tag:blogger.com,1999:blog-8044784353067686026.post1683224737130470770..comments2024-02-25T10:43:28.969+00:00Comments on m0xpd's <i>'Shack Nasties'</i>: Arduino Sudden Tx Shield Available Now!m0xpdhttp://www.blogger.com/profile/13241728975907453128noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-8044784353067686026.post-9829354815189971942015-10-14T19:12:00.175+01:002015-10-14T19:12:00.175+01:00Thanks, got it including the output filter part.
/...Thanks, got it including the output filter part.<br />/MarcusUnknownhttps://www.blogger.com/profile/07325340526108041273noreply@blogger.comtag:blogger.com,1999:blog-8044784353067686026.post-73422880023388597172015-10-13T06:11:46.029+01:002015-10-13T06:11:46.029+01:00Hi Markus
1) R5 takes a buffered version of the VF...Hi Markus<br />1) R5 takes a buffered version of the VFO signal to the "RF Bus" connector, for use in the matching Receiver System.<br />2) Yes - C10/L1 should ideally be chosen to resonate at the chosen band. However, I have found the 7MHz version works acceptably at other low HF bands as well, and never bothered to change it (though I do operate mainly at 7 MHz). The single C10/L1 filter is not enough for proper receiver pre-filtering - I suggest a specific band-pass filter for each band.<br /><br />You MUST use low-pass filtering on the output of these kind of transmitters to reduce radiation at harmonics of the intended operating frequency. These should be band-specific. The amplifier (like most other QRP "linears") is not sufficiently linear to operate without such output filtering. m0xpdhttps://www.blogger.com/profile/13241728975907453128noreply@blogger.comtag:blogger.com,1999:blog-8044784353067686026.post-89630652562578152342015-10-12T19:06:29.026+01:002015-10-12T19:06:29.026+01:00Hi,
as beginner ham I'm currently building my...Hi,<br /><br />as beginner ham I'm currently building my own shield and as I start to learn more about radio electronics some questions occurs. I'm looking at v1.4 of the schematics.<br />1. What is the purpose of R5 and its connection to the spare pin on the Arduino shield?<br />2. Won't C10 and L1 act as a band pass filter for the receiver? <br />If so, do you recommend a wider filter if I would like to cover 80m to 6m with the same shield which is basically what the AD9850 could handle? Maybe it needs some extra filtering on the TX output.<br /><br />Best regards<br />SA5PMGUnknownhttps://www.blogger.com/profile/07325340526108041273noreply@blogger.com