Noisy K-3 Receiver
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Same here. I ordered and got confirmation of payment but no hint of if or
when it would ever ship so I sent an inquiry and Lisa said about 2 weeks. Maybe by Christmas? Can't seem to get an answer about that filter module but I can see no reason to omit it. Steve N4LQ [hidden email] ----- Original Message ----- From: "Merv Schweigert" <[hidden email]> Cc: <[hidden email]> Sent: Wednesday, December 16, 2009 8:16 PM Subject: Re: [Elecraft] Noisy K-3 Receiver > Thanks for the info, last I had heard the board was not part of the new > DSP > board, but that was last month. I placed an order Nov 25 and have not > heard > a peep as yet about shipping or backorder or?? figured they were behind > in > shipping. > 73 Merv KH7C >> I'm waiting on my new DSP board to arrive and HOPE it has that filter >> module >> installed. Last time I checked, there was a 2 week delay on shipping. >> >> Steve >> N4LQ >> [hidden email] >> ----- Original Message ----- >> From: "Lyle Johnson" <[hidden email]> >> To: <[hidden email]> >> Sent: Wednesday, December 16, 2009 12:45 PM >> Subject: Re: [Elecraft] Noisy K-3 Receiver >> >> >> >>>> There is an often referred to AF filter module which installs on the >>>> main DSP board ... >>>> >>> My understanding is that this is part of the DSP board swap upgrade, >>> and is in currently shipping K3s. >>> >>> But I've been known to be wrong! >>> >>> 73, >>> >>> Lyle KK7P >>> ______________________________________________________________ >>> 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 >>> >> >> >> -------------------------------------------------------------------------------- >> >> >> >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 9.0.716 / Virus Database: 270.14.110/2568 - Release Date: >> 12/16/09 >> 03:02:00 >> >> ______________________________________________________________ >> 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 -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.716 / Virus Database: 270.14.110/2568 - Release Date: 12/16/09 03:02:00 ______________________________________________________________ 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 |
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In reply to this post by Mike Harris
Hi Mike,
I've fiddled with all of the AGC, PRE, ATT, RF, and DSP options on my K3, and still experience a relatively high noise floor - at least compared to an FT-1000 side by side. I never gave it much thought until these subject came up on the reflector. Cheers, James K2QI -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Mike Harris Sent: Wednesday, December 16, 2009 12:15 PM To: Bill W4ZV; [hidden email] Subject: Re: [Elecraft] Noisy K-3 Receiver G'day, The simple fact is that the faithful will always suggest that the K3 hears more, is more sensitive or is more transparent to band noise etc etc. Also you have to fiddle with the AGC, PRE, ATT and RF gain whereas other radios just sound nicer out of the box. I don't have a problem with fiddling with AGC and equaliser parameters to tailor the receive to my liking, but to have to do it to make it sound acceptable is another thing altogether. There is an often referred to AF filter module which installs on the main DSP board and apparently cuts out a lot of unnecessary high frequency audio. Sadly though often referred to it just isn't being made available despite very positive comment from some of those who have field tested it. The KAF2 filter for the K2 made all the difference in the world to listening to SSB. Regards, Mike VP8NO ______________________________________________________________ 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
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In reply to this post by Mike Reublin
Hi
My k3. Must be be one of the newest issued, sn 3759. Delivered by ups Monday this week. Finished the build last night, the 2 nd rx being the last item to go in. Just 2 items missing and wud you believe they are the 2....38mm zinc screws which bolt down the sub rx L shape cover!!! Dsp es Aux board newone firmware 2.49 dated 10 December 2009. I have only briefly listened on 20m cw yday, the rx, without set-up seemed pretty lively. I'm just about doing the final CAL on the radio now b4 i can let myself loose on cw es see what this baby is really like. Ken..G0ORH Sent from my iPhone On 16 Dec 2009, at 23:01, Mike <[hidden email]> wrote: > Thanks Greg - > Mine is 3539. There's a post on down the list that gives a link to a > pic > of the rev. C board. > > 73, Mike > Greg - AB7R wrote: >> One of my K3s is #3459 and it has the updated DSP board. I think >> it was right >> >> around there when they started. >> >> >> >> ------------------------- >> >> 73, >> >> Greg - AB7R >> >> Whidbey Island WA >> >> NA-065 >> >> >> >> >> >> On Wed Dec 16 14:36 , Mike sent: >> >> >> >> >>> Any idea what serial number the upgrade started shipping with? Or >>> a way >>> >> >> >>> to determine if I have it already? >>> > > > ______________________________________________________________ > 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 |
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In reply to this post by K2QI
Hi James
This has been my impression for the last 2 years when using our clubs K3's I decided to do a comparison with several radios. FT1000MP TS870S FT1000D TS850S TS930S If you blind folded yourself and did not look at the S-meter and switched between the radios, the K3 was always much more noisy. I did this test on 20 meters and 40 meters. There is no doubt that the K3's correctly calibrated S-meter shows more activity. However when you dont look at the S-meter and just listen you can hear this apparent greater "noise activity" What is interesting if there is just signs of a starting thunder storm or light QRN, the K3 seems to make the QRN sound much worst. However when the QRN is very heavy its as bad as any other radio. I did also play with AGC setting and this result was always repeatable. I thought it was the AGC doing this, however I changed the slope and it appears to be the same. There seems to be a mid range window in the K3 that makes the radio sound much more lively. Above and below this windows thresholds it appears to be normal in every other respect. One thing thats very obvious with the K3 is that you need to play with the receiver EQ all the time. The difference can be very stunning when you get it right. There can be no one EQ setting that is good for weak and general purpose listening for both CW and SSB. The K3 on a flat EQ response is poor at very weak signal SSB work. However, when you adjust the EQ it seems to bring the radio back to life. The K3 needs a default setting thats similar to most analog radios, a defined bandpass filter that needs no EQ adjustment for CW and SSB. The K3 for some reason needs a lot of highs and treble to sound decent. Even the CW note comes alive with real body like a analog radio when the EQ is set to high /treble boost. My belief is that most who say that the K3 sounds poor is for this reason. However when you boost the highs the receiver is very tiring on your ears. So you cant seem to win here There is something strange about how the DSP and the receiver chain works. It sounds great with strong normal signals on a quiet band. I do want to try a SCAF filter or some other audio filter to see if I can improve things. I dont have hearing problems and generally i try and leave the EQ set flat. However this has proved problematic for me, especially on weak SSB and CW. I am a casual K3 user and I dont own a K3, however I have spent enough time operating our clubs K3's which have a broad range of serial numbers many factory assembled. I would like to try and get the new DSP board to see if that changes much. Maybe it is because I am a casual K3 user that I notice all these quirks, these probably may disappear if i used a K3 every day. In the meantime I prefer any old analog contest radio at the moment. John --- On Wed, 12/16/09, James Sarte <[hidden email]> wrote: > From: James Sarte <[hidden email]> > Subject: Re: [Elecraft] Noisy K-3 Receiver > To: [hidden email] > Date: Wednesday, December 16, 2009, 9:42 PM > Hi Mike, > > I've fiddled with all of the AGC, PRE, ATT, RF, and DSP > options on my K3, > and still experience a relatively high noise floor - at > least compared to an > FT-1000 side by side. > > I never gave it much thought until these subject came up on > the reflector. > > Cheers, > James K2QI > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] > On Behalf Of Mike Harris > Sent: Wednesday, December 16, 2009 12:15 PM > To: Bill W4ZV; [hidden email] > Subject: Re: [Elecraft] Noisy K-3 Receiver > > G'day, > > The simple fact is that the faithful will always suggest > that the K3 > hears more, is more sensitive or is more transparent to > band noise > etc etc. Also you have to fiddle with the AGC, PRE, > ATT and RF gain > whereas other radios just sound nicer out of the box. > I don't have > a problem with fiddling with AGC and equaliser parameters > to tailor > the receive to my liking, but to have to do it to make it > sound > acceptable is another thing altogether. > > There is an often referred to AF filter module which > installs on the > main DSP board and apparently cuts out a lot of unnecessary > high > frequency audio. Sadly though often referred to it > just isn't being > made available despite very positive comment from some of > those who > have field tested it. > > The KAF2 filter for the K2 made all the difference in the > world to > listening to SSB. > > Regards, > > Mike VP8NO > > ______________________________________________________________ > 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 |
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A new noise has recently started appearing at this QTH on 10m, which was previously a quiet band. Normally the S meter would read about S2, but now it reads about S5. This noise, heard through the K3, has a distinct "buzzing" sound.
I decided to switch the antenna to the FT-817 in order to record the noise, because the 817 is connected to the default sound card that Windows Recorder will record from. On that radio the noise sounded completely different. The buzz was not audible at all, it was just a sort of "mush". Except for the increased level (the FT-817 S-meter was reading S8 with preamp on) you might think you were listening to band noise. Now why would noise sound different on one radio to another? I'm sure the buzz is really there, coming from some new device a neighbour has acquired, and the K3 isn't making it up. So perhaps the K3 is reproducing the sound of the band as it really is, while the lesser receiver has a lot more intermodulation that is mixing up all the noise which just happens to make it sound less harsh and easier on the ears? I find it hard to believe that the K3 receiver is actually noisy, in the sense that it is generating noise internally that makes it harder to hear weak signals compared to another RX. Those MDS figures can't lie, surely? So why is a new DSP board needed, except to "fudge" the sound so that it doesn't sound as noisy? You aren't going to hear anything with the new board that you wouldn't have heard without it.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by Eric NO3M
This subject of "K3 receiver noise" has illustrated how
differently we view our radios. After seriously competing in the recent ARRL 10M and 160M contests ... and scoring very well... I commented to Rose and radio club friends how -quiet- the receiver(s) are. After a seven-month wait to get my K3 (S/N 56), I evaluated it against my FT-1000D, FT-990 and an IC-756PROII over a several week period. I then sold all three on E-Bay. The main radio has these 8-pole roofing filters: 13 kHz, 6.0 kHz, 2.8 kHz, 1.0 kHz and 400 Hz. The 2nd receiver has a 2.8 kHz and a 1.8 kHz. The 2nd RX is mostly used for monitoring 6M. When not contesting, I'm primarily a CW rag-chewer on 30M and 40M, with an occasional SSB QSO with friends on 75M or 160M. I have 315 CW DXCC countries. My antenna farm is better than most, with four towers, RX loops for 160M and 80M, an 80M 1/2 wave CF Zepp at 65', a fully insulated 1/4 wave tower for 160M, etc. I "hear" well, and the K3 is a joy to use. I don't mean to "brag" here ... just illustrate that the radio gets a lot of "serious" use in a well-equipped station. I use a Heil headset and -have- "tweaked" the TX equalization with the help of a friend 800 miles away who was watching my signal on his Flex. I've never felt the need to change the RX equalization from "flat", other than to experiment with it as a kind of audio-peaking filter. Now, it's time to order another container of Elecraft Kool-Aid. 73! Ken Kopp - K0PP [hidden email] http://tinyurl.com/7lm3m5 ______________________________________________________________ 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 |
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In reply to this post by juergen piezo
My suggestion:
1, upgrade to lastest f/w 2, tune the center of the passband to 1.4~1.45k(very important) Hope those will helps! all the best! David,BA4RF 2009/12/17 juergen piezo <[hidden email]> > Hi James > > This has been my impression for the last 2 years when using our clubs K3's > > I decided to do a comparison with several radios. > > FT1000MP > TS870S > FT1000D > TS850S > TS930S > > If you blind folded yourself and did not look at the S-meter and switched > between the radios, the K3 was always much more noisy. I did this test on 20 > meters and 40 meters. There is no doubt that the K3's correctly calibrated > S-meter shows more activity. However when you dont look at the S-meter and > just listen you can hear this apparent greater "noise activity" > > What is interesting if there is just signs of a starting thunder storm or > light QRN, the K3 seems to make the QRN sound much worst. However when the > QRN is very heavy its as bad as any other radio. I did also play with AGC > setting and this result was always repeatable. I thought it was the AGC > doing this, however I changed the slope and it appears to be the same. > > There seems to be a mid range window in the K3 that makes the radio sound > much more lively. Above and below this windows thresholds it appears to be > normal in every other respect. > > One thing thats very obvious with the K3 is that you need to play with the > receiver EQ all the time. The difference can be very stunning when you get > it right. > > There can be no one EQ setting that is good for weak and general purpose > listening for both CW and SSB. The K3 on a flat EQ response is poor at very > weak signal SSB work. However, when you adjust the EQ it seems to bring the > radio back to life. > > The K3 needs a default setting thats similar to most analog radios, a > defined bandpass filter that needs no EQ adjustment for CW and SSB. The K3 > for some reason needs a lot of highs and treble to sound decent. Even the > CW note comes alive with real body like a analog radio when the EQ is set > to high /treble boost. My belief is that most who say that the K3 sounds > poor is for this reason. However when you boost the highs the receiver is > very tiring on your ears. So you cant seem to win here > > There is something strange about how the DSP and the receiver chain works. > It sounds great with strong normal signals on a quiet band. I do want to try > a SCAF filter or some other audio filter to see if I can improve things. I > dont have hearing problems and generally i try and leave the EQ set flat. > However this has proved problematic for me, especially on weak SSB and CW. > > I am a casual K3 user and I dont own a K3, however I have spent enough time > operating our clubs K3's which have a broad range of serial numbers many > factory assembled. I would like to try and get the new DSP board to see if > that changes much. Maybe it is because I am a casual K3 user that I notice > all these quirks, these probably may disappear if i used a K3 every day. In > the meantime I prefer any old analog contest radio at the moment. > > John > > --- On Wed, 12/16/09, James Sarte <[hidden email]> wrote: > > > From: James Sarte <[hidden email]> > > Subject: Re: [Elecraft] Noisy K-3 Receiver > > To: [hidden email] > > Date: Wednesday, December 16, 2009, 9:42 PM > > Hi Mike, > > > > I've fiddled with all of the AGC, PRE, ATT, RF, and DSP > > options on my K3, > > and still experience a relatively high noise floor - at > > least compared to an > > FT-1000 side by side. > > > > I never gave it much thought until these subject came up on > > the reflector. > > > > Cheers, > > James K2QI > > > > -----Original Message----- > > From: [hidden email] > > [mailto:[hidden email]] > > On Behalf Of Mike Harris > > Sent: Wednesday, December 16, 2009 12:15 PM > > To: Bill W4ZV; [hidden email] > > Subject: Re: [Elecraft] Noisy K-3 Receiver > > > > G'day, > > > > The simple fact is that the faithful will always suggest > > that the K3 > > hears more, is more sensitive or is more transparent to > > band noise > > etc etc. Also you have to fiddle with the AGC, PRE, > > ATT and RF gain > > whereas other radios just sound nicer out of the box. > > I don't have > > a problem with fiddling with AGC and equaliser parameters > > to tailor > > the receive to my liking, but to have to do it to make it > > sound > > acceptable is another thing altogether. > > > > There is an often referred to AF filter module which > > installs on the > > main DSP board and apparently cuts out a lot of unnecessary > > high > > frequency audio. Sadly though often referred to it > > just isn't being > > made available despite very positive comment from some of > > those who > > have field tested it. > > > > The KAF2 filter for the K2 made all the difference in the > > world to > > listening to SSB. > > > > Regards, > > > > Mike VP8NO > > > > ______________________________________________________________ > > 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 > -- -------------------------------- All the best! David,ba4rf ______________________________________________________________ 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 |
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The other thing that helps (and helps a LOT) is to reduce the RF Gain
until the band noise is at a lower level - just barely present. Yes, it will likely be different for each band, but can be quickly set by listening to a spot with no signals and listen for the "frying noise" to be barely perceivable. Turning on the attenuator is also helpful. Right now, I am listening to an 80 meter local roundtable with the attenuator on, the RF Gain at 2 o'clock and the AF Gain at 9 o'clock. For those who are hesitant to do reduce the RF Gain because the S-meter changes when the RF Gain is reduced, the K3 has an absolute (ABS) setting for the S-meter, and you have an S-meter that is not influenced by the RF Gain nor the preamp nor ATT. 73, Don W3FPR chen dave wrote: > My suggestion: > 1, upgrade to lastest f/w > 2, tune the center of the passband to 1.4~1.45k(very important) > > Hope those will helps! > > all the best! > > David,BA4RF > > 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 |
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In reply to this post by RLVZ
Juergen and others.....
I'm glad to see this thread get so much attention; it's about time this issue was brought into focus. In spite of my huge appreciation for this radio, I find it to be very noisy and fatiguing to listen to, especially with weak signals. I have, like others, tried all the adjustments mentioned, but with no real improvement. I can switch to my FT-1000D for relief when this gets to the point of being difficult. I find myself doing this more and more often. I used the K-3 in CQWW SSB and CW, and enjoyed the great features and ease of use, especially using the N1MM settings to access the KDVR audio during the SSB contest. But... all these great features have come at some cost.... dealing with the receiver noise. Even the EQ settings are a tradeoff because the noise follows boost in the low range for CW (I listen at 350hz). We still need separate EQ settings for SSB, too. I'm also wondering if the DSP board upgrade for low range will help to solve some of this problem.... The RX MIX audio arrangement in the FT-1000D is still far superior to the K-3, also. The newest options for this helped, but the Yaesu is still better in dual receiving mode with the balance control. Jim W6YA ______________________________________________________________ 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 |
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If it's weak signal work where this is being noticed, one test of the
overall noise floor is to run the headphone output from several rigs, individually switched into a PC sound card with a FFT software program running. The AF outputs would require normalizing at various signal-strength levels across receivers with say a 1 kHz tone for wider bandwidths and perhaps 500 Hz tone for narrower modes. For SSB, 1 kHz should represent an area of the IF and AF passband where minimal attenuation occurs for any receiver. Even if the IF selectivity is not identical across the receivers, the FFT software will still produce some meaningful results. The test should include AGC on and AGC off settings. Paul, W9AC ----- Original Message ----- From: "Jim McCook" <[hidden email]> To: <[hidden email]> Sent: Thursday, December 17, 2009 10:06 AM Subject: Re: [Elecraft] Noisy K-3 Receiver > Juergen and others..... > > I'm glad to see this thread get so much attention; it's about time this > issue was brought into focus. In spite of my huge appreciation for this > radio, I find it to be very noisy and fatiguing to listen to, especially > with weak signals. > > I have, like others, tried all the adjustments mentioned, but with no > real improvement. I can switch to my FT-1000D for relief when this gets > to the point of being difficult. I find myself doing this more and more > often. I used the K-3 in CQWW SSB and CW, and enjoyed the great > features and ease of use, especially using the N1MM settings to access > the KDVR audio during the SSB contest. But... all these great features > have come at some cost.... dealing with the receiver noise. Even the EQ > settings are a tradeoff because the noise follows boost in the low range > for CW (I listen at 350hz). We still need separate EQ settings for SSB, > too. > > I'm also wondering if the DSP board upgrade for low range will help to > solve some of this problem.... > > The RX MIX audio arrangement in the FT-1000D is still far superior to > the K-3, also. The newest options for this helped, but the Yaesu is > still better in dual receiving mode with the balance control. > > Jim > W6YA > > > > ______________________________________________________________ > 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 |
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In reply to this post by Bill W4ZV
This statement (If you run RF GAIN wide open the receiver will sound noisy
and you are limiting your dynamic range) is only true for the bands where the band noise is high, but on the higher bands (eg 6m), the band noise is only a little higher than the receiver noise (and maybe not at all if you don't have an external preamp). And on my K3 (as reported previously with f/w 3.63) backing off the rf gain *reduces* the S/N because the front end noise no longer overcomes the IF/AF noise. There's lots of noise generated in the later stages of the rx, which can still be heard with the rf gain backed off. This does not appear to be a function of the AGC settings. This is a major irritation that has only surfaced with recent firmware changes - the problem wasn't there in f/w 3.27. Other receivers I've used keep the S/N constant with the rf gain backed off presumably because they are reducing the IF gain further back in the rx. And let's be clear I'm NOT talking about 160 or 80m where the band noise may be many dB above the receiver front end noise. Graham ------------------------------- Previous comments include:- > If you run RF GAIN wide open the receiver will sound noisy and you are limiting your dynamic range. and >I find it hard to believe that the K3 receiver is actually noisy, in the sense that it is generating noise internally that makes it harder to hear weak signals compared to another RX. Those MDS figures can't lie, surely? ______________________________________________________________ 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 |
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Graham,
BUT - the K3 "RF Gain" control ONLY controls the IF gain - it does not reduce the gain of the receiver front end - in that respect, the K3 is similar to those other receivers that you referred to.. The preamp and attenuator DO change the front end gain. 73, Don W3FPR Graham Kimbell (G3TCT) wrote: > This is a major irritation that has only surfaced with recent firmware > changes - the problem wasn't there in f/w 3.27. Other receivers I've used > keep the S/N constant with the rf gain backed off presumably because they > are reducing the IF gain further back in the rx. > > > ______________________________________________________________ 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 |
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OK Don, well it must be controlling the gain of the first IF amp then, and
that must be important to the receiver's noise figure. All I know is that turning down the RF gain reduces S/N (on my K3 at least). And this wasn't the case in f/w 3.27. Graham ----- Original Message ----- From: "Don Wilhelm" <[hidden email]> To: "Graham Kimbell (G3TCT)" <[hidden email]> Cc: "Elecraft reflector" <[hidden email]> Sent: Thursday, December 17, 2009 6:36 PM Subject: Re: [Elecraft] Noisy K-3 Receiver > Graham, > > BUT - the K3 "RF Gain" control ONLY controls the IF gain - it does not > reduce the gain of the receiver front end - in that respect, the K3 is > similar to those other receivers that you referred to.. The preamp and > attenuator DO change the front end gain. > > 73, > Don W3FPR > > Graham Kimbell (G3TCT) wrote: > > This is a major irritation that has only surfaced with recent firmware > > changes - the problem wasn't there in f/w 3.27. Other receivers I've > > keep the S/N constant with the rf gain backed off presumably because they > > are reducing the IF gain further back in the rx. > > > > > > ______________________________________________________________ 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: Noisy K-3 Receiver
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In reply to this post by KK7P
The on-list descriptions of K3DSPUPGD say it changes a few capacitors and other components to extend frequency response for TX and RX (in combination with firmware) below 300 Hz, but has no effect on the line in/line out jacks used by digimode programs. Is that still the description? In other words, is this change mostly for ESSB and high-quality audio needs, or is there some other advantage that might come about now our in the future from having this board? (Presumably with a KRX3 you need two of these and that gets a little pricey for something with uncertain benefit.) Leigh/WA5ZNU |
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