Re: [Elecraft] APF on CW

> The APF function on my KX3 makes the signal jump out of the noise > > Hope the feature remains in the K4 line It does. There are now two bandwidth settings, too. Wayne > > Regards, Jan K1ND ~ stay-safe ~ > > > -- > This email has been checked for viruses by AVG. > https://www.avg.com >

[Elecraft] APF on CW

January is SKCC K3Y month ~ come join us for some straight key (or bug) CW fun~ The APF function on my KX3 makes the signal jump out of the noise Hope the feature remains in the K4 line Regards, Jan K1ND  ~ stay-safe ~ -- This email has been checked for viruses by AVG. https://www.avg.com

Re: [Elecraft] APF Primer?

The K3 APF has a very sharp peak (about 30 Hz @ 3 dB) but broader shoulders (about 300 Hz wide). It is not in the AGC loop, so any signals inside the bandwidth set by the bandwidth control may activate the AGC. Therefore, if you have nearby strong signals, you should reduce the bandwidth to

Re: [Elecraft] APF Primer?

this out. Have fun! 73, Brian, K0DTJ -Original Message- From: "kevinr" Sent: Monday, August 24, 2020 19:33 To: "Elecraft Reflector" Subject: [Elecraft] APF Primer? 1) What are the best band conditions to try APF? Does it work under medium QSB against medium

Re: [Elecraft] APF Primer?

Kevin: 1)  For a K3, APF seems to be very dependent on current AGC action. If there are very strong signals close in and the AGC is doing its thing, APF doesn't seem to work.  You can adjust the AGC parameters, however my experience is that I use APF infrequently enough that it's better to

[Elecraft] APF Primer?

I have used APF a number of times.  Sometimes it worked, but often the ringing makes it hard to hear anything intelligible. I have a two families of questions to hopefully remedy my problem. 1) What are the best band conditions to try APF?  Does it work under medium QSB against medium to high

[Elecraft] APF on RTTY and TrueTTY

Hi! I have tried to solve the problem when using TrueTTY and K3s APF. Everything works fine without APF (using rev data) but if I turn APF on I lose all the tracks on the waterfall. I have tried all mark and shift combination. APF works ok with MMTTY but it is too clumsy program for me so

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Thanks for all the discussion on the APF. I've got a technique now and I think I can refine it into something useful. vy 73,Dave N4KD On Saturday, February 6, 2016 8:02 AM, Chuck Guenther wrote: I've been using APF in my K3 since it was in Beta testing.  I love

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Well actually I prefer copying CW with a certain amount of noise present. Pure tone, no noise CW, as from a practice oscillator or an S9++ signal quickly becomes boring and I loose concentration(or something). It's perhaps why I prefer to dig out weak signals (ESP) from the noise on the band.

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

will come, Hi!) 73, Ron AC7AC -Original Message- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of F5vjc Sent: Sunday, February 7, 2016 4:56 AM To: Bill W4ZV Cc: Elecraft Reflector Subject: Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3 Well actually

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

tand by, that will come, Hi!) > > 73, Ron AC7AC > > -Original Message- > From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of > F5vjc > Sent: Sunday, February 7, 2016 4:56 AM > To: Bill W4ZV > Cc: Elecraft Reflector > Subject: Re: [Elecraft] AP

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I have heard people using voice synthesizers on voice modes. I believe they have had issues which keep them for speaking and this is their way of being able to get on the air. It is certainly my way of doing 25+ wpm DX contacts, but I keep trying to learn. I also QSOed with a guy on PSK31 who

[Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I've been using APF in my K3 since it was in Beta testing. I love it! I've found it necessary to use both the shift and Fine tuning-- these are not optional for effective use of APF. I've been using macros to engage and dis-engage the APF. One reason I keep combing through the Elecraft

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

N1EU wrote > I suspect that when the K3 APF was first engineered, the Yaesu FT-1000D > APF > (original hi-Q version) was used as the model because many prominent > dx'ers/topbanders always raved about it. I lifted the "original" FT-1000D APF from the schematic in 2009 and Al W6LX did a circuit

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Also, you can move the "peak" left/right by rotating the SHIFT knob. You will see APF setting appear in the VFO B area and the ref point is denoted by an "*" next to 45. Sent from my iPhone ...nr4c. bill > On Feb 5, 2016, at 10:27 AM, David Kuechenmeister wrote: > >

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

The receiver has to be tuned precisely to the signal in question for APF to work. 73, Barry N1EU On Fri, Feb 5, 2016 at 9:53 AM, David Kuechenmeister wrote: > I tried this the other day with no success. That is, the weak signal that > was barely detectable, became so buried

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

one must also discover the artful use of the RF Gain control as well Adjustment of the RF gain control is not mentioned in Wayne's note on using APF. When I tried it here, the RF gain might have made some small difference but it still did not allow un-copyable signals to be copied. When

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I went from a TenTec Orion to my K3 ( whose box I opened almost the very day the K3S was announced which is total BS) and I really mis the SAF feature in the Orion. The APF in my K3 doesn't touch it. W5SUM Sent from Ronnie's IPhone > On Feb 5, 2016, at 09:56, dave wrote:

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

While I find the APF works really nice, one must also discover the artful use of the RF Gain control as well. Most hams seem to use excessive RF Gain which will force noise through the filter and all of those undesirable artifacts will be heard. If in doubt, reduce the RF Gain. Using this

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

The technique I'm using with the APF also involves NR like so: On an uncrowded band, set the DSP BW to 700 to 1000 Hz. If you have a roofing filter in that range stay within it. Turn on NR set to mF5-3 or there about. The wide BW helps the NR work well. The "mix" mode lets a little

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I tried this the other day with no success. That is, the weak signal that was barely detectable, became so buried in ringing that I couldn't detect it at all. I think I followed the procedure outlined in Wayne's email below... Noise was around S5 on 40m and the K3 was configured with APF active.

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I'd agree. My experience with APF is that it will indeed pop a signal that is already copyable, if a bit weak, out of the noise. Makes for easier copy. However the ringing is so bad on a really weak signal that it is of no help. I guess it depends on what you view as 'weak' and your noise

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Thanks. I'll try again and be very careful this time. vy 73,Dave N4KD On Friday, February 5, 2016 10:08 AM, Barry N1EU wrote: The receiver has to be tuned precisely to the signal in question for APF to work. 73, Barry N1EU On Fri, Feb 5, 2016 at 9:53 AM, David

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I've seen it written that it helps to offset the IF slightly, although to be honest I have never myself got the APF to work to my satisfaction. Oddly, and I communicated with Wayne about this at the time, the first beta (I think) implementation of it was stunning, but a later release lost it for

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Lightning has dramatic effect on the AGC system of many to most receivers. Rob Sherwood has had a lot to say about this. Elecraft has taken steps to minimize the effect. Yes different types of noise clearly have different characteristics and thus the reason for suggesting reducing the RF

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

In the last month of listening to really weak signals here in 9 land I've found it helpful but not radical. Just for fun I tried tuning some of the same VP8SGI signals on a Drake 2B/2BQ and found adding the 2BQ in the mix more user friendly and making a bigger difference, but hey, the 2B

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I suspect that when the K3 APF was first engineered, the Yaesu FT-1000D APF (original hi-Q version) was used as the model because many prominent dx'ers/topbanders always raved about it. 73, Barry N1EU On Fri, Feb 5, 2016 at 12:37 PM, Scott via Elecraft < elecraft@mailman.qth.net> wrote: > > In

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Stephen is correct. Several of us lobbied for an APF feature shortly after the K3 debuted in 2007, drawing on our experiences with the FT-1000D. There /were/ two firmware versions that Wayne developed, and the consensus among some of us was that the first one was better than the second. As I

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

I followed my interpretation of Wayne's instructions when trying to copy VP8SGI on 80M. I have an inverted V antenna with the peak at about 12 meters (44'). When I started, I could barely hear him. When I got the APF tuned in, I could hear him clearly, and actually managed to work him with

[Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Hi all, This morning I was hearing lots of very weak signals in the 40-meter CW band, right at today's noise floor of about S-5. (Among others, I copied BG4GOV in Shanghai.) Many of the signals were not copyable until I turned on APF (audio peaking filter). This filter's center peak is very

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

As a new K3S owner {since last August}, I agree. The APF seems to lift signals out of the noise when otherwise, one would not know they are present. I've used it successfully many times on weak signal QSO's. Thanks for designing a great radio for the ham market. 73 Bob, K4TAX K3S, s/n

Re: [Elecraft] APF (audio peaking filter) on the K3/K3S/KX3

Dang.tnx for the reminder about APF, Wayne --- still getting "comfortable" with my KX3 so forgot about its value while engaged in self-flagellation i.e., operating in the CQ 160 contest last weekend. 72 de Jim Rodenkirch K9JWV -- View this message in context:

[Elecraft] APF

Whatever happened to the plan to provide adjustable or stepped values of selectivity for the APF function? I rigged up a kluge consisting of an old Autek QF-1A but would much rather have it's function built-in. 73 Roger __ Elecraft

[Elecraft] APF filter band width adjustment

*/I agree I always liked to adjust my ft1000d APF a bit off center as well. Regards Art ka9zap /* On 2/14/2015 9:42 PM, Guy Olinger K2AV wrote: One thing I like about it is that a hold on the SUB button now puts you back in diversity immediately. Quick way to get it back when a split spot has

[Elecraft] APF

Dear List Readers Eureka moment! I finally figured out how to use the APF effectively, and it really does work on digging out weak sigs. XZ1Z was virtually indecipherable until I started messing with the APF. All of a sudden, I heard him Q5 (enough) to hear him come back to me distinctly. Thank

[Elecraft] APF

I have received 2 inquiries about how to use the APF. Well, I’ll put it to you this way. I used to be a photographer and used a 5X7 view camera. The image on the viewing glass was upside down, both the front (lens board) and rear (view glass) board swiveled from side to side and up and down. It

Re: [Elecraft] APF

Todd, I am not going to weigh in on anything you said. In the case of APF, the instructions by your very Zen instructor may the best appropriate answer. Before you need to use it, give it a try on some weak signals and play with the width and shift controls until you get a feel for it. It

Re: [Elecraft] APF

My formula for tuning very weak signals - almost can't see them on the P3 - is as follows: - Set the WIDTH to 700 Hz to 1 KHz QRM permitting. - Turn on NR and set to 5m3 or there about. - Turn on APF and tune for best audio. Setting the rate to FINE sometimes helps. This almost completely

Re: [Elecraft] APF

Brian, Yes, using APF with a wider bandwidth helps, but a width more narrow than 700 Hz should be usable - 400 Hz and more narrow may be iffy. FINE tuning with APF turned on is a necessity. 73, Don W3FPR On 3/16/2014 8:44 PM, Brian Hunt wrote: My formula for tuning very weak signals -

Re: [Elecraft] APF

Thanks, Don. My choice of 700-1000 Hz is more for the NR than for the APF. The idea is to get the noise going into the NR routine as uncorrelated as practical. The knee of that curve seems to be around 700 Hz. Any lower and the NR doesn't work as well. It's a bit subjective. Also using the

Re: [Elecraft] APF

IMHO K3WC's APF suggestion is WAY TOO COMPLICATED. I use APF virtually all the time and never use RIT, SHIFT, etc. Just HOLD DUAL PB to actuate APF and use the VFO to zero beat. COARSE (10 Hz) VFO steps is usually close enough but you can switch to FINE (1 Hz) if necessary for ultra weak

Re: [Elecraft] APF

I too often use APF on both the K3 and KX3. I prefer tuning APF with 1 Hz steps. The KX3 enables 1 HZ steps when APF is enabled. I miss that feature with the K3. A new feature request; when in SPLIT and VFO A at 1 Hz, leave VFO B at 10 Hz. John KN5L On 12/08/2013 04:48 AM, Bill W4ZV wrote: I

Re: [Elecraft] APF

I agree with Bill. There's no need to fiddle with the RIT control. I think Dusty's original suggestion implies that he found the APF to be more effective at a slightly lower frequency (20Hz lower) than his nominal CW pitch setting. This may be true but it can be more easily accomplished by tuning

Re: [Elecraft] APF

Hi all, and Sam; Message: 7 Date: Sat, 07 Dec 2013 19:38:20 -0600 From: Sam Morgan k5oai@gmail.com To: elecraft@mailman.qth.net elecraft@mailman.qth.net Subject: Re: [Elecraft] APF Message-ID: 52a3cd8c.2090...@gmail.com Content-Type: text/plain

Re: [Elecraft] APF

Sam; Your explanation is really good Sam, but it seems that something doesn't follow for me. cut... Turn on the RIT control (tap the RIT button). Next, lower the RIT frequency -20 Hz. (You must have CONFIG:PB CTRL in the config menu set to .01 to move in 10 Hz

Re: [Elecraft] APF

1st of all let me be clear, I was merely quoting from my notes that I had copied from a post (or web site?) that Dusty K3WC wrote that said yes it was the Shift knob Dusty was speaking of calling it the Shift Fc (frequency) knob when I turn mine it says (in the VFO B window) APF *0.48 (my

[Elecraft] APF

The subject line should read APF of course, sorry! Sam, thank you for the tips on APF. One remark though: Switching between the two filters is as easy as HOLDING the SHIFT knob in. I suppose you mean the WIDTH knob... 73 Richard - HB9ANM

[Elecraft] APF

Can someone explain how to engage and use the Audio Peak Filter on the K3? thanks in advance todd WB2ZAB __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post:

Re: [Elecraft] APF

I'll copy and paste from my notes, hope it helps clear it up for you. sm APF on the K3 The APF is an easy tool to use. However, one of the main concerns people are talking about now is the fact that the filter seems to be a bit tight, and tends to ring. This, of

Re: [Elecraft] APF

one more fyi on the [XFIL/DUALPB] button when in RTTY, both AFSK A and FSK D, it's a Dual Passband Filter when in CW mode it acts like the single peak APF there's an image of the APF in use on N1EU site: http://n1eu.com/K3/K3_apf.htm On 11/30/2013 11:56 AM, Sam Morgan wrote: I'll copy and

[Elecraft] APF and Tuning Speed

Hello all and Happy Thanksgiving: I am trying to create a macro to do the following: 1. Set radio to Fine tuning mode (1 hz increments) 2. Turn on APF Then with another push of a button 1. Turn off APF 2. Return radio to regular tuning speed (in my case 10 hz increments) I realize this would

[Elecraft] APF question

When using the APF function on my K3 I am getting a real tinny sound to the point were it is difficult to understand the code. I was wondering if settings were ok. Here is what I do. 1. Zero beat the CW signal with the spot feature and tuning is set to fine. 2. The filter is set at either

Re: [Elecraft] APF question

VE3WDM wrote: When using the APF function on my K3 I am getting a real tinny sound to the point were it is difficult to understand the code. I was wondering if settings were ok. Here is what I do. 1. Zero beat the CW signal with the spot feature and tuning is set to fine. 2. The filter

Re: [Elecraft] APF question

Hello Mike, The APF, because of the high Q will naturally produce ringing with a strong signal. Just back down the RF Gain control until you can clearly hear the keying elements. However, I'd suggest that if the signal is that strong to begin with, you probably don't need to use the APF

[Elecraft] APF - New things

Well even really old dogs can learn new stuff. Tuning around on 30m, with AFP enabled, something I have never done before -- I just forgot to turn it off, I found signals ... and worked one I did not hear with AFP turned off. I'm becoming convinced that my K3 [and K2 for that matter], are

Re: [Elecraft] APF Macro

To: Ron D'Eau Claire Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] APF Macro There are some samples in K3 Utility help, look for command macros in the index. I'm open to adding and annotating more samples. This isn't to discourage use of other repositories, however. 73 de Dick, K6KR On Feb

[Elecraft] APF Macro

It is tough to get old and find most of your electronics know-how is out of date- so much so that creating a macro from scratch seems beyond my ken. APF is a very useful function, and I use it along with RIT as the fine tuning mechanism. How would one generate and execute as either a

Re: [Elecraft] APF Macro

to make a small change than to start from scratch. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of n...@aol.com Sent: Saturday, February 12, 2011 2:56 PM To: elecraft@mailman.qth.net Subject: [Elecraft] APF Macro

Re: [Elecraft] APF Macro

@mailman.qth.net Subject: Re: [Elecraft] APF Macro Age notwithstanding, many of us find messing with macros or other 'programming' activities right up there in desirability with hauling out the trash. Perhaps it would be possible for Elecraft to start building a macro library. Even if a macro

Re: [Elecraft] APF Macro

The help file of the K3 Utility program has lots of useful macros as well as the information on how to send them to the radio and assign them to radio buttons using the CONFIG menu. For anyone using DXLab's Commander rig control program, that program offers an alternative to macros in the K3.

Re: [Elecraft] APF Macro

: [Elecraft] APF Macro To: elecraft@mailman.qth.net Date: Saturday, February 12, 2011, 3:55 PM It is tough to get old and find most of your electronics know-how  is out of date- so much so that creating a macro from scratch seems beyond my  ken. APF is a very useful function, and I use it along

Re: [Elecraft] APF Macro

change than to start from scratch. Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of n...@aol.com Sent: Saturday, February 12, 2011 2:56 PM To: elecraft@mailman.qth.net Subject: [Elecraft] APF Macro

[Elecraft] APF Macros

I reported a macro for turning on APF, RIT, and FINE and shifting RIT down 20 Hz in a reflector message dated November 4, 2010. I also included a macro for clearing all these functions, since I could not seem to come up with a toggleable version. Since I wrote that, I revised my macro's to the

[Elecraft] APF measurements: FW 4.17 vs FW4.25 revisited

All, Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS again, and again. Question was: if the filter plots are exactly the same, where does the measured (marginal) difference of 2 dB come from? Found no difference this time. Seems that the XG2 drifted a bit in yesterdays

Re: [Elecraft] APF measurements: FW 4.17 vs FW4.25 revisited

PA3A wrote: Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS again, and again. Question was: if the filter plots are exactly the same, where does the measured (marginal) difference of 2 dB come from? Found no difference this time. Seems that the XG2 drifted a bit in

[Elecraft] APF re-check: Rev. 4.17 vs. 4.25 (no difference found)

Lyle (KK7P), our DSP engineer--a very meticulous guy--just did a very careful re-test of the two versions of code referred to in this thread. He found no difference between 4.17 and 4.25. I see that Arie (PA3A) also confirmed no difference when he repeated his own test. (Thanks for doing

Re: [Elecraft] APF re-check: Rev. 4.17 vs. 4.25 (no difference found)

I am not smart enough to comment regarding the real stuff going on behind the sceines in the code. However, since the new update the NR and NB pretty much take care of my Plasma TV noise. So there is something that changed in the combination and I say thanks for this improvement. Don KD8NNU

[Elecraft] APF Really Works

Just worked VP8ORK on 12cw. No copy without the APF. Workable with it Other spots saying only esp. Guess they weren't using a K3!!! Thanks again to Wayne and Eric for an outstanding radio. 73 Elliott WA6TLA __ Elecraft mailing

Re: [Elecraft] APF Really Works

Elliott, Congratulations on working VP8ORK ! I hope to work them also, armed with my K3 APF battle gear. 73, Bob K6UJ On Jan 28, 2011, at 12:46 PM, Elliott Lawrence wrote: Just worked VP8ORK on 12cw. No copy without the APF. Workable with it Other spots saying only esp. Guess they

Re: [Elecraft] APF Really Works

Thank goodness (and Elecraft) most of the DXpeditions these days are packing K3s. That means I stand a chance that they'll hear little pistols like me! 73, Ken Alexander VE3HLS --- On Fri, 1/28/11, Elliott Lawrence wa6...@roadrunner.com wrote: Just worked VP8ORK on 12cw.  No copy without

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Bill, the K3s dBv and AF Mv meters are true RMS. We added that feature for automated MDS testing in K3 production. 73, Eric www.elecraft.com _..._ On Jan 27, 2011, at 11:17 AM, Bill W4ZV btipp...@alum.mit.edu wrote: Arie Kleingeld PA3A-2 wrote: I have no lab equipment but I have a

[Elecraft] APF measurements: FW 4.17 better results by 2 dB

Hello all, Did some measurements on the different frimware versions. This time not a BW-plot but I measured S+N/N ratio's. I have no lab equipment but I have a K3 with dBV measurements, XG2 and the stepped attenuator from elecraft. I measured the difference of the K3 dBV-reading in signal

[Elecraft] APF

Good advice from N1EU and K2AV here, folks! Also, see Wayne's posting: Tips for using APF. I'm a junkie for trying out new firmware, and I can attest that the APF is as good as it ever was-- in fact you need the latest version of it to be sure you have the 5 Hz resolution in the APF shift

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

All, where I mentioned Dual PB, I mean ofcourse the APF, because that the discussion here. Sorry If that is not clear. 73 Arie PA3A Op 27-1-2011 12:44, Arie Kleingeld PA3A schreef: Hello all, Did some measurements on the different frimware versions. This time not a BW-plot but I measured

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Arie Kleingeld PA3A-2 wrote: I have no lab equipment but I have a K3 with dBV measurements, XG2 and the stepped attenuator from elecraft. Arie I believe you may have some measurement error. I'm sure you know that noise can only be measured correctly with a True RMS responding

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Page 36 of the K3 owner's manual: AFV shows the true RMS value of receiver AF output (mVp-p), unaffected by AF GAIN control. 73, Scott K9MA On Jan 27, 2011, at 1:17 PM, Bill W4ZV wrote: I'm sure you know that noise can only be measured correctly with a True RMS responding

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

...@xs4all.nl To: elecraft@mailman.qth.net Sent: Thursday, January 27, 2011 6:44 AM Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB Hello all, Did some measurements on the different frimware versions. This time not a BW-plot but I measured S+N/N ratio's. I have no lab

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

- From: Arie Kleingeld PA3A [hidden email]http://user/SendEmail.jtp?type=nodenode=5967599i=0 To: [hidden email] http://user/SendEmail.jtp?type=nodenode=5967599i=1 Sent: Thursday, January 27, 2011 6:44 AM Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB Hello all, Did

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Scott Ellington wrote: Page 36 of the K3 owner's manual: AFV shows the true RMS value of receiver AF output (mVp-p), unaffected by AF GAIN control. While that may be true for sinusoidal signals I doubt it holds for noise measurements. Accurate noise measurements require a true

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Bill, Thanks for your added comments. As I said, I do not have the lab equipment to do this. But there are people in this group that have and can measure far better than I. The APF (for me) is not about selectivity. I use it when digging into the noise and get a better copy of weak signals.

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Hi, Doing true RMS over the selected passband is very easy to do with DSP and I have no reason to doubt that the K3 dBV meter is a very close approximation to true RMS even on signals that are far from sinusoidal (such as noise). Analog is a different story and I agree that there are many false

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Within the band-limited audio passband of the K3, the RMS metering is very accurate. The algorithm is: 1) measure and square each reading 2) sum with the previous readings (accumulate) 3) do this for 500 ms or 1 sec 4) divide the sum by the number of samples taken 5) compute the square root 6)

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

=nodenode=5967599i=1 Sent: Thursday, January 27, 2011 6:44 AM Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB Hello all, Did some measurements on the different frimware versions. This time not a BW-plot but I measured S+N/N ratio's. I have no lab equipment

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Barry N1EU wrote: 4.16 APF has the same response curve as all the other versions. Q.E.D. If it has an identical response curve it has identical S/N performance. Anything else is either differences in noise conditions or human imagination. 73, Bill -- View this message in context:

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

But Bill, I had a sage manager many years ago who often stated Perception is 99% of reality. Being of a scientific mind, I had my doubts at the time thinking people will be convinced by the facts of science. In later years, I have mellowed and now agree with that manager. Perception IS 99%

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Don Wilhelm-4 wrote: I had a sage manager many years ago who often stated Perception is 99% of reality. Being of a scientific mind, I had my doubts at the time thinking people will be convinced by the facts of science. In later years, I have mellowed and now agree with that manager.

Re: [Elecraft] APF measurements: FW 4.17 better results by 2 dB

Bill, I am not suggesting Elecraft do anything other than the explanations that have already transpired. Yet even with such dialog and tests that say Q. E. D., there will be many who remain unconvinced, and will want to stick with the old version because it is better. They will not be

[Elecraft] APF

Did anything change with APF in the latest release ? Seemed to perform better before rev 2.45. Maybe I 'm just loosing my touch. 73 Dave Lear NE5DL __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

Re: [Elecraft] APF

other factors at play. I dont really have the answer. I am keeping the original firmware just for contests. 73 John --- On Wed, 1/26/11, David Lear del...@charter.net wrote: From: David Lear del...@charter.net Subject: [Elecraft] APF To: Elecraft@mailman.qth.net Date: Wednesday, January

Re: [Elecraft] APF

Leardel...@charter.net Subject: [Elecraft] APF To: Elecraft@mailman.qth.net Date: Wednesday, January 26, 2011, 11:27 AM Did anything change with APF in the latest release ? Seemed to perform better before rev 2.45. Maybe I 'm just loosing my touch. 73 Dave Lear NE5DL

Re: [Elecraft] APF

Okay, what version of firmware has the original APF that worked better for you guys? I'll try and run a spectral comparison of the two and post the results. I'm skeptical that there's a difference but I'm willing to give it a go. Barry N1EU juergen piezo wrote: I like you cant get the

Re: [Elecraft] APF

wrote: From: David Lear del...@charter.net Subject: [Elecraft] APF To: Elecraft@mailman.qth.net Date: Wednesday, January 26, 2011, 11:27 AM Did anything change with APF in the latest release ? Seemed to perform better before rev 2.45. Maybe I 'm just loosing my touch. 73 Dave Lear NE5DL

Re: [Elecraft] APF

only be blown off once? Steve N4LQ - Original Message - From: Barry N1EU barry.n...@gmail.com To: elecraft@mailman.qth.net Sent: Wednesday, January 26, 2011 6:12 PM Subject: Re: [Elecraft] APF Okay, what version of firmware has the original APF that worked better for you guys? I'll

Re: [Elecraft] APF

Forget it - full stop! I just ran a spectral analysis of the current firmware versus the very first APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a byte). Have a look: http://n1eu.com/k3apf.gif

Re: [Elecraft] APF

May I suggest that one of the necessities of using APF is to throttle back the RF gain so that the AGC is not pushing up the noise to the level of forcing what sounds like ringing. When I'm hearing what sounds like ringing, moving back the RF gain (or removing PRE, or using ATT) will usually

Re: [Elecraft] APF

the original firmware just for contests. 73 John --- On Wed, 1/26/11, David Lear del...@charter.net wrote: From: David Lear del...@charter.net Subject: [Elecraft] APF To: Elecraft@mailman.qth.net Date: Wednesday, January 26, 2011, 11:27 AM Did anything change with APF

Re: [Elecraft] APF

Hi Barry, I'm curious too. This has come up before. I'd be interested in what you see. 73, Bob K6UJ On Jan 26, 2011, at 3:12 PM, Barry N1EU wrote: Okay, what version of firmware has the original APF that worked better for you guys? I'll try and run a spectral comparison of the two and

[Elecraft] APF effectiveness...

APF ringing and over powering... I have had input from two Elecraft support fellows one of which was helpful. That being move the receiver off frequency (RIT) about 10Hz then adjust the APF center frequency to match. Some help - yes. But... The Elecraft implementation of APF in MCU 4.22 just

Re: [Elecraft] APF effectiveness...

- From: Bob Lanning bob.w6...@gmail.com To: elecraft@mailman.qth.net Sent: Tuesday, January 25, 2011 3:11 PM Subject: [Elecraft] APF effectiveness... APF ringing and over powering... I have had input from two Elecraft support fellows one of which was helpful. That being move the receiver off

Re: [Elecraft] APF effectiveness...

I've found that using the APF with the 400 filter (or wider) dialed-in provides less ringing than using APF with the 50 filter (DSP) dialed-in. Either way, it's effectiveness is excellent, and that from a twelve-year FT-1000D owner. 73, Kent K9ZTV Jefferson City, MO

  1   2   3   4   >