Re: [time-nuts] minimalist sine to square
Yes, I was just trying to see how far the circuit could be pushed (+27dBm input was still OK). With +13dBm input peak diode current without 100R and 330R resistors is about 20mA for the 3.3V circuit with an impedance step up from 50 to 400 ohm. My 100MHz Wenzel OCXO has an output of around +19dBm or so. I measure the output of all my sources before I connect them. Bruce > > On 20 January 2018 at 15:27 Bob kb8tq wrote: > > Hi > > My main point is that a +22 dbm (or even 16 dbm) OCXO is a *very* rare > item. If your > signal generator is set to +22 dbm … shame on you. If the part can do > well over +7 to > +13 dbm, that will cover the vast majority of the 10 MHz oscillators / > signal sources out there. > > Bob > > > > > > On Jan 19, 2018, at 8:51 PM, Bruce Griffiths > > wrote: > > > > Even the modern PICs spec 50mA max input currents. > > Simulation indicates 20mA peak diode currents without the 330 ohm > > resistors for a 2V pp input, even more for higher input signal levels. If > > one can guarantee that input is around 1V pp then the extra diodes and > > resistors aren't required. If its possible that an input of 16dBm or more > > may be used then the extra diodes and resistors are required. I simulated > > the circuit for inputs up to +22dBm. > > Current flowing in the IC protection diodes can degrade the timing > > jitter substantially (tens of picosec for HCMOS). > > > > Bruce > > > > > > > > > > On 20 January 2018 at 14:34 Bob kb8tq wrote: > > > > > > Hi > > > > > > Unless you really beat on the thing for days on end, you can > > > do without the 330 ohm and 100 ohm > > > resistors (along with the two diodes). Most modern gates have > > > pretty robust protection diodes. The > > > source impedance is high enough after the transform that the > > > available current is pretty low. On a > > > NC7SZ125 the negative diode is rated for 50 ma max and the > > > positive diode is rated for 20 ma > > > > > > Some math: > > > > > > If the two 1K’s properly terminate the circuit, you have a > > > 250 ohm source. (500 ohm load and 500 ohm > > > transformed from the sine input). A 1V overdrive (1/2 V + and > > > 1/2 V -) will put 2 ma into the diodes on the > > > peaks. The more likely case is that the negative is hit a bit > > > harder. The bias is most likely a bit below > > > 1/2 Vcc for best symmetry. > > > > > > None of this is to say you *should* hit the diodes. No matter > > > what sort they are, the performance will > > > degrade a bit when you do. How much is of course a “that > > > depends”. Most of us are not driving the > > > gate with a -180 dbc/Hz source and expecting -177 out of the > > > gate. > > > > > > Bob > > > > > > > > > > > > > > On Jan 19, 2018, at 8:14 PM, Bruce Griffiths > > > > wrote: > > > > > > > > Something like the attached circuit is suitable for > > > > driving the MCU clock input directly. > > > > The diodes should be schottky signal diodes like the > > > > 1N5711 series. The series resistors limit the diode peak current and > > > > the CLK input protection network current. It should work with inputs > > > > from 1V pp to 8Vpp. If SMT components were used it should all fit on a > > > > DIP compatible daughter board. > > > > > > > > Bruce > > > > > > > > > > > > > > > > > > On 20 January 2018 at 12:37 Bob kb8tq > > > > > wrote: > > > > > > > > > > Bob > > > > > > > > > > With a 1V p-p sort of output, a simple matching > > > > > network will get you into the 4 to 6V p-p range. > > > > > Drive that into a 5V compatible CMOS gate and > > > > > move on …. If you have a super hot output, put > > > > > a 3 db pad on it. > > > > > > > > > > Bob > > > > > > > > > > > > > > > > > > > > > > On Jan 19, 2018, at 5:40 PM, Tom Van Baak > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > Tom > > > > > > > What's the input signal amplitude? > > > > > > > What's the desired output signal (eg > > > > > > > 5V CMOS, 3.3V CMOS etc)? > > > > > > > Bruce > > > > > > > > > > > > > > > > > > > > > > > > > > It's for a typical 5 or 10 MHz OCXO / Rb / > > > > > > Cs with sinewave output; say, 1 Vpp. The output should be 3.3 or 5 > > > > > > V depending on what the MCU needs. It doesn't have to have stunnin
Re: [time-nuts] minimalist sine to square
Hi My main point is that a +22 dbm (or even 16 dbm) OCXO is a *very* rare item. If your signal generator is set to +22 dbm … shame on you. If the part can do well over +7 to +13 dbm, that will cover the vast majority of the 10 MHz oscillators / signal sources out there. Bob > On Jan 19, 2018, at 8:51 PM, Bruce Griffiths > wrote: > > Even the modern PICs spec 50mA max input currents. > Simulation indicates 20mA peak diode currents without the 330 ohm resistors > for a 2V pp input, even more for higher input signal levels. If one can > guarantee that input is around 1V pp then the extra diodes and resistors > aren't required. If its possible that an input of 16dBm or more may be used > then the extra diodes and resistors are required. I simulated the circuit for > inputs up to +22dBm. > Current flowing in the IC protection diodes can degrade the timing jitter > substantially (tens of picosec for HCMOS). > > Bruce >> On 20 January 2018 at 14:34 Bob kb8tq wrote: >> >> >> Hi >> >> Unless you really beat on the thing for days on end, you can do without the >> 330 ohm and 100 ohm >> resistors (along with the two diodes). Most modern gates have pretty robust >> protection diodes. The >> source impedance is high enough after the transform that the available >> current is pretty low. On a >> NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is >> rated for 20 ma >> >> Some math: >> >> If the two 1K’s properly terminate the circuit, you have a 250 ohm source. >> (500 ohm load and 500 ohm >> transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will >> put 2 ma into the diodes on the >> peaks. The more likely case is that the negative is hit a bit harder. The >> bias is most likely a bit below >> 1/2 Vcc for best symmetry. >> >> None of this is to say you *should* hit the diodes. No matter what sort they >> are, the performance will >> degrade a bit when you do. How much is of course a “that depends”. Most of >> us are not driving the >> gate with a -180 dbc/Hz source and expecting -177 out of the gate. >> >> Bob >> >>> On Jan 19, 2018, at 8:14 PM, Bruce Griffiths >>> wrote: >>> >>> Something like the attached circuit is suitable for driving the MCU clock >>> input directly. >>> The diodes should be schottky signal diodes like the 1N5711 series. The >>> series resistors limit the diode peak current and the CLK input protection >>> network current. It should work with inputs from 1V pp to 8Vpp. If SMT >>> components were used it should all fit on a DIP compatible daughter board. >>> >>> Bruce On 20 January 2018 at 12:37 Bob kb8tq wrote: Bob With a 1V p-p sort of output, a simple matching network will get you into the 4 to 6V p-p range. Drive that into a 5V compatible CMOS gate and move on …. If you have a super hot output, put a 3 db pad on it. Bob > On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: > >> Tom >> What's the input signal amplitude? >> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? >> Bruce > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, > 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. > It doesn't have to have stunning performance: think breadboard, PIC, > Arduino sort of stuff. I was looking for something in a PDIP-8 package; > the same as all the picDIV or picPET chips I use. That's why older parts > like µA9637 / DS9637 came to mind. > > /tvb > > ___ > 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.
Re: [time-nuts] minimalist sine to square
Even the modern PICs spec 50mA max input currents. Simulation indicates 20mA peak diode currents without the 330 ohm resistors for a 2V pp input, even more for higher input signal levels. If one can guarantee that input is around 1V pp then the extra diodes and resistors aren't required. If its possible that an input of 16dBm or more may be used then the extra diodes and resistors are required. I simulated the circuit for inputs up to +22dBm. Current flowing in the IC protection diodes can degrade the timing jitter substantially (tens of picosec for HCMOS). Bruce > On 20 January 2018 at 14:34 Bob kb8tq wrote: > > > Hi > > Unless you really beat on the thing for days on end, you can do without the > 330 ohm and 100 ohm > resistors (along with the two diodes). Most modern gates have pretty robust > protection diodes. The > source impedance is high enough after the transform that the available > current is pretty low. On a > NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is > rated for 20 ma > > Some math: > > If the two 1K’s properly terminate the circuit, you have a 250 ohm source. > (500 ohm load and 500 ohm > transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will > put 2 ma into the diodes on the > peaks. The more likely case is that the negative is hit a bit harder. The > bias is most likely a bit below > 1/2 Vcc for best symmetry. > > None of this is to say you *should* hit the diodes. No matter what sort they > are, the performance will > degrade a bit when you do. How much is of course a “that depends”. Most of us > are not driving the > gate with a -180 dbc/Hz source and expecting -177 out of the gate. > > Bob > > > On Jan 19, 2018, at 8:14 PM, Bruce Griffiths > > wrote: > > > > Something like the attached circuit is suitable for driving the MCU clock > > input directly. > > The diodes should be schottky signal diodes like the 1N5711 series. The > > series resistors limit the diode peak current and the CLK input protection > > network current. It should work with inputs from 1V pp to 8Vpp. If SMT > > components were used it should all fit on a DIP compatible daughter board. > > > > Bruce > >> On 20 January 2018 at 12:37 Bob kb8tq wrote: > >> > >> > >> Bob > >> > >> With a 1V p-p sort of output, a simple matching network will get you into > >> the 4 to 6V p-p range. > >> Drive that into a 5V compatible CMOS gate and move on …. If you have a > >> super hot output, put > >> a 3 db pad on it. > >> > >> Bob > >> > >>> On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: > >>> > Tom > What's the input signal amplitude? > What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? > Bruce > >>> > >>> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, > >>> 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. > >>> It doesn't have to have stunning performance: think breadboard, PIC, > >>> Arduino sort of stuff. I was looking for something in a PDIP-8 package; > >>> the same as all the picDIV or picPET chips I use. That's why older parts > >>> like µA9637 / DS9637 came to mind. > >>> > >>> /tvb > >>> > >>> ___ > >>> 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.
Re: [time-nuts] minimalist sine to square
That network was for a 10MHz input. For 5MHz double the L and C values. For 3.3V one could use a lower step up say from 50 to 400 ohms rather than from 50 to 800 ohms. 1uH and 150pF and change 1k6 resistors to 820R. Swap the 5V supply for a 3.3V supply. L and C values aren't critical 5% or somewhat looser tolerance should be suffice. Bruce > > On 20 January 2018 at 14:14 Bruce Griffiths > wrote: > > Something like the attached circuit is suitable for driving the MCU clock > input directly. > The diodes should be schottky signal diodes like the 1N5711 series. The > series resistors limit the diode peak current and the CLK input protection > network current. It should work with inputs from 1V pp to 8Vpp. If SMT > components were used it should all fit on a DIP compatible daughter board. > > Bruce > > > > > > On 20 January 2018 at 12:37 Bob kb8tq wrote: > > > > Bob > > > > With a 1V p-p sort of output, a simple matching network will get > > you into the 4 to 6V p-p range. > > Drive that into a 5V compatible CMOS gate and move on …. If you > > have a super hot output, put > > a 3 db pad on it. > > > > Bob > > > > > > > > > > On Jan 19, 2018, at 5:40 PM, Tom Van Baak > > > wrote: > > > > > > > > > > > > > > Tom > > > > What's the input signal amplitude? > > > > What's the desired output signal (eg 5V CMOS, 3.3V CMOS > > > > etc)? > > > > Bruce > > > > > > > > > > > > > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave > > > output; say, 1 Vpp. The output should be 3.3 or 5 V depending on what the > > > MCU needs. It doesn't have to have stunning performance: think > > > breadboard, PIC, Arduino sort of stuff. I was looking for something in a > > > PDIP-8 package; the same as all the picDIV or picPET chips I use. That's > > > why older parts like µA9637 / DS9637 came to mind. > > > > > > /tvb > > > > > > ___ > > > 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.
Re: [time-nuts] minimalist sine to square
Hi Unless you really beat on the thing for days on end, you can do without the 330 ohm and 100 ohm resistors (along with the two diodes). Most modern gates have pretty robust protection diodes. The source impedance is high enough after the transform that the available current is pretty low. On a NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is rated for 20 ma Some math: If the two 1K’s properly terminate the circuit, you have a 250 ohm source. (500 ohm load and 500 ohm transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will put 2 ma into the diodes on the peaks. The more likely case is that the negative is hit a bit harder. The bias is most likely a bit below 1/2 Vcc for best symmetry. None of this is to say you *should* hit the diodes. No matter what sort they are, the performance will degrade a bit when you do. How much is of course a “that depends”. Most of us are not driving the gate with a -180 dbc/Hz source and expecting -177 out of the gate. Bob > On Jan 19, 2018, at 8:14 PM, Bruce Griffiths > wrote: > > Something like the attached circuit is suitable for driving the MCU clock > input directly. > The diodes should be schottky signal diodes like the 1N5711 series. The > series resistors limit the diode peak current and the CLK input protection > network current. It should work with inputs from 1V pp to 8Vpp. If SMT > components were used it should all fit on a DIP compatible daughter board. > > Bruce >> On 20 January 2018 at 12:37 Bob kb8tq wrote: >> >> >> Bob >> >> With a 1V p-p sort of output, a simple matching network will get you into >> the 4 to 6V p-p range. >> Drive that into a 5V compatible CMOS gate and move on …. If you have a super >> hot output, put >> a 3 db pad on it. >> >> Bob >> >>> On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: >>> Tom What's the input signal amplitude? What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? Bruce >>> >>> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 >>> Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It >>> doesn't have to have stunning performance: think breadboard, PIC, Arduino >>> sort of stuff. I was looking for something in a PDIP-8 package; the same as >>> all the picDIV or picPET chips I use. That's why older parts like µA9637 / >>> DS9637 came to mind. >>> >>> /tvb >>> >>> ___ >>> 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] minimalist sine to square
Tom, Hook the 53132A calibrator that I sent you and check one of the calibrator outputs for signal goodness. It uses the sine-square circuit in the LPRO-101 manual (input cap connected to center of a 39K/39K voltage divider connected to a 74HC gate (74AC gates have some advantages and disadvantages here).It's the simplest excellent bang-for-the buck squarer (three passives and a single CMOS gate). You can use single-gate chips. I'm using the same circuit on the LPFRS/LPRO/OCXO interface board. I'm also pondering doing a small board with a sine/square wave input, square wave output, PICDIV, PICPET, and a 10 MHz square to sine filter. Attached is the xDEV plot of the calibrator (using TAPR-TICC, TADD2-mini, 5071A reference).___ 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] minimalist sine to square
Something like the attached circuit is suitable for driving the MCU clock input directly. The diodes should be schottky signal diodes like the 1N5711 series. The series resistors limit the diode peak current and the CLK input protection network current. It should work with inputs from 1V pp to 8Vpp. If SMT components were used it should all fit on a DIP compatible daughter board. Bruce > On 20 January 2018 at 12:37 Bob kb8tq wrote: > > > Bob > > With a 1V p-p sort of output, a simple matching network will get you into the > 4 to 6V p-p range. > Drive that into a 5V compatible CMOS gate and move on …. If you have a super > hot output, put > a 3 db pad on it. > > Bob > > > On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: > > > >> Tom > >> What's the input signal amplitude? > >> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? > >> Bruce > > > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 > > Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It > > doesn't have to have stunning performance: think breadboard, PIC, Arduino > > sort of stuff. I was looking for something in a PDIP-8 package; the same as > > all the picDIV or picPET chips I use. That's why older parts like µA9637 / > > DS9637 came to mind. > > > > /tvb > > > > ___ > > 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] minimalist sine to square
The Efratom/Tektronix PTB-100 took the 10Mhz sine out of the FRK brick, AC coupled it to the input of an 74LS14 biased with a votage divider from +5 to ground. 4 parts! Cheers, Corby ___ 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] TADD-1 question
Hi Joe, On 01/19/2018 09:52 PM, Joseph Gray wrote: > I have a sig gen that uses a single BNC for input/output of the 10 MHz > reference. You have to set it for in or out using the interface. However, > if the sig gen thinks that the external reference is no longer there, it > automatically switches to using the internal reference, and outputing it on > the BNC. > > My question is, will the TADD-1 be harmed if the sig gen is sending 10 MHz > into one of the TADD-1 outputs? How strong is the signal output? I think that should be a fairly trivial analysis from there on. Compare it to strong reflection on unterminated outputs on the TADD-1. I think you see where I am going with this analysis. 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.
Re: [time-nuts] minimalist sine to square
Bob With a 1V p-p sort of output, a simple matching network will get you into the 4 to 6V p-p range. Drive that into a 5V compatible CMOS gate and move on …. If you have a super hot output, put a 3 db pad on it. Bob > On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote: > >> Tom >> What's the input signal amplitude? >> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? >> Bruce > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 > Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It > doesn't have to have stunning performance: think breadboard, PIC, Arduino > sort of stuff. I was looking for something in a PDIP-8 package; the same as > all the picDIV or picPET chips I use. That's why older parts like µA9637 / > DS9637 came to mind. > > /tvb > > ___ > 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.
Re: [time-nuts] minimalist sine to square
A fast DIP comparator such as an LT1016 should work but it won't perform well without an effective ground plane. If a CMOS gate is used then a low Q LC impedance step up network or equivalent will be needed to increase the signal swing at the gate input. Add a couple of schottky diode clamps for overvoltage clamping (internal CMOS gate clamp devices usually degrade performance if they conduct). Bruce > > On 20 January 2018 at 11:40 Tom Van Baak wrote: > > > > > > Tom > > What's the input signal amplitude? > > What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? > > Bruce > > > > > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, > 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It > doesn't have to have stunning performance: think breadboard, PIC, Arduino > sort of stuff. I was looking for something in a PDIP-8 package; the same as > all the picDIV or picPET chips I use. That's why older parts like µA9637 / > DS9637 came to mind. > > /tvb > > ___ > 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.
Re: [time-nuts] minimalist sine to square
Now, if one added an optional TTL threshold 5V CMOS single gate inverter/buffer to produce 5V output when required and added an SMT 5V->3.3V regulator and mounted it all on a small PCB with pins to make it DIP compatible that would meet the brief and then some. Otherwise an SMT (not many DIP ones left) comparator mounted on a DIP/SMT converter board would also work albeit with a PN/jitter performance penalty. Bruce > On 20 January 2018 at 11:37 Gerhard Hoffmann wrote: > > > > > Am 19.01.2018 um 20:31 schrieb Tom Van Baak: > > John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It > > performs very well but requires +10 V. > > > > I'm looking for a solution that works at 5 V (e.g., USB powered) and also > > uses fewer parts. Wenzel also mentions using a differential line receiver > > [2]. That would be an ideal single-chip 5 V solution for me but the two > > parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for > > a 10 MHz input. > > > > Can any of you circuit experts suggest some line receivers that would work? > > Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite > > as good as the TADD-2. > < http://cds.linear.com/docs/en/datasheet/6957fb.pdf > > < http://cds.linear.com/docs/en/design-note/dn514f.pdf > > > I have used it, found no problems. It is somewhat small :-) > > regards, Gerhard > > > > ___ > 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.
Re: [time-nuts] minimalist sine to square
> Tom > What's the input signal amplitude? > What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? > Bruce It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It doesn't have to have stunning performance: think breadboard, PIC, Arduino sort of stuff. I was looking for something in a PDIP-8 package; the same as all the picDIV or picPET chips I use. That's why older parts like µA9637 / DS9637 came to mind. /tvb ___ 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] minimalist sine to square
Am 19.01.2018 um 20:31 schrieb Tom Van Baak: John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs very well but requires +10 V. I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses fewer parts. Wenzel also mentions using a differential line receiver [2]. That would be an ideal single-chip 5 V solution for me but the two parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz input. Can any of you circuit experts suggest some line receivers that would work? Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite as good as the TADD-2. < http://cds.linear.com/docs/en/datasheet/6957fb.pdf > < http://cds.linear.com/docs/en/design-note/dn514f.pdf > I have used it, found no problems. It is somewhat small :-) regards, Gerhard ___ 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] "Confessions of a Reformed Frequency Standard Nut"
And if I do some longer term averaging, I can get another one after that. :-) --- Graham == On Fri, Jan 19, 2018 at 11:16 AM, Ron Bean wrote: > https://hackaday.com/2018/01/17/confessions-of-a-reformed- > frequency-standard-nut/ > > "Or are you chasing that last digit just because it’s 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.
Re: [time-nuts] minimalist sine to square
Tom What's the input signal amplitude? What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)? Bruce > On 20 January 2018 at 08:31 Tom Van Baak wrote: > > > John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs > very well but requires +10 V. > > I'm looking for a solution that works at 5 V (e.g., USB powered) and also > uses fewer parts. Wenzel also mentions using a differential line receiver > [2]. That would be an ideal single-chip 5 V solution for me but the two parts > he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 > MHz input. > > Can any of you circuit experts suggest some line receivers that would work? > Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite > as good as the TADD-2. > > Thanks, > /tvb > > [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf > [2] http://www.wenzel.com/documents/waveform.html > [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF > [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf > [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf > > > ___ > 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.
Re: [time-nuts] minimalist sine to square
SN65LVDS34D --- Graham / KE9H == On Fri, Jan 19, 2018 at 3:45 PM, Vlad wrote: > > > On 2018-01-19 14:31, Tom Van Baak wrote: > >> John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It >> performs very well but requires +10 V. >> > > > I am using Wenzel approach without modification to drive it from +5V. I > didn't see any issues for my applications (usually it perform > sine-to-square conversion from OCXO to feed MCU clock). > > > -- > WBW, > > V.P. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/m > ailman/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.
Re: [time-nuts] minimalist sine to square
On 2018-01-19 14:31, Tom Van Baak wrote: John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs very well but requires +10 V. I am using Wenzel approach without modification to drive it from +5V. I didn't see any issues for my applications (usually it perform sine-to-square conversion from OCXO to feed MCU clock). -- WBW, V.P. ___ 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] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
> What's in the antenna that makes North interesting? and/or how would a > receiver take advantage of it? Hal, The people that work at the mm level get very picky about details; antenna reception is not perfectly symmetrical or centered or equal at every frequency or angle. There is a massive database of antenna calibrations here: https://www.ngs.noaa.gov/ANTCAL/ Click on "Browse Antenna Information by Manufacturer and Model", pick some vendor, and hover over Drawing, Label, Side, Top. Then see the raw data for the calibration. Here's a random example: https://www.ngs.noaa.gov/ANTCAL/LoadFile?file=TRM105000.10_NONE.atx Or view a 10 MB database: https://www.ngs.noaa.gov/ANTCAL/LoadFile?file=ngs14.atx See also: https://www.ngs.noaa.gov/ANTCAL/FAQ.xhtml Here's a couple of random links to give you an idea what this is all about: "How to Use IGS Antenna Phase Center Corrections" http://acc.igs.org/antennas/igs-pcvs_gpsworld10.pdf "ANTENNA PHASE CENTER VARIATIONS CORRECTIONS IN PROCESSING OF GPS OBSERVATIONS WITH USE OF COMMERCIAL SOFTWARE" http://www.uwm.edu.pl/wnt/technicalsc/tech_13/B12.PDF "Influence of GPS antenna phase center variation on precise positioning" https://www.sciencedirect.com/science/article/pii/S2090997713000515 "Satellite Antenna Phase Center Offsets and the Terrestrial Scale" http://www.igs.org/assets/pdf/W2016%20-%20PY0703%20-%20Rothacher.pdf That will keep you busy for a while. /tvb ___ 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] minimalist sine to square
On 1/19/18 12:54 PM, Poul-Henning Kamp wrote: In message <898171c2-0e9a-6a2a-dcfc-b7d893f89...@earthlink.net>, jimlux writes: What about the plethora of LVDS receivers - they're basically a differential input thresholder, with deliberate hysteresis, looking for a 300 mV shift across a 100 ohm resistor. I played with that, I used a small transformer to balance the signal and then into LVDS receiver through a voltage divider. Worked well, but I didn't measure the jitter, it was just for a micro-controller. You can also do it with capacitive dc block to one side, and some resistors - the ap notes describe it. The receivers are a fairly high Z input, so you pick the voltage divider resistors to make the termination resistance right for the incoming signal. ___ 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] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
Hi The antenna has a measured / documented pattern (amplitude and more importantly phase). If you have it pointed in a known direction, that information can be used when post processing carrier phase information. If you are trying to get to mm / picosecond levels on an multi hour L1/L2 dataset, that sort of thing can be significant. Bob > On Jan 19, 2018, at 4:00 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> If indeed dual frequency GPS is part of the intended use, the survey >> oriented gear will be slightly happier if the “right” corner faces north. > > What's in the antenna that makes North interesting? and/or how would a > receiver take advantage of it? > > > > -- > These are my opinions. I hate spam. > > > > ___ > 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.
Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
kb...@n1k.org said: > If indeed dual frequency GPS is part of the intended use, the survey > oriented gear will be slightly happier if the ârightâ corner faces north. What's in the antenna that makes North interesting? and/or how would a receiver take advantage of it? -- These are my opinions. I hate spam. ___ 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] minimalist sine to square
In message <63ae173b-93f4-ffe4-ddf1-655761665...@earthlink.net>, jimlux writes: >On 1/19/18 11:31 AM, Tom Van Baak wrote: >You do want to watch the common mode voltages - some of the parts are >not good about having the signals swing near the rails (or beyond). Also be aware that specs are for balanced input signals, if you tie one of the inputs to a threshold voltage, published specs may not apply, in particular speed. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] minimalist sine to square
In message <898171c2-0e9a-6a2a-dcfc-b7d893f89...@earthlink.net>, jimlux writes: >What about the plethora of LVDS receivers - they're basically a >differential input thresholder, with deliberate hysteresis, looking for >a 300 mV shift across a 100 ohm resistor. I played with that, I used a small transformer to balance the signal and then into LVDS receiver through a voltage divider. Worked well, but I didn't measure the jitter, it was just for a micro-controller. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] TADD-1 question
I have a sig gen that uses a single BNC for input/output of the 10 MHz reference. You have to set it for in or out using the interface. However, if the sig gen thinks that the external reference is no longer there, it automatically switches to using the internal reference, and outputing it on the BNC. My question is, will the TADD-1 be harmed if the sig gen is sending 10 MHz into one of the TADD-1 outputs? Joe Gray W5JG ___ 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] minimalist sine to square
Tom, I recently built such a device using a couple of stages of a 74HC04, with the RF input to the 1st stage AC coupled and the input biased by a high-value (a couple of megohms) resistor feeding back from the output of the first inverter stage to the input of that stage. It's so dirt simple, it's hard to beat. I was not particularly concerned about jitter, so if you're not already familiar enough with the circuit to know whether or not it's good enough, it might be worth a try. BTW, I am running at 10 MHz from a PRS-10 Rb, and just wanted something to drive a count-down chain. And there's always the 74AC04 if you wanted faster edges. Dana Whitlow On Fri, Jan 19, 2018 at 1:31 PM, Tom Van Baak wrote: > John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It > performs very well but requires +10 V. > > I'm looking for a solution that works at 5 V (e.g., USB powered) and also > uses fewer parts. Wenzel also mentions using a differential line receiver > [2]. That would be an ideal single-chip 5 V solution for me but the two > parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for > a 10 MHz input. > > Can any of you circuit experts suggest some line receivers that would > work? Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be > quite as good as the TADD-2. > > Thanks, > /tvb > > [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf > [2] http://www.wenzel.com/documents/waveform.html > [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF > [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf > [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf > > > ___ > 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.
Re: [time-nuts] minimalist sine to square
On 1/19/18 11:31 AM, Tom Van Baak wrote: John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs very well but requires +10 V. I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses fewer parts. Wenzel also mentions using a differential line receiver [2]. That would be an ideal single-chip 5 V solution for me but the two parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz input. There are tons of LVDS that run on 3.3 or 5V, Maxim, TI both have parts. The first Maxim part google turned up with "LVDS receiver" was a quad, esd protected unit good to 400 MHz, 2ns prop delay, 50mV hysteresis. You do want to watch the common mode voltages - some of the parts are not good about having the signals swing near the rails (or beyond). ___ 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] minimalist sine to square
On 1/19/18 11:31 AM, Tom Van Baak wrote: John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs very well but requires +10 V. I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses fewer parts. Wenzel also mentions using a differential line receiver [2]. That would be an ideal single-chip 5 V solution for me but the two parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz input. Can any of you circuit experts suggest some line receivers that would work? Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite as good as the TADD-2. What about the plethora of LVDS receivers - they're basically a differential input thresholder, with deliberate hysteresis, looking for a 300 mV shift across a 100 ohm resistor. Plenty fast (GHz) Thanks, /tvb [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf [2] http://www.wenzel.com/documents/waveform.html [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf ___ 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] minimalist sine to square
John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs very well but requires +10 V. I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses fewer parts. Wenzel also mentions using a differential line receiver [2]. That would be an ideal single-chip 5 V solution for me but the two parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz input. Can any of you circuit experts suggest some line receivers that would work? Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite as good as the TADD-2. Thanks, /tvb [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf [2] http://www.wenzel.com/documents/waveform.html [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf ___ 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] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
If that Leica antenna is the same one as the antennas that were sold on Ebay a few years back, they run just fine on 5V. I have used them on Thunderbolts quite a bit. > I decided that the Leica choke ring antenna I got a while back took 12 volts because the power input went to an 8 volt regulator, and I figured 12 volts should work ok. ___ 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] "Confessions of a Reformed Frequency Standard Nut"
https://hackaday.com/2018/01/17/confessions-of-a-reformed-frequency-standard-nut/ "Or are you chasing that last digit just because it’s 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.
Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
Hi Since this *is* an L1 / L2 antenna, there are a lot of things you might be doing with it. If indeed dual frequency GPS is part of the intended use, the survey oriented gear will be slightly happier if the “right” corner faces north. It only really counts in that sort of L1 / L2 data reduction setting. Of course, if you are really after “the best”, that’s the way to go …. Bob > On Jan 19, 2018, at 9:50 AM, Warren Kumari wrote: > > On Thu, Jan 18, 2018 at 1:39 PM, John Green wrote: > >> I have been gone for a good while, but now that I am officially retired, I >> thought I would get back into the time/frequency hobby. I recently bought a >> Trimble 33429-00 antenna off eBay. I can't seem to find much on the >> internet about it. Google has not been my friend. First, I assume the >> "micro centered" refers to the phase center being located with precision. >> Mine was meant to be used with the ground plane, which did not come with >> it, so the marks indication the part to be pointed north are missing. > > > I believe that there is a little white line on the antenna itself, which > indicates which *corner* faces North. > Doesn't hurt to try orient it that way. > W > > > >> It >> doesn't matter in my use since I won't be surveying anyway. Can someone >> tell me what voltage it takes? I decided that the Leica choke ring antenna >> I got a while back took 12 volts because the power input went to an 8 volt >> regulator, and I figured 12 volts should work ok. On this one, the power >> goes to a 2951 adjustable regulator, leaving me a bit in the dark. I will >> probably try hooking an adjustable power supply to it and slowly raising >> the voltage until the output of the regulator stabilizes. They seem to have >> made two versions of this antenna. One with groundplane, and one without. >> Since I will be feeding a GPSDO, would a groundplane be of benefit? In >> looking through the archives, it seems I have missed a lot of good >> discussions. Good to be back. >> ___ >> 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. >> > > > > -- > I don't think the execution is relevant when it was obviously a bad idea in > the first place. > This is like putting rabid weasels in your pants, and later expressing > regret at having chosen those particular rabid weasels and that pair of > pants. > ---maf > ___ > 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.
Re: [time-nuts] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
On Thu, Jan 18, 2018 at 1:39 PM, John Green wrote: > I have been gone for a good while, but now that I am officially retired, I > thought I would get back into the time/frequency hobby. I recently bought a > Trimble 33429-00 antenna off eBay. I can't seem to find much on the > internet about it. Google has not been my friend. First, I assume the > "micro centered" refers to the phase center being located with precision. > Mine was meant to be used with the ground plane, which did not come with > it, so the marks indication the part to be pointed north are missing. I believe that there is a little white line on the antenna itself, which indicates which *corner* faces North. Doesn't hurt to try orient it that way. W > It > doesn't matter in my use since I won't be surveying anyway. Can someone > tell me what voltage it takes? I decided that the Leica choke ring antenna > I got a while back took 12 volts because the power input went to an 8 volt > regulator, and I figured 12 volts should work ok. On this one, the power > goes to a 2951 adjustable regulator, leaving me a bit in the dark. I will > probably try hooking an adjustable power supply to it and slowly raising > the voltage until the output of the regulator stabilizes. They seem to have > made two versions of this antenna. One with groundplane, and one without. > Since I will be feeding a GPSDO, would a groundplane be of benefit? In > looking through the archives, it seems I have missed a lot of good > discussions. Good to be back. > ___ > 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. > -- I don't think the execution is relevant when it was obviously a bad idea in the first place. This is like putting rabid weasels in your pants, and later expressing regret at having chosen those particular rabid weasels and that pair of pants. ---maf ___ 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] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
Hi It is very much a 12V antenna. It also is a “50 db gain” antenna as well. Most of the timing gear is looking for 20 to 30 db less gain than that in an antenna. The good news is that you can run a really big splitter after one to drive lots of stuff. The bad news is that you may still need attenuators. Looking at the snow piles on my GPS antennas, I would not recommend using the ground plane. It will significantly increase the load on the mount …. Bob > On Jan 18, 2018, at 1:39 PM, John Green wrote: > > I have been gone for a good while, but now that I am officially retired, I > thought I would get back into the time/frequency hobby. I recently bought a > Trimble 33429-00 antenna off eBay. I can't seem to find much on the > internet about it. Google has not been my friend. First, I assume the > "micro centered" refers to the phase center being located with precision. > Mine was meant to be used with the ground plane, which did not come with > it, so the marks indication the part to be pointed north are missing. It > doesn't matter in my use since I won't be surveying anyway. Can someone > tell me what voltage it takes? I decided that the Leica choke ring antenna > I got a while back took 12 volts because the power input went to an 8 volt > regulator, and I figured 12 volts should work ok. On this one, the power > goes to a 2951 adjustable regulator, leaving me a bit in the dark. I will > probably try hooking an adjustable power supply to it and slowly raising > the voltage until the output of the regulator stabilizes. They seem to have > made two versions of this antenna. One with groundplane, and one without. > Since I will be feeding a GPSDO, would a groundplane be of benefit? In > looking through the archives, it seems I have missed a lot of good > discussions. Good to be back. > ___ > 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.
Re: [time-nuts] MTI-Milliren OCXO Issue
Hi They always had a pretty lean operation and some unique approaches as part of their business plan. That said, they do seem to be a going concern. Bob > On Jan 19, 2018, at 3:54 AM, John C. Westmoreland, P.E. > wrote: > > Hello All, > > Just wondering - has anyone made any recent purchases with MTI-Milliren > regarding OCXO's? > > I've had a recent interaction with them that makes me think their OCXO's > could go the way of the > dinosaur; maybe it's just me; hoping someone on the list has some recent > experience with MTI-Milliren and can respond. > > Thanks In Advance, > John W. > AJ6BC > ___ > 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.
Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??
On Jan 19, 2018 6:01 AM, "John Ackermann N8UR" wrote: > Sorry to hijack the thread, but the Si5351 looks interesting for another > project I'm working on. I know it specifies "low jitter" but has anyone > looked at the phase noise? Is it usable for RF applications? > Datasheet states jitter in the 40-70 ps range. That is not very good. If you want something suitable for RF applications, look at the Si5328. It has jitter on the order of 300fs. I believe Leo Bodnar uses it in his GPSDOs and I can confirm the phase noise and Allan Deviation others have found and it is suitable for me for RF applications. It is not nearly as good as the Thunderbolt though. It will generate almost any frequency you want. Mark > ___ 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] trimble Thunderbolt, how to get 25 or 27 mHz from it??
Sorry to hijack the thread, but the Si5351 looks interesting for another project I'm working on. I know it specifies "low jitter" but has anyone looked at the phase noise? Is it usable for RF applications? Thanks, John On 01/18/2018 08:53 AM, D. Jeff Dionne wrote: Chris, You don't need to do that. The SiLabs part will accept the 10MHz sin from an OCXO directly into the XA pin. That pin normally connects to a crystal, so there is a high gain amp in the chip to square it up already... I did the tests a while back, see the thread here: https://www.silabs.com/community/timing/forum.topic.html/si5351_msop10_packag-wocK Caveats: others had trouble with biasing, and found just squaring the OCXO up first worked for them. SiLabs software is not set up to allow any other frequencies except 25 or 27MHz, so you do need to calculate the register values yourself. J. Is there an easy way to get 25 or 27 MHz from my Trimble Thunderbolt as a reference clock at 1v P to P square wave for a Si5351a synthesizer chip please? I have the David Partridge divider board from way back that is still going strong, but 25 MHz is not an option as it divides only. Thanks, please keep replies to the level an idiot might comprehend :) -- Best Regards, Chris Wilson. mailto: chris at chriswilson.tv ___ 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] Looking for information regarding Trimble 33429-00 microcentered GPS antenna.
I have been gone for a good while, but now that I am officially retired, I thought I would get back into the time/frequency hobby. I recently bought a Trimble 33429-00 antenna off eBay. I can't seem to find much on the internet about it. Google has not been my friend. First, I assume the "micro centered" refers to the phase center being located with precision. Mine was meant to be used with the ground plane, which did not come with it, so the marks indication the part to be pointed north are missing. It doesn't matter in my use since I won't be surveying anyway. Can someone tell me what voltage it takes? I decided that the Leica choke ring antenna I got a while back took 12 volts because the power input went to an 8 volt regulator, and I figured 12 volts should work ok. On this one, the power goes to a 2951 adjustable regulator, leaving me a bit in the dark. I will probably try hooking an adjustable power supply to it and slowly raising the voltage until the output of the regulator stabilizes. They seem to have made two versions of this antenna. One with groundplane, and one without. Since I will be feeding a GPSDO, would a groundplane be of benefit? In looking through the archives, it seems I have missed a lot of good discussions. Good to be back. ___ 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] Time interval measurement vs dual mixer
Hi, Thanks for all answers. I'm trying to estimate the uncertainty of GPS Common View data (which is based on TIE measurement) and compare it to data from dual mixer method. Message: 6 Date: Wed, 17 Jan 2018 11:08:45 -0500 From: Bob kb8tq To: Luciano Paramithiotti , Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Time interval measurement vs dual mixer method Message-ID: Content-Type: text/plain; charset=utf-8 Hi If the time offset gets to the point that it bothers the measurement, you likely are running to low a difference frequency. It is quite possible (though not easy) to get low parts in 10^-13 running an offset of 8 or 9 Hz at 10 MHz. If you are running very precise signals, then line stretchers can be used to get everything so it hits at the same point. There are NBS papers where they talk about doing exactly this sort of thing. Results were âświthin a couple of microseconds” as I recall. Bob > On Jan 17, 2018, at 1:44 AM, tim...@timeok.it wrote: > > > Hi Slawek, > I have tried two versions of DMTD and I think the biggest problem with this > method is the fact that two measures made on the same DUT never coincide. > The DMTD suffers from time wrap and the measurement results are linked to > the time difference presetted by t1 and t2. > At the moment I am using the TICC with good results, attached to the noise > floor. > I think that in order to have a better resolution we need to focus on a > recent production > error multiplier such as the A7 of Quartzlock or a similar one to be > self-constructing. > http://quartzlock.com/userfiles/downloads/manuals/A7-A_&_A7-MX_Manual.pdf > Luciano > www.timeok.it > > > Da "time-nuts" time-nuts-boun...@febo.com > A "time-nuts" time-nuts@febo.com > Cc > Data Tue, 16 Jan 2018 17:58:18 +0100 > Oggetto [time-nuts] Time interval measurement vs dual mixer method > > Hello to the group! > > Have you ever measured frequency standard (or other precision oscillator) > simultanously by time interval method (difference between 1 pps ref and 1 pps > DUT) and dual mixer method (e.q. with phase/frequency comparator)? I'm very > interested in results. > > Slawek > ___ 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] trimble Thunderbolt, how to get 25 or 27 mHz from it??
Chris, You don't need to do that. The SiLabs part will accept the 10MHz sin from an OCXO directly into the XA pin. That pin normally connects to a crystal, so there is a high gain amp in the chip to square it up already... I did the tests a while back, see the thread here: https://www.silabs.com/community/timing/forum.topic.html/si5351_msop10_packag-wocK Caveats: others had trouble with biasing, and found just squaring the OCXO up first worked for them. SiLabs software is not set up to allow any other frequencies except 25 or 27MHz, so you do need to calculate the register values yourself. J. > Is there an easy way to get 25 or 27 MHz from my Trimble Thunderbolt as a > reference clock at 1v P to P square wave for a Si5351a synthesizer chip > please? I have the David Partridge divider board from way back that is still > going strong, but 25 MHz is not an option as it divides only. Thanks, please > keep replies to the level an idiot might comprehend :) -- Best Regards, Chris > Wilson. mailto: chris at chriswilson.tv ___ 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] MTI-Milliren OCXO Issue
Hello All, Just wondering - has anyone made any recent purchases with MTI-Milliren regarding OCXO's? I've had a recent interaction with them that makes me think their OCXO's could go the way of the dinosaur; maybe it's just me; hoping someone on the list has some recent experience with MTI-Milliren and can respond. Thanks In Advance, John W. AJ6BC ___ 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.
