Re: [Elecraft] RTL SDR dongle
If I could throw my .02c in here: Not all rtl dongles are the same. I have 2 of the rtl-sdr dongles sitting in front of me. The earliest ones received 27mhz thru appx 1700 mhz. There is no front end to speak of, and they are prone to overload. To receive below 27 mhz required a hardware mod that many times would destroy the device unless you are skilled with soldering smt devices. Also the software (rtl_fm) wasn't capable of using the bypass - it needed to be modified. some of the newer software did work OK. As an HF receiver, it was a horrible solution. The folks at rtl-sdr.com realized this and a few years ago put out a new version known as the V3 model. The marking on the device is "RTL2832U R820T2 TCXO+BIAS T+ HF". It is the same size and comes in a shiny (sort of) aluminum case is is today about $25 on Amazon etc. The V3 model does receive on HF down to a few 100 khz since the bypass parts are already installed. Many of the newer sdr programs know to use the Q mode receive and tuner bypass options to receive in the HF region. With gqrx, as mentioned before, there is a no limits checkbox that needs to be checked for the software to work below 27 mhz. I've been using one of these for a couple of years and it works, but not that well. Without an AM band notch filter the am broadcast stations wreck hf band reception. A decent one is about $10. Next, there are image issues across the hf band, greater when above about 14 mhz. The sensitivity is not good and, again, they are prone to overload. I tried it connected to the IF out of my K3 and would not do it again. As was suggested, the sdr SdrPlay rsp1 receiver is about $100 (there are newer and better sdrPlay units) works and doesn't require the am notch filter. (Aside - you may not require the notch filter when coming out of the IF port of the K3 - I didn't try). There are newer dongles from other suppliers that do not cover HF by default and may or may not work in HF. I think almost all require an upconverter (another $45 to $75) to be useable. But now you have 3 devices (am filter, converter, rtl dongle) on your desk. The rtl-sdr dongles are a good solution for those just learning what radio is and want to play without spending much more than dinner money, but if you can afford a K3 you can do better than using an rtl dongle for a panadapter display. > Using an sdrPlay rsp1 works (somewhat) when used with the right software, and may be an option for you. I can't recommend the rtl-sdr option. Kurt > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to theis.k...@gmail.com > -- Kurt Theis __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] RTL SDR dongle
If I could throw my .02c in here: Not all rtl dongles are the same. I have 2 of the rtl-sdr dongles sitting in front of me. The earliest ones received 27mhz thru appx 1700 mhz. There is no front end to speak of, and they are prone to overload. To receive below 27 mhz required a hardware mod that many times would destroy the device unless you are skilled with soldering smt devices. Also the software (rtl_fm) wasn't capable of using the bypass - it needed to be modified. some of the newer software did work OK. As an HF receiver, it was a horrible solution. The folks at rtl-sdr.com realized this and a few years ago put out a new version known as the V3 model. The marking on the device is "RTL2832U R820T2 TCXO+BIAS T+ HF". It is the same size and comes in a shiny (sort of) aluminum case is is today about $25 on Amazon etc. The V3 model does receive on HF down to a few 100 khz since the bypass parts are already installed. Many of the newer sdr programs know to use the Q mode receive and tuner bypass options to receive in the HF region. With gqrx, as mentioned before, there is a no limits checkbox that needs to be checked for the software to work below 27 mhz. I've been using one of these for a couple of years and it works, but not that well. Without an AM band notch filter the am broadcast stations wreck hf band reception. A decent one is about $10. Next, there are image issues across the hf band, greater when above about 14 mhz. The sensitivity is not good and, again, they are prone to overload. I tried it connected to the IF out of my K3 and would not do it again. As was suggested, the sdr SdrPlay rsp1 receiver is about $100 (there are newer and better sdrPlay units) works and doesn't require the am notch filter. (Aside - you may not require the notch filter when coming out of the IF port of the K3 - I didn't try). There are newer dongles from other suppliers that do not cover HF by default and may or may not work in HF. I think almost all require an upconverter (another $45 to $75) to be useable. But now you have 3 devices (am filter, converter, rtl dongle) on your desk. The rtl-sdr dongles are a good solution for those just learning what radio is and want to play without spending much more than dinner money, but if you can afford a K3 you can do better than using an rtl dongle for a panadapter display. > Using an sdrPlay rsp1 works (somewhat) when used with the right software, and may be an option for you. I can't recommend the rtl-sdr option. Kurt -- Kurt Theis __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] RTL SDR dongle
On 2021-02-08 8:48 a.m., Eric Lanzl wrote: Regarding the RTL SDR dongle. I notice that it says that the dongle will go down to 500 khz with reduced sampling below 24 mhz. I wias wondering if one needs to get an up converter to get it to work? The tuner chip does have a sort of "bypass" mode that lets you see the very low frequency signals that are below what is considered the normal tuning range. It comes at a price. If you are really interested in the lower frequencies the use of an external up converter would be a good idea. -- Cheers! Kevin. http://www.ve3syb.ca/ | "Nerds make the shiny things that https://www.patreon.com/KevinCozens | distract the mouth-breathers, and | that's why we're powerful" Owner of Elecraft K2 #2172 | #include | --Chris Hardwick __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] RTL SDR dongle
Eric, I have a NooElec R820T that does work from 25.85 MHz to 1766 MHz Anything lower that that needs an upconverter afaik. I can tell GQRX to go lower but it then detects nothing anymore... GQRX is a Linux SDR program where a funcion that says "No limits" allows to tune higher and lower than these two frequency limits. I suppose you more likely need an attenuator between the upmixer and the dongle. 73, Peter PA0PJE Op 08-02-2021 om 14:48 schreef Eric Lanzl: Regarding the RTL SDR dongle. I notice that it says that the dongle will go down to 500 khz with reduced sampling below 24 mhz. I wias wondering if one needs to get an up converter to get it to work? Or will the reduced functioning be ok for a basic pan adapter. Also, does it require a buffer amp or not for the K3? Thanks, Eric WB9JNZ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to pa0...@xs4all.nl __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] RTL SDR dongle
These dongles are mediocre, yes they are cheap, but they are virtually useless for anything other than a door stop. The lowest cost, but useful, SDR receiver is an SDRPLAY RSP1A. With the free RSPUno software the RSP1A will track a K3 via Omnirig, clicking on a signal on the RSPUno spectrum jumps the K3 to the frequency. You can display DX Cluster spots on the spectrum too. Cost approx $120. I use an RSPDX with a home made ferrite splitter on the RF IN/OUT on my K3, details of the splitter are on my page at: https://www.qsl.net/g4aon/elecraft_mods/ 73 Dave -- Sent from my iPhone SE __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] RTL SDR dongle
Regarding the RTL SDR dongle. I notice that it says that the dongle will go down to 500 khz with reduced sampling below 24 mhz. I wias wondering if one needs to get an up converter to get it to work? Or will the reduced functioning be ok for a basic pan adapter. Also, does it require a buffer amp or not for the K3? Thanks, Eric WB9JNZ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
