Wanted: cheap audio vario

On 2 Sep, 11:57, Martin Gregorie
wrote:
On Tue, 02 Sep 2008 02:04:19 -0700, Ian wrote:

I think the M-nav is a bit more recent than your CAV50. As its an 80mm
instrument, it may be worth grabbing one if you see it.

Thanks. However, I think anything with "nav" in its name would be too
expensive. We're talking Pirat, here...

Ian

On Tue, 02 Sep 2008 05:25:09 -0700, Ian wrote:

On 2 Sep, 11:57, Martin Gregorie
wrote:
On Tue, 02 Sep 2008 02:04:19 -0700, Ian wrote:

I think the M-nav is a bit more recent than your CAV50. As its an 80mm
instrument, it may be worth grabbing one if you see it.

Thanks. However, I think anything with "nav" in its name would be too
expensive. We're talking Pirat, here...

Understood.

I managed to record the wrong name in my notes because I found the
Cambridge website confusing when it came to identifying and naming their
older instruments. Cambridge call the vario we had in the Peg a Mk 4
Vario. I described it correctly, though I had the name wrong. It is just
a simple audio vario with selectable sensitivities and response rates:

http://www.bas.uk.net/docs/Mk4_Vario.zip

Despite the URL this is the link from their site.

I have used an M-nav - our older Discus had one fitted. It worked OK as a
vario, but I never really liked the way it handled other functions. You
had to manually put the final glide distance and wind in on toggle
switches because it had no GPS link, though in fairness it probably
predates GPS. Once the final glide details were entered entered, it
counted distance etc down on dead reckoning. That has also been replaced
with a C3.

I don't know what happened to either instrument though I can try to find
out if you're interested.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Sep 2, 11:31*am, Martin Gregorie
wrote:
.. You
had to manually put the final glide distance and wind in on toggle
switches because it had no GPS link, though in fairness it probably
predates GPS. Once the final glide details were entered entered, it
counted distance etc down on dead reckoning.

Yes, the MNAV was hot stuff long before GPS and when the alternative
was a prayer wheel. I used one in my 19 for years. The MNAV was not
dead reckoning though, it decremented glide distance based on
integrated airspeed, offset by a pilot entered wind estimate. Repeated
fixes allowed the wind estimate to be refined as the glide
progressed. When GPS came available the final glide distance could be
manually set from the GPS rather than taking fixes off the chart which
made things much easier and gave a quicker final glide wind
solution.

Integrated glide computers with GPS and moving maps make flying a
whole different game from those days.

Andy