Hi,

Just thought I'd ask, and mention a Bit More, Re My scanner AM "Reception
"Problems"

a. is there a concept as "intrinsic antenna noise" for a receiving scanner
antenna type ?

On AM scanner frequencies, around 118 MHz or so, I find my Disconne is a lot
quieter than a Scantenna I have.

Both are in the same attic spot, and use similar coax downfeeds.

The Scantenna uses a balun of sorts; I think it's 300 to 50 ohm.

b. I've mentioned the problems I have in picking up, well, an airport
control tower about 8 miles away.
I think I've come to the conclusion that it's "simply" a case of AM (always)
being a lot noisier than FM.
Does this make any sense ?

If it's some sort of overload on the scanner, using the scanner ATTN does
not help.

c. Funny thing is that when I use my JRC NRD 545, with either the Scantenna
or the Disconne, it comes in really clear.
This is without resorting to any of the fancy filtering or notching that the
545 has.
Hard to understand why it should be so much better with just its basic
settings.

Perhaps the fact that it uses DSP helps a lot on AM, in some manner ?

Bob

On Apr 1, 1:40*pm, "Robert11" wrote:
Hi,

Just thought I'd ask, and mention a Bit More, Re My scanner AM "Reception
"Problems"

a. *is there a concept as "intrinsic antenna noise" for a receiving scanner
antenna type ?

On AM scanner frequencies, around 118 MHz or so, I find my Disconne is a lot
quieter than a Scantenna I have.

Both are in the same attic spot, and use similar coax downfeeds.

The Scantenna uses a balun of sorts; I think it's 300 to 50 ohm.

b. *I've mentioned the problems I have in picking up, well, an airport
control tower about 8 miles away.
I think I've come to the conclusion that it's "simply" a case of AM (always)
being a lot noisier than FM.
Does this make any sense ?

If it's some sort of overload on the scanner, using the scanner ATTN does
not help.

c. *Funny thing is that when I use my JRC NRD 545, with either the Scantenna
or the Disconne, it comes in really clear.
This is without resorting to any of the fancy filtering or notching that the
545 has.
Hard to understand why it should be so much better with just its basic
settings.

Perhaps the fact that it uses DSP helps a lot on AM, in some manner ?

Bob

If the rx is for FM only it makes a lot od sense.
The limiter in the FM receiver actually removes AM modulation.

Jimmie

On Apr 1, 11:40 am, "Robert11" wrote:
Hi,

Just thought I'd ask, and mention a Bit More, Re My scanner AM "Reception
"Problems"

a. is there a concept as "intrinsic antenna noise" for a receiving scanner
antenna type ?

On AM scanner frequencies, around 118 MHz or so, I find my Disconne is a lot
quieter than a Scantenna I have.

Both are in the same attic spot, and use similar coax downfeeds.

The Scantenna uses a balun of sorts; I think it's 300 to 50 ohm.

b. I've mentioned the problems I have in picking up, well, an airport
control tower about 8 miles away.
I think I've come to the conclusion that it's "simply" a case of AM (always)
being a lot noisier than FM.
Does this make any sense ?

If it's some sort of overload on the scanner, using the scanner ATTN does
not help.

c. Funny thing is that when I use my JRC NRD 545, with either the Scantenna
or the Disconne, it comes in really clear.
This is without resorting to any of the fancy filtering or notching that the
545 has.
Hard to understand why it should be so much better with just its basic
settings.

Perhaps the fact that it uses DSP helps a lot on AM, in some manner ?

Bob

Basically, one receiver is good. One not so good...
I'd rig up a simple 3 el yagi and point it at the airport.
Then either one will probably work ok. :/
I see the same here with various radios. I have 3-4
that pick up aircraft. 2-3 scanners, and the Icom 706mk2g.
The 706 smokes the scanners as far as sensitivity on
the air bands. The scanners are all fairly cheap radio
shack models, and while they work, you get what you
pay for. All the JRC's are fairly decent radios.
Wouldn't surprise me at all to see one smoke a typical
scanner on VHF.