davis anemometer 6410 vs 7911

[defed]

while looking for a 6410, i stumbled on the 7911.  they look the same, but the pricing is different.  i can't seem to find any detailed info on what the differences are between them.  best i can find is that the 7911 is 'older', but nothing on what 'changed' in the 6410.  does anyone know?

thanks
Dave

[mackbig]

6410 is for Pro and Pro2 stations.  7911 is for Wizard (and Perception???) stations.  I doubt they are compatible, but you could call Davis.  Only $2 diff in list price, so not worth rolling the dice.

Andrew

[defed]

i did notice they were for different stations, but if both have reed sensors for the anemometer, i don't see how they couldn't be interchangeable.  unless the wind direction uses different sensors, or maybe different plugs?

i'm not using it on a station tho.  i've been talking to a guy who uses the 6410 w/ his own software and interfaces it into his PC.  i want to also try to connect it to a bike speedo for readings on site...so instead of cutting the davis plug off to get to the wires, i'm going to try and make a pigtail w/ a phone cable extension.  i figure as long as i can get the right pairs of wires, it should work like they do with the inspeeds.

i also found the 7911 for $10 cheaper, still not alot, but if they were the 'same', i would get the cheaper.

[Bushman]

The 7911 can be had for about 90 bucks.  It should be identical in operation, but you should check the pin outs.  Speaking of which...  http://www.emesystems.com/OL2wind.htm

[graculus]

I believe the only difference is that the 6410 has a 100 ohm resistor added in series with the anemometer reed switch. That difference should make no difference in your application.

[defed]

thanks Bushman...i was at tat sight before, but forgot about it!

sounds reasonable to me, Graculus, thanks.

[defed]

The 7911 can be had for about 90 bucks.

i have found it for under $90, but the same place also has the 6410 for under $100...unfortunately, the places w/ the cheap prices want a lot for shipping...so in the end, most places end up costing me about the same in total.

[johnd]

The main difference between 7911 and 6410 is in the arm shape. The 6410 arm is kicked up more so that the wind cups sit a couple of inches higher and the steeper slope of the arm is a bit less attractive for birds to sit on.

The two are electrically interchangeable.

What you do need to be careful of is that the reed switch design of both 7911 and 6410 changed in - when was it, 2003?? - from vertical to horizontal magnets. (There was also a detail change to how the switch is fitted.) So old and new versions of both 7911 and 6410 don't have interchangeable parts even between anemometers with the same nominal part number, ie wind cups and arms must be matched.

[defed]

think i will try the 7911.  the price difference between it and the 6410 is only $13 at the cheapest place i have found, but the shipping difference is $20!  so i can either get the 6410 shipped for $122, or the 7911 shipped for $89.

[defed]

i got the 7911.  horizontal magnet, the support arm is basically horizontal where as the 6410 seems to be more upright.  pretty much everything you guys mentioned here was right on.

to hook this up to the bike speedo, i didn't want to cut the davis rj11 connector off, so i plugged it into a rj11 coupler and plugged a phone extension into the other side.  i cut the end off the phone ext and the sensor off of the bike speedo, found the correct pair of wires from the phone cable and connected them to the bike speedo.

had a windless day yesterday, so i tried to calibrate the bike speedo w/ the truck speedo.  worked ok, but not sure about the low end accuracy.  seems it was 'right on' at 10mph, 15mph and 20mph....presuming the truck is accurate.

work has a vp2, so i may take it there and try to get it more accurate w/ that.

overall, appears to have worked really well.