Topband: Choke Construction Info Needed

[ZR]

That is only 226 Ohms at 1.8MHz and at 1500W will be dissipating about 30W in a 50 Ohm system but Phil didnt say how he is feeding his tower which is resonant well below 160M.

Yes it will work as well as survive a lot of energy at 35-50 Ohms compared to a larger inductance 1A choke.

Carl
KM1H
  ----- Original Message ----- 
  From: DAVID CUTHBERT 
  To: ZR 
  Cc: philclements at centurylink.net ; topband at contesting.com 
  Sent: Thursday, July 26, 2012 4:35 PM
  Subject: Re: Topband: Choke Construction Info Needed


  20 uH should be sufficient at the base of a 1/4 wave length vertical.

  #4 copper wire is used to connect towers to ground for direct strikes.

  Such an inductor can be close-wound with insulated #4 wire, diameter 8", 8 turns.

  It should survive intact except for the insulation.

  Dave WX7G


  On Jul 26, 2012 2:02 PM, "ZR" <zr at jeremy.mv.com> wrote:

    It all depends upon how much survivability you want, nothing will survive a
    direct hit.  Any 1.5 to 2.5 mH choke will suffice, just look at the safety
    choke in a commercial amp for the smallest choice.

    The big ones are often found in scrapped BCB transmitters and tuning units
    as well as show up at hamfests and on Fleabay as old military gear had
    various candidates.

    Carl
    KM1H


    ----- Original Message -----
    From: "Phil Clements" <philclements at centurylink.net>
    To: <topband at contesting.com>
    Sent: Thursday, July 26, 2012 3:03 PM
    Subject: Topband: Choke Construction Info Needed


    >I need to construct a heavy-duty choke to be installed from the feed point
    > of my 160 meter vertical to ground, for static drain and for lightning
    > protection. How large does the wire, form, and inductance need to be?
    >
    >
    >
    > Thanks in advance for your expertize!
    >
    >
    >
    > (((73)))
    >
    > Phil, K5PC
    >
    >
    >
    > _______________________________________________
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