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-   -   Antennas in my remote-sensor thermometer (https://www.radiobanter.com/shortwave/117098-antennas-my-remote-sensor-thermometer.html)

Alex Coleman March 23rd 07 07:02 PM

Antennas in my remote-sensor thermometer
 
I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.

The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:

http://www.flickr.com/photos/7472570@N06/430806010/
http://www.flickr.com/photos/7472570@N06/430806012/

The base unit's antenna is just a short length of wire. See these
pics:

http://www.flickr.com/photos/7472570@N06/430806014/
http://www.flickr.com/photos/7472570@N06/430806016/

----

TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.

TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!

Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?

labtech1 March 23rd 07 08:35 PM

Antennas in my remote-sensor thermometer
 
Could be a diode or a thermistor depending on the design and cost
considerations
I use to have a remote temp sensor for my computer via an A/D ( analog to
digital )
board. The remote sensor used several diodes in series.



"Alex Coleman" wrote in message
...
I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.

The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:

http://www.flickr.com/photos/7472570@N06/430806010/
http://www.flickr.com/photos/7472570@N06/430806012/

The base unit's antenna is just a short length of wire. See these
pics:

http://www.flickr.com/photos/7472570@N06/430806014/
http://www.flickr.com/photos/7472570@N06/430806016/

----

TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.

TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!

Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?




janospetrik March 24th 07 12:43 AM

Antennas in my remote-sensor thermometer
 
On Mar 23, 4:35 pm, "labtech1" wrote:
Could be a diode or a thermistor depending on the design and cost
considerations
I use to have a remote temp sensor for my computer via an A/D ( analog to
digital )
board. The remote sensor used several diodes in series.

"Alex Coleman" wrote in message

...

I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.
The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:


http://www.flickr.com/photos/7472570@N06/430806010/
http://www.flickr.com/photos/7472570@N06/430806012/


The base unit's antenna is just a short length of wire. See these
pics:


http://www.flickr.com/photos/7472570@N06/430806014/
http://www.flickr.com/photos/7472570@N06/430806016/


----


TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.


TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!


Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?



Did it come with a tinfoil hat?
Put it on. The government will beam you the information.


Telamon March 24th 07 04:52 AM

Antennas in my remote-sensor thermometer
 
In article ,
Alex Coleman wrote:

I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.

The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:

http://www.flickr.com/photos/7472570@N06/430806010/
http://www.flickr.com/photos/7472570@N06/430806012/

The base unit's antenna is just a short length of wire. See these
pics:

http://www.flickr.com/photos/7472570@N06/430806014/
http://www.flickr.com/photos/7472570@N06/430806016/

----

TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.


For a short distance the orientation does not matter other than it be
the same for transmitter and receiver.

TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!


Most likely a thermocouple is the sensor. Heat is radiant energy so as
long as the case is transparent to that energy wavelength then it would
not need an air vent.

Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?


The base unit probably generates a little heat and the air vents are for
circulation.

--
Telamon
Ventura, California

Mark Zenier March 24th 07 06:44 PM

Antennas in my remote-sensor thermometer
 
In article ,
Alex Coleman wrote:
I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.

The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:


If the sender unit has a FCC ID number on it, you can go to
http://www.fcc.gov and put that into a search form webpage and
get the frequency that it operates on.

TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.


TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!

Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?


They're low enough power that they don't generate much internal
heat. So the sensor is just another part on the circuit board. On a
cost basis , probably a thermistor, (a temperature sensitive resistor),
that would just be an epoxy coated (or glass) blob with a couple of
leads on it. They could also use a diode, or a temperature sensor IC
(that looks like a transistor).

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)


Brian O March 24th 07 08:05 PM

Antennas in my remote-sensor thermometer
 

"Alex Coleman" wrote in message
...
I have got a thermometer with a remore temperature sensor that sends
radio signals to update the base unit's display. The base unit also
has its own temperature sensor to let it display the indoors
temperature as well as the sensor's temperature.

The sender unit's antenna is a coil of wire which is about 1/4-inch
diameter and a couple of inches long. See these pics:

http://www.flickr.com/photos/7472570@N06/430806010/
http://www.flickr.com/photos/7472570@N06/430806012/

The base unit's antenna is just a short length of wire. See these
pics:

http://www.flickr.com/photos/7472570@N06/430806014/
http://www.flickr.com/photos/7472570@N06/430806016/

----

TWO QUESTIONS: What is the best orientation for each of these units
so their antennas are postioned optimally? For simplicity I am
assuming no obstructions.


Just of the top of my head, I would think that the axis of the coil, and the
length of the rx antenna need to be in the same plane, and perpindicular to
each other.

TWO MORE QUESTIONS: which component in the sender is the temperature
sensor? The sender's case seems sealed with no air vent!

Similarly, which component in the base unit is the sensor for the
indoors temperature? You can see the air vents in the base unit in
one picture linked above but which component is the temp sensor?


Its either some sort of solid state device, not sure what it would be, or it
would be a thermistor perhaps, or a thermocouple of some type. It would
depend on the unit, manufacturer, and design.
B




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