[Amps] coil 3.72

Jim Thomson jim.thom at telus.net
Sun Nov 24 12:13:44 EST 2019


Should have  added... 

I use  his  coil  program  for  loading coils for 40m  yagis...  and  also tank  coils  for  hb amps.  Since  it  spits out RF  resistance for a given freq,  and  knowing the exact RF  current  flowing  through the  coil, pretty  easy  to  then  calculate the  diss in watts...in  the  coil.   For  tapped  tubing  coils,  like a 20m  tubing coil,  tapped  for 17,15, 12,10m....and  say on  15M, any  heat is  localized to  the  portion  of  the coil  being used.  I  would have  thought the  un-used portion of
the  coil would act as a heat  sink....  it  does not !   Unused turns  remain  at ambient  room  temp.....  while used  turns can  be  extremely  hot  to  the  touch.    

Jim   VE7RF


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