Brett, What is the width of your OP1 filter? The initial ones were 2.1 kHz wide for best use with a QRP K2, then it was changed to 2.4 kHz for better fidelity. A 2.6 kHz width will sound even better. Elecraft offers a capacitor kit to allow you to change the width to either the 2.1, 2.4 or 2.6 kHz width.
Yes, the variable filter looks a bit 'ratty' at wide widths, but if the filter passband is positioned properly (low frequency corner at 300 Hz), it provides a means of cutting out QRM while listening to SSB despite the great passband ripple. It is never used for transmitting SSB. 73, Don W3FPR Brett Gazdzinski wrote: > Today, I could pick up the time signal on 20 MHz and did the setup with > moving the probe between tp1 and tp2 to get the readings the same. > It seems spot on now, and I was in a qso on 80 meters and was right on > frequency on both TX and RX. > Same report as far as the audio goes, restricted but clean. > Its likely to sound a bit better with a real microphone. > The station I was talking to sounded VERY nice using an external speaker. > > I have been told the variable xtal filter looks bad on ssb with spectrogram, > and assume that is normal. > > I am really pleased with the K2 and the ssb part of it also. > > Who needs a K3! > > Brett > N2DTS > > > > ----- Original Message ----- > From: "Don Wilhelm" <[email protected]> > To: "Brett Gazdzinski" <[email protected]> > Cc: <[email protected]> > Sent: Thursday, January 29, 2009 10:36 PM > Subject: Re: [Elecraft] K2 freq calibration... > > > >> Brett, >> >> You ask several questions, and I will delay on all of them except the one >> about calibration. >> You are relying on too many variables when setting the 4 MHz reference >> oscillator. >> To reduce those variables, use the "N6KR" method that is documented at >> http://www.elecraft.com/Apps/K2%20C22%20Adjust%20App%20Note.pdf. If you >> can tune WWV accurately, all other variables are cancelled out by that >> method. >> >> You may also find helpful information in the K2 Dial Calibration article >> on my website www.w3fpr.com. For your restriceted SSB audio, consider the >> comments in that article about the low frequency corner of the SSB filter >> passband carefully - 300 Hz is the 'magic' frequency. >> >> After you get the dial calibration correct (within 20 Hz or less), ask >> about the other items. >> >> 73, >> Don W3FPR >> >> >> Brett Gazdzinski wrote: >> >>> I am having a hard time getting the frequency calibration on my K2 closer >>> than 80 Hz. >>> I set the osc to exactly 4Mhz, plus or minus a Hz on the pro3 switching >>> between usb and lsb, it also agrees with the HP spectrum analyzer, I then >>> run the cal pll, and the bfo calibration, and when tuning in ssb signals, >>> they sound normal 80 or more Hz higher than they should (as tuned in on >>> the pro 3). >>> >>> Is this as good as it gets on ssb? >>> I have compared CW signals between the two rigs and they are very close, >>> within about 10 Hz on 80 meters anyway. >>> >>> It seems the freq counter, pll cal, and bfo all sort of interact, but if >>> the freq counter calibration is spot on, why the 80 Hz difference? >>> (80 Hz is as close as I have gotten it in many attempts) >>> >>> Also, is it normal for the non ssb filters to look SO bad on >>> spectrogram?? >>> >>> I got the ssb option on Tuesday, it was done Tuesday night, the antenna >>> tuner was done Wednesday, no problems with them, no missing parts, no >>> issues, I made my first ssb contact yesterday on 80 meters using the hand >>> mic from the pro 3. >>> SSB from the K2 sounds good in the pro 3, the report I got said it >>> sounded a bit restricted, the hand mic sounds poor on the pro 3... >>> >>> What would be a nice sounding microphone to use with the K2? >>> >>> Also, I have been thinking of taking down the home made G5RV and trying >>> an alpha delta dx-lb plus (160 through 10), the G5RV does not seem to >>> work as good as the 40 meter dipole on 40, and its likely worse on other >>> bands... >>> >>> Anyone got anything bad to say about the dx-lb plus, I know its not as >>> good as a full size 160 m antenna, but I have about 110 feet max between >>> trees. >>> >>> I sure am enjoying the K2! >>> >>> >>> Brett >>> N2DTS >>> >>> > _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
