The old radios of the past that were the good ones such as the R390 had
mechaincal filters in them. When you used a 4 khz BW filter in AM mode on
an R390, your total BW was 4 khz. Your audio passband was 0 to 2 khz since
for AM you have DSB with carrier. So it was consistent to call a filter
that was 4 khz wide, a 4 khz filter.
The rx320, rx330, rx331, rx340, Pegasus, Jupiter in Peg mode, all use the
above scheme. That is the audio passband in AM mode is half of the selected
filter BW. The Orion V1 scheme violated this setup. That is when you
selected a 4 khz filter on AM mode, you actually got an 8 khz filter. This
gave you a 4 khz audio passband if PBT was centered. The Orion II and Orion
V2 have fixed this inconsistency by giving you the filter you select. What
needs to be done is to add a few more filter selections like 8 khz and 10
khz which would yield 4 khz and 5 khz audio passbands.
Carl Moreschi N4PY
121 Little Bell Drive
Bell Mountain
Hays, NC 28635
----- Original Message -----
From: "Sinisa Hristov" <shristov@ptt.yu>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Thursday, March 16, 2006 5:21 PM
Subject: Re: [TenTec] Orion Sub Receiver BW
> Barry LaZar wrote:
>
> > Going to a bandwidth in excess of 10 KHz. really isn't useful.
> > The FCC limits the AM BC'ers to a 10 KHz channel and the CCIR
> > limits are less in the SW bands.
>
>
> Of course 10 kHz may be too much, but 8 or 9 kHz
> BW is actually transmitted, and a 3 kHz V2 audio sounds
> substantially worse than 4 or 4.5 KHz V1 audio.
>
>
> 73,
>
> Sinisa YT1NT, VE3EA
> _______________________________________________
> 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
|