Topic: WMR200 repeater?

[jhoff]

Hi,

I just replaced an old OS WMR968 with a WMR200 and with the 968, I had to use a repeater (RT918) for one of the sensors.  OS doesn't sell a similar product for the WMR200 (433mhz v3 protocol).  Does anyone know of a solution?

Thanks!
Jerry

[aweatherguy]

Depends on sensor placement. What is the distance between sensor and receiver? How many building walls in between and of what type construction? Other than walls is it line of sight between sensor and receiver?

There are various mods to the WMR200 antenna presented in this forum; I've had very good results with that but it will obviously void the warranty on your brand new WMR200 so you might not want to go there. I've not heard of a repeater for the version 3.0 sensors.

[jhoff]

It's about 75 feet.  The WMR200 is inside my house, in our "office" so it can be connected to my computer.  The sensor is outside the house in a greenhouse that is a metal frame and double-wall poly-carbonate.  Between the two is one inside wall, one outside wall, some cabinets and it may slant down thru a hot tub and a deck.  It's a bit hard to tell...  I moved it from the center of the room (where there was a metal filing cabinet in between and maybe a dryer) to on top of the metal cabinet and that helped but it still looses connection occasionally.  Seems like I need to get a longer USB cable and figure out the optimal placement for it. 

The slots on the back to hang it on the wall aren't great but that seems like what will work the best.

Sad that there's not just a repeater - the RT918 worked reliably for me with the WMR968.

I'm curious about the antenna mods?  Do you have links?  Also, seems like I could also put a corner reflector behind the sensor?  Any plans / diagrams folks have made for that?

Thanks,
Jerry

[jhoff]

Here's the site:
https://www.google.com/maps/@47.5469071,-122.3650954,41m/data=!3m1!1e3

The house is 2 stories plus a basement.  The sensor is on the east wall of the greenhouse, approx in the middle.  The WMR200 is on the middle floor, approx at the centerline of the house maybe 5' from the north wall.  The back yard slopes down such that the greenhouse floor is probably about 30 feet below the floor of the room where the WMR200 is.  And the greenhouse is about 15 feet wide for scale.  So it's more than 75 feet really because it's about 75 feet horizontally and maybe 30-40 feet down.  Which if I did my math right makes it more like 83 feet?  I think the walls and other stuff in between is the bigger issue tho.

[aweatherguy]

It sounds like the sensor is probably line of sight especially since you do get reception at least part of the time. I suspect an antenna mod would help but that's no guarantee and you'll need to decide for yourself if you want to void the warranty.

Try searching this forum for "WMR200 antenna mod" and you will find several hits. They vary from modifications of the existing antenna to installing a connector so you can attach an external antenna.

BTW, here's a nice external antenna made by Linx Technologies: part number ANT-433-MHW-SMA-L

It has a 15-foot cable and might allow you to place the anttena for a better line-of-sight to the sensor. It may be available from Digikey or Mouser and other vendors as well.

You could certainly try a corner reflector first since it would not require modification of the WMR200. I don't know if that would be aesthetically acceptable, but maybe worth a try. Some aluminum foil of the appropriate dimensions (maybe taped onto a piece of cardboard folded at 90 degrees in the middle) would work for experimentation. One of the problems with all this is the WMR200 does not give a signal strength reading -- so if things get better you don't know if it was just barely or a lot.

[jhoff]

Thanks much for the response and the PM which I responded to.  I currently have the WMR200 mounted up high on a wall to minimize what's between it and the furthest sensor and it seems to be working.  Cabling isn't ideal for it tho - I've ordered a longer USB cable...

Thanks again,
Jerry