Yes Jim, but that is when running high power.
Most of the time people running antennas like these here in Europe are
running only 100w.
And in Carter's case, he was having problems even at much lower levels
(though it may not be cmc on the feedline).
The best solution I've found for the case you pointed out is to not use
ferrite in the choke.
You don't have as much impedance to cmc without the ferrite but it doesn't
fry when running less than one KW.
I've been doing it for 15 years.
Prior to switching to that, I did fry a lot of baluns with much higher power
ratings.
Your suggestion for a good balun at the feedpoint works for coax fed
antennas.
Due to very limited space, hundreds of people here in Europe have just one
short dipole, fed with openwire.
They want to cover as many bands as possible, and "openwire-fed" is
considered to be the best way to do that.
Since link-coupled symmetrical tuners are very rare, people end up using a
choke/balun between the openwire and the asymmetrical tuner. In fact the
trend is to use an auto-tuner.
What is your suggestion there?
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Thursday, May 15, 2014 7:47 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Eagle problem?
On 5/14/2014 10:33 PM, Rick - DJ0IP / NJ0IP wrote:
> Jim, can you elaborate on that please.
>
> By "not practical", do you mean from an electrical standpoint (ie. it
> does not help) or do you mean from a physical standpoint (the
> mechanics of building it)?
>
> It is done often here in Europe.
N6BV has shown quite convincingly, and I confirmed his analysis, that there
are many conditions that, depend upon feedline length and severe mismatch
where even the most robust conceivable choke will fry with high power.
The problem occurs when the SWR is quite high --for example, an 80M resonant
dipole loaded on 40M.
73, Jim K9YC
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