My new VP 2 is reporting
Total packets received 5505
Total packets missed 439
Number of resynchronizations 1
The largest number of packets in a row that were received 51
and the number of CRC errors detected. 433
The current reception 93%
SIgnal Strength is around 30
Total packets received 5505 - console got these OK
Total packets missed 439 - econsole xpected these too, but didn’t get them, they are lost in space somewhere
Number of resynchronizations 1 - got confused once and had to start over
The largest number of packets in a row that were received 51 - longest string of packets received before missing one.
The number of CRC errors detected. 433 - CRC is a checksum system, a calculated number included with the data that allows the console to determine if the data has been received correctly, if not the packet is rejected. You had 433 packets rejected for this reason.
The current reception 93%
SIgnal Strength is around 30
This is good. Anything over 90% is really good. Many VP users find the reception percentage fluctuates with atmospheric conditions, local interference etc. The VP can stand a lot of missed packets and still give good data.
I’d be very surprised if atmospheric conditions could affect radio signals over distances of less than 100m. The only thing I can think of that might have an effect is a nearby aurora. I doubt if high pressure radio ‘lift’ conditions would bring in strong enough signals on the same frequency from many miles away to cause serious interference from such a local signal.
Incidentally, I always thought ISS was the International Space Station!
:lol: I was going to say “weather” but thought that would be confusing. Based on postings on various forums it appears that cold and especially wet weather does negatively impact the reception. I thought the atmosphere came all the way down to the ground - no?
It does! However the atmospheric conditions that can affect radio signals are really macro effects, i.e. they affect signals over 10-1000’s of miles, not 100m. I’m can’t think of anything related to the cold that would affect signals…unless the transmitter circuitry is susceptible to the cold!
Wet weather could affect signals slightly…there would probably be a little extra attenuation of the signal if the transmitter and receiver were on opposite sides of a very dense wet bush/tree…less so in winter when the leaves fall off many trees. Satellite TV signals (coming 24000km) can be affected by large wet trees or even very heavy rain, but those signals are likely to be a lot weaker than the signal from a weather station. WX station signals aren’t that weak, compared to SatTV…my rain gauge signal is received without a problem through three walls and one floor on a simple vertical antenna at each end, yet a SatTV signal needs a dish, plus a low noise receiver at the dish feed point and is still affected by heavy rain/wet trees.
A lot of VP type 1 owners would argue with that statement (where’s Aardvark when you need him) The new VP has redesigned wireless system and should be a lot better.
I don’t know what it is, maybe the moisture on surfaces that the VP signal has to penetrate, but there does seem to be a correlation between rain and poor reception, at least in my experience.
Hmmm…rain tends to come from clouds, which tend to hide the sun. Perhaps the transmitter power is lower when the solar cell isn’t providing any voltage to charge the battery?
That’s a possibility, but then it would be lower every night too, have to look at that. In the old version the electronics actually run off a supercap that’s charged by the solar cell when sunny or a 3v lithium battery when not. There is a very short burst of pulses transmitted every 2.5 seconds so the duty cycle is very low.
If the cause of poor reception is rain or wind or aliens or 11cm Hams, then you must suffer an awful lot from whichever one causes the problem to get a reception graph like you have for last year. If the cause of the problem is rain, then you must have had rain 50% of the time for the first 6 months of last year. Now it may rain a lot where you are, but I doubt if it rains that much. Same goes for wind, aliens and 11cm hams.
Wind…I’m not sure how wind or wind direction could ever ‘bounce an electromagnetic signal around’ unless it’s blowing the antennaa, but that’s a physical thing rather than affecting the signal itself. I don’t know what shape/size the antenna is on the VP, but I’d suspect it’s pretty small and therefore unlikely to be bent/affected much by the wind (assuming it’s exposed in the first place).
Humidity and rain…I would be very surprised if humidity or rain could cause significant loss of signal over the distance of less than 100m. I can’t quickly find any sources about rain attenuation of radio signals at 900MHz, especially over such short distances (path loss software usually talks in miles/kms). However, up to 300MHz rain doesn’t cause attenuation problems. From 3000-30000MHz rain can be a problem over radio paths longer than 10km. In this case we’re talking about a 900MHz signal over a path of less than 100m, so it’s highly unlikely that rain/humidity affecting the signal itself can be the cause of the problem. That’s not to say that the transmitter circuitry doesn’t work well when cold and damp. It should be easy to discount rain/humidity (and indeed wind/wind direction). You’re running a weather station, so correlate the days when you have poor reception with the weather conditions on those days. Find a statistically significant effect and you might be on to something.
Standing in the way of the signal would attenuate it to an extent. At 900MHz signals are predominantly line of sight. So if you put something extra in the way you will increase the lpath loss. I’m surprised that a human bosy can have such an effect when the link is presumably supposed to get through a solid wall or three…unless the path loss is already so great that any tiny extra loss pushes it over the edge.
11cm hams…this one makes me wonder about the receiver. The VP transmitters work at approx 900MHz. The 11cm band is approx 2.4GHz (2400MHz). In radio terms those frequencies are a long way apart. A decent receiver should easily be able to avoid co-channel interference that is approx 2.5 times the receive frequency. The only thing I can think of which might spoil this idea is that perhaps to get a signal on 2.4GHz hams might be using a frequency mixer involving 900MHz inputs. If they are then this is a simple interference problem (although not necessarily simple to fix). I don’t know what frequencies your mobiles work at in the US, but in the UK there’s a lot of power floating around in the 900MHz region from phones. If the receiver is a little ‘wide’, i.e. it accepts too wide a range of frequencies, you might find that phone (and maybe 11cm hams) might well affect it. Perhaps you have a local phone mast or fanatical phone users in your area. If phones are the culprit their usage patterns are also more likely to match your excessive receiver problems.
Finally, I don’t really know what is causing your problems. I sounds more like interference than atmospheric to me. I assume that VPs must work OK for some people. Can you find anything by looking at where people are who have problems? Do rural users tend to have fewer problems than townies?
I’m not sure about the 11cm* ham thing, that sounds unlikely to me. I’m trying desperately to recall the supplier of the RF chips (actually hybrids in hermetic package) but as I do recall the RX is something like a wideband TRF with a ceramic filter in front of it.
*update: maybe this should have referred to the 33cm band?
I do have one in a rural area, at least 200 yards to the nearest neighbor, and see reception fluctuations, probably worse than the other one that’s in a residential neighborhood. I did test the system with both TX and RX just in an open field, no trees or anything and couldn’t get reliable communication at 100 feet, which should be well within the range if you believe Davis.
The TX antenna is a downward pointing vertical, it’s a big question whether it’s resonant or not, but if it’s a quarter wave then I think that means it’s firing down into the ground at a 45 degree angle ??
The VP2 has a completely different wireless system, designed to overcome the issues with the original version, so don’t take any of the above as arguing against the VP2.
If wire isn’t inconvenient, and you don’t want extra sensors beyond what come with the station (you can add solar and UV but not extra temp or soil temp/moisture) then go wired.
If you want the convenience of no wiring, and/or want to add the extra sensors then go wireless and expect to spend a little time finding the “sweet spot” for the units.
Rain definitely can cause signal degradation in the 850-900MHz band. Most wireless VP1 owners who are using 40-50m range and who monitor reception carefully will have seen significant reception drops in heavy rain with the only credible cause being signal attenuation by the liquid water of rain. (Though this isn’t anything material to worry about in terms of accuracy because of packet redundancy) And anything in the signal path that gets coated with a
How can I determine which firmware my VP2 is using? I think I just updated it with the latest… but want to be sure the labels on the updater weren’t lying to me before I send it back!
Actually it is the International association of Slippery Snakes…
One other factor that can cause a low reception is sitting by the station in a similar setup like I have, me being a single blocker by my shape ( humans have that issue as well)http://home.mchsi.com/~vppictures/newdeskshot2.jpg Figured that my best reception was when I wasn’t at my desk.
Other factors are huge and a google or other search can enlighten one. Such as the number of additional sensors on the system. For example take the loaded unit with fan and solar/uv count as one. but add a wireless anenometer, soil temperature station, additional temperature station, then the console waits for the next item to send and the percent reception ( which is related to the number of wind packets received, even if no wind) drops.
I have another console in the kitchen and it gets no less than 92% from the ISS and 94% from the basement sensor by the mead supply… By the computer that is 89% and 86% from the basement. I also have that sensor only listening for two units. And it is furthest from the ISS, plus a refrig and more barriers such as walls, dog and assorted crap.
Look at it this way… if you are getting data consistently and no dashed out lines or missing data, you are going to be fine. Now to find the Slippery Snakes International… :roll:
That’s what mine read when I finished. The download from Davis was dated Nov 2005, so I assume it’s the latest. Didn’t have the forethought to check before the update.
Even if it isn’t we can now download a up date w/o an Updater.