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About Ramius-II

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    RC-Cam Visitor

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  • Location
    Lomita, CA
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    R C Submarines
  1. Hi Guys: I did a little more research and the pitot approach is the best for high speeds as there is a fair amount of pressure to work with. There is an alternative method which is via a "flow meter". Basically, it's a tube where the inside is shaped like a wing. The advantage is by looking at the pressure comming into the tube there is a vacuum on the back side making the whole thing more sensitive. The ratio of the inside of the tube (largest part) to the hole is 3:1. This comes from an air flow engineer at the Honeywell Corporation. I have not tried this ap
  2. Hi Terry: Brass is mostly copper so that is where is falls. What I was pointing out to you is that a dipole does not do as good a job as say a ground plane style of antenna. Dipoles are typically 300 ohms so again, I wonder if you have a true dipole? Most off the shelf systems I've seen use a single wire off the output of the transmitter so not seeing what you have or what you are working with does make it a bit difficult to come up with soild recommendations for improvements. Generally, in airborne applications there is no advantage of transmitting up above the aircraft unless
  3. Hi Terry: If you go to www.cool-amp.com you can see the product. basically, if you have a clean surface of copper or brass, you take a damp cloth, add some of the powder and rub it onto the surface you wish to silver plate. In the order of conductivity, it's silver, copper, gold then aluminium. Silver is the best conductor and notice most high frequency components are silver. Moving on to antenna's, you might look at using a colinear antenna for the transmitter. The advantage is you can get some very good gain and still remain omni-directional. At 2.4 GHz the lenghts are short, theref
  4. Hi Terry: I think what you might be missing is several key factors. Receive gain is best accomplished with the antenna. A simple co-linear antenna or PC board yagi can give as much gain as the amplifier. The coax you mention is terrible for 2.4 GHz. Rule of thumb is every 3 db is 1/2 the signal. The coax you mention has a loss of 3.2 db per foot! If you went to RG-6 it would be more like .8 db per foot. Part of the "getting the best reception" formula is to have the transmitted signal be as strong as possible. Again, incorporating a good transmitting antenna, especially with a de
  5. Wow! Thanks Jeff! I have not done the math, and with 0-1 psi being represented by 0-5 volts and a 12 bit A-D I think it will work Thank you so much! Best Ed
  6. Hi All: I've been searching for information on using a differential pressure sensor (Pitot vs Static pressure) to measure airspeed. I know the pressure is less than 1 psi, what I do not know is how much pressure represents what speed? The plan is to program the information into a PIC. Can anyone help or point me in the right direction? Thanks, Ed Ramius-ii-AT-earthlink.net
  7. Hi Dee: Just a few inputs for you. Adding wire can reduce the transmitters signal if the wire is not a "low loss" type. Typically, the smaller the cable, the more loss. Next is frequency. The resonant frequency of water is 2.4 GHz which means the water will absorb more signal than other frequencies. This is why microwave ovens are on this frequency. Even still there are some people who are using 2.4 and can receive a signal from a depth of 18 inches with 800 mw of power. Best, Ed
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