The center follows the K3 you can tell where it is based on the fact that there is a K3 next to you. So long as you've got the two synced and don't have a center offset in you know where the center is.
~Brett (N7MG) On Wed, Aug 11, 2010 at 9:19 PM, The Smiths <[email protected]> wrote: > > Bill, > > I'm going to try to be as least condescending as I can. Please forgive me if > I go astray. I tend to get very snippety when I'm being treated as if I'm > dumb... > > Before you can even begin to set the Ref-Cal on the P3 you must FIRST know > that the center line on the P3 is actually the center of the Freq. it is > displaying. I'm sure by seeing your answer to my email that this is > something that has completely alluded you. What you are suggesting, and the > manual for that matter, is that what ever the display says is the center > Freq. is going to be an accurate reading. This is just plain and outright > ridiculous. If you have taken the time to really think about what is going > on here you would come to the realization that there is only 1 ONE digit > after the KHz freq. display on the P3 Center line (IE 10.000.0) > > If you look at the centering adjustment for the P3 you will notice that the > display will NOT change from the 10.000.0 position until you reach the > 10.000.1 (+100Hz) or 9.999.9 (-100Hz) frequency. Therefore logic dictates > that if you try to adjust a center and just arbitrarily use any position > between 10.000.1 and 9.999.9 as your center you have a 1 in 100Hz chance of > being centered on the Zero beat of WWV in this case (10.000.000 being the > center carrier freq. of wwv in the USA. Not 10.000.099). > > In other words, this means that if you were to even attempt to adjust your > Ref-cal alignment on the P3 before finding the best "FUZZY" center of > 10.000.000 you can, your REF-CAL alignment will NEVER be closer than the > center you have set it to. So, now adding both the complete inaccuracy of the > "Center alignment" of up to 100Hz, and the best possible marker accuracy of > 5Hz (in the 2KHz span), you can NEVER set the P3 closer than 5Hz with any > actual accuracy. And That of of course would require you making a really > really good guesstimation of where the Fuzzy Center on the P3 is by finding > the highest number before the flip, and the lowest number before the flip > from 10.000.0, then moving the select knob to as close a center of each as > you can. > > Would you put your K3 on 10.000.0, turning off the extra 2 digits and try to > set your Config: Ref-Cal alignment to Zero beat WWV? Because this is exactly > what you are suggesting others do by telling them that the "Center" alignment > has nothing to do with the Ref Cal alignment on the P3. > Elecraft has GOT TO add those two other digits into the display if anyone is > going to have an accurate centering of their P3 before they do the Ref Cal > alignment. This is IMPERATIVE to the CW operator that relies on being able > to use 50Hz wide filters. > > This is forgetting the fact that on 3 of the units I have helped align so far > they have ALL been off frequency with both Center and Ref Cal by as much as > -300. Well, -160 when first turned on, -220 about a half hour later, and > then -300 about an hour later. The drift is incredible on the P3, a .05 or > even 1ppm crystal it does not have. > I would suggest to EVERYONE that has the P3 they wait AT LEAST and hour > (assuming you generally use your P3 for more than an hour when you operate it > on a normal day) before setting their REF Cal alignment. But without doubt, > before you do that, make sure that you know the center mark on your P3 is > actually the center you're looking for. > > I think it's time for the manual to change how the alignment has been > written, not how I'm doing my alignment. Thank you. > > > > > >> Date: Wed, 11 Aug 2010 12:08:04 -0700 >> From: [email protected] >> To: [email protected] >> Subject: Re: [Elecraft] P3: a modest proposal for QSY >> >> >> >> The Smiths wrote: >> > >> > Because the accuracy of the display readout when doing the "CENTER" >> > alignment is short by 2 digits, it causes the centering of the P3 to be >> > within only 100Hz of the actual center. It is imperative to the CW guys >> > that the extra 2 digits be displayed on the Top center read out. This >> > would allow us to both CENTER and REF CAL our WWV carrier right on Zero >> > Beat, and not just within 100Hz. Right now this is the most crippling blow >> > to the CW guys. >> > >> >> You may not be doing Reference Calibration correctly if you are using the >> digital frequency readout on the P3. You don't need anything except the >> Spectrum display (step 5 below). From page 19 of the manual: >> >> Frequency Calibration >> >> Turn on the transceiver and P3 and allow >> them to warm up for 30 minutes, minimum, >> before performing the calibration. >> >> 1. If the transceiver has a calibration procedure to >> correct its frequency errors, perform that >> procedure first. >> >> 2. Using a well-calibrated signal generator or an >> on-the air carrier signal of known frequency, >> tune in the signal on the transceiver. An A.M. >> broadcast station can serve as a suitable test >> signal. >> >> 3. Adjust the transceiver frequency to the known >> frequency of the test signal. Depending upon >> the modulation mode of the transceiver, the >> signal may not be audible. >> >> 4. Set the P3 for minimum span and adjust the >> reference level and scale so you can easily see >> the signal. >> >> 5. Select MENU:Ref Cal, tap the SELECT >> knob, and adjust the frequency calibration until >> the carrier is centered horizontally on the >> display. If the required correction is more than a >> few kHz, it may be that the I.F. frequency is set >> incorrectly. That can be adjusted via >> MENU:Xcvr Def. >> >> The P3's Ref Cal steps in the menu are 10 Hz but that's close enough for >> accurately QSYing to even a 50 Hz bandwidth. >> >> 73, Bill >> >> -- >> View this message in context: >> http://elecraft.365791.n2.nabble.com/P3-a-modest-proposal-for-QSY-tp5410950p5413530.html >> Sent from the [K3] 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:[email protected] >> >> 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
