Hi Dave I connect the SDRplay through a 3dB splitter at the 28MHz RX output of the transverter. A hybrid splitter is used to maximize the isolation between the SDR and the K3's receiver.
This method is used in preference to the internal 8.2MHz IF output of the K3 because the transverter output port can deliver a higher signal/noise ratio to the input of the SDR, which improves its ability to display extremely weak VHF/UHF signals. 73 from Ian GM3SEK >-----Original Message----- >From: elecraft-boun...@mailman.qth.net [mailto:elecraft- >boun...@mailman.qth.net] On Behalf Of Dave Fugleberg >Sent: 30 September 2017 14:15 >To: Ian White; Elecraft@mailman.qth.net >Subject: Re: [Elecraft] SDRPlay as panadapter > >You raise some great points, Ian. The choice of which type of panadapter to >use, as well as how to configure and integrate it, depends greatly on what >your purpose is for using one in the first place. We certainly have an >abundance of riches in the choices available today! >You've inspired me to spend some more time tinkering with the RSP1 and >HDSDR. I use my K3 with transverters for VHF+ contesting as well, although >I'm usually a rover station so monitor space is very limited... >You said you connect the SDR at the 28 MHZ transverter IF... Do you simply >add it to the IF daisy chain on the receive side? >Thanks for the thoughtful response. I learn a lot from this list. >73 de W0ZF >On Sat, Sep 30, 2017 at 4:12 AM Ian White <gm3...@ifwtech.co.uk> wrote: > >> N7WS wrote: >> >> > >> >"SpectraVue software is the only SDR software I've ever liked. It >> interfaces >> >with the K3 seamlessly. Every other program I've tried has been >> installed >> >and >> >quickly uninstalled. Sometimes more than once, usually having me ask >> >myself, >> >"Self, what were you thinking?" before uninstalling again. Apparently, >> >programmers do not think like normal people do and try to turn a >> relatively >> >simple tool into a video game. " Sorry Lyle:-) >> > >> >> For measurement purposes I love the SDR-IQ and SpectraVue; but >operating >> and contesting are a different application. >> >> When operating, I focus almost entirely on the waterfall display because >> that presents a time-history of everything that has been happening for the >> past several minutes across the entire displayed bandwidth. The waterfall >> is a huge information resource. On an empty band the waterfall shows >> instantly where new stations are popping up, while on a full band it shows >> if there are any free channels and how long they have been free. >Meanwhile >> the color shading shows which signals are strongest, and instantly >> identifies which ones are spreading more than they should. >> >> Compared with that wealth of operating information from the waterfall, I >> find the spectrum-analyzer display is almost worthless (but remember >we're >> talking about here operating, as distinct from making measurements). >> >> To extract the maximum possible information from the waterfall, I >normally >> maximize the vertical size, aiming for a time-span of 3-5 minutes. The >> spectrum analyzer display is always minimized (and if the display software >> allows, I get rid of it entirely). When operating, the waterfall display is >> front-and-center on a wide-screen monitor. For most modes, only the >small >> log input windows need to share display space at the bottom of the >screen, >> and all other operating windows are displayed on a second monitor. RTTY >is >> the only exception, where multiple decoder windows take over the center >> screen and the waterfall has to take second place. >> >> I currently have two K3s with different types of spectrum/waterfall >> displays. The HF/50MHz setup uses a P3, which of course has the >advantage >> of very tight integration with the K3. However, I do find that the P3 >> requires the SVGA adapter to display the wealth of detail that the >> waterfall has to offer. The P3's own screen is bright and clear, but is >> simply too small (in terms of pixels). And unfortunately the P3/SVGA has a >> number of disadvantages compared with the SDR-PC competition. There is >an >> issue with the P3SVGA's limited color palette which tends to suppress >> weaker signals. The P3 also lacks any method to QSY *quickly* across a >wide >> frequency span to grab fleeting DX opportunities on a nearly empty band. >> >> The other K3 is used with external VHF/UHF transverters, and for this >> application I decided not to buy another P3 but to play the market of >> separate SDRs and PC software. >> >> The SDR is attached to the K3 at the transverter IF frequency of 28MHz, >> which gives much better display sensitivity than the 8.2MHz IF. For >VHF/UHF >> contesting and DXing it is essential to display everything that lives and >> breathes across the entire "contest sub-band", which in Europe extends >over >> at least 250kHz. Important multipliers tend to lurk at both the top and >> bottom ends of that range, so 200kHz is not acceptable. Several good >SDRs >> with 190-200kHz maximum bandwidths, including the SDR-IQ and the P3, >had to >> be ruled out for that reason. After some searching I found that the >SDRplay >> RSP-1 delivered the best combination of dynamic range, available >spectrum >> width (far more than I need) and value for money. >> >> Again after some experimentation, I settled on the HDSDR software, which >> gives a very readable and sensitive display on the large screen and >> provides most of the facilities of a second receiver. Integration with the >> K3 was not easy to configure, but after some work it now has all the >> frequency agility that is so lacking in the P3. The SDR frequency is linked >> to VFO B on the K3, and can be tuned using any combination of the VFO B >> knob, point-and-click on the display (rolling the mouse wheel for fine >> tuning), clicking on the bandmap in N1MM+, or typing frequencies directly >> into the callsign window. Thanks to HDSDR's built-in Omnirig interface, >any >> one of those frequency inputs will automatically update all the others. As >> a receiver, the SDR is more than adequate for searching the band and >> finding new stations to work, interleaved with calling CQ on the K3. If a >> new station appears on the SDR, its frequency is already pre-loaded into >> VFO B on the K3 so one tap of VFO A/B will sw >> ap that signal into the K3, ready to call at the right moment. >> >> I do share Wes's dislike of "video-game" displays. I hate how modern >> software so often arrives with every possible function activated at once... >> but if you take the time to strip away the dross, the end result can be >> quite lean and functional. Maximizing the waterfall display and hiding the >> controls tends to remove most of those annoyances, and the advantages >of a >> really good panadapter have persuaded me to live with the rest. >> >> >> 73 from Ian GM3SEK >> >> >> ______________________________________________________________ >> 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 dave.w...@gmail.com >> >______________________________________________________________ >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 gm3...@ifwtech.co.uk ______________________________________________________________ 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
