TOMK5RC@aol.com wrote:
some interesting stuff that I clipped, and then said:
> When you introduce ferrite to RF, you generate heat. In time, the heat can
> change the properties of the ferrite. Impurities in the ferrite can also lead
> to potential failure points. Sometimes you cannot avoid ferrite devices. Some
> are very reliable, others are marginal.
While Ed Gilbert suggested in the article that I just reposted, that the losses
in
both the coax choke and the Aztec ferrite balun were "negligible," the ferrite
balun had a loss ten times that of the coax choke.
> To keep it simple, I use coax whenever possible. It would be nice to summarize
> the reliability experiences with ferrite devices reported in this thread to
> help us select the appropriate one for our applications.
>
> Tom, K5RC/7
As I said earlier, I burned up a box full of BN-86s before turning to W2DU style
ferrite choke. My latest failure was with a W2DU made by W2AU. It was a heat
failure near the antenna end of the choke. Charred the PVC and undoubtedly
messed
up the innards too, but haven't surgically inspected it yet. All this done with
1500 watts or less. ;-]
--
Ken K4XL
grimm@lynchburg.net
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