Pulse won't find analog?

This afternoon a friend and I were doing some beacon practice.  He just bought a Tracker 2.  I have a Barryvox Pulse and an Ortovox F1 (the powder blue and yellow fisher price model).  I only use the F1 for practice these days.  On single burial scenarios all transceivers found all types of beacons.  On multiple burials, however, the Pulse would always find the tracker 2 first.  When I hit the " mark" button it would mask the tracker just like it is supposed to, but It would not find the signal of the Ortovox!  All batteries appeared okay.  The Pulse is running software version 3.0. 

I ski with some guys that still use analog transievers, so this is a huge concern for me.  Has anyone else noticed something like this?  I would appreciate any info from someone that is more knowledable about how these things work.   I am thinking I should get my software upgraded, but i don't know if it will help.

Incidently, the Tracker 2 picked up the Pulse and the F1 in a multiple search.  I was under the impression that the Pulse was one of the best beacons on the market.  Mine didn't show it today. 

Perhaps the transmit frequency of the F1 has drifted? This might make the F1 harder to recognize as a beacon. You could conduct other experiments, e.g. switch the Pulse to receive near the transmitting F1 and far from the Tracker2. By varying the distance of the remote Tracker2 you can smoothly go between detecting an isolated F1 and the multiple burial situation.

I had a similar experience while practicing with a Pulse and searching for multiples (another Pulse and 2 Ortovox M2's). It could find one or two, but when I marked it/them and searched for the other, I couldn't pick up a signal from 1 ft away. I lost a lot of confidence in the digital beacons (they seem to get confused so easily). This was a while ago and I eventually accepted that even the best new beacons are not perfect.

More recently, when practicing at a beacon park, I had a similar experience where an Ortovox 3+ only picked up one signal out of three. The Pulse seemed much better in this instance and I was able to pinpoint 3 signals in as little as 2m30s.

I believe that all 457kHz transmissions are an analog signal, so it would be in the digital translation (by the receiving beacon) that the info was lost.

Fortunately I don't rely on beacons to keep me safe (although I always wear one).

"If the snowpack is a problem, terrain is the solution."

On a recent hut trip in Canada, when we did the start-of-trip beacon/probe/shovel practice, the guide wanted to know at the outset if anyone had analog beacons. He was happy that the digital Ortovox M2s that a few of us had were the oldest units in the group. I don't recall exactly what he said, but I thought the gist was that some of the newer beacons would not always find the analog beacons. These guides see a wide range of equipment and mixes of equipment in lots of action so generally know which bindings break in what ways etc. (and this particular guy does training work for the CAA as well so presumably sees and hears about beacons a bit more than most guides).

He also mentioned that having either cell phones or radios near the newer transmitting beacons could screw their signals up as well. Something else to keep in mind (but having the phone in your pack and the beacon on your chest had apparently not caused any problems that he'd yet seen).

As I understand it, newer beacons (2-4 years old) have tighter tolerances for signal drift than older digital beacons, tolerances that are actually within what was the accepted signal difference at time of manufacture for even older analog beacons.

So be very careful with beacons more than 5 years old, and consider refusing beacons more than 10 years old. I keep an extra Tracker 2 in my ski box for just this.

Chris

A few thoughts, in no particular order:

- The "problem" might be not in the transmitting beacon but rather in your testing configuration, which could be more complicated than it would seem . . . for example, try the "Marking/Masking/Flagging Trade-Offs: 5-25/5-20 Walk-the-Line Test" that I describe here: www.wildsnow.com/1609/jonathans-wildsnow-beacon-test-notes/

- For frequency drift, see #7 here: www.wildsnow.com/6031/older-beacon-test-how-to/

- For toleration of frequency drift, nothing has changed, although this varies widely among models.

- For interference with *transmission* I've never seen any tests on that (and my brief experiments haven't shown anything).