Ambient 7 Day Forecaster

Please post the FCC ID number from the serial number sticker and I'll see what I can find out about the receiver section. I couldn't find anything on the device due to the lack of a model number and FCC-ID number:

If it updates slowly, my guess(tm) is that your unit is experiencing a high data error rate. There's probably an ECC (error correcting code) involved somewhere, that takes a few duplicate transmissions to decode and correct the data.

Hmmm... is suppose to produce a coverage map for the weather service. Instead, it produces a text page suggesting you call Ambient Support.

For troubleshooting, see: Check the signal strength indicator in the upper right corner of the screen. Zero or 1 bar isn't good enough.

review/

No model or FCC ID number anywhere on this thing (it's Chinese). Either on the outside, it the battery compartment or internally. What appears to be the receiver section has a sticker on it that reads '929.6125'. Taking a wild gues that this is MHz, that puts it in a pager band.

Ambient support is pretty much defunct. Although they do seem to be broadcasting updates.

Yeah. One bar most of the time. Although I did try an interesting experiment. I took the thing with me in my car and drove to the neighborhood grocery store. One bar pretty much everywhere except for one location about a block from my house. The signal strength meter pegs in front of one house.

I'm toying with the idea of putting together a spectrum analyzer app for my SDR dongle and sniffing around for spurious sources around that frequency.

Lovely. So much for FCC type certification. Probably arrived in the US by the back door.

The label is suppose to be plainly visible on the outside of the unit.

Yep, that's a pager frequency. Probably USA Mobility running Flex, not POCSAG: Are you near one of these cities? If so, I might be able to find the location of the local paging transmiters using 929.6125 Mhz.

Yep. Over the years, I've bought quite a bit of weather station related stuff from them.

The weather updates are not coming from Ambient. They're coming from some service that uses the paging frequencies for distribution. Pager users are usually (not always) expected to pay for such added services. My guess(tm) is that data originates from the NOAA "Weather Wire" or EMWIN satellite feed: Probably not EMWIN as it was suppose to roll over and die on December

I suspect the reason it pegs is the house has a 900 MHz wireless headset or telephone in use. The receiver in your 7 day forecaster box is probably fairly crude and might have a rather wide band front end. If you have anything handy that will belch 900 MHz, see if it registers on the bar graph.

That should work. You can also decode the FLEX 3200(?) data: I use my modified Radio Shock scanner and Linux laptop running Mulimon-NG: I have a pile of RTL-SDR dongles that I use mostly for monitoring aircraft ADS-B transmissions:

I'm wondering about the difference in performance between your friends unit and yours. My guess(tm) is that there's something wrong with your receiver section. Open it up and look for a disconnected antenna connection. If you have a service monitor, try tuning the receiver for best performance. Maybe replace the antenna with a length of coax and RF connector so that you can attach an external antenna.

I ran an FCC database search on the 929.0 to 930.0 MHz pager band, centered on Seattle (close enough to my location to cover reasonable transmitter sites). No sites are licensed for exactly 929.6125 MHz. But with a wide bandwidth front end, close enough might work.

There is no actual wire antenna on/in this thing. Basically just a little brass bar soldered to the reciever board (a one turn loop). Next time I go over to visit, I'll bring my unit and see if it loads as fast as theirs.

It is interesting that, when I do get updates, it does a pretty good job, loading a 7 day forcast for 150 cities in the USA. But then it goes brain dead and the forcast data ages out. So it does work in fits and starts (without me having to smack it). When I power it down, the on-screen clock re-acquires the current time within half an hour. The pager company probably broadcasts a time signal for all its customers in a somewhat more reliable manner than the weather data.

On a hopeful note: If the pager company is still maintaining their stuff, I live about a mile from a major hospital and medical complex. Doctors being a major customer for paging services, I seriously doubt that a viable paging company would let their service go to s**t in this area.

I wish I had 900 MHz RF gear to do some testing. Most of my work is down around 60 Hz.

Thanks for the RTL-SDR and Radio Reference links. I'll do some playing with those when I get a chance.

Oops. I forgot to include the URL: Looks like Seattle is (or was) listed as having coverage.

The FCC database is rather difficult to use. I don't want to ruin my evening by trying to find something in there.

This might be of interest. See Pages 7 and 21 Looks like the Univ Washington Medical Center uses 929.6125. I doubt that UWMC is sending weather info on their paging system. It's probably coming from some other provider on the same frequency. Or, the previous provider of weather data sold the frequency to UWMC some time in the past. If I could find the license, I could lookup the history.

More:

Is there a ceramic trimmer capacitor near the brass bar? Something that small for 900 MHz is going to have a rather high Q and require tuning to get it on frequency. I think you'll find the tuning adjustment to be rather critical.

Flex Time is usually sent once per minute and is typically off by as much as 30 seconds. I presume it varies with type of pager and transmitter maintenance. How your weather station handles time signals is unknown.

The hospital might be handling their own paging. See previous mention of UWMC.