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Modifications to WS2350

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  • highpeakfarmer
    Hi I m new to this group and thought I would post a bit about what I have done so far with the WS2350. I did the modifications to the thermo-hydro unit
    Message 1 of 10 , Oct 2, 2008
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      Hi

      I'm new to this group and thought I would post a bit about what I
      have done so far with the WS2350. I did the modifications to the
      thermo-hydro unit mentioned in previous posts on here. The only
      difference I made was to use surface mount components for most of it
      which makes for a much easier job and looks really neat.

      I also added a helical antenna to made from 330mm on 0.6mm diameter
      wire coiled at wide spacing around a 5mm rod (which was removed after
      forming). I coupled this to the variable capacitor at the top of the
      board by a 1.8pF capacitor so as (hopefully) not to shift the tuning
      of the existing LC too much. I ran the antenna down the right hand
      side of the case (with a bit of fiddling to get it past the
      connectors and the electrolytic capacitor.

      Having done the mods I measured the current draw of the unit and
      found that during transmission (about 1 second every 8 seconds) it
      went up to about 4.5mA then spent about 1 second at 1.5mA (possibly
      while reading the anemometer) and then fell to below 0.2mA for the
      rest of the time. I guessed that the average draw must be less than
      1mA. My guess is that I would get perhaps 100 days of life out of the
      AA cells so decided to make up a solar charged NiMh pack to save me
      remembering to change them. This uses three 1300mAHr AA NiMh cells
      and two nominally 4.5v 100mA solar panels wired in series. These give
      an onset of charging in quite poor light (mid morning with a heavy
      overcast). I regulate this down to 3.3v - about equal to two fresh
      alkaline cells- with a 78LC33 micropower low dropout regulator.

      The result is that I get a pretty good signal from the thermo-hydro
      unit (full scale on the signal strength display on my AR8000 scanner
      receiver in my workshop (at 25 yards range and the other side of a
      500mm thick stone wall). Unfortunately I failed to see what the
      standard unit does but so far it has not missed a beat even when its
      been very wet with 1mm/minute rainfall!

      If anyone is interested I can photograph the antenna and the solar
      PSU.
    • thedvnt
      Highpeakfarmer - I, for one, would like to see the pics! I have a similar setup as well! Always interested in what someone else has come up with to modify
      Message 2 of 10 , Oct 2, 2008
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        Highpeakfarmer -

        I, for one, would like to see the pics! I have a similar setup as
        well! Always interested in what someone else has come up with to
        modify the bits!


        --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
        <highpeakfarmer@...> wrote:
        >
        > Hi
        >
        > I'm new to this group and thought I would post a bit about what I
        > have done so far with the WS2350. I did the modifications to the
        > thermo-hydro unit mentioned in previous posts on here. The only
        > difference I made was to use surface mount components for most of
        it
        > which makes for a much easier job and looks really neat.
        >
        > I also added a helical antenna to made from 330mm on 0.6mm diameter
        > wire coiled at wide spacing around a 5mm rod (which was removed
        after
        > forming). I coupled this to the variable capacitor at the top of
        the
        > board by a 1.8pF capacitor so as (hopefully) not to shift the
        tuning
        > of the existing LC too much. I ran the antenna down the right hand
        > side of the case (with a bit of fiddling to get it past the
        > connectors and the electrolytic capacitor.
        >
        > Having done the mods I measured the current draw of the unit and
        > found that during transmission (about 1 second every 8 seconds) it
        > went up to about 4.5mA then spent about 1 second at 1.5mA (possibly
        > while reading the anemometer) and then fell to below 0.2mA for the
        > rest of the time. I guessed that the average draw must be less than
        > 1mA. My guess is that I would get perhaps 100 days of life out of
        the
        > AA cells so decided to make up a solar charged NiMh pack to save me
        > remembering to change them. This uses three 1300mAHr AA NiMh cells
        > and two nominally 4.5v 100mA solar panels wired in series. These
        give
        > an onset of charging in quite poor light (mid morning with a heavy
        > overcast). I regulate this down to 3.3v - about equal to two fresh
        > alkaline cells- with a 78LC33 micropower low dropout regulator.
        >
        > The result is that I get a pretty good signal from the thermo-hydro
        > unit (full scale on the signal strength display on my AR8000
        scanner
        > receiver in my workshop (at 25 yards range and the other side of a
        > 500mm thick stone wall). Unfortunately I failed to see what the
        > standard unit does but so far it has not missed a beat even when
        its
        > been very wet with 1mm/minute rainfall!
        >
        > If anyone is interested I can photograph the antenna and the solar
        > PSU.
        >
      • highpeakfarmer
        Hi Dimitris When I get a chance I will bring the thermo-hydro unit in and photograph the antenna I have put in. The idea is really quite similar to the one you
        Message 3 of 10 , Oct 2, 2008
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          Hi Dimitris

          When I get a chance I will bring the thermo-hydro unit in and
          photograph the antenna I have put in. The idea is really quite similar
          to the one you have added but I have effectively coiled up the wire so
          that it fits within the case rather than being external. This is
          something I played with while using the Radiometrix modules for
          another 433MHz application. There Radiometrix data sheet:-

          http://www.radiometrix.co.uk/dsheets/ntx2nrx2.pdf

          has a little information about helical antennas. As they say they are
          not as effective as 1/4 wave whips but are short so useful for
          locating inside small units. I am lucky to be in a low-noise location
          so I don't think I will need more antenna gain as my scanner picks up
          the signal very strongly at over 150 yards with no other transmissions
          being heard.

          The 1.8pF capacitor I have used is a fixed value ceramic type and is
          in series with the antenna. It simply prevents the tuning of the LC in
          the transmitter being changed too much by capacitance between the
          antenna and the circuit ground. It would probably work OK without this
          capacitor.

          I'll get the photography done as soon as the weather becomes more
          boring - we have been having spells of 30mm/hour rain in the last few
          days and I don't want to miss recording them!


          --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
          <petros0022@...> wrote:
          >
          > Hello highpeakfarmer and welcome to group .
          > I am not sure if the helical antenna do you mean telescopic
          > antenna ?
          > If you mean telescopic antenna i had experiment with it and the
          > results it is bad .
          >
          > http://i19.servimg.com/u/f19/11/22/64/62/weathe18.jpg
          >
          > After from many tests i saw better modification from antenna it is
          > it inside to console but more length 34,5 cm ,the red cable
          >
          > http://i19.servimg.com/u/f19/11/22/64/62/meteo810.jpg
          >
          > and to put more external cable to out remote thermo/hygro sensor
          > 34,5 cm
          >
          > http://i34.servimg.com/u/f34/11/22/64/62/sensor10.jpg
          > http://i34.servimg.com/u/f34/11/22/64/62/sensor11.jpg
          >
          > I do not understand very well where you put the variable capacitor
          > for better tuning ?
          >
          > You coupled one capacitor 1,8 pF to variable capacitor (trimmer)
          > antenna ?how ? parallel ?
          >
          > Sorry my English it is not so good !!.
          > If you can send us pictures from all your modification (thermo-
          > hygro ,solap panel,antenna.
          >
          > Thank you
          >
          > Best regards from Greece
          > Dimitris
          > http://www.geocities.com/meteo19671967
          >
          >
          >
          > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
          > <highpeakfarmer@> wrote:
          > >
          > > Hi
          > >
          > > I'm new to this group and thought I would post a bit about what I
          > > have done so far with the WS2350. I did the modifications to the
          > > thermo-hydro unit mentioned in previous posts on here. The only
          > > difference I made was to use surface mount components for most of
          > it
          > > which makes for a much easier job and looks really neat.
          > >
          > > I also added a helical antenna to made from 330mm on 0.6mm
          > diameter
          > > wire coiled at wide spacing around a 5mm rod (which was removed
          > after
          > > forming). I coupled this to the variable capacitor at the top of
          > the
          > > board by a 1.8pF capacitor so as (hopefully) not to shift the
          > tuning
          > > of the existing LC too much. I ran the antenna down the right hand
          > > side of the case (with a bit of fiddling to get it past the
          > > connectors and the electrolytic capacitor.
          > >
          > > Having done the mods I measured the current draw of the unit and
          > > found that during transmission (about 1 second every 8 seconds) it
          > > went up to about 4.5mA then spent about 1 second at 1.5mA
          > (possibly
          > > while reading the anemometer) and then fell to below 0.2mA for the
          > > rest of the time. I guessed that the average draw must be less
          > than
          > > 1mA. My guess is that I would get perhaps 100 days of life out of
          > the
          > > AA cells so decided to make up a solar charged NiMh pack to save
          > me
          > > remembering to change them. This uses three 1300mAHr AA NiMh cells
          > > and two nominally 4.5v 100mA solar panels wired in series. These
          > give
          > > an onset of charging in quite poor light (mid morning with a heavy
          > > overcast). I regulate this down to 3.3v - about equal to two fresh
          > > alkaline cells- with a 78LC33 micropower low dropout regulator.
          > >
          > > The result is that I get a pretty good signal from the thermo-
          > hydro
          > > unit (full scale on the signal strength display on my AR8000
          > scanner
          > > receiver in my workshop (at 25 yards range and the other side of a
          > > 500mm thick stone wall). Unfortunately I failed to see what the
          > > standard unit does but so far it has not missed a beat even when
          > its
          > > been very wet with 1mm/minute rainfall!
          > >
          > > If anyone is interested I can photograph the antenna and the solar
          > > PSU.
          > >
          >
        • Marco-Luis SALCEDO TOVAR
          Hello Dimitris, I believe that some people call it Wendell Antenna.... Marco-Luis YV1HX Cabimas-Zulia-Venezuela http://www.cvm.org.ve/red/SAMT_1/SAMT.html ...
          Message 4 of 10 , Oct 3, 2008
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            Hello Dimitris,

            I believe that some people call it Wendell Antenna....

            Marco-Luis

            YV1HX
            Cabimas-Zulia-Venezuela
            http://www.cvm.org.ve/red/SAMT_1/SAMT.html

            ----- Original Message -----
            From: "petros0022" <petros0022@...>
            To: <Lacrosse_weather_stations@yahoogroups.com>
            Sent: Friday, October 03, 2008 2:17 AM
            Subject: [LacrosseWS] Re: Modifications to WS2350


            > Hi again .
            > Now i understand very well about helical antenna,i know it but i do
            > not know it name at England !!!.
            > You use 1/4 wave tuning ,i use 34,4 cm L/2 tuning for 433 MHZ.
            > You use 24 turns for tuning at 433 MHZ 0,5 mm wire and close wound
            > 3,2 mm .
            > Today i make a test i take 0,5 mm wire ,lenght 34,5 cm L/2 tuning
            > for 433 MHZ and i make a helical antenna with 10 turns over to AAA
            > 1,5 volt batery ,for to see if it is better from my whip antenna
            > like now .
            >
            > http://i42.servimg.com/u/f42/11/22/64/62/helica10.jpg
            >
            > Ok we will wait for your modification
            >
            > Best regards from Greece
            > Dimitris
            > http://www.geocities.com/meteo19671967
            >
            >
            >
            > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
            > <highpeakfarmer@...> wrote:
            >>
            >> Hi Dimitris
            >>
            >> When I get a chance I will bring the thermo-hydro unit in and
            >> photograph the antenna I have put in. The idea is really quite
            > similar
            >> to the one you have added but I have effectively coiled up the
            > wire so
            >> that it fits within the case rather than being external. This is
            >> something I played with while using the Radiometrix modules for
            >> another 433MHz application. There Radiometrix data sheet:-
            >>
            >> http://www.radiometrix.co.uk/dsheets/ntx2nrx2.pdf
            >>
            >> has a little information about helical antennas. As they say they
            > are
            >> not as effective as 1/4 wave whips but are short so useful for
            >> locating inside small units. I am lucky to be in a low-noise
            > location
            >> so I don't think I will need more antenna gain as my scanner picks
            > up
            >> the signal very strongly at over 150 yards with no other
            > transmissions
            >> being heard.
            >>
            >> The 1.8pF capacitor I have used is a fixed value ceramic type and
            > is
            >> in series with the antenna. It simply prevents the tuning of the
            > LC in
            >> the transmitter being changed too much by capacitance between the
            >> antenna and the circuit ground. It would probably work OK without
            > this
            >> capacitor.
            >>
            >> I'll get the photography done as soon as the weather becomes more
            >> boring - we have been having spells of 30mm/hour rain in the last
            > few
            >> days and I don't want to miss recording them!
            >
            >
            >
            > ------------------------------------
            >
            > Yahoo! Groups Links
            >
            >
            >
          • highpeakfarmer
            Hi I have posted a few pictures of what I have done in the photos section. The antenna is effectively 1/2 wave being 330mm of wire. I wanted to use 1/2 wave as
            Message 5 of 10 , Oct 3, 2008
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              Hi

              I have posted a few pictures of what I have done in the photos
              section. The antenna is effectively 1/2 wave being 330mm of wire. I
              wanted to use 1/2 wave as I did not think the transmitter would drive
              happily into the low impedance of a 1/4 wave antenna. Although it was
              partly done by guess-work as the connector block rather gets in the
              way but I opened out the coil most at the input end so as to keep the
              inductance/unit length as low as possible at the input end where the
              current is highest and close up the turns more at the 'free' end where
              the current is lowest and the inductance have least effect.

              I think the unit benefits from having a supply voltage of 3.3v as this
              is more that the transmitter will get except on absolutely new
              batteries and my guess is that the output of the transmitter goes up
              almost as the square of the supply voltage. I will post a circuit
              diagram and other details of the solar charged supply when I have the
              time.

              By removing the batteries from the unit we have also reduced the
              thermal inertia of it so perhaps it will respond quicker to
              temperature changes in light-wind conditions. Since I have not had
              time to make a proper screen I have simply made a loose fitting
              polystyrene cover for the thermo hydro unit that slips over the
              supplied shield. I plan to add two more of the same solar panels to
              drive a 40mm fan to improve ventilation when the unit is in full
              sunshine. I also plan to modify the wind-vane as it seems somewhat
              under-damped and seems to swing excessively in light but gusty
              conditions. I think simply lightening the vane by cutting large holes
              in it and covering it in a lightweight aeromodelling film such as
              solar-film and re-balancing it would help a lot. I might increase the
              area of the vane somewhat at the same time.




              --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
              <petros0022@...> wrote:
              >
              > Hi again .
              > Now i understand very well about helical antenna,i know it but i do
              > not know it name at England !!!.
              > You use 1/4 wave tuning ,i use 34,4 cm L/2 tuning for 433 MHZ.
              > You use 24 turns for tuning at 433 MHZ 0,5 mm wire and close wound
              > 3,2 mm .
              > Today i make a test i take 0,5 mm wire ,lenght 34,5 cm L/2 tuning
              > for 433 MHZ and i make a helical antenna with 10 turns over to AAA
              > 1,5 volt batery ,for to see if it is better from my whip antenna
              > like now .
              >
              > http://i42.servimg.com/u/f42/11/22/64/62/helica10.jpg
              >
              > And i make another one more small over to screwdriver about 3,5 mm
              > with 30 turns and total lenght 34,5 cm for to make test
              >
              > http://i42.servimg.com/u/f42/11/22/64/62/antenn23.jpg
              >
              >
              > Ok we will wait for your modification
              >
              > Best regards from Greece
              > Dimitris
              > http://www.geocities.com/meteo19671967
              >
              >
              >
              > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
              > <highpeakfarmer@> wrote:
              > >
              > > Hi Dimitris
              > >
              > > When I get a chance I will bring the thermo-hydro unit in and
              > > photograph the antenna I have put in. The idea is really quite
              > similar
              > > to the one you have added but I have effectively coiled up the
              > wire so
              > > that it fits within the case rather than being external. This is
              > > something I played with while using the Radiometrix modules for
              > > another 433MHz application. There Radiometrix data sheet:-
              > >
              > > http://www.radiometrix.co.uk/dsheets/ntx2nrx2.pdf
              > >
              > > has a little information about helical antennas. As they say they
              > are
              > > not as effective as 1/4 wave whips but are short so useful for
              > > locating inside small units. I am lucky to be in a low-noise
              > location
              > > so I don't think I will need more antenna gain as my scanner picks
              > up
              > > the signal very strongly at over 150 yards with no other
              > transmissions
              > > being heard.
              > >
              > > The 1.8pF capacitor I have used is a fixed value ceramic type and
              > is
              > > in series with the antenna. It simply prevents the tuning of the
              > LC in
              > > the transmitter being changed too much by capacitance between the
              > > antenna and the circuit ground. It would probably work OK without
              > this
              > > capacitor.
              > >
              > > I'll get the photography done as soon as the weather becomes more
              > > boring - we have been having spells of 30mm/hour rain in the last
              > few
              > > days and I don't want to miss recording them!
              > >
              > >
              >
            • highpeakfarmer
              Hi Dimitris The modification I made for high data rate is the same as given in http://www.fabriziosalvadori.com/ws2300_mods.htm but I have used surface mount
              Message 6 of 10 , Oct 3, 2008
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                Hi Dimitris

                The modification I made for high data rate is the same as given in
                http://www.fabriziosalvadori.com/ws2300_mods.htm but I have used
                surface mount components (except for the diodes) I have posted a photo
                to show where the SM components are.

                The 78LC33 regulator I used was from ON Semiconductors and the data
                sheet is:-

                http://www.onsemi.com/pub_link/Collateral/MC78LC00-D.PDF

                If you use an LM317 you will have a bigger dropout (minimum voltage
                between input and output) and may have a bigger current use by the
                regulator itself but if you have lots of sunshine (unlike England!)
                you will be OK.

                --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
                <petros0022@...> wrote:
                >
                >
                > Hi again and congratulations you have make a very good job there.
                >
                > I saw this photos and have some questions
                > I saw your electronic modification over to PCB it is different from
                > the original from Sarwa from Italy
                >
                > http://www.fabriziosalvadori.com/ws2300_mods.htm
                >
                > I saw you use 3 diode only ,and one capacitor for better tuning
                > antenna ,your result for 8 sec more fast wireless data is fine ?
                > Ant when you have time send us the electronic design from your
                > modification it.
                >
                > Finally and you use 1/2 wave antenna like me and not 1/4 it is
                > better ,my one thing is to use the future L/1 690 mm wave helical
                > antenna and to console and to out thermo-hygro sensor for test .
                > Before i had experiment with 1/4 wave antenna 172 mm, but the result
                > it is not so good like now with 1/2 wave.
                >
                > One observe ,your<< Stevenson screen >> it is not good ,it want
                > better plastic dishes like it .With corect temperatures i had
                > experiments many time and finally i see the correct temp it was
                > radiation shield with plastic dishes
                >
                > http://www.geocities.com/peristerimeteo/radiationshield.html
                >
                > or Stevenson screen with woods
                > http://www.geocities.com/meteoperisteri/Klovos.html
                >
                > And 2 of them it is very perfect with little patents ,but the
                > plastic dishes it is more cheap .
                >
                > Very clever move to put out the bateries fron the out remote
                > sensor,you are correct ,and i had think it ,with the bateries inside
                > to sensor possible to give more hot at hot days to sensor .
                >
                > If you have a solar panell 5 watts it is ok for fan ,at night not
                > needs the fan ,there you can not put bateries for the night .The fan
                > it is necessary only the day .
                >
                > I found out for regulator 78LC33 and i found it about details
                >
                > http://www.katalog.micros.com.pl/089071073-stabilizatory-stale-100-
                > 150ma.html
                >
                > Here to Greece this motorola regulator is to difficult to found and
                > we use the LM317 ,and we change the resistor for diferent out put
                > voltage .
                > http://www.electronics-lab.com/articles/LM317/
                >
                >
                > Best regards from Greece
                > Dimitris
                > http://www.geocities.com/meteo19671967
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                >
                > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
                > <highpeakfarmer@> wrote:
                > >
                > > Hi
                > >
                > > I have posted a few pictures of what I have done in the photos
                > > section. The antenna is effectively 1/2 wave being 330mm of wire. I
                > > wanted to use 1/2 wave as I did not think the transmitter would
                > drive
                > > happily into the low impedance of a 1/4 wave antenna. Although it
                > was
                > > partly done by guess-work as the connector block rather gets in the
                > > way but I opened out the coil most at the input end so as to keep
                > the
                > > inductance/unit length as low as possible at the input end where
                > the
                > > current is highest and close up the turns more at the 'free' end
                > where
                > > the current is lowest and the inductance have least effect.
                > >
                > > I think the unit benefits from having a supply voltage of 3.3v as
                > this
                > > is more that the transmitter will get except on absolutely new
                > > batteries and my guess is that the output of the transmitter goes
                > up
                > > almost as the square of the supply voltage. I will post a circuit
                > > diagram and other details of the solar charged supply when I have
                > the
                > > time.
                > >
                > > By removing the batteries from the unit we have also reduced the
                > > thermal inertia of it so perhaps it will respond quicker to
                > > temperature changes in light-wind conditions. Since I have not had
                > > time to make a proper screen I have simply made a loose fitting
                > > polystyrene cover for the thermo hydro unit that slips over the
                > > supplied shield. I plan to add two more of the same solar panels to
                > > drive a 40mm fan to improve ventilation when the unit is in full
                > > sunshine. I also plan to modify the wind-vane as it seems somewhat
                > > under-damped and seems to swing excessively in light but gusty
                > > conditions. I think simply lightening the vane by cutting large
                > holes
                > > in it and covering it in a lightweight aeromodelling film such as
                > > solar-film and re-balancing it would help a lot. I might increase
                > the
                > > area of the vane somewhat at the same time.
                > >
                > >
                > >
                > >
                >
              • highpeakfarmer
                Well, I agree that its not wonderful but a vast improvement over the standard arrangement (which even in UK sunshine is not too good!) It s certainly worth the
                Message 7 of 10 , Oct 3, 2008
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                  Well, I agree that its not wonderful but a vast improvement over the
                  standard arrangement (which even in UK sunshine is not too good!) It's
                  certainly worth the 10 minutes work it takes for anyone not willing to
                  do more!

                  I think a fan enclosure is the only way to go. If I recall right the
                  standard Stevenson screen can be in error by over 5 degrees in zero
                  wind and full equatorial sun.

                  --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"

                  > One observe ,your<< Stevenson screen >> it is not good
                • petros0022
                  Hi again The fan help to stand air at days with very sun and no winds ,to put out the closed air out to the roof .It is necessary equatorial sun and here to
                  Message 8 of 10 , Oct 3, 2008
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                    Hi again
                    The fan help to stand air at days with very sun and no winds ,to put
                    out the closed air out to the roof .It is necessary equatorial sun
                    and here to Greece .Here i have observe with no fan the Stevenson
                    screen it have more temp 2 c at days with no wind and very hot sun
                    at summer time.
                    I am sure at near future you will build a very nice Stevenson screen
                    box.

                    Now will go to modification, now you added and i saw clear this
                    photo,you use SM components ,i want to know where you found it ?
                    from another application ? because here in the electronic shop ,do
                    not they sell SM components.

                    http://tinyurl.com/4ljt4c

                    And one question with the capacitor 1,8 pF at antena trimmer do you
                    see better results ? I saw you have put it paralel with trimer
                    antena ,my opinion it is not absolutely neccesary .

                    PS:If you like tell me your name .Because it is no good from me to
                    tell you highpeakfarmer ha ha ha..!!(joke)

                    Best regards from Greece
                    Dimitris
                    http://www.geocities.com/meteo19671967








                    --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
                    <highpeakfarmer@...> wrote:
                    >
                    > Well, I agree that its not wonderful but a vast improvement over
                    the
                    > standard arrangement (which even in UK sunshine is not too good!)
                    It's
                    > certainly worth the 10 minutes work it takes for anyone not
                    willing to
                    > do more!
                    >
                    > I think a fan enclosure is the only way to go. If I recall right
                    the
                    > standard Stevenson screen can be in error by over 5 degrees in zero
                    > wind and full equatorial sun.
                    >
                    > --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
                    >
                    > > One observe ,your<< Stevenson screen >> it is not good
                    >
                  • highpeakfarmer
                    Hi Dimitris I get most of my components from a UK company called Rapid Electronics . There website is:- http://www.rapidonline.com/ They do a good selection of
                    Message 9 of 10 , Oct 3, 2008
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                      Hi Dimitris

                      I get most of my components from a UK company called Rapid Electronics
                      . There website is:-
                      http://www.rapidonline.com/
                      They do a good selection of surface mount components and generally I
                      find their prices to be competitive.
                      I think they do delivery to all EU countries but I don't know what
                      their delivery rates are.

                      It is not easy to see from the photo but the 1.8pF capacitor is not in
                      parallel with the trimmer. I have used the unused circular land on the
                      PCB as a point to solder the end of the antenna to and then bridged
                      between one end of the trimmer and the antenna so the 1.8pF is in
                      series with the antenna.

                      Best regards

                      Colin

                      --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
                      <petros0022@...> wrote:
                      >
                      > Hi again
                      > The fan help to stand air at days with very sun and no winds ,to put
                      > out the closed air out to the roof .It is necessary equatorial sun
                      > and here to Greece .Here i have observe with no fan the Stevenson
                      > screen it have more temp 2 c at days with no wind and very hot sun
                      > at summer time.
                      > I am sure at near future you will build a very nice Stevenson screen
                      > box.
                      >
                      > Now will go to modification, now you added and i saw clear this
                      > photo,you use SM components ,i want to know where you found it ?
                      > from another application ? because here in the electronic shop ,do
                      > not they sell SM components.
                      >
                      > http://tinyurl.com/4ljt4c
                      >
                      > And one question with the capacitor 1,8 pF at antena trimmer do you
                      > see better results ? I saw you have put it paralel with trimer
                      > antena ,my opinion it is not absolutely neccesary .
                      >
                      > PS:If you like tell me your name .Because it is no good from me to
                      > tell you highpeakfarmer ha ha ha..!!(joke)
                      >
                      > Best regards from Greece
                      > Dimitris
                      > http://www.geocities.com/meteo19671967
                      >
                      >
                      >
                      >
                      >
                      >
                      >
                      >
                      > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
                      > <highpeakfarmer@> wrote:
                      > >
                      > > Well, I agree that its not wonderful but a vast improvement over
                      > the
                      > > standard arrangement (which even in UK sunshine is not too good!)
                      > It's
                      > > certainly worth the 10 minutes work it takes for anyone not
                      > willing to
                      > > do more!
                      > >
                      > > I think a fan enclosure is the only way to go. If I recall right
                      > the
                      > > standard Stevenson screen can be in error by over 5 degrees in zero
                      > > wind and full equatorial sun.
                      > >
                      > > --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
                      > >
                      > > > One observe ,your<< Stevenson screen >> it is not good
                      > >
                      >
                    • highpeakfarmer
                      Hi Dimitris I have not tried the antenna without the 1.8pF capacitor. It is quite possible that the performance will be better without it so long as the
                      Message 10 of 10 , Oct 4, 2008
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                        Hi Dimitris

                        I have not tried the antenna without the 1.8pF capacitor. It is quite
                        possible that the performance will be better without it so long as the
                        antenna does not shift the tuning of the LC too far. One interesting
                        possibility is to scratch off the solder resist from the loop on the
                        PCB at several points and try soldering the antenna to each point in
                        turn as a way of trying different degrees of coupling between the LC
                        and the antenna to see which gave the best performance.

                        If I was going for extreme range I think I would use a Yagi at both Tx
                        and Rx. If I get around to setting up a second station (say for 10
                        metre wind) somewhere else on the farm I may well investigate this
                        possibility.

                        Good weekend!

                        Best regards

                        Colin
                        --- In Lacrosse_weather_stations@yahoogroups.com, "petros0022"
                        <petros0022@...> wrote:
                        >
                        > Hi Colin .
                        > One last question ,now i saw more clear the PCB and i saw the
                        > capasitor 1,7 pF way one side it go to trimmer antenna and the other
                        > side you put the antenna modification 1/2 wave.
                        > My question is for who reason you put the capacitor 1,7 pF
                        > there ,maybe for more better tuning antenna i thing ,and you try to
                        > make a test without capacitor ? there are differents with or without
                        > capacitor ? for better radio signal .
                        >
                        > Sorry and for my bad English and specially at grammatic !!.
                        >
                        > And good weekend to everybody.
                        >
                        > Best regards from Greece
                        > Dimitris
                        > http://www.geocities.com/meteo19671967
                        >
                        >
                        >
                        > --- In Lacrosse_weather_stations@yahoogroups.com, "highpeakfarmer"
                        > <highpeakfarmer@> wrote:
                        > >
                        > > Hi Dimitris
                        > >
                        > > I get most of my components from a UK company called Rapid
                        > Electronics
                        > > . There website is:-
                        > > http://www.rapidonline.com/
                        > > They do a good selection of surface mount components and generally
                        > I
                        > > find their prices to be competitive.
                        > > I think they do delivery to all EU countries but I don't know what
                        > > their delivery rates are.
                        > >
                        > > It is not easy to see from the photo but the 1.8pF capacitor is
                        > not in
                        > > parallel with the trimmer. I have used the unused circular land on
                        > the
                        > > PCB as a point to solder the end of the antenna to and then bridged
                        > > between one end of the trimmer and the antenna so the 1.8pF is in
                        > > series with the antenna.
                        > >
                        > > Best regards
                        > >
                        > > Colin
                        > >
                        >
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