Hypno Toad

I've been using the original Varia (RTL500) since roughly 2016, it was getting close to end of life with limited battery life. But the reason I replaced it was that it was dropping connection with my Edge 1040s, and it always chimes when it drops connection and when it reconnects, and that was getting so annoyingly frequent. The thing that has me scratching my head, my other sensors were disconnecting and reconnecting too, like heart rate monitor, power meter, and SRAM eTap. During a training ride, I'd lose my power sensor and my training block power numbers would be impacted, that was getting old fast! Last week I took my March Madness office pool winnings (that was blind luck) to get a new Varia RTL515, and on my first few rides, I'm not seeing any sensors dropping; I've yet to hit the very densely populated areas, like Midtown Greenway in Minneapolis ... that was always the worst place for connection issues, while riding in rural areas was rarely an issue.

The question to any electronic wizards: can one sensor disconnecting/reconnecting cause other sensors to lose connection? This seems like it shouldn't happen, but my experience is making it seem like this was the issue. When my schedule allows, I'll share an update after I ride into the city and test that these high signal areas aren't causing any issues.
Follow up questions, does an ANT+ communications 'chip' (?) degrade with age, I'd guess it does, but I have older sensors, like a speed sensor, that are still working fine.

For reference, my old RTL500 on the left and new RTL515 on the right:

Iride01 

Did you ever update the software on the RTL500? It might just be that newer versions of the software on your GPS device are not able to to maintain the connection properly if the Varia hasn't ever been updated to what ever the last update version was for it.

version 3.40 of the Varia software had ANT+ improvements to it. And there are minor ANT+ fixes in later versions.

Pearson100

I have the newer RTL515 and it often disconnects/reconnects. I haven't been able to find a "pattern" of when this occurs. (I don't have any other senors so can't address your question regarding that issue).

Hypno Toad

Garmin let me know that the old RTL500 is no longer supported. I still checked from time-to-time to see if there was any new updates, but no luck.

PeteHski

Mine occasionally does this too. It only happens momentarily and doesn’t appear to affect other sensor connections. I just get the disconnection warning and then it reconnects straight away.

denis_987

My Varia RVR315 (radar only/no light) does the same ... no apparent reason

Polaris OBark

I have both of these (pictured). My wife rides with the older one now, and I use the newer one. I have noticed, reproducibly, that when we get separated on the road and then she or I catches up to get within range, this kind of disconnection happens. Also, when her Edge 130+ starts up, it often will prompt her to add my radar. In addition, I occasionally will get passed by someone else with a radar, and that often causes a (temporary) disconnection of mine.

Hypno Toad

I've seen major improvements with the new RTL515, but yesterday I had some sensors drop out - HRM for sure - will riding the densely populated Midtown Greenway in Minneapolis. This was a more simple setup, just HRM, Rally pedals, and Varia. It was a very quick dropout, I couldn't find it in the data after the ride; and the Varia never showed disconnected. Still annoying and never saw this with my previous Edge units (510,520, 1030).

SoSmellyAir

My RTL515, which is connected via BlueTooth to the Varia app on my iPhone, randomly disconnects momentarily a few times per ride too, without affecting my Apple watch or my HRM. I guess (from this thread) that this also happens with ANT+ connections to Garmin GPS head units.