Re: [Elecraft] SW broadcast to calibrate against.
GB3RAL at 50.05MHz should be a good signal in Warfield. I do not know how accurate it is, it is well beyond my ability to measure it here at home. The reference it is driven from is locked to GPS with a long time constant and should be close to one part in 10^10. However, the frequency is DDS derived and there may be a very small fixed offset error of a mHz or so due to the limitations of a 48 bit frequency control register. For most purposes it will do. There is also a companion beacon on 70.05 MHz you could use. Mike Ian White GM3SEK wrote: David Ferrington, M0XDF wrote: I'd like to get a list of KNOWN frequencies of broadcast stations in 10 - 40m in the UK - it's been pointed out tpo me that using BBC WS at 648 KHz is a not so good, because its a low freq. The higher the reference frequency, the more accurately you can set the TCXO. Don't forget you have 50MHz now, and from your Callbook QTH in IO91, you may be able to receive the GB3RAL beacon on 50.050MHz. (I'm fairly sure it is locked to GPS, but not sure about ERP and operational status... we'll soon find out, because Mr Beacon Keeper is an Elecraft user!) -- 73 from Ian GM3SEK ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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 -- View this message in context: http://www.nabble.com/SW-broadcast-to-calibrate-against.-tp14777212p14783758.html Sent from the Elecraft mailing list archive at Nabble.com. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
Thanks Trevor, but of course, I wanted something now, and not when I've built it :( And I have the 1ppm TCXO, so when firmware permits me to enter the offsets from its calibration sheet, I'll be all set. And Elecraft make the XG1 and XG2 kits too. On 12/1/08 23:47, Trevor Smithers [EMAIL PROTECTED] sent: Rather than a BC station, how about a fairly accurate 10Mhz frequency standard like http://www.aade.com/freqstd/freqstd.html 73 to all Trevor G0KTN -- For all our conceits about being the center of the universe, we live in a routine planet of a humdrum star stuck away in an obscure corner ... on an unexceptional galaxy which is one of about 100 billion galaxies. ... That is the fundamental fact of the universe we inhabit, and it is very good for us to understand that. -Carl Sagan, astronomer and writer (1934-1996) ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
David Ferrington, M0XDF wrote: I'd like to get a list of KNOWN frequencies of broadcast stations in 10 - 40m in the UK - it's been pointed out tpo me that using BBC WS at 648 KHz is a not so good, because its a low freq. The World Service is on on multiple HF frequencies and there are also BBC transmissions for specific regions. I imagine the BBC web site will give details. The actual high precision BBC transmission is at 198.00 kHz, but that is even lower in frequency. In practice, though, most Euopean HF broadcast stations are on properly assigned frequencies and therefore are on multiples of 5kHz. You will probably get quite a good estimate by simply finding the largest cluster of stations with the same apparent offset from this, which will represent your tuning error. (European LF and MF stations use 9kHz channels. Droitwich used to be on 200.0 kHz, before this was standardized.) With a respectable crystal, you should be well within 300Hz at 30MHz, so there should be no problem in knowing which 5kHz you are on. (Hope I have the right number of zeroes in the above, and that Droitwich is still a frequency standard.) -- David Woolley Emails are not formal business letters, whatever businesses may want. RFC1855 says there should be an address here, but, in a world of spam, that is no longer good advice, as archive address hiding may not work. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
RE: [Elecraft] SW broadcast to calibrate against.
Ian wrote: The higher the reference frequency, the more accurately you can set the TCXO --- Is that correct? I don't know the details of Wayne's firmware, but the accuracy of a synthesized rig is normally independent of the frequency being received. I go for the highest frequency standard available when I'm trying to zero beat some lower-frequency oscillator as accurately as possible (such as when I set my 4.000MHz counter reference oscillator zero beat to WWV at 20 MHz), but that I don't believe that's what we're doing here. The accuracy at 50 MHz should be the same as at 500 kHz, excluding any rounding errors in the algorithm math. I have set my K3 on a BCB band station at 830 kHz to within 1 Hz and noted that WWV at 15.000 MHz is still within 1 Hz. Ron AC7AC ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
Ron D'Eau Claire wrote: Ian wrote: The higher the reference frequency, the more accurately you can set the TCXO --- Is that correct? I don't know the details of Wayne's firmware, but the accuracy of a synthesized rig is normally independent of the frequency being received. The error in ppm is independent of the frequency, but the resulting error in Hz is proportional to the frequency. I go for the highest frequency standard available when I'm trying to zero beat some lower-frequency oscillator as accurately as possible (such as when I set my 4.000MHz counter reference oscillator zero beat to WWV at 20 MHz), but that I don't believe that's what we're doing here. On the contrary, that is exactly what you are doing with the K3 as well. The firmware initially assumes that the TCXO frequency is 49,380,000Hz. The REF CAL adjustment is telling the firmware what the true frequency of the TXCO is, and then the firmware will re-calculate all the transmitted, received and displayed frequencies in proportion to that new value. To set REF CAL with the minimum possible error in ppm, the zero-beating should therefore be done at the highest possible signal frequency. I have set my K3 on a BCB band station at 830 kHz to within 1 Hz and noted that WWV at 15.000 MHz is still within 1 Hz. That is because you did a really good job at 830kHz :-) -- 73 from Ian GM3SEK ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
W5FTD wrote: Let me ask this again. Are you saying, that since the mixer signal is a multiple of the TCXO freq Multiple isn't quite the right word, but every synthesized signal in the box is directly proportional to the TXCO frequency. If the TCXO is 1 ppm high, for example, then all frequencies derived from it will have that same +1ppm error. that any errors in the TCXO will be magnified as the ref signal goes higher in frequency. This will then magnify the difference in audio note of (say) 10 MHz vs 20 MHz for the same TCXO setting. A one cps zero beat error at 10 MHz will be 2 cps at 20 MHz (or some such)? You got it. So, if you can adjust the REF CAL frequency within 1Hz at 50MHz, then at 1MHz it will be within 0.02Hz. That's the basic principle, anyway. There will be some small errors introduced by the calculations in firmware, as Ron pointed out; and in the longer term the TCXO will drift. -- 73 from Ian GM3SEK ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
M0XDF wrote: I'd like to get a list of KNOWN frequencies of broadcast stations in 10 - 40m in the UK - it's been pointed out tpo me that using BBC WS at 648 KHz is a not so good, because its a low freq. David (by the way, you can now delete the 'Waiting for K3' from your signature...). We are unfortunate in Europe that after MSF stopped broadcasting time standards on HF (apart from 60kHz) in not having a reliable standard to check against. WWV (always recommended by Elecraft) is normally inaudible here. The only available one is RWM on 9998kHz (also on 14996) and is what I originally used to calibrate my K2 against. But I can't even hear that at the moment... For a rough check, most of the broadcast stations at 7MHz are fairly accurate and on the 5kHz intervals. I just checked and the one on 7200 is pretty spot on as far as I am concerned. 73 Dave G3YMC -- View this message in context: http://www.nabble.com/SW-broadcast-to-calibrate-against.-tp14777212p14777595.html Sent from the Elecraft mailing list archive at Nabble.com. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
Thank you Dave, as always, your response is invaluable. Yes, I was finding it hard to determine what to listen to and was concerned about accuracy - I used 7200. Good luck in AFS CW tomorrow. On 12/1/08 19:06, G3YMC [EMAIL PROTECTED] sent: M0XDF wrote: I'd like to get a list of KNOWN frequencies of broadcast stations in 10 - 40m in the UK - it's been pointed out tpo me that using BBC WS at 648 KHz is a not so good, because its a low freq. David (by the way, you can now delete the 'Waiting for K3' from your signature...). We are unfortunate in Europe that after MSF stopped broadcasting time standards on HF (apart from 60kHz) in not having a reliable standard to check against. WWV (always recommended by Elecraft) is normally inaudible here. The only available one is RWM on 9998kHz (also on 14996) and is what I originally used to calibrate my K2 against. But I can't even hear that at the moment... For a rough check, most of the broadcast stations at 7MHz are fairly accurate and on the 5kHz intervals. I just checked and the one on 7200 is pretty spot on as far as I am concerned. 73 Dave G3YMC -- Black holes are where God divided by zero. -Steven Wright, comedian (1955-) ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
Trevor, I would tend to believe that the carrier frequency of a broadcast station would be better accuracy than that 'fairly accurate' 10 MHz secondary frequency standard. That being said - use a secondary standard if that is your only choice and if you trust it. Your K3 calibration will be as accurate as the standard that you used to calibrate the reference with. Keep in mind that the K3 reference is easily calibrated (just a turn of the knob after entering the menu), so use whatever accurate source you have available now and refine it as better standards become available to you. 73, Don W3FPR Trevor Smithers wrote: Rather than a BC station, how about a fairly accurate 10Mhz frequency standard like http://www.aade.com/freqstd/freqstd.html 73 to all Trevor G0KTN ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
http://www.aade.com/freqstd/freqstd.html I can second that item... I bought one several years ago, I calibrated mine to less than 0.1 cps at 10MHz. Using a 9V battery and a 5 minute warm-up, it has maintained its calibration to date. There is a multi-turn pot on the PCB for fine tuning - Dave G, KK7SS '65 MKIII Sprite, Richland, WA ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] SW broadcast to calibrate against.
Thanks Geoff: The higher the frequency of the signal you use as your 'standard' the more accurate your REF CAL adjustment will be. If you can use WWV / WWVH, try to use it, and at the HIGHEST frequency at which you can hear it... 20MHz if possible, then 15 MHz, and lastly 10 MHz if the higher frequencies cannot be received. When performing K3 REF CAL, BEFORE going into CONFIG | REF CAL, find WWV and then adjust your SPOT tone (using MONITOR in CW mode) so the level of the SPOT tone is as close to the level of the WWV signal as possible. This will give you the deepest nulls when attempting to achieve a really close zero beat during REF CAL. NOTE: Unless Wayne's recently fixed it, there is a bug in the firmware which can cause some odd actions if you attempt to change the SPOT tone PITCH while you are in REF CAL, so be sure to make any adjustments to the SPOT tone outside of REF CAL. 73, Tom N0SS At 16:53 01/12/2008, Geoffrey Mackenzie-Kennedy wrote: David Ferrington, M0XDF [EMAIL PROTECTED] wrote: I'd like to get a list of KNOWN frequencies of broadcast stations in 10 - 40m in the UK - it's been pointed out tpo me that using BBC WS at 648 KHz is a not so good, because its a low freq. -- The World Radio TV Handbook is one useful source of this kind of information. Using a frequency marker which can be phase locked to Allouis, France ( 162 kHz - 2 Megawatts), I have found that the frequency of most if not all the BC stations above 7100 kHz are at the 5 kHz intervals as listed when the propagation is stable. Although WWV at 10 MHz can be quite strong here, down to S4 at the moment due to Aurora, 10 MHz is a busy frequency at times here with WWVH, BPM and others sharing the frequency and IMHO is not the best reference to use - putting aside any possible effects on accuracy due to propagation over the long distance to the UK. 73, Geoff GM4ESD ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
