To amplify Lee's point;
for a very dramatic spectrum display of the HF noise, take a look at
the demonstration that Alan K2WS did with his Audigy-2zs card!
http://www.n9vv.com/K2WS.html (scroll down)
Ken
Pedlow, Lee wrote:
The use of A weighting in A/D D/A measurements is a bit of
; FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] Audiocards, USB, etc.
The use of A weighting in A/D D/A measurements is a bit of snake-oil
marketeering. It hides the HF artifacts present in delta-sigma
conversion. There is a big difference in specs for a given DS device
measured
;
FlexRadio@flex-radio.biz
Subject: RE: [Flexradio] Audiocards, USB, etc.
Unweighted dynamic range is approximately 3dB below A weighted. Some
converters specify both.
Gerald
K5SDR
At 07:08 PM 9/26/2005, Pedlow, Lee wrote:
While the aggregate effect of A weighting vs. unweighted might appear
to be only 3dB, the power spectral density (PSD) difference is
enormous! The whole point of the apparent 100 plus dB SNR on a
delta-sigma device is a technique where the conversion
Hello Ahti!
In my previous message the input signal specification should read:
AKM (Asahi Kasei) recommends before the ADC (AK5394A) a balanced input
buffer (NJM5534) that reduces the input signal from max ±12.7Vpp to
±2.4Vpp. Sorry for ignoring the + and - signs.
Are you using a commercial
-
From: Lyle Johnson [EMAIL PROTECTED]
To: Ahti Aintila [EMAIL PROTECTED]
Cc: Tayloe Dan-P26412 [EMAIL PROTECTED];
FlexRadio@flex-radio.biz
Sent: Sunday, September 25, 2005 11:54 PM
Subject: Re: [Flexradio] Audiocards, USB, etc.
Hello Ahti!
In my previous message the input signal specification
: [Flexradio] Audiocards, USB, etc.
This 29v pk-pk sound card range is the essence of my concern
about sound cards. The gain must not be constant.
Sound cards use A/D converter. The two best audio A/D converts
I know of (and there may be others) are the Texas Instruments
PCM1084 and the Wolfson
PROTECTED]; Ahti Aintila [EMAIL PROTECTED];
FlexRadio@flex-radio.biz
Sent: Saturday, September 24, 2005 6:20 AM
Subject: Re: [Flexradio] Audiocards, USB, etc.
At 05:40 PM 9/23/2005, Tayloe Dan-P26412 wrote:
I would think that on top of the audio blocking test we also want to
run audio IP3 tests
, N7VE
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ahti Aintila
Sent: Saturday, September 24, 2005 7:47 AM
To: FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] Audiocards, USB, etc.
Thank you Dan and Jim for the good comments. Sure I noticed how difficult
At 02:45 PM 9/24/2005, Tayloe Dan-P26412 wrote:
I forgot to say that your measurements show that your sound card
shows a 114 db dynamic range which is 5 to 6 db better than the
specs guarantee them to be. Looks like there is some margin in
the A/D converter specs.
Sounds like someone need to
Hi,
Bob:
Esi Juli unbalanced loopback @ 24-bit, 48 kHz mode:
http://www.hot.ee/es7aaz/Juli.htm
P.S. It was RMAA 5.4 when I did this measurement.
Rgds,
Riho, ES7AAZ.
Robert W McGwier wrote:
I sure do wish ESI/Audiotrak DirectWire 3.0 worked with other products.
Please read the manufacturers
Riho:
Muchas gracias!
Spectacular. Only my Lynx L22 has measured better.
73
Bob
rihob., es7aaz wrote:
Hi,
Bob:
Esi Juli unbalanced loopback @ 24-bit, 48 kHz mode:
http://www.hot.ee/es7aaz/Juli.htm
P.S. It was RMAA 5.4 when I did this measurement.
Rgds,
Riho, ES7AAZ.
the correctness of my measurement values, but
clearly the limitations seem to be on the SDR-1000 hardware side.
73, Ahti OH2RZ
- Original Message -
From: rihob., es7aaz [EMAIL PROTECTED]
To: FlexRadio@flex-radio.biz
Sent: Friday, September 23, 2005 7:15 PM
Subject: Re: [Flexradio] Audiocards, USB
: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ahti Aintila
Sent: Friday, September 23, 2005 4:09 PM
To: FlexRadio@flex-radio.biz
Subject: Re: [Flexradio] Audiocards, USB, etc.
Hi Riho and Bob,
If I am not mistaken, the dynamic range of the loopback measurement in this
case may be limited
At 05:05 PM 9/23/2005, Tayloe Dan-P26412 wrote:
You might not be getting a true measure simply
by checking sensitivity (noise floor) and clipping
(largest signal). I think this measurement would be
good only if the card is known not to change its
internal gain between these two measurements
At 05:40 PM 9/23/2005, Tayloe Dan-P26412 wrote:
I would think that on top of the audio blocking test we also want to
run audio IP3 tests and audio IP2 dynamic range tests as well to make
sure that the distortion characteristics are at least as good as the
SDR1000 front end.
- Dan, N7VE
Such
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