Topic: Freak VP2 transmission distance?

[d_l]

The other day my VP2 station suddenly had a temperature spike jumping from ~19 °F to 25 °F with a concurrent drop in relative humidity from ~69% to 57% all during a five-minute archive interval.  Now I frequently have sudden temperature changes when the wind kicks up or dies down or the sun sets behind the mountains and with a 24-hour FARS, the station will re-equilibrate to the new conditions quite rapidly; however, these changes will still occur over a 10- to 20-minute period.  So I happened to check the ISS reception stats for the station and noticed that the reception had dropped from ~95-100% to ~10-25%.  This transmission is between the station and an Envoy located in my office at a distance of about 80 feet.  I also checked my console at ~50 feet from my VP2 which read only 19 °F and 69% humidity.

At this point I was a bit perplexed as to what was happening.  I then checked the online Weatherlink map, which has previouslyly shown seven other stations within a two mile radius of mine.  I was looking for the sudden appearance of a close by, new station that might be interfering with mine.  One of the seven known stations was reporting 25 °F and 57% exactly as my Envoy was receiving.

I concluded that my Envoy had locked on that station which is over 1.1 miles away and about 250 feet higher elevation than my VP2.  I forced a reset of my Envoy's reception by the standard method of hitting the OK button in the Set Transceiver in Weatherlink without any other changes to the settings.  The Envoy then correctly reacquired my VP2.

As far as I know I've never had any interference at this sort of distance happen before.  I HAD interference from a neighbor's VP2 about a thousand feet away and 60 feet higher when I first set up my VP2 so I've had to set my VP2 to the #2 channel.  I think his higher elevation difference is what caused his transmissions to overpower mine on channel #1.

Has anyone had any similar experiences with interference at extreme distances?  Short of "war driving" by the suspected interfering station with my console in my car to see if it is set to channel #2, I can't think of any other way to check my suspicions.

[brett c]

What you most likely had happen is RF-ducting in the atmosphere. It causes RF propagation to become more level with the earth rather rise with distance. https://en.wikipedia.org/wiki/Atmospheric_duct for the basics, and http://www.radartutorial.eu/07.waves/wa17.en.html for a little more technical aspect of it. During the spring, summer and fall months when the atmosphere is warm/hot you can observe this same phenomenon on weather radars (seeing wind farms hundreds of miles away when you usually don't "see" said wind farm normally).

There's always the option of using an antenna reflector on both transmitter and receiver - both reflectors tightly pointed towards one another. However, doing that on the console antenna risks the chance of it magnifying the distant signals even more.

Unfortunately Davis's hardware doesn't support of hardware auth pairing (much like how blue tooth functions), so you're stuck changing the dip switches on the transmitting site and changing the console settings.

[d_l]

What you most likely had happen is RF-ducting in the atmosphere. It causes RF propagation to become more level with the earth rather rise with distance. https://en.wikipedia.org/wiki/Atmospheric_duct for the basics, and http://www.radartutorial.eu/07.waves/wa17.en.html for a little more technical aspect of it. During the spring, summer and fall months when the atmosphere is warm/hot you can observe this same phenomenon on weather radars (seeing wind farms hundreds of miles away when you usually don't "see" said wind farm normally).

There's always the option of using an antenna reflector on both transmitter and receiver - both reflectors tightly pointed towards one another. However, doing that on the console antenna risks the chance of it magnifying the distant signals even more.

Unfortunately Davis's hardware doesn't support of hardware auth pairing (much like how blue tooth functions), so you're stuck changing the dip switches on the transmitting site and changing the console settings.

Your explanation is probably correct, but it is a fact that the transmission distance from an ISS is improved IF it is much higher (10s of feet or more)  than the console or Envoy.

I've used homemade, parabolic reflectors in the past on WiFi.  They do work, but they have to be aimed correctly.  I think wind gusts on the ISS reflectors might cause a problem with the aiming alignment over time.

On a similar topic, the squirrel cage fan in my furnace lies roughly (but not exactly on the line of sight) between my console and my VP2.  Every winter when the furnace is running, I get infrequent disconnects at the console, but not at the other Envoy which doesn't have the fan in between.  I've attributed these disconnects to radio wave reflections bouncing off the spinning cage fan confusing the console's reception.  I don't want to move the console as it is in the perfect place for viewing the weather, so I live with the occasional disconnects.  I think the disconnects require both the spinning of the fan and certain atmospheric conditions, i.e. humidity, temp, etc.

[EA1EF]

Sould be easy check busy ID numbers in "receiving from" screen... If you can intercalate free ID number better.
Could be low battery that force stop your ISS to silent transmission and switch to receive lower signal far ISS??
High speeds can up power consumption in ISS?
ISS are perfect dry in all PCB CIRCUITS?

[d_l]

Sould be easy check busy ID numbers in "receiving from" screen... If you can intercalate free ID number better.
Could be low battery that force stop your ISS to silent transmission and switch to receive lower signal far ISS??
High speeds can up power consumption in ISS?
ISS are perfect dry in all PCB CIRCUITS?

The Li batteries in the ISS were fine.  Replaced about a month ago.  Note only the signal was switched on an Envoy, but stayed correctly connected on a console.  All circuits were bone dry.  I've attributed it to freak atmospheric conditions to enable long range transmission..