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W3FJW-Ron

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Everything posted by W3FJW-Ron

  1. Vertical polarization. Circular polarization is used for satellite communications (Hams). Don't remember for sure (lost too many brain cells due to ageing), but I don't think there is such a thing as linear polarization that pertains to RF waves.
  2. Doesn't work on the bands available to us anyway. It's cell phone bands only.
  3. 800mw may be swamping your RX. 1.2 + 1.2ghz = 2.4ghz. Thats the second harmonic of your vid Tx...
  4. Did ya manage to catch the 3D TVs? Maybe some day they'll be available in FPV goggles. 3D FPV combat.. YEAH!!
  5. Hope y'all had a great Christmas as well. Only about 6 hrs before I can break out the bottle. Hope y'all have a great 365.
  6. EagleTree has a new item out for a diversity ground station that might be of good use for $89. Just ordered one. http://www.rcgroups.com/forums/showthread.php?t=1048046
  7. That is probably correct. All model aircraft have some degree of down thrust. Most also have some right (IIRC) thrust built in as well.
  8. Any wireless cam from Radio Shack or similar store would do. The battery life would be the problem unless an ac adaptor could be used. No ac outlet handy? Where would you need to mount the cam?
  9. It won't cause any problems with the engine. It's more likely the engines spark ignition would interfere with the co-pilot and all other eledctronics.
  10. Why not just have the starter keylock changed so he can't start the car? Or, put in a hidden switch cutting the starter/ignition circuit off so he can't start it?
  11. Lookin good. Too bad it doesn't span about 72"
  12. If you're not good at soldering, I would practice until you get it down pat. A blob or cold joint of solder doesn't mean much at 72mhz, but it can often be the the difference between success and failure at these frequencies.
  13. Just a thought went through my mind. Maybe there will be no cheap gear pretty soon, but very expensive stuff only available through a limited bunch of suppliers. 1,000 % profit or more seems to linger in the dark recesses of my cranium. Is it not so that there are maybe only 2 or 3 mfgrs of the RF chips used in these devices and can be gotten for somewhere around $3 each in single quantities?
  14. An X8 module is an Assan product sold by Hobbyking. There have been consistantly good reviews of their products. http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=8354&Product_Name=X8D_2.4GHz_trainer_port_X8-hack_module_(PPM_Only) http://www.hobbyking.com/hobbycity/store/uh_listCategoriesAndProducts.asp?catname=2%2E4Ghz+Assan&idCategory=296&ParentCat=190 As Terry said, check your antenna first. If you go 2.4ghz for airborne equipment, then you would have to change your vid Tx & Rx to 900mhz, 1.2 ghz, or 5.8ghz.
  15. An alternative may be to use an X8 hack module & convert to 2.4ghz. Probably be much cheaper than having it fixed.
  16. Why not a ground plane? fold a 1/4 wave of the shielding back over the coax exposing the inner conductor with insulation for a 1/4 wave element effectively giving you a 1/2 wave antenna. Tie with a string to a tree limb or tywrap the length to a fiber glass rod that is the length you want to get it into the air. This will give you a vertically polarized dipole. To match it, trim both ends (shield element & driven element) to the lowest SWR possible. Make the feed line (coax) a multiple of a half wave in length. But, you didn't say whether this was to be on the plane or on the groun
  17. As an example, usually a file is used to change the length of an antenna or tuned circuit at UHF frequencies. Unless you have equipment sensitive enough to detect the change the stroke or two a file makes, you will never be sucessful. And it gets more critical the higher you go in frequency. When it comes to ckt board lands as part of a filter, usually, trimming a ckt board land by 1/256" too much will render a filter useless. VHF test equipment is fairly inexpensive but, UHF test equipment usually costs 4 to 6 times as much.
  18. I would think that Hams would not have a problem with buying this equipment as we could choose not to use the out of band frequency or channel.
  19. I found that when working with (not for) city or state inspection agencies for over 15 years that a bottle of good whiskey usually worked miracles.
  20. I only posted about the construction co to mention that the 2.4 gear wasn't the only thing being looked at. Haven't looked lately but my impression was that DPCAV equipment was all legal so should not cause you any worry.
  21. I mentioned more than a year ago that the FCC was going to do a lot more enforcement even though the budget was lower and was somewhat poo-pooed about my comment. Glad to see they're doing more for the Ham frequencies 2.4ghz not being the only ones. The following about illegal 2M useage from last Fridays ARRL bulletin. On September 28, the FCC issued a Notice of Apparent Liability for Forfeiture (NAL) to a California firm that the Commission maintains was using amateur frequencies to conduct business. According to the Commission, Shimmick Construction Company, Inc/Obayashi Corporation,
  22. I haven't been keeping up with resistor designations, but, the first two numbers are probably the value and the third number should be the number of zeros, so, for example 683 would probably be a 68,000 ohm resistor. Verify this with an ohm meter. Rather than swapping would be better to just buy one resistor and swap only one to see what the outlook would be. Easier on the ckt board lands this way. Another way would be to tack solder a 100,000 ohm resistor in parallel with one of the 68,000 ohm resistors which would give a resistance of around 47,000 (off the top of my head) and try that.
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