Just completed assembly of the RF Board, Part II. Getting closer by the day!
I have the counter probe on TP3 and measuring 12099 kHz as I should according to the manual. However, it is changing back and forth somewhat rapidly between 12099.28 and 12099.29 kHz. Is this normal or do I have something wrong with the PLL Reference Oscillator? Thanks -- JT Croteau, N1ESE - Manchester, NH _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
On Mon, Aug 27, 2007 at 12:16:17PM -0400, JT Croteau wrote:
> I have the counter probe on TP3 and measuring 12099 kHz as I should > according to the manual. However, it is changing back and forth > somewhat rapidly between 12099.28 and 12099.29 kHz. Is this normal or > do I have something wrong with the PLL Reference Oscillator? This is normal. The frequency isn't changing - it is just that you occasionally have one more - or less - count during the gate time of the frequency counter. Tree N6TR _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
In reply to this post by JT Croteau
JT,
That is the 'last digit indecision' type flicker, and it is not avoidable in a digital display except for really high end and expensive equipment. The actual frequency is in between 12099.28 and 12099.29 and the gate interval of the counter sometimes picks up one more cycle than at other times. Rapid variations in the higher order digits are an indication of a problem, but no problem when just the last digit is flickering between 2 consecutive digits. 73, Don W3FPR JT Croteau wrote: > Just completed assembly of the RF Board, Part II. Getting closer by the day! > > I have the counter probe on TP3 and measuring 12099 kHz as I should > according to the manual. However, it is changing back and forth > somewhat rapidly between 12099.28 and 12099.29 kHz. Is this normal or > do I have something wrong with the PLL Reference Oscillator? > > Thanks > > Elecraft mailing list Post to: [hidden email] 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 |
Thanks to N6TR, N0SS, and W3FPR for their explanations and reassurances.
I've just completed all of the Part II test/alignment procedures except for the Band Pass Filter Alignment. I'm ordering an N-Gen next week and may hold off on this alignment until it arrives. My 40-Meter dipole is currently coiled up under the bench waiting for helpers to come over and get it in the air. The only antenna up at the moment here is an indoor 6-Meter dipole. -- JT Croteau, N1ESE - Manchester, NH _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
JT,
No need to wait for the N-Gen for the Bandpass filter alignment - just initially peak the BPF in receive using only band noise (connect your 6 meter antenna or just a piece of wire to the antenna jack center conductor). Once you have the BPF peaked on receive (this is only an initial alignment to get things 'into the ballpark' - peak for maximum antenna noise), then do the Transmit BPF alignment. It is easier to observe the peak during the transmit alignment, and when that is done, it will be correct for both receive and transmit. The N-Gen will come in handy when you are doing the IF filter alignment (CAL FIL) using the Spectrogram display - for that process, a broadband noise source is best - and the N-Gen is a broadband noise generator. 73, Don W3FPR JT Croteau wrote: > Thanks to N6TR, N0SS, and W3FPR for their explanations and reassurances. > > I've just completed all of the Part II test/alignment procedures > except for the Band Pass Filter Alignment. I'm ordering an N-Gen next > week and may hold off on this alignment until it arrives. My 40-Meter > dipole is currently coiled up under the bench waiting for helpers to > come over and get it in the air. The only antenna up at the moment > here is an indoor 6-Meter dipole. > > Elecraft mailing list Post to: [hidden email] 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 |
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