Barryvox Pulse - not receiving old beacon signal?

[fern]

 

Has anyone played around and encountered this behaviour?

 

We were working with a brand new out of the box Barryvox Pulse as the search beacon, with 2 old Ortovox F1s and an older model Barryvox as the multiple burial units.

 

In digital search mode the Pulse showed zero indication of even receiving one of the F1 units. Even standing right on top of the F1.

 

Checking all other permutations of the other units as search beacon we could find that F1 just fine, and with the Pulse switched to analog mode we could detect it too. So the only problem was with the Barryvox Pulse in standard digital mode.

 

I am speculating that the F1 has drifted a little bit off of the 457kHz frequency, and that the Pulse is set to discriminate the frequency too tightly?

 

It is a bit creepy though, both in terms of feeling like this new beacon is unreliable, as well as worry for my friend who regularily skis with that F1.

[tomtom]

Sounds like the old beacons are unreliable.

[fern]

I disagree. The old beacon could be received by the older beacons which range in age from about 6yr to 3yrs old, and could itself receive all the beacons old and new. It was the newest beacon in the newest mode that failed to find all the signals. The lack of reliability is in the new technology.

[alps]

I've read about that issue some time ago - not regarding the Barryvox Pulse but some other of the new-generation beacons. I think in this case the beacon whose signal couldn't be received also was an old Ortovox beacon. As you guessed, it seems like those have too large of a spread in frequency to make sure that they always are inside the tight tolerance band of some new models.

[mkporwit]

Fern, you might find this helpful:

http://www.wildsnow.com/1677/pieps-dsp-beacon-review/

 

Specifically, look at the comments by Jonathan Shefftz

[Hugh Conway]

I disagree. The old beacon could be received by the older beacons which range in age from about 6yr to 3yrs old, and could itself receive all the beacons old and new. It was the newest beacon in the newest mode that failed to find all the signals. The lack of reliability is in the new technology.

 

If the old beacon isn't transmitting in the standard frequency range anymore isn't the problem the old beacon's frequency drift?

 

You can google "beacon frequency drift" and get reams of useless bullshit (like linked above)

[tomtom]

How much more drift will you accept in a reliable beacon?

[OlympicMtnBoy]

On my last avy course the instructors recommended retiring beacons that old. If it's drifted out of the (likely narrower) digital tolerance of the newer beacons, who knows how long you have till it drifts far enough to also not be picked up by other older beacons? Better safe than sorry. When in doubt, throw it out, just like much of the other things we use for safety while climbing.

 

Or feel free to continue to bash on changes in the modern world . . . ;-)

[Hugh Conway]

On my last avy course the instructors recommended retiring beacons that old. If it's drifted out of the (likely narrower) digital tolerance of the newer beacons, who knows how long you have till it drifts far enough to also not be picked up by other older beacons? Better safe than sorry. When in doubt, throw it out, just like much of the other things we use for safety while climbing.

 

You should be able to get your beacon inspected and serviced by the manfacturer/importer for much less than replacement if you aren't into mandatory gear whoring.

[snoboy]

I have not encountered this either in person or reading. I would suspect frequency drift in the F1. Do they show up as OK if you do a group check with the Pulse? There are standards for send and receive, and I would be suprised if a new Pulse would be out of spec.

 

One issue that I am aware of with the F1 vs Pulses or other marking beacons (S1, DSP) is that the continous carrier transmission of the F1 (and perhaps other analog beacons) can cause ghosting or slow down discrimination of the number of burials. How long did you give it to "find" the other signal?

[snoboy]

I guess in one sense this is a known problem:

 

http://www.backcountryaccess.com/english/research/documents/FreqDrift.pdf

 

 

[nhluhr]

This is why you do beacon check at the trailhead. Sounds to me like you have identified a beacon with drift. Why would you continue to use it just because it can still be picked up by other old beacons?