Re: [Elecraft] K3S DSP Filter Plots

In fact I've always calibrated my K3 S-meter to be 5 dB per division both above and below S9. This seems to me to be a consistent way to do it that's easy to read and easy to mentally convert to dBm. And the K3 amazingly consistently sticks to this 5 dB calibration from S1 to 50 dB over. Al

Re: [Elecraft] K3S DSP Filter Plots

Alan writes: > From Wikipedia: https://en.wikipedia.org/wiki/S_meter > >"IARU Region 1 Technical Recommendation R.1 defines S9 for the >HF bands to be a receiver input power of -73 dBm. This is a level >of 50 microvolts at the receiver's antenna input assuming the >

Re: [Elecraft] K3S DSP Filter Plots

Both the P3 and the K3 use S9 = -93 dBm on 2 meters. The P3 can read out in either S units or dBm. And they both treat 6 meters the same as HF: S9 = -73 dBm. Alan N1AL On 11/18/2015 05:18 PM, Greg Troxel wrote: Alan writes: From Wikipedia:

Re: [Elecraft] K3S DSP Filter Plots

From Wikipedia: https://en.wikipedia.org/wiki/S_meter "IARU Region 1 Technical Recommendation R.1 defines S9 for the HF bands to be a receiver input power of -73 dBm. This is a level of 50 microvolts at the receiver's antenna input assuming the input impedance of the receiver is 50

Re: [Elecraft] K3S DSP Filter Plots

With my Down East Microwave transverters, I am able to adjust the IF output of each such that the S meter on the K3S corresponds to 50 uV being equal to S-9 on the VHF or UHF bands. The transverters typically have 10 to 15 dB of gain as measured from input to output in receive. It is nice

Re: [Elecraft] K3S DSP Filter Plots

The original S meter development for HF radios was done by Art Collins. At that time the number used was 100 uV for S-9 to coincide with the RST system. Later the value was revised to 50 uV for S-9. Values above S - 9 are stated usually in dB although I've seen some in microvolts. If one

Re: [Elecraft] K3S DSP Filter Plots

aw - K4TAX Sent: Wednesday, November 18, 2015 3:46 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3S DSP Filter Plots The original S meter development for HF radios was done by Art Collins. At that time the number used was 100 uV for S-9 to coincide with the RST system. Later

Re: [Elecraft] K3S DSP Filter Plots

I believe there's more than one correct answer. In earlier times, the "Collins Standard" was 6 dB/S-unit and 50 uv = S9. My 75S3 came in at 53 uv for S9, and pretty much held to the 6 dB/S-unit below that. Not so much above S9 With my service monitor feeding my K3, it is exactly 50 uv = S9

Re: [Elecraft] K3S DSP filter plots

Hi Charles, You mention "interaction" as if it were some phenomenon to be avoided. In the K3 the roofing filter is in the analog 8 MHz IF and the DSP filter is program code working on the number soup somewhere after the RX analog to digital signal conversion. The only "interaction" possible is

[Elecraft] K3S DSP filter plots

Thanks for the reply Joe. I'm hoping that the constant slope you described is not the way the DSP filters are implemented, because that would mean the 50hz filter has a 5.625:1 shape factor, the the 100hz filter has a 5:1 shape factor, the 200 hz filter has a 3:1 shape factor and the 400hz

Re: [Elecraft] K3S DSP filter plots

I suspect you have researched these pages. But in case you haven't, I found these links to be helpful. Also the KE7X book has K3 roofing and dsp information. This is not exactly what you requested, regarding plots, but I think it may answer some

Re: [Elecraft] K3S DSP filter plots

Does anyone have Elecraft published plots of the narrow CW DSP filters, To the best of my knowledge, Elecraft have never published "curves" of the DSP response since the DSP is so dynamic. However, I remember Lyle commenting that the DSP has a constant skirt slope something on the order of

Re: [Elecraft] K3S DSP filter plots

Here is a site that provides free computer based spectrum displays. I use Spectrum View in conjunction with the USB soundcard within the K3S. It can be run in real time and you observe the changes that occur as the various parameters of BW and Shift are utilized. Easy to use and best of all,

Re: [Elecraft] K3S DSP filter plots

Charles, Getting a plot is not difficult to do. Just connect an audio spectrum analyzer such as Spectrogram or SpectrumLab to the audio output of the K3 and feed the antenna input with a broadband noise generator. I use that technique most every day when aligning the IF filters on K2s -

[Elecraft] K3S DSP filter plots

Thanks for the reply Guy. I understand your rationale for aligning IF and DSP filters for additional out-of-passband rejection in crowded contest conditions. My concern stems from using IF shift to move the DSP filter within the roofing filter passband. The Elecraft rep I spoke to last week

[Elecraft] K3S DSP filter plots

50 I only had time this morning to measure two filter settings on one slope of each filter. I'll let you plot the data. I hope you find this information useful until you get some better information. 73, Bill - NA5DX [Elecraft] K3S DSP filter plots *charles at k5ua.com*charles at

Re: [Elecraft] K3S DSP filter plots

It would be nice to know the DSP filter shape factors of the various narrow CW DSP filters http://marc.info/?l=elecraft=120716404727944=2 Dave Hachadorian, K6LL Yuma, AZ . __ Elecraft mailing list Home:

Re: [Elecraft] K3S DSP filter plots

Charles, I believe most operators use the RIT control rather than IF Shift to tune for off frequency stations. The IF shift is normally used to reduce interference from an "offending station". That along with the Width control can isolate a single station with ease and with the 50 Hz minimum

Re: [Elecraft] K3S DSP filter plots

Are we interested in the shape of the DSP filters inside the roofing filters or are we interested in the performance of the receiver using recovered audio? I have done measurements using a broadband noise for the source and measured spectrum of the recovered audio. Of course as the DSP BW is

Re: [Elecraft] K3S DSP filter plots

The DSP filtering is not stepped, but is continuously variable with the WIDTH control. There are no discrete DSP filters. 73, Don W3FPR On 11/16/2015 7:24 PM, Bob McGraw - K4TAX wrote: Is the reference to the DSP filter system or the roofing filter system? Since the reference is CW x

Re: [Elecraft] K3S DSP filter plots

No doubt Wayne is qualified, however he has deferred on several occasions to Lyle who I believe actually writes the code. And a teeny point from a math major ... inasmuch as arithmetic is a part of math, it is clearly "done mathematically." The "real" math however is in figuring out what

Re: [Elecraft] K3S DSP filter plots

Is the reference to the DSP filter system or the roofing filter system? Since the reference is CW x Filters, as a misnomer, one would presume the reference is actually to the roofing filters. Where as the DSP filter system is stepped from 50 Hz, 100 Hz, 150 Hz and etc. as such. 73

Re: [Elecraft] K3S DSP filter plots

The narrowest filter settings (50 Hz and 100 Hz) are actually steeper than this, and the IIR filters (menu selection) are different, too. I see all sorts of notes in this thread about S Meter readings. Much easier to turn AGC off and use the dB metering function in the radio. Of course, I admit

Re: [Elecraft] K3S DSP filter plots

On 11/16/2015 07:38 PM, Dave Hachadorian wrote: ... The inference I drew from Lyle's response is: DSP 60 dB BW = DSP Setting + 300 Hz. You can see that DSP "shape factor" varies with the DSP setting, so it is easier to remember the DSP+300 formula. It's worth mentioning that a similar thing

[Elecraft] K3S DSP Filter Plots

Hi Bill, Thanks so much for the data for the two filter configurations. This will give me a pretty good idea of the shape factor of the 200hz DSP filter. I just ordered a K3S, and the technician that helped me with some of my questions said that no one has ever asked him about the shape

Re: [Elecraft] K3S DSP filter plots

Is the reference to the DSP filter system or the roofing filter system? It is all about the DSP system. Lyle performed an experimental test of a 500 Hz DSP filter inside a 2.8 KHz roofing filter, so the DSP filter was the determinant factor. Here is his email again:

Re: [Elecraft] K3S DSP filter plots

: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3S DSP filter plots And I will add a filter is not a filter. No, I am not crazy. There are many types of filters with various trade-offs. In band ripple.loss..phase shift...skirt shapeare just some of the trade offs. DSP

Re: [Elecraft] K3S DSP filter plots

Oops. Hit the go button too fast. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Jeff AC0C Sent: Monday, November 16, 2015 8:25 PM To: George Fritkin ; k6...@foothill.net Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3S DSP filter plots It's

Re: [Elecraft] K3S DSP filter plots

And I will add a filter is not a filter. No, I am not crazy. There are many types of filters with various trade-offs. In band ripple.loss..phase shift...skirt shapeare just some of the trade offs. DSP software can emulate any or combos George, W6GF Sent from my iPad >

Re: [Elecraft] K3S DSP Filter Plots

I believe 5 dB is the correct number. But Lyle's suggestion to use the dBV function is a good one. Vic 4X6GP/K2VCO > On 17 Nov 2015, at 1:04 AM, char...@k5ua.com wrote: > > We are also going to assume that the K3 S-meter is 6 dB per S-unit all the > way from S5 to S9+40dB.

Re: [Elecraft] K3S DSP filter plots

Having a constant slope makes a lot of engineering sense. I believe, at least at some bandwidths, the K3 offers both IIR and FIR (infinite and finite impulse response filters). For data modes, FIR filters are better, as they are linear phase filters. The skirt slope of such a filter is

[Elecraft] K3S DSP filter plots

Although Elecraft has documented the response curves of their 5 and 8 pole roofing filters, I can't find any plots of their narrow DSP CW filters, like the 50, 100, 150 or 200 hz filters. Does anyone have Elecraft published plots of the narrow CW DSP filters, or has anyone use a signal