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JohnE

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Everything posted by JohnE

  1. no problem I'll keep my eyes/ears open and let you know if I come across anything.
  2. might move this to SI if I can get the space. I have to see how long/type of cable/antenna is used the plot the pattern and see if its worth it.
  3. I'll take a look on Monday see what I have floating around.
  4. PG its 35mi between 2 mountain tops in a vacuum. I would really like to know where and how they came up w/that.
  5. I was unaware that radio mobile was now more user friendly. last time I played w/it you had to download a bunch of files. going to fart around w/it tonight.
  6. 9dBd or dbi
  7. look at my thread here this will better explain how I set it up. this will give you a general idea of how far the your machine can transmit . the receive side is a little different. http://forums.mygmrs.com/topic/8-ers-ny-650/?do=findComment&comment=437
  8. putting this out there again these are RX only amplifiers http://www.anglelinear.com/ one of the best out there for commercial or HAM. I have these in multiples in many sites, low noise high gain. http://www.downeastmicrowave.com/ mostly HAM related stuff but makes a nice pre amp for commercial use. again low noise high gain. I have one of these on my private repeater and works great. http://www.advancedreceiver.com/ had a few of these over the yrs but found they over load pretty easily in high RF environments. on the plus side they make an inline RF switched pre amp that will handle up to 160W. very nice for control or mobile application. all of these either use GasFet, PHEMT or EPHEMT devices. the old bi-polar transistor types are still out there but have a much higher noise figure. I also suggest that these be used w/pass/notch filters w/better than 100dB of isolation between the ports.
  9. have a look at this w/regard to grounding your antennas. very long. http://www.scribd.com/doc/41782971/R56-Guidelines
  10. I put up a couple of pics of my control antenna in my gallery
  11. JohnE

    control antenna

  12. not every one will agree w/me on this but I'll put it out there anyway. in my 30 yrs of doing RF I have found that grounding an antenna just makes it a better "target". I have 6 major sites in NYC all above 400' asl none have any real antenna grounding system and I can count on one hand how many times I have had to replace an antenna from a hit. on the other hand there is a customers site that was properly grounded and every 2-3yrs i have to go change an exploded cigar, not too fun. now towers are a completely different animal altogether. again this has been my experience in the north east, where you are in FL is probably a completely different matter. for a control station w/antenna 15' above the roof line I wouldn't sweat it too much. what in the immediate area will be higher than that,light pole ,phone pole,ect..... you get where I'm goin' w/this. some things to look at. https://www.tessco.com/products/displayProductInfo.do?sku=68433&eventPage=1 I may have some of these around, if you want one let me know I'll send one down. you can pick up an 8' ground rod at home depot.
  13. all is well. both machines working well hope all is good by you.
  14. to the tip ~9M
  15. I would get in touch w/local HAM's and see where they have their equipment. hopefully they are willing to give you some space and help w/what you want to do. just a thought. also w/regards to no HOA you still have local laws regarding antenna height I'm sure. I know I do.
  16. I use these a lot my 650 has the 7dB and the 575 has a 5dB. light weight relatively cheap. this is my preferred yagi for control stations on master systems. http://www.tessco.com/products/displayProductInfo.do?sku=37145&eventPage=5 I have a pair of these I keep for my own use. http://www.tessco.com/products/displayProductInfo.do?sku=56400&eventPage=5 http://i42.photobucket.com/albums/e341/rftekk/35005.jpg
  17. http://www.tessco.com/products/displayProducts.do?groupId=372&subgroupId=37 http://www.tessco.com/products/displayProducts.do?groupId=372&subgroupId=40
  18. there should have been a fuse in the power line. a 10 or 15 ATC blade type. I would suggest an Astron ,Samlex or dura comm supplies. they're not cheap but will last for yrs.
  19. they are more or less "toys" for the most part. half watt, 12.5 Kc's and the molded antenna doesn't help. just my thoughts
  20. screen shots of the "new" duplexer tune are in my gallery. these were taken off of the network analyzer it was tuned with, it shows insertion loss and swr. I hope to put it into service soon and add the power amp I have standing by.
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