[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Transmit filtering

From: John Ackermann N8UR
Subject: Re: [Discuss-gnuradio] Transmit filtering
Date: Mon, 5 Sep 2011 12:55:00 -0400

Hi Marcus --

I am selecting complex taps from the drop down, but still get an error at 
runtime if either cutoff frequency is 0 or smaller.



On Sep 5, 2011, at 11:46 AM, "Marcus D. Leech" <address@hidden> wrote:

> On 05/09/11 10:19 AM, John Ackermann N8UR wrote:
>> I'm generating two NBFM signals, offsetting them plus and minus 25 kHz
>> with FreqXlatingFilters, and combining the output in an adder which
>> then drives a USRP sink.  It seems sensible to put a bandpass filter
>> on the result.
>> I have a basic conceptual confusion.  I would think that you'd specify
>> a bandpass filter around zero with a low cutoff of, say, -40e3 and a
>> high cutoff of +40e3.  However, this doesn't work -- the bandpass
>> filter seems to require a number >0 for the lowpass frequency.
> Make sure that you specify complex-taps.  I assume you're using GRC.  By
> default, it uses the version of
>  the bandpass filter with real taps.  But if you specify complex taps,
> you can use negative frequencies.
> -- 
> Principal Investigator
> Shirleys Bay Radio Astronomy Consortium
> http://www.sbrac.org
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

reply via email to

[Prev in Thread] Current Thread [Next in Thread]