[K3 / K3S] KIO3B NF
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After the dust settles with all the new K3Ss being ordered, I’d like to hear from some digital operators what your impressions are of the KIO3B - specifically reception and NF levels.
I am currently using a CreativeLabs E-MU 0204 and have a low NF (I don’t remember exactly) and can decode JT65 on HF down to -25 to -26. I just recently modded a SignaLink USB and and decoding down to a -23 (so far). I guess my thoughts are that if the KIO3B has a comparable NF, I’ll just get rid of all my external devices and further consolidate into one piece of equipment. 73, Joel - W4JBB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On 2015-07-04 9:44 AM, Joel Black wrote:
> I guess my thoughts are that if the KIO3B has a comparable NF, I’ll > just get rid of all my external devices and further consolidate into > one piece of equipment. Given the design flaws in Signalink USB, a basic TI USB CODEC which is used by most inbuilt USB sound implementations should have a noise floor six to ten dB lower than the Signalink. If the "sky noise" is set 10 to 20 dB above the noise floor of the CODEC implementation, you should see JT65 decodes very close theoretical -24 dB 50% threshold while JT9 decodes should be about two to three dB better (-26 dB) at the 50% threshold. Most Signalink units can be improved at least 6 dB by improving the noise bypassing (decoupling) on the 5V bus within the unit, adding proper filtering to the USB 5V input, and replacing the voltage divider used as a reference for the CODEC and audio op-amps with a low noise 2.3 V regulator. Signalink's transmit quality can be improved to a significant degree by turning down the CODEC output (Windows "slider") to prevent distortion in the CODEC and clipping in the op-amps then use an external PTT signal. 73, ... Joe, W4TV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On Sat, 4 Jul 2015, Joe Subich, W4TV wrote:
> Most Signalink units can be improved at least 6 dB by improving the > noise bypassing (decoupling) on the 5V bus within the unit, adding > proper filtering to the USB 5V input, and replacing the voltage divider > used as a reference for the CODEC and audio op-amps with a low noise > 2.3 V regulator. Signalink's transmit quality can be improved to a > significant degree by turning down the CODEC output (Windows "slider") > to prevent distortion in the CODEC and clipping in the op-amps then > use an external PTT signal. Do you have any background info on this? I don't remember getting a schematic or board layout with my SignaLink and if I did, I don't know where I'd find it. -- Hisashi T Fujinaka - [hidden email] BSEE + BSChem + BAEnglish + MSCS + $2.50 = coffee ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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On 2015-07-04 12:11 PM, Hisashi T Fujinaka wrote:
> Do you have any background info on this? I don't remember getting a > schematic or board layout with my SignaLink and if I did, I don't > know where I'd find it. Signalink do not provide that data. Most of the issues are summarized here: http://www.frenning.dk/OZ1PIF_HOMEPAGE/SignaLinkUSB-mods.html including links to other sources, modifications and reverse engineered schematics. 73, ... Joe, W4TV On 2015-07-04 12:11 PM, Hisashi T Fujinaka wrote: > On Sat, 4 Jul 2015, Joe Subich, W4TV wrote: > >> Most Signalink units can be improved at least 6 dB by improving the >> noise bypassing (decoupling) on the 5V bus within the unit, adding >> proper filtering to the USB 5V input, and replacing the voltage divider >> used as a reference for the CODEC and audio op-amps with a low noise >> 2.3 V regulator. Signalink's transmit quality can be improved to a >> significant degree by turning down the CODEC output (Windows "slider") >> to prevent distortion in the CODEC and clipping in the op-amps then >> use an external PTT signal. > > Do you have any background info on this? I don't remember getting a > schematic or board layout with my SignaLink and if I did, I don't know > where I'd find it. > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Joel Black-2
Actually JT65 is capable of decoding to -28/-29 if your radio NF and
sky noise is low enough. I regularly decode 2m-eme signals that are below -27 and sometimes -29. But then my 2m system MDS is -174 dBm (Rx NF = 0.56 dB) which one is unlikely to achieve on HF (mostly because sky noise and local noise set the lower limits of sensitivity and not the radio). ---------------------- snip=== you should see JT65 decodes very close theoretical -24 dB 50% threshold while JT9 decodes should be about two to three dB better (-26 dB) at the 50% threshold. snip=== 73, ... Joe, W4TV 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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The numbers I listed came straight from Joe Taylor's documentation (Online User Guide) for WSJT-X. 73, ... Joe, W4TV On 2015-07-04 3:39 PM, Edward R Cole wrote: > Actually JT65 is capable of decoding to -28/-29 if your radio NF and sky > noise is low enough. I regularly decode 2m-eme signals that are below > -27 and sometimes -29. But then my 2m system MDS is -174 dBm (Rx NF = > 0.56 dB) which one is unlikely to achieve on HF (mostly because sky > noise and local noise set the lower limits of sensitivity and not the > radio). > > ---------------------- > snip=== > you should see JT65 decodes very close theoretical -24 dB 50% threshold > while JT9 decodes should be about two to three dB better (-26 dB) at > the 50% threshold. > snip=== > > 73, ... Joe, W4TV > > 73, Ed - KL7UW > http://www.kl7uw.com > "Kits made by KL7UW" > Dubus Mag business: > [hidden email] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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