Hi, The flowgraph contains a sinusoidal source and a USRP sink. You may notice that the sample rate is quite high. It is part of the requirements. Regards, Moses. [image: image.png]
On Mon, Nov 9, 2020 at 6:19 PM <discuss-gnuradio-requ...@gnu.org> wrote: > Send Discuss-gnuradio mailing list submissions to > discuss-gnuradio@gnu.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > or, via email, send a message with subject or body 'help' to > discuss-gnuradio-requ...@gnu.org > > You can reach the person managing the list at > discuss-gnuradio-ow...@gnu.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Discuss-gnuradio digest..." > > > Today's Topics: > > 1. Re: Measuring transmission power from USRP B210 (Marcus D. Leech) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 09 Nov 2020 12:01:24 -0500 > From: "Marcus D. Leech" <patchvonbr...@gmail.com> > To: discuss-gnuradio@gnu.org > Subject: Re: Measuring transmission power from USRP B210 > Message-ID: <5fa975e4.9020...@gmail.com> > Content-Type: text/plain; charset="utf-8"; Format="flowed" > > On 11/09/2020 11:39 AM, Moses Browne Mwakyanjala wrote: > > Hello everyone, > > I'm in the process of testing a GNU Radio transmitter. The transmitter > > will be connected to a solid-state power amplifier (SSPA) for > > near-Earth satellite communications. The SSPA expects an input of 0dm > > from the USRP TX port. > > > > The first step is thus to measure the power from the USRP. To that > > end, the flowgraph generates a complex sinusoidal signal with a unit > > magnitude. The UHD:USRP Sink block is set to maximum gain (i.e. > > normalized gain of 1.0). Unfortunately, the maximum power I can see > > from the spectrum analyzer is around -6.93 dBm as shown below. To my > > understanding, the USRP can transmit up to 20 dBm as reported in the > > "External Connections" section at this Ettus link : > > https://files.ettus.com/manual/page_usrp_b200.html. > > Could anyone explain why I can't achieve a 20 dBm (or anything around > > it) power level? > > IMG_3475.JPG > > Thanks in advance, > > Moses. > > > Could we perhaps see a minimal flow-graph that demonstrates the issue? > > Generally, setting the baseband magnitude to 1.0 at the same times as > setting to MAX gain can cause linearity issues. > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20201109/e3b13728/attachment.html > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: not available > Type: image/jpeg > Size: 1112823 bytes > Desc: not available > URL: < > https://lists.gnu.org/archive/html/discuss-gnuradio/attachments/20201109/e3b13728/attachment.jpe > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > ------------------------------ > > End of Discuss-gnuradio Digest, Vol 217, Issue 10 > ************************************************* >
