----- 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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