Hi John,

I enjoyed reading your comments on your classy new IC-7700!

Speaking of ECSS tuning with 2 khz filters, I have often thought that the
SDR receivers I have owned sound very good in ECSS with narrower bandwidths.
For comparison, you might like to listen to two MP3 files (recorded during
the same song).

The first is ECSS (I chose LSB) tuning of my local 1360 khz station (Spanish
lang.) with exactly a 2.0 khz bandwidth chosen:

http://www.guyatkins.com/files/sdr/p..._2khz_ecss.mp3

The 2nd recording, to compare to a fuller fidelity, Synchronous-AM mode at a
wide 12 kHz filter setting, is he

http://www.guyatkins.com/files/sdr/p...hz-sync-am.mp3

I think you'll agree that the 2 kHz wide recording is perfectly acceptable
in fidelity for DXing and even program listening if required in a situation
where interfering signals are close in frequency. The shape factor of the
filtering in the Perseus SDR is nearly textbook perfect at 1 to 1.1
(conservatively). I know your IC-7700 is similarly excellent in shape
factor.

The 12 kHz recording is quite a bit "fuller" sounding, with more upper
midrange in the voice and treble in the trumpets. On the spectrum display
for 1360 kHz, the station shows a modulation envelope slightly over 20 kHz
wide, but I note extremely little improvement in treble when I tune it with
a filter bandwidth greater than 12 kHz.

Best DX,

Guy Atkins
Puyallup, WA USA
www.perseus-sdr.blogspot.com



wrote in message
...
Having great fun cruising my new Bentley Continental GT. See:
http://www.bentleymotors.com/Corpora...spx?infid=1523

No, actually I have been cruising the airwaves with my new Icom
IC-7700 and having great fun. See:
http://www.ab4oj.com/icom/ic7700/main.html
upgrading from my IC-756PROIII is like upgrading to a Bentley =
orgasmic!

Getting AFN Pearl Harbour, Guam, Diego Garcia and Key West as clear as
a bell with it's wonderful NR noise reduction and tight filters.
And "Big L" from Holland, a 20 Kw MW station nice and clear.

This is the only radio I have owned that will actually clearly work AM
stations on ECSS with a 2.0 kHz filter (all the other radio's are too
muffled at this tight setting).
SNIP

On Jun 15, 12:06*am, "Guy Atkins" wrote:
Hi John,

I enjoyed reading your comments on your classy new IC-7700!

Speaking of ECSS tuning with 2 khz filters, I have often thought that the
SDR receivers I have owned sound very good in ECSS with narrower bandwidths.
For comparison, you might like to listen to two MP3 files (recorded during
the same song).

The first is ECSS (I chose LSB) tuning of my local 1360 khz station (Spanish
lang.) with exactly a 2.0 khz bandwidth chosen:

http://www.guyatkins.com/files/sdr/p..._2khz_ecss.mp3

The 2nd recording, to compare to a fuller fidelity, Synchronous-AM mode at a
wide 12 kHz filter setting, is he

http://www.guyatkins.com/files/sdr/p...hz-sync-am.mp3

I think you'll agree that the 2 kHz wide recording is perfectly acceptable
in fidelity for DXing and even program listening if required in a situation
where interfering signals are close in frequency. The shape factor of the
filtering in the Perseus SDR is nearly textbook perfect at 1 to 1.1
(conservatively). I know your IC-7700 is similarly excellent in shape
factor.

The 12 kHz recording is quite a bit "fuller" sounding, with more upper
midrange in the voice and treble in the trumpets. On the spectrum display
for 1360 kHz, the station shows a modulation envelope slightly over 20 kHz
wide, but I note extremely little improvement in treble when I tune it with
a filter bandwidth greater than 12 kHz.

Best DX,

Guy Atkins
Puyallup, WA USA
www.perseus-sdr.blogspot.com

Hi Guy,
Certainly very impressive recordings from your Perseus = nice! I
read John Bryant's review of your Perseus next to his WinRadio 313 and
he is also most impressed with the Perseus (see Guy's Perseus
blogspot)

I think the reason my 7700 does better on ECSS with a tight filter is
because it has a later more developed DSP and also maybe the passband
offset works better as well. To get the optimum sound quality on an AM
station in ECSS it is necessary to shift the passband offset - in my
case it is optimal at minus -250 Hz setting. My 756Pro3, good as it
is, cannot match the 7700 with the 2 kHz filter.

JP

"dave" wrote in message
...
Is it an IBOC station? aka HD?

------------------

Hi Dave,

No, that 1360 local station of mine is not IBOC. It's just a regular
AM-modulated station. In my opinion, any well-maintained transmitter and
studio that doesn't go overboard on the compression/companding/processing
(etc.) of the audio can sound this good on any low distortion receiver
capable of wide bandwidth. I have heard similar results with other receivers
I've owned like the AR7030, RA6790/GM, and the SDR-1000.

If you enjoy audio comparisons, there are three more MP3s he
http://perseus-sdr.blogspot.com/2006...o-quality.html
These files from a couple years ago demonstrate the audio quality of the
SDR-1000 on music and DX signals. Be sure to use good speakers or hi-fi
headphones to appreciate the two local medium wave station MP3s. In my
opinion, the SDR-1000 has audio quality that surpasses the Perseus. However,
the computer running the SDR-1000 also had a $300 semi-pro grade sound card
installed. (Due to receiver architecture differences, a high grade sound
card does very little for the Perseus.)

73,

Guy Atkins
Puyallup, WA USA
www.perseus-sdr.blogspot.com