Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Hi Tim it is this amp which I mean: http://www.techlib.com/files/lowamp.pdf Actually I dont care too much about TO92 because I mostly use SMD parts anyways. Using dead-bug technique, they are even suitable for prototypes and experiments. Tobias On Sat., 4 Apr. 2020, 13:41 Tim Shoppa, wrote: > Tobias, are you talking about the Wenzel AF Preamp > that uses paralleled JFET's? That uses a 2SK369 JFET which is actually > still in production and distribution and commonly available in TO-92 even. > > (Contrast with J310 which was once pure jellybean but today no longer made > new in TO-92!!!) > > Tim N3QE > > On Fri, Apr 3, 2020 at 7:55 PM Tobias Pluess wrote: > > > Hi Taka > > > > what are those discrete amp designs you mention? I have seen some, but > not > > those you mention. These which I have seen seem to be quite dated, use > > strange or old parts (selected 2SC... transistors which are not so easy > to > > obtain here) or have other issues. > > There is also the Wenzel amp, but building it seems to involve some black > > magic as it works only with some very sophisticated, selected, exotic > parts > > and I have never seen a proper explanation about how it really works and > > how the part values are calculated (for example if you want to change the > > gain). > > As I am (mostly) not afraid of discrete circuits it would be interesting > to > > which designs you mean. > > > > Best > > Tobias > > HB9FSX > > > > > > On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < > > time-nuts@lists.febo.com> wrote: > > > > > I'm seeing a fairly obvious trend on this list. When it comes to > buffer > > > amplifiers, many people, in fact, most I've seen recommends fast OP > Amp. > > > Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, > > and > > > others are mentioned only sometimes. Trends are similar for > distribution > > > amps. Video amps are generally not recommended. > > > > > > But I have never seen a suggestion of MMIC like ones from > Mini-circuits. > > > There are few that work from DC, fairly good NF, but often too high of > > > gain. Other than high gain, are there reason NOT to use MMIC? > > > > > > --- > > > (Mr.) Taka Kamiya > > > KB4EMF / ex JF2DKG > > > ___ > > > time-nuts mailing list -- time-nuts@lists.febo.com > > > To unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > > and follow the instructions there. > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] PRS-10 PPS output
Hi Pulling the output of a normal CMOS gate to ground through a small resistor is not generally a good idea. That’s what an attenuator or far end termination of the coax is doing. It’s not specifically outlawed in the spec, but it’s still not what they are designed to do. Also the output level is going to be pretty wimpy run through an attenuator. One way to “fix” the problem is with a 50 ohm series resistor at the source end. That only works to the degree that the output impedance of the gate is very low when in saturation. How true this is …. that depends. A far better approach is to buffer the output through something like a set of 2, 3, or 4 NC7SZ125’s (or similar) in parallel. The output from something like that has much higher drive capability than a single gate output. Source termination with a single 50 ohm or with 100, 150, or 200 ohms on each gate works pretty well in this case. (If you want to dig further into the details of “why source termination?” there are several posts from Said back about 4 or 5 years ago). You do have the problem of not knowing what the “far end” is expecting. If it has a 50 ohm load *and* is looking for a 5V logic signal …. source termination isn’t going to work with normal logic gates doing the drive end of things. You would need a high speed gate that is happy with a 10V supply to do that ….. Unfortunately, there *is* gear out there that terminates a PPS with a 50 ohm load *and* expects some sort of logic level. Is it set up for 1.2V, 1.65V, 2.5V …. Often this is not very well documented. If you *do* set up to “straight drive” a 50 ohm end termination to 5V in order to do right by a 2.5V logic level: Spend some time looking at the power distribution approach on your board. That’s a 0.1A 10 us wide pulse you are thumping onto the supply rail….. Bob > On Apr 4, 2020, at 1:20 PM, Joseph Gwinn wrote: > > On Fri, 03 Apr 2020 20:00:59 -0400, time-nuts-requ...@lists.febo.com > wrote: > > Re: time-nuts Digest, Vol 189, Issue 7 > - >> >> Message: 1 >> Date: Fri, 3 Apr 2020 15:48:50 -0400 >> From: Bob kb8tq >> To: Discussion of precise time and frequency measurement >> >> Subject: Re: [time-nuts] PRS-10 PPS output >> >> Hi >> >> At least according to page 20 in: >> >> https://www.thinksrs.com/downloads/pdfs/manuals/PRS10m.pdf >> >> the ?raw? PPS output from the PRS-10 is just a CMOS gate output. >> There is nothing suggesting it is designed to drive a 50 ohm load >> or a coax cable. >> > [snip] >> >> Best guess: It's doing what it's supposed to, but not quite what >> you expected it to do. >> >> >> Message: 2 >> Date: Fri, 3 Apr 2020 20:27:25 + (UTC) >> From: Taka Kamiya >> To: Discussion of precise time and frequency measurement >> >> Subject: Re: [time-nuts] PRS-10 PPS output >> >> I've seen this with my own.? You are catching the leading edge of >> ringing of the signal.? >> >> Since the output is CMOS, and high impedance, it really doesn't have >> enough current to push through low impedance cables.? Try shorter and >> different cable.? Terminate it with 50 ohms.? Set the trigger level >> little higher.? In my setup, the cable is actually a very short >> twisted pair, and only 2" long into a buffer board. > > I've had this issue with coax 1PPS outputs across the board. What I > generally do is to attach a coaxial 50-ohm attenuator between > instrument coax output connector and the 50-ohm cable it will drive. > The attenuator matches the output impedance to the coax impedance. I > use attenuators between 3 dB and 10 db. The actual attenuation is not > as marked, because of the mismatch between the ~1K output impedance and > the 50-ohm input of the attenuator. I suppose that a 75-ohm attenuator > may work as well or better to drive 50-ohm cable, but have not tried > it. All the ringing et al are suppressed because the length of the > mismatched part of the path is maybe an inch or two. > > Joe Gwinn > >> >> End of time-nuts Digest, Vol 189, Issue 7 >> * > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] PRS-10 PPS output
On Fri, 03 Apr 2020 20:00:59 -0400, time-nuts-requ...@lists.febo.com wrote: Re: time-nuts Digest, Vol 189, Issue 7 - > > Message: 1 > Date: Fri, 3 Apr 2020 15:48:50 -0400 > From: Bob kb8tq > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] PRS-10 PPS output > > Hi > > At least according to page 20 in: > > https://www.thinksrs.com/downloads/pdfs/manuals/PRS10m.pdf > > the ?raw? PPS output from the PRS-10 is just a CMOS gate output. > There is nothing suggesting it is designed to drive a 50 ohm load > or a coax cable. > [snip] > > Best guess: It's doing what it's supposed to, but not quite what > you expected it to do. > > > Message: 2 > Date: Fri, 3 Apr 2020 20:27:25 + (UTC) > From: Taka Kamiya > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] PRS-10 PPS output > > I've seen this with my own.? You are catching the leading edge of > ringing of the signal.? > > Since the output is CMOS, and high impedance, it really doesn't have > enough current to push through low impedance cables.? Try shorter and > different cable.? Terminate it with 50 ohms.? Set the trigger level > little higher.? In my setup, the cable is actually a very short > twisted pair, and only 2" long into a buffer board. I've had this issue with coax 1PPS outputs across the board. What I generally do is to attach a coaxial 50-ohm attenuator between instrument coax output connector and the 50-ohm cable it will drive. The attenuator matches the output impedance to the coax impedance. I use attenuators between 3 dB and 10 db. The actual attenuation is not as marked, because of the mismatch between the ~1K output impedance and the 50-ohm input of the attenuator. I suppose that a 75-ohm attenuator may work as well or better to drive 50-ohm cable, but have not tried it. All the ringing et al are suppressed because the length of the mismatched part of the path is maybe an inch or two. Joe Gwinn > > End of time-nuts Digest, Vol 189, Issue 7 > * ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Some vendors say "LF-1GHz" etc instead of the misleading "DC". True DC coupled amplifiers are a different universe. They must be differential. Search for differential amplifier IC'S from the usual suspects. You will find that the NF will be at least 7 dB and up. I'm not exactly sure why, but I have never seen an exception so it must be baked into the cake. There are over-the-top bias TEE's that go from audio to GHz from extreme vendors such as Picosecond Pulse Labs. Again, those bias tees are a different universe than ordinary ones. Probably too pricey for hobby use. We used to have to mess around with all this stuff when I worked for Agilent Labs. Rick N6RK On 4/4/2020 3:02 AM, David C. Partridge wrote: If you look at the way the power is supplied to and output is taken from an MMIC there's no way that I can see that they could go all the way to DC as there's always a capacitor in the output ... I got all excited a while back when I considered an MMIC for a project because the spec said DC-xGHz. Sadly the specified circuit for using it meant there's no way it could get the DC, though a large output capacitor in parallel with a RF cap would allow audio to GHz. Hmmm where did I leave the 1 MegaFarad capacitor. D. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Hi The file you reference is showing a rather complex single mixer setup. It simply omits the mixer from the schematic. The audio amplifier that is part of that setup is going to improve the measurement floor by a couple of db. With most people saying that it’s way to complex to set up to measure this stuff, I’d suggest that a “get it going” rig that is within a couple db (but wires up in an afternoon) is the better approach. The main issue of doing it in an afternoon is that it needs to be done from the small parts you have on hand. What sort of bypass caps do you stock? Which voltage regulators are already at hand? Do you do your breadboards with 1206 parts? Any real design will need to be adapted to “fit” that part of things. Some examples: +/- 18V is a nice supply for some of this. 79L18’s are “uncommon”. If you have them then this or that op amp makes a lot of sense. If the highest you want to play with is +/- 12V then a very different set of op amps make sense. The RPD series of mixers are much better at this than other parts. Maybe you don’t want to use them. Since they are 500 ohm output and most other mixers are 50 ohm, the circuit changes more than just a little bit. Lots of variables. Bob > On Apr 4, 2020, at 7:36 AM, Tobias Pluess wrote: > > Hi Dana > > No I don't have insight into the Wenzel stuff. > The Wenzel amp I mentioned is this: > > http://www.techlib.com/files/lowamp.pdf > > > Tobias > > On Sat., 4 Apr. 2020, 12:25 Dana Whitlow, wrote: > >> What is a "Wenzel amp"? Are you referring to the broad line of amplifiers >> made by Wenzel Assoc? >> You sound like you've got some insight into what is inside these things, >> that is not available from >> the datasheets from Wenzel, but I don't even know if these are what you >> refer to. >> >> Please elucidate. >> >> Thanks, >> >> Dana >> >> >> On Fri, Apr 3, 2020 at 6:55 PM Tobias Pluess wrote: >> >>> Hi Taka >>> >>> what are those discrete amp designs you mention? I have seen some, but >> not >>> those you mention. These which I have seen seem to be quite dated, use >>> strange or old parts (selected 2SC... transistors which are not so easy >> to >>> obtain here) or have other issues. >>> There is also the Wenzel amp, but building it seems to involve some black >>> magic as it works only with some very sophisticated, selected, exotic >> parts >>> and I have never seen a proper explanation about how it really works and >>> how the part values are calculated (for example if you want to change the >>> gain). >>> As I am (mostly) not afraid of discrete circuits it would be interesting >> to >>> which designs you mean. >>> >>> Best >>> Tobias >>> HB9FSX >>> >>> >>> On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < >>> time-nuts@lists.febo.com> wrote: >>> I'm seeing a fairly obvious trend on this list. When it comes to >> buffer amplifiers, many people, in fact, most I've seen recommends fast OP >> Amp. Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, >>> and others are mentioned only sometimes. Trends are similar for >> distribution amps. Video amps are generally not recommended. But I have never seen a suggestion of MMIC like ones from >> Mini-circuits. There are few that work from DC, fairly good NF, but often too high of gain. Other than high gain, are there reason NOT to use MMIC? --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. >>> ___ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Tobias, are you talking about the Wenzel AF Preamp that uses paralleled JFET's? That uses a 2SK369 JFET which is actually still in production and distribution and commonly available in TO-92 even. (Contrast with J310 which was once pure jellybean but today no longer made new in TO-92!!!) Tim N3QE On Fri, Apr 3, 2020 at 7:55 PM Tobias Pluess wrote: > Hi Taka > > what are those discrete amp designs you mention? I have seen some, but not > those you mention. These which I have seen seem to be quite dated, use > strange or old parts (selected 2SC... transistors which are not so easy to > obtain here) or have other issues. > There is also the Wenzel amp, but building it seems to involve some black > magic as it works only with some very sophisticated, selected, exotic parts > and I have never seen a proper explanation about how it really works and > how the part values are calculated (for example if you want to change the > gain). > As I am (mostly) not afraid of discrete circuits it would be interesting to > which designs you mean. > > Best > Tobias > HB9FSX > > > On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < > time-nuts@lists.febo.com> wrote: > > > I'm seeing a fairly obvious trend on this list. When it comes to buffer > > amplifiers, many people, in fact, most I've seen recommends fast OP Amp. > > Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, > and > > others are mentioned only sometimes. Trends are similar for distribution > > amps. Video amps are generally not recommended. > > > > But I have never seen a suggestion of MMIC like ones from Mini-circuits. > > There are few that work from DC, fairly good NF, but often too high of > > gain. Other than high gain, are there reason NOT to use MMIC? > > > > --- > > (Mr.) Taka Kamiya > > KB4EMF / ex JF2DKG > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Hi Dana No I don't have insight into the Wenzel stuff. The Wenzel amp I mentioned is this: http://www.techlib.com/files/lowamp.pdf Tobias On Sat., 4 Apr. 2020, 12:25 Dana Whitlow, wrote: > What is a "Wenzel amp"? Are you referring to the broad line of amplifiers > made by Wenzel Assoc? > You sound like you've got some insight into what is inside these things, > that is not available from > the datasheets from Wenzel, but I don't even know if these are what you > refer to. > > Please elucidate. > > Thanks, > > Dana > > > On Fri, Apr 3, 2020 at 6:55 PM Tobias Pluess wrote: > > > Hi Taka > > > > what are those discrete amp designs you mention? I have seen some, but > not > > those you mention. These which I have seen seem to be quite dated, use > > strange or old parts (selected 2SC... transistors which are not so easy > to > > obtain here) or have other issues. > > There is also the Wenzel amp, but building it seems to involve some black > > magic as it works only with some very sophisticated, selected, exotic > parts > > and I have never seen a proper explanation about how it really works and > > how the part values are calculated (for example if you want to change the > > gain). > > As I am (mostly) not afraid of discrete circuits it would be interesting > to > > which designs you mean. > > > > Best > > Tobias > > HB9FSX > > > > > > On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < > > time-nuts@lists.febo.com> wrote: > > > > > I'm seeing a fairly obvious trend on this list. When it comes to > buffer > > > amplifiers, many people, in fact, most I've seen recommends fast OP > Amp. > > > Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, > > and > > > others are mentioned only sometimes. Trends are similar for > distribution > > > amps. Video amps are generally not recommended. > > > > > > But I have never seen a suggestion of MMIC like ones from > Mini-circuits. > > > There are few that work from DC, fairly good NF, but often too high of > > > gain. Other than high gain, are there reason NOT to use MMIC? > > > > > > --- > > > (Mr.) Taka Kamiya > > > KB4EMF / ex JF2DKG > > > ___ > > > time-nuts mailing list -- time-nuts@lists.febo.com > > > To unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > > and follow the instructions there. > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
Search for Wenzel in the Manuals pages on my web site www.ko4bb.com Didier KO4BB On Sat, Apr 4, 2020, 5:25 AM Dana Whitlow wrote: > What is a "Wenzel amp"? Are you referring to the broad line of amplifiers > made by Wenzel Assoc? > You sound like you've got some insight into what is inside these things, > that is not available from > the datasheets from Wenzel, but I don't even know if these are what you > refer to. > > Please elucidate. > > Thanks, > > Dana > > > On Fri, Apr 3, 2020 at 6:55 PM Tobias Pluess wrote: > > > Hi Taka > > > > what are those discrete amp designs you mention? I have seen some, but > not > > those you mention. These which I have seen seem to be quite dated, use > > strange or old parts (selected 2SC... transistors which are not so easy > to > > obtain here) or have other issues. > > There is also the Wenzel amp, but building it seems to involve some black > > magic as it works only with some very sophisticated, selected, exotic > parts > > and I have never seen a proper explanation about how it really works and > > how the part values are calculated (for example if you want to change the > > gain). > > As I am (mostly) not afraid of discrete circuits it would be interesting > to > > which designs you mean. > > > > Best > > Tobias > > HB9FSX > > > > > > On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < > > time-nuts@lists.febo.com> wrote: > > > > > I'm seeing a fairly obvious trend on this list. When it comes to > buffer > > > amplifiers, many people, in fact, most I've seen recommends fast OP > Amp. > > > Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, > > and > > > others are mentioned only sometimes. Trends are similar for > distribution > > > amps. Video amps are generally not recommended. > > > > > > But I have never seen a suggestion of MMIC like ones from > Mini-circuits. > > > There are few that work from DC, fairly good NF, but often too high of > > > gain. Other than high gain, are there reason NOT to use MMIC? > > > > > > --- > > > (Mr.) Taka Kamiya > > > KB4EMF / ex JF2DKG > > > ___ > > > time-nuts mailing list -- time-nuts@lists.febo.com > > > To unsubscribe, go to > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > > and follow the instructions there. > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
What is a "Wenzel amp"? Are you referring to the broad line of amplifiers made by Wenzel Assoc? You sound like you've got some insight into what is inside these things, that is not available from the datasheets from Wenzel, but I don't even know if these are what you refer to. Please elucidate. Thanks, Dana On Fri, Apr 3, 2020 at 6:55 PM Tobias Pluess wrote: > Hi Taka > > what are those discrete amp designs you mention? I have seen some, but not > those you mention. These which I have seen seem to be quite dated, use > strange or old parts (selected 2SC... transistors which are not so easy to > obtain here) or have other issues. > There is also the Wenzel amp, but building it seems to involve some black > magic as it works only with some very sophisticated, selected, exotic parts > and I have never seen a proper explanation about how it really works and > how the part values are calculated (for example if you want to change the > gain). > As I am (mostly) not afraid of discrete circuits it would be interesting to > which designs you mean. > > Best > Tobias > HB9FSX > > > On Sat., 4 Apr. 2020, 00:07 Taka Kamiya via time-nuts, < > time-nuts@lists.febo.com> wrote: > > > I'm seeing a fairly obvious trend on this list. When it comes to buffer > > amplifiers, many people, in fact, most I've seen recommends fast OP Amp. > > Discrete Amp, such as ones from K5FX design, NIST design, Clifton amp, > and > > others are mentioned only sometimes. Trends are similar for distribution > > amps. Video amps are generally not recommended. > > > > But I have never seen a suggestion of MMIC like ones from Mini-circuits. > > There are few that work from DC, fairly good NF, but often too high of > > gain. Other than high gain, are there reason NOT to use MMIC? > > > > --- > > (Mr.) Taka Kamiya > > KB4EMF / ex JF2DKG > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete?
If you look at the way the power is supplied to and output is taken from an MMIC there's no way that I can see that they could go all the way to DC as there's always a capacitor in the output ... I got all excited a while back when I considered an MMIC for a project because the spec said DC-xGHz. Sadly the specified circuit for using it meant there's no way it could get the DC, though a large output capacitor in parallel with a RF cap would allow audio to GHz. Hmmm where did I leave the 1 MegaFarad capacitor. D. -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of Taka Kamiya via time-nuts Sent: 03 April 2020 23:07 To: Discussion of Precise Time and Frequency Measurement Cc: Taka Kamiya Subject: [time-nuts] Buffer amplifier, OP Amp, vs MMIC, vs discrete? > But I have never seen a suggestion of MMIC like ones from Mini-circuits. > There are few that work from DC, fairly good NF, but often too high of gain. > Other than high gain, are there reason NOT to use MMIC? --- (Mr.) Taka Kamiya KB4EMF / ex JF2DKG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
