On one side of my Sony ICF-SW7600GR there's an AM antenna jack, thus I would
like to give a try with a long wire.

The main question is what appears to be a 3.5 jack, is it a stereo or a mono
one?

Is there any chance to be improving LW/MW/SW reception using a 100 feet wire
(10 feet above the ground) rather than the usual wind up antenna?

I hope not to be bothering you all with this issue.

On Mon, 17 Oct 2005 13:12:03 GMT, "acmac" wrote:


On one side of my Sony ICF-SW7600GR there's an AM antenna jack, thus I would
like to give a try with a long wire.

The main question is what appears to be a 3.5 jack, is it a stereo or a mono
one?

Is there any chance to be improving LW/MW/SW reception using a 100 feet wire
(10 feet above the ground) rather than the usual wind up antenna?

I hope not to be bothering you all with this issue.


Since you are just using the Tip for the long wire (nad maybe the
Sleeve for the ground) whether there's a Ring (in the case of a Stereo
3.5 mm plug) doesn't matter. If you use a Stereo plug, short the Ring
and Sleeve together, just to make sure.

I wouldn't go longer than about 30 feet with that radio (less if
strange signals start popping up).

I agree that 100 feet of wire is indeed too much in this case. And if I
were going to try a 100 ft wire, I'd use an alligator clip to attach it
directly to the 7600's antenna, rather than to the antenna jack, as it
seems to me you're less likely to blow an FET or something. Also, I'd
make sure the attenuation is turned up pretty high.

Steve

Steve,

Two Things that most 'portable' AM/FM Shortwave Radios Could Use
for "Improved" Shortwave Radio Listening (SWL) :
http://groups.yahoo.com/group/Shortw...a/message/5867

1. External Antenna Input Isolator :
The simplest way to Protect most of the Front-Ends of these
'portable' AM/FM Shortwave Radios is to use a TV 75 Ohm to
300 Ohm Matching Transformer between the Coax cable and the
1/8" Mono-Plug that is used to Plug into the Radio's External
Antenna Input 1/8" Mono-Jack. The two 300 Ohm Leads of the
Matching Transformer are connected one to the Tip (Antenna)
and the other to the Barrel (Ground) of the 1/8" Mono-Plug.
You now have your External Antenna Input Isolator to use
with your these 'portable' AM/FM Shortwave Radios. Good for
Shortwave and FM Radio Reception with some built-in Attenuation
of the AM/MW Broadcast Band which is generally a good thing
with these 'portable' AM/FM Shortwave Radio. This is because
most these 'portable' AM/FM Shortwave Radios often suffer
from Front-End Signal Overload from AM/MW Radio Stations when
they are Hooked-Up to an External Shortwave Antenna that is
longer than 35 to 50 Feet or more.

2. Moderate Size Low Noise Inverted "L" Antenna :
The simplest Antenna for most of these 'portable' AM/FM Shortwave
Radios is an Inverted "L" Antenna of about 45 Feet long with a
15 Foot Vertical-Up-Leg and a 30 Foot Horizontal-Out-Arm.
Use a TV Matching Transformer with one of the 300 Ohm Leads
connected to the Wire Antenna Element; and the other Lead
connected to a Ground Rod/Point. Connect the 75 Ohm end of
the TV Matching Transformer to 75 Ohm RG6 Quad-Shield Coax
Cable; and connect the other end of the Coax Cable to the
External Antenna Input Isolator.

TIP - For these 'shorter'Shortwave Listener (SWL) Antennas :
I like FLEX-WEAVE Antenna Wire the so called "Cadillac of
Aerial Wire".
http://www.davisrf.com/ham1/flexweve.htm
FLEX-WEAVE comes in #14 (168 Strands of #36 Copper Wire)
http://www.davisrf.com/ham1/flexweve.htm
Highly UV Resistant PVC Jackets (Insulatated Covering) of
Clear, Black, and Camouflage Green.
http://www.davisrf.com/ham1/flexweve.htm

FWIW - RF Junkie now offers an "SWLZ" 9:1 Matching Transformer
that uses an "F" Connector for use with RG6 Coax Cable for
Shortwave Listeners (SWLs)
http://groups.yahoo.com/group/Shortw...a/message/4245
SWLZ = http://www.geocities.com/qrp_baluns/SWLZ.html
These work better then the common TV 300 Ohm to 75 Ohm Matching
Transformers and give good performance from 500 kHz to 30 MHz
for the Shortwave Radio Listener.
IMAGE - Hooking-Up the SWLZ as a Low Noise Inverted "L" Antenna
http://www.geocities.com/qrp_baluns/APP-SWLZ.html

READY-MADE - Shortwave Listener (SWL) Antenna that fits into
the 45 Foot Long Range is the PAR Electronics EF-SWL Antenna.
It come with the Matching Transformer and 45 Feet of Flex-Weave
Wire Antenna Element; and all you need to do is Install your
Ground Rod; Rig the Wire Antenna Element; and Attach your Coax
Cable. = http://www.parelectronics.com/swl_end.htm
http://www.grove-ent.com/ANT8.html
http://www.universal-radio.com/catalog/sw_ant/2205.html
Read - Building an Inverted "L" Antenna
using the PAR Electronics EF-SWL Antenna
http://groups.yahoo.com/group/Shortw...a/message/3089


iane ~ RHF

ACMAC,

The Sony ICF-SW7600GR's External Antenna Input is an 1/8"
Mono-Jack as are most 'portable' AM/FM Shortwave Radios.

Note - The Sangean ATS-909 Radio is an exception to this and
uses a 1/8" Stereo-Jack for the Radio's External Antenna Input.

hope this helps - iane ~ RHF