position. As Clyde mentioned, and I agree, considering the cost of these things compared to for example a $35 dual band two-way radio transceiver, one would expect the on/off switch to be a bit less problematic. Sigh. In the end, as I mentioned some time ago in my Mammut beacon review, we’ll be less forgiving about these switches. If I fall short on that, please remind me.
Also, I cold soaked the beacon to negative 3 degrees Fahrenheit and depressed the lock button 300 times, to test for the cracking that’s been reported. The lock button remained intact.
Lou
I finally got around to testing mine. If I pressed the button, then the slider, it seemed like it needed quite a bit of pressure on the button to move the slider. So much, in fact, that it doesn’t seem possible that it could accidentally fail like that. If I reversed it, however, and started to pressure the slider down first, and then pressed the button, it took only a small percentage of the pressure required on the button in the opposite scenario to get the slider to move.
Lou any thoughts on the DSP advanced?
https://www.wildsnow.com/1677/pieps-dsp-beacon-review/
I can’t get the same behaviour, but I guess the duct tape solution will work there.
David, nope, we don’t have one to test. It’s not that tough to test yourself, sounds like you did so. And yeah, it’s duct tape but it aint wrong (smile). Lou
Frank, testing this is difficult. It seems that different angles of pressure as well as different sequences of events create different behaviors. To be fair to Pieps, I abstained from being overly aggressive with my testing. But yeah, I can sit here at my desk, fiddle around with the DSP sport and find ways it’ll slip out of transmit/send super easily. “Best” method: as you did, gently press on the slider switch, towards the “off” position, then depress the lock button. Bam, it’ll turn off with hardly any resistance. Again, duct tape is the answer, or a different beacon. Lou
It goes on, and on. In the interest of being thorough, I should mention that the DSP slider switch can be set to transmit/send without moving far enough to lock. In my opinion, that’s a design flaw and pretty astounding for a PPE device that’s so otherwise technically sophisticated. I’ll add a photo illustrating this.
I now know more about my beacon than I ever wanted to!
The problem with the Pieps DSP could probably be fixed with a better case. The older case the whole transceiver was enclosed, with the Sport/Pro case the switch is exposed and not protected. If you are buried in a slide the first thing you hope for is that you have survived, the second is that your transceiver has also survived. Having a hard case would not only protect the switch but also provide a bit more protection in getting smashed if you get strained through some trees,
It will be interesting to see how they deal with this situation. I had a DSP sport that I bought new in Fall of 2017. I cracked my locking mech because I carried that beacon in my pocket. BD warrantied it and I used the holster for the last two seasons. I just filed a warranty claim last night for an upgraded model.
I added a photo showing the DSP seemingly locked in the “SEND” position, but it is not… yet another possible failure mode.
By the way, I alluded to this in the post above, but want to go on record clearly stating that some other brands/models avy beacons have switches I’m not entirely happy with. The Arva Evo5 for example. Again, duct tape might be the solution. Ridiculous but reality. Lou
In all fairness Lou the Evo5 you complained about the tension going from search to send, and it was addressed by the company from the prototype you had to production (the internet works!). I also have no personal issue search to send since it should be in your palm and in front of your eyes. More importantly, and relative to what is going on here, if you think about any sort of accidental mechanical switch being moved from extreme impact, regardless of model or brand. Arva actually wisely addressed this in the Evo5, and Err’d on the side of caution/safety, where you would end up either with your beacon in send (by means of Auto-revert), or remaining turned on and in send (using off confirmation). I know at least one company that wishes there engineers had thought of this a few years ago 🙂 There is no one best beacon design, but its most important have a modern beacon, know its functions, and to be practiced with whatever model you use; and of course have a strong arm for shoveling.. where it really matters.
my last gen barryvox element only fits in the harness one way but I usually put it in my pocket and the switch always works properly SO it is possible to engineer this stuff correctly
Ortovox dealers provide a $75 discount on their 3+ for any turned in brand of beacon. https://www.ortovox.com/us-en/beacon-retirement-program/beacon-exchange-promotion.
I have Ortovox’s and Barryvox’s in the family. The switch on the Barryvox is in a nice deep well and has range that you actually notice in practice. Ortovox has had software recalls that were pretty seamless. My old Ortovox F2s with the headphones still work-not that I use them of course.
I’m relatively new to the world of BC skiing, but seeing the switch design on the BCA Tracker2, I don’t understand why everyone, including BCA are not making all their beacons with a similar design. It seems nearly impossible to have an inadvertent switch from “send” to “search”, and if you were ever caught in a secondary slide, there seems a fair likelihood that the mechanical switch would be jostled back into “send” mode, thereby providing a secondary back-up to the auto-switching in the software/firmware. Am I missing something?
Kevin, This design has been recorded in accidents as delaying search due to accidentally being pushed from “search” to “send” with accidental movement, therefore throwing a search off when folks walk to a searcher or beacon instead of the victim, yes a human error, but none the less there are some better switches out with new models. The idea of “manually” reverting back to send in an accident is something good to practice for, and this is likely why no beacon locks in search mode. The best beacon is the one you know how to use, and I guess you can add doesnt turn off easily.
I had mine go to search just from inserting it in the holster. Thought it was operator error but going for a return and purchase of another brand.
What happened to Lou’s post about the homebrew clip fix for the DSP?
Doh, see the link up above now. I thought I had seen that post on Wild Snow, but maybe I was halucinating.
Tom, your were not hallucinating, the post was here for a short while then moved to my personal website. We were concerned about it being construed as a product we recommended, which it was not, it was a proof of concept that could be 3d printed and tested if someone so desired. More appropriate on a smaller, personal website. https://www.loudawson.com/28583/pieps-dsp-switch-lockout-clip/
I watched the video of Nick McNutt using this beacon inward facing and saw how simple it was to switch modes. It is so easy that I could imagine it happening through clothes in a fall/avalanche. It is sad that we have had so many casualties to this beacon’s issues. It makes me wonder if it could be replicated in pocket with the newer BD/Pieps beacons in the least favorable conditions. If that beacon were to shift to face outward in the pocket, an exceptional situation (stick, pole, ski) could strike and unlock the switch. I understand this is not likely, but perhaps worth considering when in avalanche terrain for owners. I recently talked to my local shop and they have pulled the DSP Sport and Pro from shelves and only sell current generation beacons. I certainly have not heard of issues with the current generation BD/Pieps but I am amble to imagine unfavorable conditions that could replicate a failure of this kind. Has anyone seen or heard of this happening?
“Has anyone seen or heard of this happening?” I think that would be impossible with the newer design. Or at least so unlikely as to be just as equally unlikely as with any other beacon. The new switch might look the same in picture, but the locking feature is not a tab to be depressed. Rather, a force needs to simultaneously move the lock switch in one direction while a totally different force moves the 3-position mode switch in a perpendicular direction. Within the realm of the physically possible, sure, but no more vulnerable to such a freak occurrence than any other switch.