tag:blogger.com,1999:blog-2554001380039969960.post3952077154232150986..comments2024-03-26T01:18:16.882+01:00Comments on LA3ZA Radio & Electronics: Car keys in the 70 cm bandSverre Holmhttp://www.blogger.com/profile/08306221557326542499noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-2554001380039969960.post-80453835381378511722014-01-05T20:51:07.618+01:002014-01-05T20:51:07.618+01:00Hi, yes I did the direct conversion mod by solderi...Hi, yes I did the direct conversion mod by soldering two wires to the capacitors on pins 1 and 2 of the RTL2832U chip. When the front-end is the R820T only the I input is used (pins 1 and 2), so I really wanted to have my HF input on the unused Q input on pins 4 and 5, but I don't have soldering iron with a fine enough tip for soldering directly on the chip's pins. <br /><br />The two wires went to a MCL T1-1T transformer and then to my antenna via my <a href="http://la3za.blogspot.no/2004/05/qrp-antenna-tuner.html" rel="nofollow">QRP antenna tuner</a> to get a minimal amount of filtering. But it needs more filtering as there is aliasing. I have tried it on the 3.5, 7 and 25 MHz bands and it works well.Sverre Holmhttps://www.blogger.com/profile/08306221557326542499noreply@blogger.comtag:blogger.com,1999:blog-2554001380039969960.post-79734321304387678312014-01-05T20:34:05.284+01:002014-01-05T20:34:05.284+01:00Sverre, did you do the direct conversion mod to RX...Sverre, did you do the direct conversion mod to RX on the HF bands below 24 MHz?<br />I saw your twitter post about 3524 kHz so I think you did, right?<br />If so, is it easy to do the mod? Any advice?<br />73!ON5ZOhttps://www.blogger.com/profile/03667314542700530483noreply@blogger.com