I see... thanks for the reply.
I was confused by the toroid in transmission. When transmitting, the
ferrite toroid is usually near the transceiver, but for other reason: to
avoid the RF catch by the coax shield or reflected due to a mismatched
antenna to reach the transceiver (it can cause RF shock to people and
interferences). In reception, yes, you're right, but I think that only
if the coax shield is correctly grounded.
The signal at the received is not the one coming through the line, but
the difference between the signal coming through the line and the signal
coming though the shield, so grounding the shield puts the shield signal
to zero, and then only the line signal is considered. If the radio is
operated from batteries or ungrounded, both signals will count and the
noise will be noticed, whether it comes through the line or through the
coax.
Maybe I'm wrong. RF is a very empirical "science" and experiencie is
more valuable than books
. I have little experiencie and few books
I spent great moments with a long wire (30 meters or 100 feet) coupled
with a MFJ antenna tunner with long wire coupler (MFJ-941E) in the
country. Now I have a constant electrical noise in the city in all the
band, about S7-S9, 24h... I'm limited to strong signals.
Best regards.
Kees wrote:
Hi
Well, the coax receives it on the outer side.
It would travel up to the balun and goes from there into the coax
inside back to the receiver.
That's why I put it up there.
Kees
On Mon, 21 Jun 2004 12:53:59 +0200, Nacho
wrote:
Hello.
Just a question.
Why is the ferrite toroid near the antenna instead of near the receiver?
It is used to supress the waves received by the coax, but at the far
side from the transceiver, the supress will be minimum...
Best regards.
Kees wrote:
Hello fellow shortwave listeners !
More info to make a T2FD yourself, like I did mine, please have a
look at:
http://members.home.nl/rita.kees/t2fdmake.html
I hope you can appreciate it and use it for your practice.
I will be glad to answer your questions.
73/cheers
Kees