Speed of a vario

On Tuesday, August 11, 2020 at 11:45:19 AM UTC-4, krasw wrote:
There is no right or wrong here. I have my inertial variometer tc is set to 1 sec, electrical to 5 sec, and mechanical somewhere between. They have all different settings, because way of measuring signal is profoundly different between instruments.

Interesting. There may be no right or wrong, but what's the best way to use the instruments when you set the three of them differently this way, in your opinion? i.e. how do you get good useful info out of them, so that they don't just add instrument confusion?

On Wednesday, 12 August 2020 at 01:53:16 UTC+3, wrote:
On Tuesday, August 11, 2020 at 11:45:19 AM UTC-4, krasw wrote:
There is no right or wrong here. I have my inertial variometer tc is set to 1 sec, electrical to 5 sec, and mechanical somewhere between. They have all different settings, because way of measuring signal is profoundly different between instruments.
Interesting. There may be no right or wrong, but what's the best way to use the instruments when you set the three of them differently this way, in your opinion? i.e. how do you get good useful info out of them, so that they don't just add instrument confusion?

TC between instruments is set according to their capability to measure reliable variometer data. Inertial variometer does not see the pitot-static errors, thus very fast tc. A good mechanical variometer is almost always best traditional way of showing TE signal, but is affected by gusts, thus couple of sec tc. Electrical variometer can be at best as good as (good) mechanical, but usually not. Mine is set up to show kind of "fast average" of thermal, thus 5 sec tc. I wan't to setup the instruments to complement their strength and hide the weaknesses. No reason to tune them to show identical signal (which is impossible with three different ways of doing things).

Fast vario example: https://youtu.be/XAjwVPRTxQE?t=120

CNv set to "0.5s" for both pointer and audio. Panel is badly underexposed, but you can see the orange needle of the old CNv display on left side. I have the vario set to suppress sink tones (I don't need to be scolded when I'm not climbing).

What the TC refers to in this case is the low pass filter on the back end of the data stream. 0.5s effectively turns the low pass "off". There is plenty of digital filtering in front of this, and imo, it works quite well. I think it is about as fast as is useful for sailplanes. There's a reliable, repeatable sequence of boot in the bum followed a couple tenths of a second later by the audio for real thermals. If the boot is missing, that's a gust. It's very easy to train yourself to detect this difference (a good vario helps).

Not yet released CNv color display at upper right (it's quite visible in real life), should be out soon.

OT: At 2:25 you get a nice look at the Appalachian Trail as it ascends Old Speck Mountain just before plunging into Grafton Notch. We fly this route fairly often... but normally a bit higher :-).

T8