Re: [time-nuts] Anybody who can record last Loran-C transmissions ?
I could make a raw capture with a 14bit Perseus or 16bit Elad FDM-S2 and a good active receiving antenna, but the station I can receive very strong is Sylt here in Germany. As far as I know this station will not shut down... 73 Joerg, DL2NI Am 19.12.2015 um 12:25 schrieb Magnus Danielson: > Hi Poul-Henning, > > On 12/19/2015 11:35 AM, Poul-Henning Kamp wrote: >> It doesn't seem like my old hack to record VLF spectrum works anymore. >> >> Are there anybody in Europe who can do a raw capture of the VLF spectrum >> over new years eve to capture the last LORAN-C transmissions as a >> historical document ? >> >> Ideally a 1 MSPS ADC directly on a good antenna, but failing that just >> a water-fall would be nice... >> > > Nice idea. An SDR with the HF mod would probably be the simplest way > to do it. As the Loran-C stations lay on top of each other, using a > multi-station Loran-C receiver in parallel would be nice. The 8000 > chain should suddenly be quite alone. > > Cheers, > Magnus > ___ > 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. -- Dipl.Ing.(FH) Jörg Logemann Veilchenstraße 3 D-89150 Laichingen Germany Tel. +49 7333 922506 Mobil +49 171 2814359 Fax. +49 7333 922507 mail: joerg.logem...@t-online.de ___ 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.
Re: [time-nuts] SMD TADD-1 distribution amplifier - seeking comments and suggestions?
Anders, the TL071 is not the right choice as it has a unity gain bandwidth of only 3MHz! You should use an OP with a unity gain bandwidth of ten times the wanted frequency at least (I guess 10MHz, so a 100MHz OP). Modern OPs are AD8045 (preferable), AD8099 (too fast and too good for this purpose;-), OPA847 and many others. The AD8045 can drive 70mA, so you could drive up to 15 outputs with 0dBm or up to 5 outputs with +10dBm simply by serial resistors (50 Ohm) from the OP output to each coaxconnector (+dc-block). Joerg, DL2NI Am 17.12.2015 um 20:44 schrieb Anders Wallin: > First prototype assembled today, tested with 12 VDC SMPS wall-wart supply > and with 12 V lead-acid battery. > Compared against a SRS FS710 and a Symmetricom 6502 and John Ackermann's > 2007 plot: > http://www.anderswallin.net/2015/12/frequency-distribution-amplifier-first-tests/ > > What does the 6502 do differently? It is maybe 5 to 8 dBc/Hz better both in > PN and AM from around 1 kHz and out. > > My 'ultra-low-noise DC-supply' in the form of a lead-acid battery improves > things somewhat, but some spurs still remain: > http://www.anderswallin.net/wp-content/uploads/2015/12/2015-12-17_fda_spurs_and_comments.png > interpretations and explanations are welcome! > The board was not enclosed in a metal can for these tests. > > The regulator is an LP38798 > http://www.ti.com/lit/ds/symlink/lp38798.pdf > > > Anders > > > On Tue, Dec 1, 2015 at 12:54 AM, Bruce Griffiths <bruce.griffi...@xtra.co.nz >> wrote: >> Anders >> U101 only needs to have a gain of 1 at dc so replace R104 and R105 with a >> capacitor connected to ground. >> Adjust the other components of the gain determining network >> accordingly.Also the junction of the power supply divider R102 and R103 >> should be heavily capacitively bypassed to ground and a resistor placed >> between this junction and U101's noninverting input. >> >> Excess Sub Hz PN is usually due power supply noise or thermal fluctuations >> due to air currents/ convection. >> Most of the so called super regulator circuits should be more than quiet >> enough with an LM329 reference.A damped LCR filter at the input will >> improve the PSRR at switchmode output frequencies. >> >> Bruce >> >> >> >> On Tuesday, 1 December 2015 9:02 AM, Anders Wallin < >> anders.e.e.wal...@gmail.com> wrote: >> >> >> HI all, >> I need to build a few distribution amplifiers (>90% for 10MHz, sometimes >> maybe 5MHz) and instead of reinventing the wheel I decided to try to >> modernize the TADD-1 into an all (almost) SMD design. Here are some draft >> sketches: >> >> http://www.anderswallin.net/2015/11/frequency-distribution-amplifier-plans-a-k-a-smd-tadd-1/ >> >> Does this sound/look reasonable or crazy? >> Any suggestions for op-amps to try and/or compare to the AD8055? >> What causes the extra phase-noise below 1 Hz offset in John A's result: >> https://www.febo.com/pages/amplifier_phase_noise/amplifier_phase_noise.png >> >> Suggestions for a low noise DC-regulator circuit? The 12-24VDC supplied to >> this board will most likely come from a switched-mode PSU, so filtering of >> common-mode noise is mandatory. >> I found the TI LP38798 shown in the schematic by googling - if someone has >> a proven a measured design that would be a safer choice. In any case more >> filtering (e.g. ferriites) is probably a good idea. >> >> This design will be available on my blog or on github when it is done - if >> anyone is interested. >> >> Thanks, >> Anders >> ___ >> 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. -- Dipl.Ing.(FH) Jörg Logemann Veilchenstraße 3 D-89150 Laichingen Germany Tel. +49 7333 922506 Mobil +49 171 2814359 Fax. +49 7333 922507 mail: joerg.logem...@t-online.de ___ 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.
Re: [time-nuts] modification Lucent RFTG
Rex, thank you for your reply! Your "minor criticism" is justified, I wil do the changes immediately (today). If you read your own article for the 20th time you don't see things like these... Thank you very much. vy73 Joerg Am 13.12.2015 um 12:00 schrieb Rex: > Joerg, > > This looks like a very useful mod on a unit that many of us have. I'm > not aware of any schematics available for these, so I guess you have > reverse-engineered the "black" part of the schematic that you > provided. -- Nice work! > > Having said that, may I offer some minor criticism (constructive and > positive, I hope) of your document? > > The schematic you provided shows the key transistors as Q1 and Q2. In > the text you refer to Q208 and Q209 (which I think are marked on the > board). From the description, I think Q1 = Q208 and Q2 = Q209. It > would be nice if the schematic had the Q-numbers changed, or at least, > you mentioned the equivalence in your text. > > (Trivial) Aren't you using an existing SMA connector for your output? > So, maybe it should be black in the schematic. > > Your picture of the board rework is pretty low resolution; even > zooming into it just gives bigger blurry image. You have added some > annotations but they are in red over the green board color. Combined > with the low resolution they are very hard to read. I'm pretty sure > they remain in German in the English version too. > > My suggestions: > - Edit the schematic to change the Q-numbers to match the board > and text, or at least give the equivalence in the text. > - Use a higher resolution picture and make the annotations more > readable with different color or background shading. > - The picture you provide is "after". It would be nice to also > have "before". If you don't have a before picture, I or some other > member could probably take one. > - Consider having picture annotations in English for the English > version. > > I think what you have done is great. I just think the sharing document > could be improved to make it easier for others to duplicate. > > If you like, I could possibly help make a more readable annotated > picture if you can provide me a higher res picture of the board. Just > an offer to help if you would consider my suggestions. I think you > will see my email in my post. > > -Rex KK6MK > > > > On 12/12/2015 4:39 PM, Jörg Logemann wrote: >> Hi, >> I worked out a modification of the Lucent GPSDO to get 10MHz out of it >> which I offer to the community. The article is available in english and >> german (attached). >> >> best 73 >> Joerg, DL2NI >> >> > > ___ > 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. -- Dipl.Ing.(FH) Jörg Logemann Veilchenstraße 3 D-89150 Laichingen Germany Tel. +49 7333 922506 Mobil +49 171 2814359 Fax. +49 7333 922507 mail: joerg.logem...@t-online.de ___ 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.
Re: [time-nuts] modification Lucent RFTG
Paul, thanks for your reply. I did not cut any trace on the pc board. The separation from the 15MHz signal is done by removing the 10nF capacitor. Yes, the short line leeding to the cap is still there but this little "stub" has no effect. Of course the line can be cut, but I like to "keep all doors open" if I want to remove the modification one day, hi. With the video amp you will have more power compared to my solution, also a good way... I will build a distribution box with 9 outputs for the 10MHz signal (4 powersplitter 1to3) and thus will need another amplifier. Perhaps you could make it passive because of more gain. 73 Joerg DL2NI Am 13.12.2015 um 16:21 schrieb paul swed: > Joerg > Yes this looks like a nice simple mod. > Its difficult to tell from the pictures but in order to use the sma it > looks like you cut the trace over by the cap. > I ran into the same thing. The lead goes into the board and its end point > is unclear. > When I released a solution about 9 months ago I used a video op-amp. This > gave gain and drive. But with more complexity. > It is a bit of a challenge to slip the boards in and out. > Thanks > Paul > WB8TSL > > On Sun, Dec 13, 2015 at 6:00 AM, Rex <r...@sonic.net> wrote: > >> Joerg, >> >> This looks like a very useful mod on a unit that many of us have. I'm not >> aware of any schematics available for these, so I guess you have >> reverse-engineered the "black" part of the schematic that you provided. -- >> Nice work! >> >> Having said that, may I offer some minor criticism (constructive and >> positive, I hope) of your document? >> >> The schematic you provided shows the key transistors as Q1 and Q2. In the >> text you refer to Q208 and Q209 (which I think are marked on the board). >> From the description, I think Q1 = Q208 and Q2 = Q209. It would be nice if >> the schematic had the Q-numbers changed, or at least, you mentioned the >> equivalence in your text. >> >> (Trivial) Aren't you using an existing SMA connector for your output? So, >> maybe it should be black in the schematic. >> >> Your picture of the board rework is pretty low resolution; even zooming >> into it just gives bigger blurry image. You have added some annotations but >> they are in red over the green board color. Combined with the low >> resolution they are very hard to read. I'm pretty sure they remain in >> German in the English version too. >> >> My suggestions: >> - Edit the schematic to change the Q-numbers to match the board and >> text, or at least give the equivalence in the text. >> - Use a higher resolution picture and make the annotations more >> readable with different color or background shading. >> - The picture you provide is "after". It would be nice to also have >> "before". If you don't have a before picture, I or some other member could >> probably take one. >> - Consider having picture annotations in English for the English >> version. >> >> I think what you have done is great. I just think the sharing document >> could be improved to make it easier for others to duplicate. >> >> If you like, I could possibly help make a more readable annotated picture >> if you can provide me a higher res picture of the board. Just an offer to >> help if you would consider my suggestions. I think you will see my email in >> my post. >> >> -Rex KK6MK >> >> >> >> On 12/12/2015 4:39 PM, Jörg Logemann wrote: >> >>> Hi, >>> I worked out a modification of the Lucent GPSDO to get 10MHz out of it >>> which I offer to the community. The article is available in english and >>> german (attached). >>> >>> best 73 >>> Joerg, DL2NI >>> >>> >>> >> ___ >> 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. -- Dipl.Ing.(FH) Jörg Logemann Veilchenstraße 3 D-89150 Laichingen Germany Tel. +49 7333 922506 Mobil +49 171 2814359 Fax. +49 7333 922507 mail: joerg.logem...@t-online.de ___ 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.
