b_weijenberg wrote:Or a http://www.radioshack.com/product/index ... PerPage=60 scanner antenna. This antenna needs a coax cable with PL-259 and SMA-male or BNC connector.

Being new to antenna, am I limited to the length of the coax going to the antenna? Ideally I would like to route this outside to get something like this out of my den, my wife would like that as well. As the coax length increases does the strength decrease?

I would suggest not to exceed a coax length of 10 meters

Well, I tried attaching an external antenna to my RFXtrx433 and the results were very strange. My hardest to reach sensors were detected but others in the home that were detected with the stock whip antenna no longer showed up. As a result I took all parts back and moved my RFXtrx433 closer to my frig which now picks up that sensor as well as the sensor in my workshop, along with all others in the home. I was able to tuck the 30' USB cable under my floor molding so it's barely visible, something I can live with (link to USB cable extension above).

Below is a photo of the Radio Shack Scanner Antenna and connectors that I tested with. I believe the cable length was 20'.

Wonder if you were running into the same gotcha that we used to have in the old CB days where a big ground plane antenna on a tall mast at a base station would cast a radio "shadow" below the plane? I remember one friend with a ranch deliberately cutting his mast down from 60 ft to 20 ft so that he could still talk to his kids and workers walkietalkies when they got within a quarter mile of the house, although he had initially put up the antenna to let him communicate with them out to 2 or 3 miles... and I remember wondering at the time if it might be better to mount the antenna up high and upside down.

Due to only testing the antenna I did not have it mounted high on a pole. I had in on a tripod in my house at about 6ft. You diagnosis would describe what I was seeing otherwise. After moving my FRFtrx433 I'm getting reception that I'm happy with so will likely bail on the antenna for now. Something to revisit in the future if the need arises. If someone has installed an external antenna on their RFXtrx433 and have seen noticeable gains I'd like to see the details of their setup.

AlaskaDave wrote:If someone has installed an external antenna on their RFXtrx433 and have seen noticeable gains I'd like to see the details of their setup.

I finally got mine set up yesterday after work; same hardware as you used, right down to the M to M sma. The only differences, I set my antenna under the desk where the Mac Tower is, straddling the UPS and used a 2 meter coax. I have 7 OSI sensors; 3 Radio Shack Temp only (return air, AC Duct, and freezer), windspeed/direction, Outside temp/humidity, and 2 rain senders (mine and a stopped up one somewhere at the neighbors... I only created a device for it because the RFX complained about unknown sensor if I didn't). My results kind of match yours; using the black stick, signal strengths in order were 5,5,4,6,6,5,5... with 2 or 3 dropouts per day on either the return air and/or freezer (I set up a schedule to check every minute and increment a counter any time the last data from any sensor was more than 5 minutes old). after about 12 hours on the new antenna, the signals are 6,5,6,7,5,5,6. The return air, freezer, wind, and neighbors rain bucket got stronger, my outdoor temperature got weaker, and the AC Duct and my rain gage showed no change, and I have had no dropouts. We'll have to see how many there are when I get home tonight... or over the next week or so.

Well, it's been 3 days and no dropouts longer than 5 minutes... a couple of times, I've seen sensors more than a minute "stale", but with 7 sensors sending blindly, there is a possibility of data collisions trashing a transmission. And on another subject, one thing that the RFX Temp/Humidity plugin is missing is the heat index. I've got an interpolation that matches the NOAA heat index chart to within 2 degrees when fed the temperature in F and the humidity in percent, and I set up a python script to take the T and H variables and load a heat index variable...

Code: Select all

Temp=indigo.variables[558530859]
RH = indigo.variables[745025510]
HI = indigo.variables[112346192]
T=float(Temp.value)
Rf=float(RH.value)
Hf = 0.363445175871445 + 0.98862 * T + 4.77711403490098 * Rf - (0.114037667429542 * T * Rf + 0.00085020778424989 * T * T + 0.02071619773671 * Rf * Rf) + 0.000687677749723988 * T * T * Rf + 0.000274953729220532 * T * Rf * Rf
if (Hf > 145) :
   Hf = 146
if (T < 70 and Hf < 65):
   Hf = T
Hf = round(Hf,1)
if (Hf < 145):
   indigo.variable.updateValue(HI,str(Hf))
else:
   indigo.variable.updateValue(HI,"Fatal")



Anyone have a particular ecommendation for an Oregon Scientific rain sensor?

hamw wrote:Anyone have a particular ecommendation for an Oregon Scientific rain sensor?

Probably donesn't matter; from looking at the specs, it appears that they all use the same sender (likely the PCR800 they advertise as an add on) and just change out the display options (barometric pressure, temperature, atomic clock, etc). Unfortunately, the one spec they DON'T give is the resolution of the bucket... the one that comes with the WMR80 station is a 1 mm (0.04 inch) resolution, while the Davis VantageVue that I'm thinking of retiring in favor of the RFX has a 0.5 mm trip (0.02 in). And yes, I know it's unnecessary geek level precision, but I still like it.

Great suggestion. I called OS and spoke with Gary, whom I believe is in sales. Their phone number is 800-853-8883. Here's the scoop: The PCR800 is their newest. It runs protocol 3.0, and is supported in RFX. It has a range of 300 ft and a resolution of 1mm, as you noted. While currently out of stock as a standalone, he *believes* it may be back in stock in a month, but no guarantees.

The lesser units, such as the RGR, run protocol 2.1, have range of 100 ft and don't have a quoted lower limit of resolution, which probably means it is not as good as the PCR800.

The WMR80A entry level pro weather station does seem to include the PCR800 and also has an anemometer and temp humidity as well, currently on sale for about $100. Might get it, but an anemometer seems like a bit of overkill in a residential neighborhood when there are other Wunderground weather stations nearby.

@johnpolasek, if you want to increase the rain sensor resolution by two you double the rain sensor funnel

b_weijenberg wrote:@johnpolasek, if you want to increase the rain sensor resolution by two you double the rain sensor funnel

True, but I'm too lazy to dig through the plugin and find the calibration factors for it. BTW, thank you for the antenna recommendation; I was getting several 15+ minute dropouts per day on some of the Radio Shack temperature senders using the supplied antenna, but in the 10 days since I set up the ground plane under the computer desk, have had only 5 5 minute dropouts, and no 10 minute losses. And although it belongs in another thread, I'd also like to ask that if you can find the room in the flashrom for more protocols, you look at the Dakota 433 MHz driveway sensors http://www.dakotaalert.com/catb2b1/product_info.php?cPath=47&products_id=123&osCsid=4lrke1vf95npf9d5k4idqhvgn2 ; they've got more range than any of the others we have used, but the EZSnRF Indigo link available for it is a very unstable device...

And although it belongs in another thread, I'd also like to ask that if you can find the room in the flashrom for more protocols, you look at the Dakota 433 MHz driveway sensors http://www.dakotaalert.com/catb2b1/product_info.php?cPath=47&products_id=123&osCsid=4lrke1vf95npf9d5k4idqhvgn2 ; they've got more range than any of the others we have used, but the EZSnRF Indigo link available for it is a very unstable device...

Double thumbs up on the Dakota protocol being included!