T3 Base shut off in the heat?

[avoidthelloyd]

My guys told me the base went down and wouldn't turn on and it was too hot to handle. Once they got it back to the office and plugged it in the lights came on. Battery indicator light is green. Anyone else experience this? I've had it get too hot to hold before, but never shut itself off.

 

[Nate The Surveyor]

Is the base broadcasting, through internal UHF?

 

[avoidthelloyd]

Is the base broadcasting, through internal UHF?

Not that time. External radio and cellular.

 

[John Rosco]

My guys told me the base went down and wouldn't turn on and it was too hot to handle. Once they got it back to the office and plugged it in the lights came on. Battery indicator light is green. Anyone else experience this? I've had it get too hot to hold before, but never shut itself off.

The Li-Ion internal battery pack has a protection circuit that will turn-off the unit when the internal temperature exceeds+60° C

 

[Nate The Surveyor]

John, what do you think about a coraplast cover, to block solar radiation? Coraplast is often used to make political signs. It is essentially Corrugated Plastic made like a cardboard box. Made into an A frame, with 2 layers on the bottom, and a hole on the bottom, where it mounts to the tripod. This would give it open ends, to vent it. And, if place in an EW orientation, it could block sun.
I can draw a pic later, if need be.
Nate

 

[Harold Dendy]

My T3 shuts off in this high August heat in Northeast Mississippi. When it is too hot for it to work, it is too hot for me to work!

 

[John Rosco]

John, what do you think about a coraplast cover, to block solar radiation? Coraplast is often used to make political signs. It is essentially Corrugated Plastic made like a cardboard box. Made into an A frame, with 2 layers on the bottom, and a hole on the bottom, where it mounts to the tripod. This would give it open ends, to vent it. And, if place in an EW orientation, it could block sun.
I can draw a pic later, if need be.
Nate

Sounds like a good solution and is low-cost and inexpensive

 

[Michael]

Looking at this design and using Nate's coraplast, do the signals go through the coraplast with no distortion to the signal to the T3?

 

[John Rosco]

Looking at this design and using Nate's coraplast, do the signals go through the coraplast with no distortion to the signal to the T3?

"Coraplast' is corrugated plastic sheet material. The corrugation provides 'stiffness' and 'strength'. It is also waterproof.
The thin plastic does not block radio signals.
For a T-3 UHF (& cellular) antenna, one can add 'a hole at the top' to allow the antenna to pass to the outside, since the antenna is ~7in (~180mm) long . . .

 

[Michael]

Thanks John. Since the plastic would be over the top of the GNSS antenna it wouldn't block those signals?

 

[Jim Frame]

For RTK use I wouldn't think that Coraplast would have a significant effect. But I note that NGS publishes different antenna parameters for various antenna/radome combinations, so "does not block" isn't necessarily the same as "does not alter."

 

[John Rosco]

For RTK use I wouldn't think that Coraplast would have a significant effect. But I note that NGS publishes different antenna parameters for various antenna/radome combinations, so "does not block" isn't necessarily the same as "does not alter."

Hi Jim,
The NGS antenna parameters only deal with the GNSS 'signal' Antenna Phase Center (APC) offset from the Antenna Reference Point (ARP).
Each GNSS antenna has a unique value.
Essentially the APC/ARP offset is the Measurement Point Height (MPH) that needs to be applied to the 'pole height offset' to the measurement point (on the ground).

See https://support.javad.com/index.php...m-calling-all-thinkers.5995/page-2#post-54816

 

[Jim Frame]

Essentially the APC/ARP offset is the Measurement Point Height (MPH) that needs to be applied to the 'pole height offset' to the measurement point (on the ground).

That's a simplified explanation. In fact, there are average offsets in North and East as well as Up, which is the reason antenna orientation matters. And the antinfo files also model the APC position based on the azimuth and elevation angle of the signal, for use with software that's designed to apply them.

More to the point, adding a plastic radome (homemade or otherwise) will change those offsets. Using the Javad GrAnt-G3 as an example, adding the JVGR radome shifts the N, E and Up position of the APC by a little less than a millimeter. Not enough to matter for RTK, but without testing we don't know if the Coraplast signal characteristics are of the same magnitude as those of the JVGR radome. Could be better, could be worse, could be the same.

Caveat emptor.

 

[Nate The Surveyor]

I'm not having any issues with heat, in Arkansas. But, I can see that possibly some users are getting theirs HOTTER than I do. Arizona, yes, where some temps are 110° plus, on a hot day.
If it were having this problem, I'd TRY the coraplast. My guess is that it may modify the signals, but probably not enough to hurt me.
If any of you try it, let me know how it goes.
Some of the design work on these happened in Russia. (several yrs ago). It does not get this hot in Russia, I don't think.
Thanks
Nate

 

[John Rosco]

All JAVAD 'designs' originate from the USA . . .
The 'heat issue' is a function of the internal electronic components (-40° C to +60° C).
The 'safety' on the Li-ION battery is a requirement for battery packs.

 

[Felix Wolter]

Is this problem / setting new to the T-3 generation of bases?

I was running my T-2 in pretty hot (40°+ in the shade) environments in direct sunlight in Iraq and Jordan. The covers colour suffered over the years, but it never shut down, even if it became super-hot. I have the overheat protection settinng active in the LS.

Thanky,
Felix