On May 24, 4:01 am, ish wrote:
Hello all,

Why does SW radio comes up with noise the moment I dial beyond AM. I
have tried tuning with several radios (including Sony 2010) and for
some reason noise level seems to increase around that band. I tried
with both AC adapter and plain old battery.

Any ideas?

TIA

I think that this part of the spectrum, due to proximity to and being
a second harmonic of, the AM MW band, is prone to quite a bit of noise
from AM MW sources, both receiver-generated and radio station-
generated. The combination of transmitter splatter, station harmonic
radiation and receiver mixing products gives you a mess to deal with.
Here in the SF Bay area, the bands are about useless for all the junk
that comes in.

David could well be right by suggesting that you cut back on
sensitivity, either using the controls on the radio or using a
"weaker" antenna; however, this area is one where sensitivity is
useful for heairng the weaker stations that inhabit these bands, so
you may just need to choose the cheap method of moving your receiver
to a remote location far from AM transmitters.

Bruce Jensen

On 24 May 2007 07:28:17 -0700, bpnjensen wrote:

On May 24, 4:01 am, ish wrote:
Hello all,

Why does SW radio comes up with noise the moment I dial beyond AM. I
have tried tuning with several radios (including Sony 2010) and for
some reason noise level seems to increase around that band. I tried
with both AC adapter and plain old battery.

Any ideas?

TIA

I think that this part of the spectrum, due to proximity to and being
a second harmonic of, the AM MW band, is prone to quite a bit of noise
from AM MW sources, both receiver-generated and radio station-
generated. The combination of transmitter splatter, station harmonic
radiation and receiver mixing products gives you a mess to deal with.
Here in the SF Bay area, the bands are about useless for all the junk
that comes in.

David could well be right by suggesting that you cut back on
sensitivity, either using the controls on the radio or using a
"weaker" antenna; however, this area is one where sensitivity is
useful for heairng the weaker stations that inhabit these bands, so
you may just need to choose the cheap method of moving your receiver
to a remote location far from AM transmitters.

Bruce Jensen

I was suggesting perhaps that the front end of the radio has so much
signal in the MWBC band that the AGC was maybe kicking-in and quieting
the radio.

Thanks for all your inputs so far. Actually what surprises me is
there is not a whole lot to hear around that frequency band, at least
using my gear. I suppose if I use a professional gear with a decent
antenna, I could probably pull out some DX stations.

Same holds true around 7 MHz during early afternoons; noise is simply
annoying. When it gets dark, though, band becomes relatively quiet.
In contrast, 15 MHz band and 21 MHz band are free from noise. And of
course when I move around 100 MHz, audio fidelity is superb. :-)

TIA.
ish

In article .com,
ish wrote:
Thanks for all your inputs so far. Actually what surprises me is
there is not a whole lot to hear around that frequency band, at least
using my gear. I suppose if I use a professional gear with a decent
antenna, I could probably pull out some DX stations.

Not much left to hear there anymore. Back 40 years or so ago, there
was a lot of short range use for maritime traffic on 2-3 MHz, along with
the 1.8 MHz LORAN signals. But LORAN moved down to 100 kHz.

the local maritime stuff went to VHF FM 156-159 MHz, (and to cell phones
since then). There used to be full duplex (two frequencies) marine to
landline telephone stations that were almost constantly busy. They went
to VHF, and I think have since been discontiued, as they needed a live
operator to take the number and dial it, and that costs way too much
these days.

All that's left seems to be some point to point utilites, and the hams
in 160 meters (who are only there when conditions are good).

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)