K3: Use VFO-B to select dBV
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Howdy K3' people:
According to the Manual, Page 36, I can use VFO-B display to see dBV after AFV settles down. I see the RMS voltage reading but I never get to see the equivalent dBV. So I rotated through the variables available, by turning the VFO-B knob, everything else is the but no dBV. And the reason I want to see this is because I just received my new XG3 Signal Source. In it they mention a way to see dBV on the K3 . -- 73 KD7YZ Bob ______________________________________________________________ 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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I am getting dBV here, Bob, the VFO-B knob being fully clockwise.
I presume you have up-to-date firmware? Mine is uC=4.61, D1/2=2.80, FL=1.15, DR=1.03. 73 de David G4DMP In a recent message, KD7YZ Bob <[hidden email]> writes >According to the Manual, Page 36, I can use VFO-B display to see dBV >after AFV settles down. > >I see the RMS voltage reading but I never get to see the equivalent dBV. >So I rotated through the variables available, by turning the VFO-B knob, >everything else is the but no dBV. -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + ______________________________________________________________ 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: Use VFO-B to select dBV
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Have you got Menu Tech Mode ON?
Gary On 15 March 2013 22:33, David G4DMP <[hidden email]> wrote: > I am getting dBV here, Bob, the VFO-B knob being fully clockwise. > > I presume you have up-to-date firmware? Mine is uC=4.61, D1/2=2.80, > FL=1.15, DR=1.03. > > 73 de David G4DMP > > In a recent message, KD7YZ Bob <[hidden email]> writes > >According to the Manual, Page 36, I can use VFO-B display to see dBV > >after AFV settles down. > > > >I see the RMS voltage reading but I never get to see the equivalent dBV. > >So I rotated through the variables available, by turning the VFO-B knob, > >everything else is the but no dBV. > > -- > + - - - - - - - - - - - - - - - - + > | David M Pratt, Kippax, Leeds. | > | Website: http://www.g4dmp.co.uk | > + - - - - - - - - - - - - - - - - + > > ______________________________________________________________ > 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 - VK1ZZ Skype: Gary.VK1ZZ Motorhome Portable The Shack* *Elecraft K3 P3 Panadapter KPA500FT KAT500FT** KX3-K * ______________________________________________________________ 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 Bob KD7YZ
You must be in Tech Mode to see it.
73,Fred/N0AZZ K3 Ser #'s 6730/5299--KX3 # 2573--K2/100--KAT/100 P3/SVGA--KPA500--KAT500--W2 -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of KD7YZ Bob Sent: Friday, March 15, 2013 6:06 AM To: K3 List Subject: [Elecraft] K3: Use VFO-B to select dBV Howdy K3' people: According to the Manual, Page 36, I can use VFO-B display to see dBV after AFV settles down. I see the RMS voltage reading but I never get to see the equivalent dBV. So I rotated through the variables available, by turning the VFO-B knob, everything else is the but no dBV. And the reason I want to see this is because I just received my new XG3 Signal Source. In it they mention a way to see dBV on the K3 . -- 73 KD7YZ Bob ______________________________________________________________ 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 message. Checked by AVG - www.avg.com Version: 2013.0.2904 / Virus Database: 2641/6173 - Release Date: 03/14/13 ______________________________________________________________ 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 Gary Gregory-2
On Friday Gregory used a Straight-Key to send: -------------Original Comment------- > Have you got Menu Tech Mode ON? Well, gee. Yes, I did have it on. Really. But now it is "OFF". So I will guess that the selection is not Persistent. Or that setting has another way of reverting to OFF. Not I am seeing 99.9dBV for an RMS reading of "1.09 A". This isn't too helpful though. Perhaps David can elaborate on how I get to a meaningful reading. thanks for the help. -- Best regards, Bob KD7YZ Win7-64bit + K3 ______________________________________________________________ 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 a recent message, KD7YZ Bob <[hidden email]> writes
> >Not I am seeing 99.9dBV for an RMS reading of "1.09 A". >This isn't too helpful though. Perhaps David >can elaborate on how I get to a meaningful reading. The 1.09A is the supply current, Bob; not at all related to the dBV. David -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + ______________________________________________________________ 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 Bob KD7YZ
Bob - The K3 manual does not give as much detail as the KX3 manual which
describes the functions as follows.... "Audio Signal Level AFV. This display shows the approximate level of the audio output, prior to the AF gain control (in other words, the AF gain control has no effect on the reading). The reading will vary with preamp and attenuator settings as well as the RF gain control. AFV is normally used in conjunction with the dBV function. "Relative audio signal (dBV). This display can be used to measure receiver sensitivity or gain/loss of various stages, or compare two signals. To use it, first select AFV and allow the voltage reading to stabilize. (This may not be possible with modulated or rapidly changing signals.) Once the signal appears stable, select dBV. You should now see a reading of around 0dBV relative to the last AFV reading. If you change the setting of the preamp or attenuator, you should see this reading change. However, it may not change as much as you expect unless you turn AGC off. (Be sure to turn AF gain down BEFORE turning AGC off, as the signal may become very loud.) Measurement of receive sensitivity (MDS) requires a calibrated 1-uV signal source such as an Elecraft XG1/2/3. These sources include instructions for measuring MDS." I hope that helps, Bob. 73 de David G4DMP In a recent message, KD7YZ Bob <[hidden email]> writes >Not I am seeing 99.9dBV for an RMS reading of "1.09 A". >This isn't too helpful though. Perhaps David >can elaborate on how I get to a meaningful reading. -- + - - - - - - - - - - - - - - - - + | David M Pratt, Kippax, Leeds. | | Website: http://www.g4dmp.co.uk | + - - - - - - - - - - - - - - - - + ______________________________________________________________ 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 Bob KD7YZ
I forgot to hit reply all.
-----Original Message----- From: Cady, Fred Sent: Friday, March 15, 2013 7:24 AM To: 'KD7YZ Bob' Subject: RE: [Elecraft] K3: Use VFO-B to select dBV Hi Bob, I'm not at my book on that topic but from memory here goes: The dBv measurement is really great once you catch on to how it works. Note that dBV is NOT dB relative to a volt. It is relative to the last time you made the AFV voltage measurement. I think Tech Mode needs to be on. It used to, but maybe a firmware update made it available. Plug in the GO to get a solid signal at, say -73 dBm. So, get the VFO B display in the right state and then turn VFO B to show the AFV display. Wait until the AFV display settles on a value. Now rotate VFO B to dBV. It should settle to 0.0 dBV. Now, WITHOUT changing the VFO B, make a change in the input conditions. E.G, change the XG3 to -107 dBm. You should see the dbV display change to show the decrease in signal strength. If you have AGC on, you probably won't see -34 dBV. The trick to all this is once you set up for 0 dBV, DON'T change the VFO B back to the AFV display. Cheers, Fred KE7X "The Elecraft K3: Design, Configuration and Operation Second Edition" www.ke7x.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of KD7YZ Bob Sent: Friday, March 15, 2013 6:46 AM To: K3 List Subject: Re: [Elecraft] K3: Use VFO-B to select dBV On Friday Gregory used a Straight-Key to send: -------------Original Comment------- > Have you got Menu Tech Mode ON? Well, gee. Yes, I did have it on. Really. But now it is "OFF". So I will guess that the selection is not Persistent. Or that setting has another way of reverting to OFF. Not I am seeing 99.9dBV for an RMS reading of "1.09 A". This isn't too helpful though. Perhaps David can elaborate on how I get to a meaningful reading. thanks for the help. -- Best regards, Bob KD7YZ Win7-64bit + K3 ______________________________________________________________ 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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On Friday Cady used a Straight-Key to send: -------------Original Comment------- > I forgot to hit reply all. > Note that dBV is NOT dB relative to a volt. It is relative to the last > time you made the AFV voltage measurement. wow Fred, great and helpful reply. I printed it out so I cn make the tests. Whoda thunk it was relative to the last measurement! I ordered some BNC attenuators in the usual ranges. Tracking says they arrive today. thanks for the help!! and RR on the forgetting to make the effort to "Reply All". This happens to me several times a day but now I don't bother to go back and re-do it on any of the "Lists" I am on. I think Admin's set it that way to reduce overall List-Traffic . I could argue either way on the topic. -- Best regards, Bob KD7YZ Win7-64bit + K3 ______________________________________________________________ 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 Gary Gregory-2
On Friday Gregory used a Straight-Key to send: -------------Original Comment------- > Have you got Menu Tech Mode ON? yes. -- Best regards, Bob KD7YZ Win7-64bit + K3 ______________________________________________________________ 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: FW: K3: Use VFO-B to select dBV
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In reply to this post by Bob KD7YZ
You are welcome Bob.
If you are going to use the attenuators to reduce signal strength to check linearity or something, you might not get what you expect if AGC is on. With AGC off the K3 is pretty linear from MDS to over s9 or so. The ke7x website has some curves showing this as does "the k3 book". Cheers, Fred www.ke7x.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of KD7YZ Bob Sent: Saturday, March 16, 2013 6:21 AM To: K3 List Subject: Re: [Elecraft] FW: K3: Use VFO-B to select dBV On Friday Cady used a Straight-Key to send: -------------Original Comment------- > I forgot to hit reply all. > Note that dBV is NOT dB relative to a volt. It is relative to the last > time you made the AFV voltage measurement. wow Fred, great and helpful reply. I printed it out so I cn make the tests. Whoda thunk it was relative to the last measurement! I ordered some BNC attenuators in the usual ranges. Tracking says they arrive today. thanks for the help!! and RR on the forgetting to make the effort to "Reply All". This happens to me several times a day but now I don't bother to go back and re-do it on any of the "Lists" I am on. I think Admin's set it that way to reduce overall List-Traffic . I could argue either way on the topic. -- Best regards, Bob KD7YZ Win7-64bit + K3 ______________________________________________________________ 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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