[TowerTalk] Ferrite, or choke baluns?

[Jim Lux]

Jim Brown wrote:
> On Fri, 18 Jan 2008 12:00:35 -0800 (PST), Michael Germino wrote:
> 
>> Palomar Engineers have a "Balun Kit" that is basically Ferrite 
>> Beads that you slip over your coax and some heat shrink that you 
>> use to keep them in place.  $16.50 for the RG-8 one.
> 
> That's one of the string of beads chokes I'm talking about. 
>> What is your take on these, Jim?  Enough Ferrite Bead? 
> 
> Not nearly enough. 
> 
>> Seemed to work OK for me up to 40 Meters
> 
> See my tutorial. 
> 
> 73,
> 
> Jim


probably jumping in late here..

Perhaps "seemed to work" is the operative phrase.  Lots of folks have 
antennas that "work ok" with absolutely no choke at the feedpoint.  'YCs 
  writeup gives good information on what one might want to use as a 
design goal (and the basis for why that's a reasonable goal), but 
clearly, one can get acceptable (where acceptable means different things 
to different people) results with other approaches.

As far as retail pricing on ferrites goes.. I think the best way to get 
low prices on these is to do a group buy.. where someone is going to 
essentially volunteer to do the administrative stuff for 10-20 hams 
combining their order.  I participated in one of these buys and have a 
box of a few hundred big toroids out in the garage.  I've given some 
away, used a few, sold a few for around what I paid for them because the 
recipient insisted on paying, and will probably have the rest for a while.

  However, I can't imagine going into a retail business doing it, at 
least if I expected to make any money at it.  Such an operation might 
make an ok mail-order project for a student (where they can get capital 
from the bank of mom and dad, and don't have to pay for rent, storage, 
etc.) or if you happen to be in a situation where you've got some spare 
space and time that can be devoted for free.  (much like other hobby 
craft operations.. most of the "profit" is in the satisfaction of doing 
the job, not in the monetary return)

Jim, W6RMK