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Old June 4th 10, 03:34 PM posted to rec.radio.shortwave
dave dave is offline
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First recorded activity by RadioBanter: Jan 2009
Posts: 5,185
Default Sony 7600GR and longwire antenna

Wimpie wrote:
On 3 jun, 23:35, wrote:
On 3 jun, 22:22, wrote:

"George wrote in message


...


I understand that attaching an external antenna will disable the build in
AM ferrite antenna.
My question, is this is a good thing? Will I pick up more with a 100 foot
longware versus a standard ferrite antenna?


The whip is disabled, not the ferrite.


Hello,

From memory I also thought that the external antenna is for short wave
only (so not for the AM broadcast band). The manual, however, says
that is does work on "MW" also (page 35GB). I don't have the receiver
over here so I cannot verify it. The manual also says it outputs DC,
so you need to avoid a short between the ext. antenna input and ground
of the receiver.

Unless you are in a very remote area, 100ft wire at reasonable height
above ground will overload the receiver very likely. You can better
use a shorter wire far from interference sources and use coaxial cable
between the antenna wire and your receiver.

You need to connect your wire to a large metallic structure or ground
away from interference sources, otherwise the cable will guide indoor
interference to your antenna.


Here I made an error: the braid of the coaxial cable at the antenna
side (outdoor side) should be grounded (not the wire itself of
course). A large metal surface or real ground provision can be used.


Best regards,

Wim
PA3DJSwww.tetech.nl
remove abc first in case of PM


As RHF mentioned, Safety is important.
A wire that runs into your house without any form of protection will
be dangerous when hit by lightning, no matter how good your house is
protected.

Running the wire into your house via correctly installed lightning
protection will make the difference between damaged electronic
equipment or your house burned-down.

You will probably going to experiment to see whether it is worth to
make a fixed antenna. In case of lightning, throw the wire out of you
house. Also make sure that when the wire breaks, it doesn't come into
contact with power lines.


Best regards,

Wim
PA3DJS


If you use a common 9:1 "MLB" autotransformer, all points of the
antenna, including the random wire, are at DC ground.