[TowerTalk] CM choke info

[Jim Thomson]

  Ok, here is the real issue  with the various  commercial manufactures of 1:1  CM chokes.    With the one exception  of the CM chokes from..myants.com.. Danny Horvat,
the  rest of them  dont provide the data we all require to evaluate.  Whats required is a graph of  Z mag   vs  freq,  like  1-30 mhz,   or   1-60 mhz.
We also require a graph of   RS  vs  freq, again  1-30 mhz...or 1-60 mhz.
We also require a graph of  XS  vs  freq, agin   1-30 mhz...or  1-60 mhz. 

We not only require ONE graph,  with  ALL  3 x of the above parameters, we also need ONE table, with ALL  3 x parameters...  for EACH  ham band. 

Without the above,  any specs are meaningless.    Ideally, we want  high Z mag..and high RS...and most importantly, we want  RS to be greater than Xs.  Below the resonance of the CM choke, the Xs  will be  inductive.
Above resonance, the   Xs  will be capacitive  ( and will have a -  sign in front of the number). 

Balun designs  will depict Z mag  in graph form,  but will  only display Rs  and  Xs  for ONE frequency !    (far right in table for their  aim  4170  info).  
Array solutions   provides some info,  like  swr, return loss etc.... not really useful.  Their choking Z vs  freq  graphs are questionable  at best, depicting  huge numbers at real low freqs... and low numbers at high freqs...and this is with just 3 turns on 4 x cores. 
DXE  provides zero info, none. 

Cherry  picking just one freq, or semi useless  info like  swr vs freq, or return loss vs one freq, etc,  is just hype..and looks impressive.. but is just confusing to most. 

Here it it, 2020.... and nobody knows how to depict  or build a cm choke....except for 1 manufacturer.    At least  plastic nema boxes, coax, and connectors and torroids are relatively cheap and available.    

Jim  VE7RF