Alan, thanks for the explanation, sounds like there is some other problem then if people are not seeing the weak signals that they can hear. Will hook up the P3 here shortly and see what mine does. If you can see -127DBm at 30 KHZ it sounds fine to me. 73 Merv K9FD / KH7C > No I didn't have to narrow the span to 2 kHz to see the -127 dBm signal. > Anything less than about 30 kHz was sufficient. > > Also, remember I had the K3 preamp off and the attenuator on. With the > attenuator off, the -127 dBm signal is visible all the way up to 200 kHz > span. > > With the K3 preamp turned on I can see a -135 dB signal, even at 200 kHz > span. (I had to use a 10 dB attenuator to get the signal generator to > go that low.) > > Alan N1AL > > > > > On Tue, 2010-09-14 at 07:51 -1000, Merv Schweigert wrote: > >> For some reason that goes against what I think many are looking for in the >> P3, if one has to narrow the span to 2khz, then I see no use for the P3 >> at all, I need >> to see what is on the band at -127DBm at 30 to 50khz or more span. If >> the signal is >> only seen at 2KHZ, I can hear that by ear and dont need the P3. I >> think VHF >> operators are saying the same thing, they need to look over a larger >> portion of the >> band and spot weak signals and move to them, not narrow to 2KHZ and sit >> there >> and tune the radio hoping to find a weak signal, thats what you do >> without a P3. >> Does the LP Pan also work that poorly that you cannot see weak signals >> 30KHZ >> away? >> I do notice that with all the P3 sales, you do not see many LP Pans for >> sale, so either >> people who buy the P3 are just buying it to have another Elecraft >> product, or they are >> keeping both and not sure yet which is the best? >> Most of my operation will be low band, 160 meters, and if I cannot see >> the weak >> signals on the band and cover at least 30 KHZ then the P3 is of no use >> at all. >> Bill W4ZV are you seeing the weak signals on 160 that are 20 or 30KHZ away? >> Or do you have to narrow the span down to see a signal that is barely >> audible? >> 160 ops would like to know. >> 73 Merv K9FD / KH7C >> >> >> >>> Hi Larry, >>> >>> It depends on the span. Unlike some other panadapters, the P3 >>> automatically reduces the sample rate as you narrow the span, which >>> improves the sensitivity. >>> >>> For example, I have my HP8656B signal generator set to 3640 kHz with the >>> amplitude as low as it will go (-127 dBm). The K3 has the preamp off, >>> the attenuator on, and default CW shift and width. Under those >>> conditions I can just barely hear the carrier. It's weak enough that if >>> it were a modulated CW signal I don't think I could copy it. >>> >>> However the carrier is clearly visible on the waterfall if I set the P3 >>> span to 2 kHz. As I increase the span the signal gradually gets harder >>> and harder to see. Above about 30 kHz or so the signal disappears into >>> the noise. >>> >>> So that's the trick. Narrow the span to make those signals pop out of >>> the noise. >>> >>> 73, >>> >>> Alan N1AL >>> >>> >>> On Tue, 2010-09-14 at 06:03 -0700, Larry K1UO wrote: >>> >>> >>>> Bill, >>>> >>>> I can tell you that just last night, on 160 meters, I copied 2 very weak >>>> stations perfectly Q5 that did not show on the P3 waterfall. Now, Its >>>> entirely possible its my adjustment skills but I dont think so. Yes..the >>>> K3 >>>> IF Mod was factory installed. This has happened more than once. For >>>> some reason I was expecting the P3 to show these very weak signals better >>>> than I could find them myself while tuning but no amount of adjustment so >>>> far will do this. I may be expecting too much? >>>> Just so you know what anothers experience has been so far. >>>> 73 >>>> >>>> >>>> >>>> >>>> I too would like to see details of the improvement over LPan etc. I am a >>>> long time user of SDR/computer panadapters for use in detecting very weak >>>> signals at UHF/VHF/microwave. I use a Softrock on the K3 IF port since I >>>> got >>>> my K3 a year ago. I have yet to see one report regarding weak sig >>>> detection >>>> with the P3 after many requests to the initial testers of the P3. ANYONE >>>> out >>>> there looking for weak weak sigs with a P3?? >>>> >>>> 73 Bill K0AWU EN37ed >>>> >>>> >>>> >>>> >>> ______________________________________________________________ >>> 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 >>> >>> >>> >> ______________________________________________________________ >> 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 >> > > > >
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