Results 1 to 5 of 5

Thread: 450ohm ladder and coax

  1. #1

    Default 450ohm ladder and coax

    My qth I have a radio room in small cupboard / room with pre existing vent duct to outside.

    Depending on route of feed to antenna location I have a run approximately 50m. And a concrete and metal workshop within 3 meters of aerial location on a bank in rear garden

    Looking at most coax it performs terriblely in power in watts lost with 6m band and long run & 2db indicated average loss.

    So my question is coax out of radio room>9:1 Balun to 450 ohm wire (avoiding resonant lengths of antenna) terminated to 9:1 Balun and short run of coax to aerial.


    Looking at if this is a cheaper, less lossy ,method to get coax loses down to aerial.

    Looking at 213/LMR 400 or LMR600 in short runs

    Thanks

  2. #2
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,107

    Default

    For H.F. nothing beats open wire feeder, particularly the lower bands.
    V.H.F. and above, you'll need the lowers loss coaxial cable you can find...

  3. #3

    Default

    What did you mean by short runs? Absolutely NOT short runs joined together - as every connector has a small amount of loss. To be honest, 2dB loss is quite workable in real life.

  4. #4

    Default

    yep, figure you would probably have less loss with one long run of good grade coax than with all the connections and baluns in that configuration.

  5. #5

    Join Date
    Jul 2012
    Location
    Stoke-on-Trent
    Posts
    13

    Default

    Hi Dan31 . After reading your query, and noting the 50 m( approx 163 feet) run to antenna, I would suggest , stay with the 450 ohms feeder line.! and use an antenna tuner , although you do not mention , just what antenna you will be using, straight dipole? multi -band non- resonant top ? etc ! The main small problem , with 450/300/ feeders is the wet weather effect, but personally speaking , I don't find that a great problem.. My own 450 ohm feeder comes thru' the roof space (attic) The small workshop you mention, would obviously be the ideal

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •