"Ron Hardin" wrote in message
...

It's just a noise rush, but not white exactly. The giveaway is that
it's on
only one sideband of the station you're trying to hear. If you hear
it on the
LSB, the offending IBOC station is 10 kHz higher (not lower as you'd
expect);
and if on USB, then 10 kHz lower.


I'm not sure I understand. The spectrum plot shows two symmetrical
peaks off the carrier frequency. The noise I observed was consistant
with that.


So you need selectable sidebands to tell, or at least a BFO and notice
whether
the noise pitch goes up as you tune up (in which case the IBOC station
is higher)
or goes down (in which case the IBOC station is lower), starting from
the
interfered-with station.
--
Ron Hardin



I turned the BFO on, and scanned across the noise. I didn't think to try
to discriminate between a upper or lower sideband transmission. I was
trying to tell if there were multiple carriers in the sideband noise. I
don't think there was, but I wasn't checking it out very long. I played
with it for a couple of minutes, then I got on the computer to check if
there was an announcement of WGN was going IBOC. There wasn't, and by
the time I got back to the radio, everything was quiet. It's been quiet
since.

Frank Dresser

Frank Dresser wrote:
It's just a noise rush, but not white exactly. The giveaway is that
it's on
only one sideband of the station you're trying to hear. If you hear
it on the
LSB, the offending IBOC station is 10 kHz higher (not lower as you'd
expect);
and if on USB, then 10 kHz lower.

I'm not sure I understand. The spectrum plot shows two symmetrical
peaks off the carrier frequency. The noise I observed was consistant
with that.

It's not symmetric around the adjacent channel station being interfered with.

If IBOC is on 700 and you're listening to 710, the the IBOC noise is at 713,
which is the upper sideband of 710. If you listen to 710 LSB, the noise
disappears.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

"Ron Hardin" wrote in message
...

It's not symmetric around the adjacent channel station being
interfered with.


OK. The noise was symmetrical around 720, and I was trying to catch
710.


If IBOC is on 700 and you're listening to 710, the the IBOC noise is
at 713,
which is the upper sideband of 710. If you listen to 710 LSB, the
noise
disappears.
--
Ron Hardin



I live a few miles from WGN's transmitter, and the normal sideband
splatter makes WOR almost unlistenable. I was just curious about
propagation that night. A station ID was all I wanted. If I ever hear
the noise again, I'll listen to it more carefully.

Frank Dresser

= = = Ron Hardin
= = = wrote in message ...
Frank Dresser wrote:
It's just a noise rush, but not white exactly. The giveaway is that
it's on
only one sideband of the station you're trying to hear. If you hear
it on the
LSB, the offending IBOC station is 10 kHz higher (not lower as you'd
expect);
and if on USB, then 10 kHz lower.

I'm not sure I understand. The spectrum plot shows two symmetrical
peaks off the carrier frequency. The noise I observed was consistant
with that.

It's not symmetric around the adjacent channel station being interfered with.

If IBOC is on 700 and you're listening to 710, the the IBOC noise is at 713,
which is the upper sideband of 710. If you listen to 710 LSB, the noise
disappears.

..

RH,

I thought that basic AM and SSB technology were different from IBOC
Digital Technology.

A 13kHz IBOC (@713kHz) off-set from 700kHz is NOT a 3kHz SSB
(@713kHz) off-set from 710kHz.

IBOC and SSB are not produced in the same manner and do not decipher
in the same manner.

Please Correct Me - If I Am Wrong ?


~ RHF

..

"RHF" wrote in message
om...

If IBOC is on 700 and you're listening to 710, the the IBOC noise is
at 713,
which is the upper sideband of 710. If you listen to 710 LSB, the
noise
disappears.

.

RH,

I thought that basic AM and SSB technology were different from IBOC
Digital Technology.

A 13kHz IBOC (@713kHz) off-set from 700kHz is NOT a 3kHz SSB
(@713kHz) off-set from 710kHz.

IBOC and SSB are not produced in the same manner and do not decipher
in the same manner.

Please Correct Me - If I Am Wrong ?


~ RHF

.

I don't think Ron's is using SSB in the sense of a modulation method,
but rather as a reception method. There's a couple of troughs in the
spectrum plot in the splits between the main analog channel and the
digital sidebands. One sideband of each adjacent channel will be in
those troughs.

http://earthsignals.com/add_CGC/KMXE.PDF

Listening SSB mode will limit the interference. Unfortunately, the
sideband with the least amount of interference will be the sideband
closest to the carrier of the unwanted station. Normally, it would be
preferable to listen to the sideband farthest away from the carrier of
the unwanted station.

I was able to tune in an actual IBOC transmission on WSAI 1530 kHz,
yesterday evening. WSAI is strong here, but I've never tuned them in
before they turned off their IBOC noisemaker. I was also able to tune
in KXEL 1540kHz inbetween WSAI's main channel and their upper IBOC
noiseband. There was splatter from the main channel and noise from the
digital channel, but it was readable. I don't have the selectivity to
listen in true sideband mode, but I think even that wouldn't totally
eliminate the interference. If the IBOC station is local, I think there
would still enough noise and splatter to overwhelm an otherwise
listenable near adjacent channel.

The current split digital/analog system is intended to be temporary.
The IBOC standard is designed to go full digital.

Frank Dresser

"Frank Dresser" wrote in message ...
"RHF" wrote in message
om...

If IBOC is on 700 and you're listening to 710, the the IBOC noise is
at 713,
which is the upper sideband of 710. If you listen to 710 LSB, the
noise
disappears.

.

RH,

I thought that basic AM and SSB technology were different from IBOC
Digital Technology.

A 13kHz IBOC (@713kHz) off-set from 700kHz is NOT a 3kHz SSB
(@713kHz) off-set from 710kHz.

IBOC and SSB are not produced in the same manner and do not decipher
in the same manner.

Please Correct Me - If I Am Wrong ?


~ RHF

.

I don't think Ron's is using SSB in the sense of a modulation method,
but rather as a reception method. There's a couple of troughs in the
spectrum plot in the splits between the main analog channel and the
digital sidebands. One sideband of each adjacent channel will be in
those troughs.

http://earthsignals.com/add_CGC/KMXE.PDF

Listening SSB mode will limit the interference. Unfortunately, the
sideband with the least amount of interference will be the sideband
closest to the carrier of the unwanted station. Normally, it would be
preferable to listen to the sideband farthest away from the carrier of
the unwanted station.

I was able to tune in an actual IBOC transmission on WSAI 1530 kHz,
yesterday evening. WSAI is strong here, but I've never tuned them in
before they turned off their IBOC noisemaker. I was also able to tune
in KXEL 1540kHz inbetween WSAI's main channel and their upper IBOC
noiseband. There was splatter from the main channel and noise from the
digital channel, but it was readable. I don't have the selectivity to
listen in true sideband mode, but I think even that wouldn't totally
eliminate the interference. If the IBOC station is local, I think there
would still enough noise and splatter to overwhelm an otherwise
listenable near adjacent channel.

The current split digital/analog system is intended to be temporary.
The IBOC standard is designed to go full digital.

Frank Dresser

..

FD,

If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
and Data/Information Channels.

Then, how do you 'decode' it and Listen to it simply using
standard "Analog" SSB ?

~ RHF

..

"RHF" wrote in message
om...
.

FD,

If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
and Data/Information Channels.

Then, how do you 'decode' it and Listen to it simply using
standard "Analog" SSB ?

~ RHF

.

I didn't take it as a method of decoding the IBOC signal. I took to
mean a way to minimize the interference from a IBOC station on a close
adjacent channel signal.

Let's say a station at 830 kHz is using IBOC and you want to hear a
station on 840 kHz. There's interference to the station at 840 from the
splatter of the main channel at 830 and the IBOC sideband centered at
843. You can minimize the interference from the IBOC sideband if you
listen to the station at 840 in LSB mode.

http://earthsignals.com/add_CGC/KMXE.PDF

Of course, normally it's preferable to listen to that station at 840 kHz
in USB mode, but the IBOC sideband interferes heavily with that
sideband.

Frank Dresser

= = = "Frank Dresser"
= = = wrote in message ...

"RHF" wrote in message
om...
.

FD,

If the IBOC Signal is a 'broadcast' as "Digital Encoded Algorithm".
Either as Dual IBOC Signals (Stereo) or as 'separate' Voice
and Data/Information Channels.

Then, how do you 'decode' it and Listen to it simply using
standard "Analog" SSB ?

~ RHF

.

I didn't take it as a method of decoding the IBOC signal. I took to
mean a way to minimize the interference from a IBOC station on a close
adjacent channel signal.

Let's say a station at 830 kHz is using IBOC and you want to hear a
station on 840 kHz. There's interference to the station at 840 from the
splatter of the main channel at 830 and the IBOC sideband centered at
843. You can minimize the interference from the IBOC sideband if you
listen to the station at 840 in LSB mode.

http://earthsignals.com/add_CGC/KMXE.PDF

Of course, normally it's preferable to listen to that station at 840 kHz
in USB mode, but the IBOC sideband interferes heavily with that
sideband.

Frank Dresser

..

FD,

I can understand what you are saying, IF (Big 'if') I was trying
to get away from one interfering IBOC Side-Channel.

BUTT (Big 'butt' ) What happens when there is 50% implementation
of IBOC and on average every other Channel is an IBOC Broadcaster
with an IBOC Side-Channel at both +15kHz and -15kHz.

So now your Old Fashion AM Station at 840kHz has a 860kHz Lower
IBOC Side-Channel and also a 820kHz Upper IBOC Side-Channel;
both sitting within -&+ 5kHz of 840kHz.

As, I read and interpret the Spectrogram the IBOC Signals are
about 12 dB above the band scan base noise level. The Main
AM Signal is another 18 dB above the IBOC Side-Channels.

While IBOC may be 'claimed' to be backwardly compatible with
the current AM Broadcast media. It is apparent to me that with
may be 33% IBOC adoption the AM Band as we know it will cease
to be; and all remaining AM Band Broadcasters will be FORCE by
the 'new' IBOC Noise Levels to transition to IBOC or NOT Be Heard.

IBOC to IBOC will not be a problem because of the specific IBOC
Side-Channel Off-Set and the Encoding and Decoding of the IBOC
"Digital Algorithm".

BUTT - To the old fashion AM Analog Radio Station the IBOC "Digital
Algorithms" from the upper and lower adjacent IBOC Side-Channels
will simply sound like NOISE "BIG TIME" !

Oh Well - I have rambled on long enough.

iboc ~ RHF
= = = I Be Overly Concerned !
..