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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
Radu,
Lothar's point regarding the frequency stepping as opposed to frequency sweep is a good one for the hobbyist to bear in mind.? For bench measurements of components and subsystems you're usually better to use a (V)NA, modern or classic.? An alternative angle is that with the low price of e.g. nanoVNA's or similar, it's probably not worth sweating too much about sweep capability in the sig gen.? Still, for the occasional quick look at e.g. filters in a multi-conversion receiver, it can be handy to sweep at signal or various intermediate frequencies while monitoring the RF chain output with a decent RF probe. Most stepped generators are slow and painful in this application, as noted.? The R&S SML 01, with its quite fast stepping and settling, is better than most, as I found the other day when looking at the overall response of a classic Collins 75S-3B receiver.? One other thing to watch with at least some modern generators is the timing jitter associated with stepping which, while not important in automated test applications (for example) utilizing data valid indicators, produces poorly synched analog displays. Generators like the Rigol DSG815 suffer badly from this effect, while the R&S unit does not. In simple terms I would suggest thinking carefully about whether the sweep capability is very important in a given environment and, if it is, to look for a sig gen with honest-to-goodness sweep and trigger/ramp outputs.? If sweeping is of secondary importance and you think you can live with a stepped generator, at least do the sums and understand what, with specified step and settling times, your frequency agility limits are. It's also worth thinking about what fraction of your potential applications require a truly calibrated sweep.? For example, some simple linear FM with a few kHz deviation would have told most of the story in the quick receiver test example mentioned earlier. Regards, Peter. |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
开云体育Dear All,Re RP protection, I think DC protection is a different matter. ?For example many SAs have an input power limit of +20 dBm and 0 V DC. ?You have to check spec. carefully. Re DC protection, it is best to have a procedure to avoid these problems, rather than rely on protection. In my vacation job days of repairing VHF radio and radar; the procedure before connecting a signal generator was: 1. Disable transmit physically- disconnect the private wires carrying keying signals; unplug fist microphone or whatever. 2. Measure the voltage between centre pin and outer of the cable connecting the signal generator to the transceiver. 3. Short the centre pin and outer of the cable to confirm. 4. Connect to signal generator. Sometimes, techs. did not follow the procedure; I remember a red-faced lad who had applied 50W straight into the output of a newly acquired R&S signal generator. He also borrowed and broke my multimeter. He did not last long at the company. As for the choice of generator, if sweep functions are required that limits the choice.? If ultra-low phase noise is not needed I would recommend the 8656B; cheap, light weight, easy to use and pretty reliable. The 8643A has better performance, but is large and heavy. The 8642 even heavier. Regards, Alwyn ? _____________________________________________________ Alwyn Seeds, Director SynOptika Ltd., 114 Beaufort Street, London, SW3 6BU, England. SynOptika Ltd., Registered in England and Wales: No. 04606737 Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________ |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
Re: the possible need for I-Q modulation, if the required generator does not have it internal it can be added as an external modulator to the output signal. External I-Q modulators are not cheap $1000+. The I-Q IC’s are less than $10 and a board would be needed with all necessary circuitry, however most of the IC mfrs. have demo modules/circuits available for free or very cheap development kits - add Vcc and cables and you are ready to go. You would also need 2 lower RF or audio sources for the modulation. I have done this for some test procedures and I have seen and handled several of the I-Q modulators demo brds. Most of them have sma-f connectors for the input, output, and modulation ports.
I probably have one, but I have no clue where to find it. Don Bitters |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
8642 is in that boat for example. But one could craft a bit of,say, Python and drive the sig gen and a suitable meter and you have a poor man's scalar filter measurement setup. Takes a bit longer maybe, but imho doable.
As a side note: I kinda like the modulation generator that is part of the 8642, I think it can go to 100kHz and is usable on its own. Wilko |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
On 3/17/22 21:00, Radu Bogdan Dicher wrote:
Ruben,Some of the GPIB controlled synthesized generators could be "swept" in GPIB code...probably not as quickly or smoothly, but...then you can code the post processing to be whatever you want, and insert the results into a python lab notebook, etc. I'm planning to use my 8657B that way. It goes to 2.1GHz. |
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Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
Bonjour à tous,
Very Fine to learn of the reemergence of Ham Fleas! I was a regular at Foothills, Lockheed in Silicon Valley and Livermore flea and LLNL salvage lot in 1980s..1990s. I attended Friedst. German Ham a few times. Over the decades the actual ham radio and vintage test equipment was gradually displaced by computer stuff, and by booths of modern stuff, oftentimes cheap Chinese. Sadly, old friends went silent key.... Jim Williams, Bob Pease, Ron Lesea, RIP. A fine memory...... Nowadays I have an overflow of equipment and documents, and seldom have a chance to participate. In France I still visit the street sales, Fleas and ebay.fr, Just the ramblings of an old retired EE Jon |
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Re: BS, was Re: [HP-Agilent-Keysight-equipment] Spread the word -- Swap Meet Returns!
Not to prolong the off-topic, but perhaps to move it in a more positive direction, I will direct your attention to recently published patent:
WO 2022/040182 You can find it with Google. There's nothing in there that most, or perhaps all of the members here couldn't accomplish, it's almost all digital (though wringing the analog gremlins out of the power supply system sufficiently well to avoid false triggering took quite a lot of time on the 'scope), and most of the work was done on a Tek scope (but a couple Agilent MSOs, and a HP 54201d and 16702a that they fixed up also participated), but... Essentially?all of the electronics design and development work described here, was conducted by a series of High School Junior or Senior research-capstone students.? ?The very first version was developed by an Ohio State University computer-science Junior, but it kept catching on fire (literally), so the first HS student who worked on it essentially redeveloped it piece-by piece from scratch. Dear (Brown haired) Sydney 1.0 came into the lab not knowing how to solder, and left a year later a grizzled veteran of chasing a vast amount of magic smoke, and with sufficient chops to dive into the Tek scope and fix it without being prompted when it crapped out (it wasn't a major problem - a simultaneous power supply and LCD-backlight issue, but I will be forever impressed with her tenacity and attitude - that young lady is unstoppable). (Green-haired) Sydney 2.0 came into the lab a year later with a bit more pre-existing electronics knowledge (high-school robotics club), and decided to scrap the entire thru-hole/point-to-point system, learned how to design multilayer PCBs (on her own), then re-developed the entire thing as a monolithic, primarily surface-mount system.? She also orchestrated another group of students to develop more useful software to perform medical neuromuscular assessments. I'm a physicist.? I helped the students by pointing them to resources like data sheets for shift-buffers when they had questions like "how the heck are we going to get the input from 512 switches into 2 pins on an Arduino???".? And I coached Sydney 1.0 through episodes of "Dr. Ray, it's hard to tell because of Taumer's (original Computer-Sci student) spaghetti wiring, but I'm almost certain this wire is a dead short between the power rail for the Hall-effect sensors and the ground on the shift buffers - what should I do?? Well, let's take it out and see what happens.? Oooh - I knew that wire over there was hot, but now it's glowing!" situations, but they did this.? In High School.? ?I'm willing to bet that not many of the people suggesting that the kids are not all right, were designing and developing patentable devices when they were in HS. Will Ray |
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Re: HP YIG replacement 3-7GHz
开云体育Hello Gerald and others interested, I have a FS2772R-smt TINYig from Teledyne (4-8 GHz) that I tested on the bench and it works quite good actually. Very easy to operate and it certainly works down to 3.7 GHz. Specs are quite similar to the one shown in Geralds table. It does not have a heater. It seems very tempting to me to make it a replacement for the YIG's used in HP and other equipment that fail regularly and likely more so with age. Pout is only +6dBm (min) so normally it needs a post amplifier, a good idea anyway as this will also function as buffer. Bias is + 8 V dc and -5 V dc. Then we have to design some interface electronics as the main tuning coil needs a polarity reversible current, not seen before at the usual YIG's. Zero current is near 5.5 GHz, confirmed in my tests. I did not test FM coil. I would prefer some sort of plug in replacement: so the famous 10 (?) pole plug interface to the spec an (in my case) and sma output. Space would not normally be a problem, I think.? All the effort would only make sense to me if the TINYig is available at an affordable price. Say max 300 USD? I am in for a group buy and a group effort to design the interface. Maybe I miss something and more experienced people may comment. Best regards, Harke, PA0HRK On 17/03/2022 17:41, Peter Hansen
wrote:
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Re: What is Option G20 on an HP 8648D Signal Generator?
Lothar baier
开云体育There are a couple of ways to skin this cat , you can shoot a email to Keysight asking if they can provide you with some information on G20 , whether you get a response depends on the rep who gets a hold of your email and whether or not the option is protected ?! HP made custom options on customer request those included usually modifying specifications and/or grouping different options together for defense customers usually the letter H was used while large commercial clients the letter C was used , sometimes a option was made for one specific customer only and this included a NDA by HP not to disclose any information about the option to third parties without authorization by the client if G20 was such a option than Keysight will be tight lipped unless the customer no longer exists or the NDA expired!Another way would be to go into the system or service menu and find the option information in there , unfortunately HP never been consistent about this so some models have the options listed others dont but it’s worth a try?
On Mar 17, 2022, at 23:36, Stan via groups.io <swperk@...> wrote:
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Re: HP1662A logic analyser software?
On Thu, Mar 17, 2022 at 2:58 PM rkward via groups.io
<rkward@...> wrote:
Agilent Technologies 1660A Series 50/100-MHz State, 500-MHz Timing Logic Analyzers User’s Reference, 01660-97034 Agilent Technologies 1660A/AS-Series Logic Analyzers Programmer’s Guide, 01660-97033 HP 1660 Series Logic Analyzers Service Guide, 01660-97002 |
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What is Option G20 on an HP 8648D Signal Generator?
I have an HP 8648D signal generator that says "Option G20" on the rear label, By pushing various buttons, I've found that this option seems to include at least the modulation generator (option 1E2) and pulse modulation (option 1E6). Stan |
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Re: 8516A cable question
Lothar baier
开云体育Just double checking: you did connect the DB25 cable from the 8516 to the source ? Also what source are you using?On Mar 17, 2022, at 23:07, Lothar baier via groups.io <Lothar@...> wrote:
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Re: 8516A cable question
Lothar baier
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On Mar 17, 2022, at 23:05, Willy via groups.io <ratn9ne@...> wrote:
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
He seems to be asking about DC protection - does RP protection IMPLY DC protection ????
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Quoting Lothar baier <Lothar@...>: BTW the 4438C has reverse power protection but there are a few differences depending on the frequency! |
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Re: 8516A cable question
With the 6 foot cable my system seems to be about 40% working.
From 20-40GHz S12 and S22 sometimes fully work. S11 and S21 only up to ~30ghz works, then the NO IF FOUND errors comes up. Changing the source power has an effect on how far the sweep gets before failing. Sometimes I also get a phase lock error. I notice that the LED on the sweeper source gets very intermittent when the NO IF error shows up. The sweeper has been tested good with a 8515 before this 8516 was thrown into the mix. |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
Lothar baier
开云体育BTW the 4438C has reverse power protection but there are a few differences depending on the frequency!The 4438C was available in 2GHz , 3GHz , 4GHz and 6GHz , versions to 4GHz were protected up to 50W to 2GHz and 25W above 2GHz as well as 50V DC , the 6GHz version used a different attenuator and had no DC protection and could only handle 1W RF ( dont ask
me how i know ?)?
Also while the power handling was 25 or 50W the RPP actually tripped at 1W? On Mar 17, 2022, at 22:31, Lothar baier <Lothar@...> wrote:
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
Lothar baier
开云体育One word to this subject, some generators had RPP offered as option so you might want to double check?On Mar 17, 2022, at 22:31, Lothar baier <Lothar@...> wrote:
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
If component level data is available, look at the diagram and parts list to determine the type of DC protection.
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Cheers! Bruce Quoting Radu Bogdan Dicher <vondicher@...>: Honestly, probably worth its separate topic is how many of these units have |
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Moderated
Re: Recommendation for an "up to 1GHz" generator + sweeper
Lothar baier
开云体育I guess my question would be why you want sweep to begin with ? ?If you want to measure filters than sweeping is only half the rent, you still need some way to display your response in a dB linear format so that brings you to a scaler analyzer or a VNA but most signal generators with sweep function are not compatible with scaler analyzers ! Also I have to point out that the sweep on sig gens usually is a digital sweep which depending on step size can be taking some timeOn Mar 17, 2022, at 22:22, Radu Bogdan Dicher via groups.io <vondicher@...> wrote:
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Peter Hall, VK6HP/VK6MJM
Froggie the Gremlin
RubenRubio
Willy