tag:blogger.com,1999:blog-1142737426092510126.post259175923335079101..comments2024-03-27T18:30:37.287-05:00Comments on AE5X: Video: transmitter IMD of (tr)uSDXJohn AE5Xhttp://www.blogger.com/profile/06884676867006975179noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-1142737426092510126.post-1098276609140731762023-01-12T13:09:13.842-06:002023-01-12T13:09:13.842-06:00Interesting...so the question is, is the excessive...Interesting...so the question is, is the excessive bandwidth created within the (tr)uSDX or is it allowing excessive audio bandwidth into the audio input? If the latter, your solution might (probably would) work.John AE5Xhttps://www.blogger.com/profile/06884676867006975179noreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-14719787430554512422023-01-11T09:06:08.654-06:002023-01-11T09:06:08.654-06:00Thanks
Jerry Terres aa1ofThanks<br />Jerry Terres aa1ofAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-69945278083635990442023-01-11T09:04:33.324-06:002023-01-11T09:04:33.324-06:00What is the transmit audio bandwidth when the rece...What is the transmit audio bandwidth when the receive bandwidth is set to 1.8kHz? And, when so set, what is the center frequency of the transmit audio bandwidth?<br /><br />What I am thinking is I f we limited the audio coming out of the mic element to that bandwidth and centered it so that below 500 Hz was cut off, would it help recuse the imd products and the splatter problem?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-53859576972628312892023-01-11T08:48:11.326-06:002023-01-11T08:48:11.326-06:00When the receive band with is set at 1.8kHz, 1) wh...When the receive band with is set at 1.8kHz, 1) what is the center frequency for the transmit audio bandwidth and 2) is the transmit audio bandwidth also 1.8kHz? And if not, then what is it? <br /><br />I wonder if one can one create a filter between the mic capsule and the rig that limits the supplied audio to that same bandwidth, and cuts off below 500 Hz. And would that help limit the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-11172592684031339752022-12-05T05:33:36.454-06:002022-12-05T05:33:36.454-06:00I see the same bahavior if I overload the Input, w...I see the same bahavior if I overload the Input, which is very easy to do.... The Audio Input Signal needs to be set -starting at zero- until the point of max output power (SSB). Not further. Once you go beyond that point, everything goes south. However: We found some firmware issues, and are working on a fix. But this is not related to overdriving input. More related to behavior when injecting Manuel; DL2MANhttps://dl2man.denoreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-50003424986053347222022-12-04T08:44:47.644-06:002022-12-04T08:44:47.644-06:00It should also be fine on FT8, WSPR, etc as only o...It should also be fine on FT8, WSPR, etc as only one tone at a time is transmitted in those modes.<br /><br />73,<br />John AE5XJohn AE5Xhttps://www.blogger.com/profile/06884676867006975179noreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-52407635983807748312022-11-23T19:36:28.834-06:002022-11-23T19:36:28.834-06:00Near as I can tell the mic is directly connected t...Near as I can tell the mic is directly connected to the processor. So i guess firmware is required, if possible, as a fix, but I believe the designers are mostly done with investing large amounts of time to trusdx project, Great CW radio. Thanks DL2MAN, & PE1NNZAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-9568248096740407162022-11-20T11:32:02.227-06:002022-11-20T11:32:02.227-06:00My (tr)uSDX is also from newdiytech and was pre-bu...My (tr)uSDX is also from newdiytech and was pre-built by them. I don't think they have done anything wrong - the issues we are seeing are inherent in the design and the method by which SSB is produced...although I hope I'm wrong and that a firmware update can fix the issue. This doesn't seem likely though, based on the most recent video from the designer:<br />https://www.youtube.com/John AE5Xhttps://www.blogger.com/profile/06884676867006975179noreply@blogger.comtag:blogger.com,1999:blog-1142737426092510126.post-77173481720165205582022-11-20T11:00:16.128-06:002022-11-20T11:00:16.128-06:00I checked my trusdx and the 3rd order IMD is down ...I checked my trusdx and the 3rd order IMD is down about 10 db, lsb, 7.150 MHz. It is a kit build by me and sourced from newdiytech. I also have a classic kit from Amazon that displays similar results. Thanks for posting your test results. My external mic connection is to a 500, 1900, two tone from my Siglent freq generator providing. The IMD doesn't change much even at 50 mv p-p still isAnonymousnoreply@blogger.com