Like I mentioned in an earlier thread I'm playing around with setting up an antenna for my much under used Icom IC-R75 receiver.
Yesterday I setup a pretty poor basic antenna but this was purely a "what if" experiment, not intended to become a real antenna.
It is a horizontal wire about 33 ft. long, mounted about 7ft off the ground.
One end is directly attached to a metal hook screwed into a wooden structure (that encloses my chickens) the other is also attached to a metal hook screwed into the masonry wall near where my workshop/garage door is, that hook is electrically insulated (well galvanically) because it is screwed into a plastic wall plug.
That end of the wire has a tough multi stranded copper wire joined as part of the wire's crimp, for now it's just coming in through a gap on the garage door, of course the door and supporting frame is all steel and aluminum, a lot of metal.
The wire is stainless steel and I used aluminum "crimpable" sleeves to create the end loops of the wire.
Here are a few pics:
So this is a crude, poor "long wire" antenna I suppose, with the "feed" being a direct connection to one end.
The receiver has two antenna connectors available:
On the right, the red/black are Ant2 and the SO239 is Ant1, the one in operation is selectable from the front panel.
My antenna is connected to the red and there is nothing connected (yet) to the black.
I believe I have a DSP option installed (Can't recall because I bought this new in 2001 and have hardly ever used it).
OK, so having said all that and given you the details of the setup, here's the big observation, I can get some signals but there's a lot of noise. In particular there's a noisy "tone" that's fairly constant across a wide spectrum from like 5MHz up to around 25MHz where it begins to diminish.
That noisy tone is greatly reduced in LSB/USB mode, but very pronounced in AM mode.
What might that noise be? if its some local RF interference then that's pretty much the end of any DXing aspiration because I have no idea what it is, where it comes from or whether it can be reduced.
This was just a crude experiment, I have all sorts of insulators on order as well as coax and other stuff and fully intended to do a much better job, this was just to see what kind of stuff I experience with a very crude setup and the noise is a concern.
Thoughts?
PS: I don't have a simple portable transistor radio around just now, but I do seem to recall very decent reception when I did have one, can't recall if I ever tried that portable on AM though...
Yesterday I setup a pretty poor basic antenna but this was purely a "what if" experiment, not intended to become a real antenna.
It is a horizontal wire about 33 ft. long, mounted about 7ft off the ground.
One end is directly attached to a metal hook screwed into a wooden structure (that encloses my chickens) the other is also attached to a metal hook screwed into the masonry wall near where my workshop/garage door is, that hook is electrically insulated (well galvanically) because it is screwed into a plastic wall plug.
That end of the wire has a tough multi stranded copper wire joined as part of the wire's crimp, for now it's just coming in through a gap on the garage door, of course the door and supporting frame is all steel and aluminum, a lot of metal.
The wire is stainless steel and I used aluminum "crimpable" sleeves to create the end loops of the wire.
Here are a few pics:
So this is a crude, poor "long wire" antenna I suppose, with the "feed" being a direct connection to one end.
The receiver has two antenna connectors available:
On the right, the red/black are Ant2 and the SO239 is Ant1, the one in operation is selectable from the front panel.
My antenna is connected to the red and there is nothing connected (yet) to the black.
I believe I have a DSP option installed (Can't recall because I bought this new in 2001 and have hardly ever used it).
OK, so having said all that and given you the details of the setup, here's the big observation, I can get some signals but there's a lot of noise. In particular there's a noisy "tone" that's fairly constant across a wide spectrum from like 5MHz up to around 25MHz where it begins to diminish.
That noisy tone is greatly reduced in LSB/USB mode, but very pronounced in AM mode.
What might that noise be? if its some local RF interference then that's pretty much the end of any DXing aspiration because I have no idea what it is, where it comes from or whether it can be reduced.
This was just a crude experiment, I have all sorts of insulators on order as well as coax and other stuff and fully intended to do a much better job, this was just to see what kind of stuff I experience with a very crude setup and the noise is a concern.
Thoughts?
PS: I don't have a simple portable transistor radio around just now, but I do seem to recall very decent reception when I did have one, can't recall if I ever tried that portable on AM though...
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