I just looked up what it would take to build a 10:1 conjugate regenerative divider. This is not easy nor cheap. The conjugate number turn out to be f/10 and 9f/10. 9f/10 is close to f.
Question for the group? What phase noise should be expected if a conventional PPL was used? I can't believe that a PLL derived 1Mhz reference is not good enough for a 30Mhz HF transmitter. Maybe different answer if the transmitter were microwave Not arguing, this is a real question. I'm wondering how good a simple and convention PLL is. My problem is that I do the calculations and it's not "real world" and I get perfect result. Just wondering how and what cause PPL to be not perfect and by how much. On Thu, Dec 23, 2010 at 11:45 AM, paul swed <paulsw...@gmail.com> wrote: > Oh I actually understand the radio. > I was looking at the wenzel and will guess that would be quite expensive. > This from a flea market junky. > Regards > > On Thu, Dec 23, 2010 at 12:24 PM, <scmcgr...@gmail.com> wrote: > >> Because the Rockwell-Collins HF80 has sensitivity and selectivity which are >> avaialble only in Ham gear costing 7000+ definitely not in the >> 'inexpensive' category, it's transmit signal is also far cleaner than most >> synthesized HF Rigs. >> >> So it makes sense to upgrade the reference oscillator to use this radio >> with more modern modes such as PSK31 and coherent CW. (Occupied bandwith >> less than 5 Hz) >> >> Scott >> Sent from my Verizon Wireless BlackBerry >> >> -----Original Message----- >> From: Joseph Gray <jg...@zianet.com> >> Sender: time-nuts-boun...@febo.com >> Date: Tue, 21 Dec 2010 22:39:38 >> To: Discussion of precise time and frequency measurement< >> time-nuts@febo.com> >> Reply-To: Discussion of precise time and frequency measurement >> <time-nuts@febo.com> >> Subject: Re: [time-nuts] Question on GPS and reference standards >> >> Not knowing all the particulars and requirements, I may be off base, >> but instead of spending money trying to frequency stabilize a 20+ year >> old radio (HF-80), wouldn't it make more sense to spend it on a >> modern, inexpensive HF rig? You can even get a TCXO option for some >> rigs. This should be stable enough for most common HF data protocols. >> >> I assume that this is for Amateur use? If not, then my comments may not >> apply. >> >> Joe Gray >> W5JG >> >> On Tue, Dec 21, 2010 at 9:48 PM, Bruce Griffiths >> <bruce.griffi...@xtra.co.nz> wrote: >> > A conjugate regenerative divider will have asinewave output. >> > It only requires a mixer an amplifier or two and a couple of bandpass >> > filters. >> > It will have lower phase noise than all(?) alternative techniques. >> > >> > Bruce >> > >> > Tom Van Baak wrote: >> >> >> >> A good question for the group... >> >> /tvb >> >> >> >>> Hi: >> >>> >> >>> I have both a GPS Frequency standard (Trimble Thunder Bolt) which >> outputs >> >>> the 10 >> >>> MHz reference and also the 1 PPS signal. In addition, I have a Collins >> >>> AEU unit >> >>> which has a 10 MHz Rubidium reference inside. Both units work well and >> >>> produce a >> >>> very accurate reference signal for the units that require a 10 MHz >> >>> reference. >> >>> >> >>> The challenge is that I am looking for a source of a 10:1 frequency >> >>> divider so I >> >>> can create a 1 MHz reference for my Rockwell Collins HF-80 system. Can >> >>> you >> >>> suggest a source of a high quality frequency divider that outputs a >> >>> (nearly) >> >>> sine wave signal? We only need two units - one for production and one >> for >> >>> our >> >>> development lab. >> >>> >> >>> The object is to provide a very accurate source of 1 MHz and 10 MHz to >> >>> the >> >>> various radio systems used in our disaster and humanitarian relief >> radio >> >>> network. When you send data, you need to be exactly on frequency. >> >>> >> >>> Any help would be great. Just need to be pointed in the right >> direction. >> >>> While >> >>> we could try to design something to meet this objective, I am sure that >> >>> someone >> >>> has already done this. >> >>> >> >>> Thank you. >> >>> >> >>> Kevin >> >> >> >> >> >> >> >>_______________________________________________ >> >> time-nuts mailing list -- time-nuts@febo.com >> >> To unsubscribe, go to >> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> >> and follow the instructions there. >> >> >> > >> > >> > >> >_______________________________________________ >> > time-nuts mailing list -- time-nuts@febo.com >> > To unsubscribe, go to >> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> > and follow the instructions there. >> > >> > >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- ===== Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
