K3 - Filter suggestions for new builder
Locked
12
12
Re: K3 - Filter suggestions for new builder
 
|
> The only reason I had for putting the FM filter in the 2nd receiver > was to be able to hear more of the split in a broad pileup situation > (like the extremely large split widths that we saw a few months ago > with 7O6T), The width of the roofing filter has nothing at all to do with hearing more of the pile-up (unless you're talking about literally "listening" to all the signals at one time like a pile-up tape). The P3's pick- up point is ahead of any roofing filter - it can "see" up to 200 KHz at a time. The K3 transmitter and receiver can be split anywhere in the band and if the KRX3 is used with a separate antenna the K3 and KRX3 can literally transmit on one band and listen on another. 73, ... Joe, W4TV On 9/26/2012 8:58 PM, Dale Boresz wrote: > Joe, > > Good observations, all. I agree that 4.2 KHz is certainly good enough > for communications audio. > > The only reason I had for putting the FM filter in the 2nd receiver was > to be able to hear more of the split in a broad pileup situation (like > the extremely large split widths that we saw a few months ago with > 7O6T), figuring that being able to simultaneously hear the wider > bandwidth and see it on the P3 would be a great combination. I'll just > have to be a bit quicker with the VFO-B knob ;-) > > 73, Dale > WA8SRA > > > On 9/26/2012 8:10 PM, Joe Subich, W4TV wrote: >> The limit occurs several places ... adjust the "HI" setting and one >> will find 4.20 is the maximum available. There is also an analog >> lowpass filter in the audio (headphone and speaker) between the DAC >> and the headphone/speaker amplifiers. >> >> I'm sure this limitation derives from the roughly 10 KHz clock/sample >> rate used for the DAC ... Nyquist says the maximum frequency can not >> be more than half the sample (clock) rate. 4.2 KHz is plenty good >> enough for communications audio ... and not bad for AM with fading, >> noise, and interference typical of medium and high frequencies. >> >> The FM filter still provides noticeably better double sideband AM >> response (4.2 - 4.5 KHz with DSP/LPF skirts) than the AM filter >> (3.0-3.3 KHz depending on the IF filter response). >> >> 73, >> >> ... Joe, W4TV >> >> >> On 9/26/2012 7:23 PM, Don Wilhelm wrote: >>> Sorry, but yes, the K3 audio is limited at 4 kHz, no matter whether it >>> is to the headphones or to the speaker. Please do not "shoot the >>> messenger". but that information is in the archives of this reflector in >>> several places - it has been discussed periodically. >>> >>> If you want to lobby for extended audio response, that is fine, but I am >>> just saying what the limits are today. Whether those can be extended or >>> not is for the DSP designer to answer. >>> >>> 73, >>> Don W3FPR >>> >>> On 9/26/2012 7:11 PM, Dale Boresz wrote: >>>> On 9/26/2012 1:35 PM, Edward R Cole wrote: >>>>> ... But I learned that audio is limited to 4-KHz >>>>> regardless of IF filter so I ended up selling the extra 13-KHz filter. >>>>> >>>>> ... >>>>> >>>>> 73, Ed - KL7UW >>>> I really hope that this does not apply to received audio to the >>>> headphones or loudspeaker! I just purchased two FM filters (one for >>>> sub-receiver to monitor wide splits) specifically to open up the receive >>>> passband (audio included) for SWL and BCB reception. I have no intention >>>> of actually transmitting FM or AM for that matter -- just want the wider >>>> audio bandwidth for receive. >>>> >>>> So... is the received audio bandwidth *really* limited to 4 KHz? >>>> >>> ______________________________________________________________ >>> 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 >>> >> ______________________________________________________________ >> 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 >> > > ______________________________________________________________ > 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 > 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 |
|
|
In reply to this post by alorona
Another way of looking at it is this:
Just because a signal gets inside of your roofing filter doesn't mean squat. If the mixers can handle the signal's level, and the HI LO cut controls can slice off the signal, you won't even know it's there. You simply don't care! The only time this could become a problem is if the signal that squeezes into your roofing filter is huge. Then it could start polluting your passband with intermod products or activating your AGC. EVEN THEN, most hams can't even detect the first 10 dB or so of this distortion. And it's such a rare event: operating a really hot contest with a really big antenna with just the right combination of interferers; or your ham neighbor very close to you, etc. In these corner cases, you can justify extreme measures of narrow roofing filters, etc. I believe that 99% of us can get by with 1 SSB roofing filter and perhaps 1 CW-width roofing filter. The intermediate bandwidths are really overkill. So don't sweat a 2.7 vs. 2.8 kHz filter so much. You can't tell the difference when you're listening to an SSB signal with the HI LO controls set to a WIDTH of 2.4 or 2.6 kHz. Agonizing over buying a roofing filter of 2.7 or 2.1 kHz is a little like worrying if you should go for the 89 octane gasoline. If you've got the money, go for it. But you probably won't notice any difference at all. Finally, I will say this: if you find your 1.0 kHz roofing filter isn't wide enough to protect you against, you know, W4ZV's super contest signal, you're probably too close to him. In that case, just move about 600 Hz up the band. :^) With the utmost respect to W4ZV, Al W6LX ______________________________________________________________ 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 |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by Joe Subich, W4TV-4
Joe,
Understood. I wanted to be able to simultaneously hear and see 12 Khz or so of cw signals, thinking that I could more quickly identify the station being worked. For example, if I know the dx station is listening from 14.010 to 14.020 (admittedly pretty wide), I figured I could include that entire range within the FM filter bandwidth (which I still can do), AND also hear all 10 KHz of those signals (which I've learned I cannot do). Oh well; the FM filter will still let me hear a wider swath of the pile-up than my present 2.8KHz filter will... 73, Dale WA8SRA On 9/26/2012 9:25 PM, Joe Subich, W4TV wrote: >> The only reason I had for putting the FM filter in the 2nd receiver >> was to be able to hear more of the split in a broad pileup situation >> (like the extremely large split widths that we saw a few months ago >> with 7O6T), > The width of the roofing filter has nothing at all to do with hearing > more of the pile-up (unless you're talking about literally "listening" > to all the signals at one time like a pile-up tape). The P3's pick- > up point is ahead of any roofing filter - it can "see" up to 200 KHz > at a time. The K3 transmitter and receiver can be split anywhere in > the band and if the KRX3 is used with a separate antenna the K3 and > KRX3 can literally transmit on one band and listen on another. > > 73, > > ... Joe, W4TV > > > On 9/26/2012 8:58 PM, Dale Boresz wrote: >> Joe, >> >> Good observations, all. I agree that 4.2 KHz is certainly good enough >> for communications audio. >> >> The only reason I had for putting the FM filter in the 2nd receiver was >> to be able to hear more of the split in a broad pileup situation (like >> the extremely large split widths that we saw a few months ago with >> 7O6T), figuring that being able to simultaneously hear the wider >> bandwidth and see it on the P3 would be a great combination. I'll just >> have to be a bit quicker with the VFO-B knob ;-) >> >> 73, Dale >> WA8SRA >> >> >> On 9/26/2012 8:10 PM, Joe Subich, W4TV wrote: >>> The limit occurs several places ... adjust the "HI" setting and one >>> will find 4.20 is the maximum available. There is also an analog >>> lowpass filter in the audio (headphone and speaker) between the DAC >>> and the headphone/speaker amplifiers. >>> >>> I'm sure this limitation derives from the roughly 10 KHz clock/sample >>> rate used for the DAC ... Nyquist says the maximum frequency can not >>> be more than half the sample (clock) rate. 4.2 KHz is plenty good >>> enough for communications audio ... and not bad for AM with fading, >>> noise, and interference typical of medium and high frequencies. >>> >>> The FM filter still provides noticeably better double sideband AM >>> response (4.2 - 4.5 KHz with DSP/LPF skirts) than the AM filter >>> (3.0-3.3 KHz depending on the IF filter response). >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> >>> On 9/26/2012 7:23 PM, Don Wilhelm wrote: >>>> Sorry, but yes, the K3 audio is limited at 4 kHz, no matter whether it >>>> is to the headphones or to the speaker. Please do not "shoot the >>>> messenger". but that information is in the archives of this reflector in >>>> several places - it has been discussed periodically. >>>> >>>> If you want to lobby for extended audio response, that is fine, but I am >>>> just saying what the limits are today. Whether those can be extended or >>>> not is for the DSP designer to answer. >>>> >>>> 73, >>>> Don W3FPR >>>> >>>> On 9/26/2012 7:11 PM, Dale Boresz wrote: >>>>> On 9/26/2012 1:35 PM, Edward R Cole wrote: >>>>>> ... But I learned that audio is limited to 4-KHz >>>>>> regardless of IF filter so I ended up selling the extra 13-KHz filter. >>>>>> >>>>>> ... >>>>>> >>>>>> 73, Ed - KL7UW >>>>> I really hope that this does not apply to received audio to the >>>>> headphones or loudspeaker! I just purchased two FM filters (one for >>>>> sub-receiver to monitor wide splits) specifically to open up the receive >>>>> passband (audio included) for SWL and BCB reception. I have no intention >>>>> of actually transmitting FM or AM for that matter -- just want the wider >>>>> audio bandwidth for receive. >>>>> >>>>> So... is the received audio bandwidth *really* limited to 4 KHz? >>>>> >>>> ______________________________________________________________ >>>> 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 >>>> >>> ______________________________________________________________ >>> 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 >>> >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ > 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 > ______________________________________________________________ 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 |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by alorona
*Al,
whilst your statements hold true for you, I DO use the 1.8Khz almost as my default. Attention paid to Hi/Lo gives me nice intelligibility and if you were listening to 3D2C last night on 20M and witnessed the deplorable behavior of stations deliberately providing QRM on their call frequency you have not been impressed. I ran at 1.8Khz, tightened it up some more with Hi/LO, watched on the P3 and pounced, got'em, no problem. ( I see the on-line log does not show my success as yet) Whilst I have absolutely no idea why 3D2C generated so much qrm against them, I can only say it was a sad day and the operators I heard (2) running 3D2C were great to listen to. 73 * On 27 September 2012 11:06, Al Lorona <[hidden email]> wrote: > Right, Don! > > I still believe that many K3 users are under the erroneous impression that > the > roofing filter determines the receiver bandwidth. It does not. The HI and > LO > knobs do. > > The only thing the roofing filter does is determine the MAXIMUM possible > bandwidth of the receiver. > > In 99% of cases, an SSB roofing filter is good enough. (That statement is > going > to draw some fire.) > > It's a little bit like this: the roofing filter is like the credit limit > on your > Visa card. You can't go any higher than that. But in any typical month, you > spend far less than that... and on the K3 the amount you *actually* spend > is set > by the HI and LO cut controls. > > This is why I advised the original poster: you wanna know what 1.8 kHz > sounds > like? Set your HI LO controls to a bandwidth of 1.8 kHz. Then decide > whether it > 1/ is tolerable; and 2/ increases intelligibility enough to make the > investment > worth it. I happen to think that 1.8 kHz is too narrow. But that's just me. > > ________________________________ > > I say that because in all cases with the K3, it is the DSP that > determines the filter width rather than the roofing filter. What I am > saying is that even if you put in a 1.8k filter, SSB at a 1.8k width > will sound the same as it does right now using only the DSP. > > > 73, > Don W3FPR > ______________________________________________________________ > 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 > -- *Gary* *Start the day off slow, then taper off.........* K3 #679 KPA500FT #18 KAT500FT 007 P3 #1629 ______________________________________________________________ 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 |
|
|
In reply to this post by Stan AE7UT
Hello Stan.
I am an avid CW enthusiast and spend 100% of my time, usually around 4-6 hours a night on 20/40m CW. I have 2 identical loaded to the the max K3/100's and P3's purchased late this year. I have been very happy with my filter choices: 1. 13KHz FM 2. 6KHz AM INRAD 3. 2.8KHz INRAD 4. 400Hz INRAD 5. 200Hz 5-pole (lowest INRAD was 250Hz I think and I wanted the scalpel) I have all 5 filters populated on MAIN RX. I only have one filter, 2.8K on SUB. I almost never use the sub, so figured I could add them later if necessary. Only ordered the SUB's in the event I ever sold the rigs the next guy would probably want them. This is my order printout for both K3's: Item Ref. Price ea. Qty. Description 144OPT100 $0.00 1 K144XV Panel Kit for K3 /100 K144RFLK $89.95 1 K144XV REFLOCK K144XV-F $349.95 1 K3 Int. 2 M Module; Assm. K3/100-F $2249.95 1 K3 100W Xcvr. (Assembled) K3SSKT $19.95 1 K3 Stainless H/W Kit KAT3-F $339.95 1 K3 ATU (Fact. Installed) KBPF3 $149.95 1 K3 Gen. Cov. RX Module KDVR3 $129.95 1 K3 Dig. Voice Recorder KFL3A-2.8_2.7sw $129.95 2 2.8 for 2.7 kHz swap KFL3A-200 $89.95 1 K3 200 Hz, 5 pole filter KFL3A-400 $139.95 1 K3 400 Hz, 8 pole filter KFL3A-6K $139.95 2 K3 6 kHz, 8 pole filter KFL3B-FM $139.95 1 K3 FM b/w filter KRX3-F $659.95 1 K3 2nd RX (Fact. Assm.) KTCXO3-1 $99.95 1 K3 TCXO (0.5ppm) KUSB $39.95 1 Univ. Ser Bus Adapt. KXV3A $119.95 1 K3 RX Ant, IF Out & Xvrtr Int MH2 $59.95 1 Hand Mic. for K2/K3. P3-F $749.95 1 P3-F Panadapter -Assembled- P3SVGA $259.95 1 P3 Video/FFT Adapt. In case you're wondering, this order shows an extra 6KHz because I didn't originally include it on the first K3. I added it so both K3's would match in the event I wanted to do some SSB in the future. Both the MAIN and SUB filters were upgraded at order time from the 2.7K to the 2.8K. I personally LOVE the sharper skirts of the INRAD's. I was a total Icom guy before this summer when I got behind a K3. Since then I have sold 4 of the 5 Icom radios, including a brand new (2 weeks use) IC-7600. The 5th is for sale on QRZ. Icoms are very well built and have fancy displays, however, their receivers leave much to be desired when it comes to the filtering aspects. Very noisy. IMO, I buy a rig for the RX quality, quietness, sensitivity, and versatility. My choice to go Elecraft was based on a 30 day comparison of the K3 vs. the FTDX5000MP. I tried a few other rigs during that time including TnT and Kenwood, but the K3 and 5K were tops. Yes, tried the TnT, awesome break-in, but preferred the K3 and 5K over TnT. In short, here's the scoop: If you're mainly sideband, the Yaesu wins. If you're mainly CW, the K3 wins. The K3 is better on the lower bands and the 5K is better on the higher bands. However, the K3 is no slouch on SSB either. I'm sure people differ in opinions and appreciate taking their entire desk to house a big rig that weighs about 50# with tons of knobs to clean, but unless you have $12K to throw at both of them to test personally, I'd go Elecraft. That's my honest opinion. I was lucky to have a couple of friends that have them both side by side at the same time. I prefer the 8# loaded K3 that leaves room for my KPA-500, P3, paddle, and accessories as well. Anyway, for what it's worth, those are my filters and opinions on the two best rigs on the market this summer. Take care and 73 de Scott - n0nuf |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by dmb@lightstream.net
> I figured I could include that entire range within the FM filter > bandwidth (which I still can do), AND also hear all 10 KHz of those > signals (which I've learned I cannot do). Your ears are much better than mine if you can actually copy a full 10 KHz wide audio pile-up. I have enough trouble keeping up with 4 KHz or so (200 Hz to 4.2 KHz) if I open everything up in SSB mode. Note the K3 limits HI in CW to "Pitch + 1400 Hz" thus if one likes a 500 Hz tone, the highest frequency passed in CW is 1900 Hz. The *widest* bandwidth possible in CW is by using an 800 Hz sidetone which results in 2.2 KHz ... whether the "roofing filter" is 2.7, 2.8, 6 or 13 KHz wide. 73, ... Joe, W4TV On 9/26/2012 9:46 PM, Dale Boresz wrote: > Joe, > > Understood. I wanted to be able to simultaneously hear and see 12 Khz or > so of cw signals, thinking that I could more quickly identify the > station being worked. For example, if I know the dx station is listening > from 14.010 to 14.020 (admittedly pretty wide), I figured I could > include that entire range within the FM filter bandwidth (which I still > can do), AND also hear all 10 KHz of those signals (which I've learned I > cannot do). Oh well; the FM filter will still let me hear a wider swath > of the pile-up than my present 2.8KHz filter will... > > 73, Dale > WA8SRA > > > On 9/26/2012 9:25 PM, Joe Subich, W4TV wrote: >>> The only reason I had for putting the FM filter in the 2nd receiver >>> was to be able to hear more of the split in a broad pileup situation >>> (like the extremely large split widths that we saw a few months ago >>> with 7O6T), >> The width of the roofing filter has nothing at all to do with hearing >> more of the pile-up (unless you're talking about literally "listening" >> to all the signals at one time like a pile-up tape). The P3's pick- >> up point is ahead of any roofing filter - it can "see" up to 200 KHz >> at a time. The K3 transmitter and receiver can be split anywhere in >> the band and if the KRX3 is used with a separate antenna the K3 and >> KRX3 can literally transmit on one band and listen on another. >> >> 73, >> >> ... Joe, W4TV >> >> >> On 9/26/2012 8:58 PM, Dale Boresz wrote: >>> Joe, >>> >>> Good observations, all. I agree that 4.2 KHz is certainly good enough >>> for communications audio. >>> >>> The only reason I had for putting the FM filter in the 2nd receiver was >>> to be able to hear more of the split in a broad pileup situation (like >>> the extremely large split widths that we saw a few months ago with >>> 7O6T), figuring that being able to simultaneously hear the wider >>> bandwidth and see it on the P3 would be a great combination. I'll just >>> have to be a bit quicker with the VFO-B knob ;-) >>> >>> 73, Dale >>> WA8SRA >>> >>> >>> On 9/26/2012 8:10 PM, Joe Subich, W4TV wrote: >>>> The limit occurs several places ... adjust the "HI" setting and one >>>> will find 4.20 is the maximum available. There is also an analog >>>> lowpass filter in the audio (headphone and speaker) between the DAC >>>> and the headphone/speaker amplifiers. >>>> >>>> I'm sure this limitation derives from the roughly 10 KHz clock/sample >>>> rate used for the DAC ... Nyquist says the maximum frequency can not >>>> be more than half the sample (clock) rate. 4.2 KHz is plenty good >>>> enough for communications audio ... and not bad for AM with fading, >>>> noise, and interference typical of medium and high frequencies. >>>> >>>> The FM filter still provides noticeably better double sideband AM >>>> response (4.2 - 4.5 KHz with DSP/LPF skirts) than the AM filter >>>> (3.0-3.3 KHz depending on the IF filter response). >>>> >>>> 73, >>>> >>>> ... Joe, W4TV >>>> >>>> >>>> On 9/26/2012 7:23 PM, Don Wilhelm wrote: >>>>> Sorry, but yes, the K3 audio is limited at 4 kHz, no matter whether it >>>>> is to the headphones or to the speaker. Please do not "shoot the >>>>> messenger". but that information is in the archives of this reflector in >>>>> several places - it has been discussed periodically. >>>>> >>>>> If you want to lobby for extended audio response, that is fine, but I am >>>>> just saying what the limits are today. Whether those can be extended or >>>>> not is for the DSP designer to answer. >>>>> >>>>> 73, >>>>> Don W3FPR >>>>> >>>>> On 9/26/2012 7:11 PM, Dale Boresz wrote: >>>>>> On 9/26/2012 1:35 PM, Edward R Cole wrote: >>>>>>> ... But I learned that audio is limited to 4-KHz >>>>>>> regardless of IF filter so I ended up selling the extra 13-KHz filter. >>>>>>> >>>>>>> ... >>>>>>> >>>>>>> 73, Ed - KL7UW >>>>>> I really hope that this does not apply to received audio to the >>>>>> headphones or loudspeaker! I just purchased two FM filters (one for >>>>>> sub-receiver to monitor wide splits) specifically to open up the receive >>>>>> passband (audio included) for SWL and BCB reception. I have no intention >>>>>> of actually transmitting FM or AM for that matter -- just want the wider >>>>>> audio bandwidth for receive. >>>>>> >>>>>> So... is the received audio bandwidth *really* limited to 4 KHz? >>>>>> >>>>> ______________________________________________________________ >>>>> 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 >>>>> >>>> ______________________________________________________________ >>>> 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 >>>> >>> ______________________________________________________________ >>> 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 >>> >> ______________________________________________________________ >> 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 >> > > ______________________________________________________________ > 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 > 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 |
Re: K3 - Filter suggestions for new builder
|
|
No, I'm not a human 'Skimmer' -- but I can pick out an individual cw
signal within about an 8 KHz span if it's pitch falls somewhere between about 200 Hz and 8 KHz, and can probably 'guestimate' by the pitch, to which signal it corresponds on the P3, and then quickly place my TX signal nearby and make my call. I guess I'm not conveying very successfully what I was hoping to do. I can do this easily w/ the second rx of the FLEX-5K -- but we're talking completely different architectures, each with their own pluses and minuses. The FM filters and the KRX3 will be here today, so I'll be able to experiment soon enough. I suspect that just being able to monitor both the dx and the pile-up simultaneously will be a huge help, and I may not feel the need for such a wide bandwidth on the pile-up side. We'll see... 73, Dale WA8SRA On 9/27/2012 12:20 AM, Joe Subich, W4TV wrote: >> I figured I could include that entire range within the FM filter >> bandwidth (which I still can do), AND also hear all 10 KHz of those >> signals (which I've learned I cannot do). > Your ears are much better than mine if you can actually copy a full > 10 KHz wide audio pile-up. I have enough trouble keeping up with > 4 KHz or so (200 Hz to 4.2 KHz) if I open everything up in SSB mode. > Note the K3 limits HI in CW to "Pitch + 1400 Hz" thus if one likes > a 500 Hz tone, the highest frequency passed in CW is 1900 Hz. The > *widest* bandwidth possible in CW is by using an 800 Hz sidetone > which results in 2.2 KHz ... whether the "roofing filter" is 2.7, > 2.8, 6 or 13 KHz wide. > > 73, > > ... Joe, W4TV > > > On 9/26/2012 9:46 PM, Dale Boresz wrote: >> Joe, >> >> Understood. I wanted to be able to simultaneously hear and see 12 Khz or >> so of cw signals, thinking that I could more quickly identify the >> station being worked. For example, if I know the dx station is listening >> from 14.010 to 14.020 (admittedly pretty wide), I figured I could >> include that entire range within the FM filter bandwidth (which I still >> can do), AND also hear all 10 KHz of those signals (which I've learned I >> cannot do). Oh well; the FM filter will still let me hear a wider swath >> of the pile-up than my present 2.8KHz filter will... >> >> 73, Dale >> WA8SRA >> >> >> On 9/26/2012 9:25 PM, Joe Subich, W4TV wrote: >>>> The only reason I had for putting the FM filter in the 2nd receiver >>>> was to be able to hear more of the split in a broad pileup situation >>>> (like the extremely large split widths that we saw a few months ago >>>> with 7O6T), >>> The width of the roofing filter has nothing at all to do with hearing >>> more of the pile-up (unless you're talking about literally "listening" >>> to all the signals at one time like a pile-up tape). The P3's pick- >>> up point is ahead of any roofing filter - it can "see" up to 200 KHz >>> at a time. The K3 transmitter and receiver can be split anywhere in >>> the band and if the KRX3 is used with a separate antenna the K3 and >>> KRX3 can literally transmit on one band and listen on another. >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> >>> On 9/26/2012 8:58 PM, Dale Boresz wrote: >>>> Joe, >>>> >>>> Good observations, all. I agree that 4.2 KHz is certainly good enough >>>> for communications audio. >>>> >>>> The only reason I had for putting the FM filter in the 2nd receiver was >>>> to be able to hear more of the split in a broad pileup situation (like >>>> the extremely large split widths that we saw a few months ago with >>>> 7O6T), figuring that being able to simultaneously hear the wider >>>> bandwidth and see it on the P3 would be a great combination. I'll just >>>> have to be a bit quicker with the VFO-B knob ;-) >>>> >>>> 73, Dale >>>> WA8SRA >>>> >>>> >>>> On 9/26/2012 8:10 PM, Joe Subich, W4TV wrote: >>>>> The limit occurs several places ... adjust the "HI" setting and one >>>>> will find 4.20 is the maximum available. There is also an analog >>>>> lowpass filter in the audio (headphone and speaker) between the DAC >>>>> and the headphone/speaker amplifiers. >>>>> >>>>> I'm sure this limitation derives from the roughly 10 KHz clock/sample >>>>> rate used for the DAC ... Nyquist says the maximum frequency can not >>>>> be more than half the sample (clock) rate. 4.2 KHz is plenty good >>>>> enough for communications audio ... and not bad for AM with fading, >>>>> noise, and interference typical of medium and high frequencies. >>>>> >>>>> The FM filter still provides noticeably better double sideband AM >>>>> response (4.2 - 4.5 KHz with DSP/LPF skirts) than the AM filter >>>>> (3.0-3.3 KHz depending on the IF filter response). >>>>> >>>>> 73, >>>>> >>>>> ... Joe, W4TV >>>>> >>>>> >>>>> On 9/26/2012 7:23 PM, Don Wilhelm wrote: >>>>>> Sorry, but yes, the K3 audio is limited at 4 kHz, no matter whether it >>>>>> is to the headphones or to the speaker. Please do not "shoot the >>>>>> messenger". but that information is in the archives of this reflector in >>>>>> several places - it has been discussed periodically. >>>>>> >>>>>> If you want to lobby for extended audio response, that is fine, but I am >>>>>> just saying what the limits are today. Whether those can be extended or >>>>>> not is for the DSP designer to answer. >>>>>> >>>>>> 73, >>>>>> Don W3FPR >>>>>> >>>>>> On 9/26/2012 7:11 PM, Dale Boresz wrote: >>>>>>> On 9/26/2012 1:35 PM, Edward R Cole wrote: >>>>>>>> ... But I learned that audio is limited to 4-KHz >>>>>>>> regardless of IF filter so I ended up selling the extra 13-KHz filter. >>>>>>>> >>>>>>>> ... >>>>>>>> >>>>>>>> 73, Ed - KL7UW >>>>>>> I really hope that this does not apply to received audio to the >>>>>>> headphones or loudspeaker! I just purchased two FM filters (one for >>>>>>> sub-receiver to monitor wide splits) specifically to open up the receive >>>>>>> passband (audio included) for SWL and BCB reception. I have no intention >>>>>>> of actually transmitting FM or AM for that matter -- just want the wider >>>>>>> audio bandwidth for receive. >>>>>>> >>>>>>> So... is the received audio bandwidth *really* limited to 4 KHz? >>>>>>> >>>>>> ______________________________________________________________ >>>>>> 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 >>>>>> >>>>> ______________________________________________________________ >>>>> 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 >>>>> >>>> ______________________________________________________________ >>>> 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 >>>> >>> ______________________________________________________________ >>> 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 >>> >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ > 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 > ______________________________________________________________ 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 |
|
|
In reply to this post by Bruce Beford-2
I found the 1.8k is too narrow for running stations at high rates (>150 per hour) in contests. It's OK when you have time to carefully tune signals (e.g. DXing or S&P in contests), but when callers are slightly off-frequency (as many are in contests), intelligibility suffers which really slows you down. In the CQ WW SSB last year, I quickly stopped using my 1.8k and switched to the stock 2.7k set to DSP 2.0k for the remainder of the contest (won USA SOSB/10 by 30% over the next highest score). I've since installed a 2.1k which I expect will work better for high run rates...will report back after October 28. 73, Bill W4ZV |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by Stan AE7UT
Thanks, Don.
I should explain a bit more. In fact I confused running bw down to 2.1 or 1.8 KHz with running the NR function. It is the NR which adds what I termed "audio distortion" to the signal and not narrowing bw. At least not at 1.8-2.1 KHz. Ringing below 50-Hz makes it difficult/impossible for me to copy weak-CW. Typically, I run CW-eme at 100-Hz. So I will not bother to add another IF filter to run narrower bw with SSB. Having three filters in the main Rx and one in the sub-Rx is adequate. I can always reduce bw in diversity Rx with the DSP. 73, Ed - KL7UW ______________________________________________________________ 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 |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by Stan AE7UT
Stan,
Since you have decided to go with the 2.7 filter, you have a couple decisions to make. Do you pay for matched filters between the main and the sub so you can have good diversity reception, or do you "cheat" and set the filter offsets to the mean of the two filters. At a 2.7 width, the small variation from the true offsets will not make much difference, but you do need to set them to the mean for diversity reception. In other words, if one filter had a -600 Hz offset and the other -300, setting the offset for both at -450 Hz will work just fine. With more narrow filters, you may not be able to get away with that, but with wide filters, the percentage change is not as great. 73, Don W3FPR On 9/25/2012 4:06 PM, Stan AE7UT wrote: > Thanks for all the feed-back. It looks like I'm at least in the right ball > park. > I definitely want the diversity reception so I'll be doubling most if not > all filters. > I've decided to stick with the 2.7 for now. I doubt my ears could hear the > difference. > > Interesting that most here have gone with the 2.1 vs. the 1.8 KHz filters. > I'm going to have to go home and listen closer to see if I like 2.1 or 1.8. > > Thanks again. You guys have been a tremendous help. > > 73 > Stan AE7UT > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K3-Filter-suggestions-for-new-builder-tp7563280p7563295.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > 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 > ______________________________________________________________ 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 |
Re: K3 - Filter suggestions for new builder
|
Thanks for more great info Don. I figure $20 is well spent in just having them match my other 2.7Khz, 5 pole.
After reading this through a couple of times and talking with a couple of K3 users I'm going with 2.7 KHz, 5 pole - matched 2.1 KHz, 8 pole 400 Hz, 8 pole 200 Hz, 5 pole - matched Just got my check from the buyer of my O2 so I plunked down the cash for the KAT3, KRX3, KXV3a, filters and a KPA500. That's just about tapped out all of my fun money. The P3 will have to wait a month or so. Thanks for all the help. It's been fascinating all the thoughts and comments. It's nice the K3 is so versatile. 73 Stan AE7UT |
Re: K3 - Filter suggestions for new builder
|
|
In reply to this post by Stan AE7UT
Stan,
I think your choices will work fine. In mine the only difference is I chose to put an 8 pole 500hz plus 8 pole 250hz in my mainRX as I mostly do CW and RTTY in contests. In my subRX I have 2.7khz and 400hz. This setup works fine on diversity BTW. GL -Robby VY2SS |
«
Return to [K3]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |