Well that might be the answer!!!!!!!!
I am using 15 turns of 2.36mm wire. The 50 ohm tap is at 9 turns.
I will try again ith more turns of a bit thinner wire to see what happens.
Thanks Niels!
73, Dick PA4VHF
----- Original Message -----
From: Niels Rudberg J?rgensen <[email protected]>
To: <[email protected]>
Sent: Monday, March 28, 2005 8:52 PM
Subject: LF: Re: the use of Epcos cores on LF
----- Original Message -----
From: "Dick" <[email protected]>
To: <[email protected]>
Sent: Monday, March 28, 2005 5:00 PM
Subject: LF: the use of Epcos cores on LF
> A question, especially for our German members.
>
> Epcos makes (big) cores of so called N30 material.
> I previously used an 58mm core to match 50 Ohm to 135Ohm, but it got
> really hot at around 400-500Watt or so.
> I wonder if this is normal or not (Ui=4300)
>
> These cores are relatively cheap, so I hoped it was a good solution for
big
> (output) transformers.
> Now I am not to sure anymore...........
>
> Also interested to know if anyone has experience in using a low
beverage,
> let's say 400-500m long at 1m heigth as TX antenna.
> Not earthed/resistor at the end, just a simple very long wire at 1m
heigth.
>
> 73
>
> Dick, pa4vhf
>
The core mentioned is OK for this purpose. I suspect you made the
transformer
with too few turns.
For 500 W (SWR = 1:1) a turns number of 25:40 will be OK.
Too few turns causes a too high magnetizing current with subsequent
heating of the core.
73 Niels, OZ8NJ+
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