Having worked in the telecommunications industry for over twenty-two years,
with the initial five years with telephone transmission and switching of 300
Hz to 3000 Hz (2.7 kHz bandwidth) circuits as optimized originally by Mr.
Fletcher and Mr. Munson of Bell Labs (see
http://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves ), any filter of
2.7 kHz or greater in the AM position will sound better assuming the low
frequency rolloff can be pushed towards 200 Hz without rolling off the high
frequencies near 3000 Hz. But its more than just bandwidth, the transmitted
frequency response must be compensated in some manner or the audio will
sound muddy and loose intelligibility. It is a good idea to have have a
flat transmitted signal with the low, mid-point, and high frequencies of the
transmitted signal at about the same amplitude.
73 ES DX,
Gary -- AB9M
-----Original Message-----
From: mcelmer1
Sent: Tuesday, February 12, 2013 3:09 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] eagle
Makes sense.
Mike
W8TRN
----- Original Message -----
From: "Rodney" <w3krq@dejazzd.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Monday, February 11, 2013 11:21
Subject: Re: [TenTec] eagle
I installed the filter in the am slot did a a/b test on 40m with 4 hams got
better audio with 2.8 than 2.4.
-----Original Message-----
From: Barry N1EU
Sent: Sunday, February 10, 2013 4:24 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] eagle
Is that filter is in the tx signal path of the Eagle? The tx signal isn't
filtered entirely in dsp with configurable bandwidth?
73,
Barry N1EU
On Sun, Feb 10, 2013 at 4:04 PM, Rodney <w3krq@dejazzd.com> wrote:
I got a 2.8 filter from inrad for my Eagle got great audio reports.
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|