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Re: proper way to connect single ended to differential circuits
On Tue, Feb 25, 2025 at 07:34 AM, john23 wrote:
I think you can figure that out. ?
Andy
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Re: Batteries
On Wed, Feb 26, 2025 at 07:39 PM, wn4isx wrote:
I wondered when you might go there!? :-) ?
My only experience with vibrator power was in the automobile's radio which of course used vacuum tubes (late '50's).? We almost never turned it on.? I think the reason was fear that it would fail about every 5 times it was switched on, and nobody likes bringing the car to the service station to fix the darned radio AGAIN.
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At first I thought you were taking this topic in the direction of flashlights.? I remember my dad's big metal flashlight, which had five (yes, five) "D" cells to power one 6 Volt bulb in a big reflector.? Now wait a minute.? That's 7.5 V, powering a 6 V incandescent bulb?? To be sure, the flashlight was very bright.? I think we know why.
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Were incandescent bulbs rated in such a way that you could run them about 25% over-voltage and they happily worked and didn't give up the ghost?? It seems like a great way to make a super bright flashlight but one that went through bulbs faster than it did batteries.? And yet it did not burn out its bulbs.? It makes one wonder.? Maybe it drew so much current from the "D" cells so that their nominal voltage dropped significantly?? I wonder.
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Back to batteries.? My first exposure to NiCads was the HP-35 calculator in about 1972.? All I knew about NiCads was that NASA had experience using them in satellites, which is where they learned about their dreaded? "memory effect".
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Might be worth looking into, even at my age.
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Wow, there are so many new battery technologies - every month or so - that have 1000 times the capacity of last month's invention, so that surely by now they must be capable of powering an entire city for a year on one simple set of rechargeable batteries.? Yeah, right.
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Andy
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Batteries
wn4isx
OK I am weird, as a 3 year old (1954) I'd swipe my father's WWII MX-991/U flashlight. This is the standard right angle headed unit. I'd hide in closets, under the sink, under beds, in the small room the water heater sat in (under the stairs) and enjoy the light in the dark. Dad was frustrated, "D" cells weren't horribly expensive, but he grew tired of having to keep a supply. Mom took the view point "At least he's not using candles." A friend of Dad's worked for GE and gifted our family with early NiCad cells and a charger. Dad bought me my very own MX-991/U and I'd sit in the closet and listen to my "Boys Rocket Crystal Radio." My maternal grandfather gave me a very old Prango 2 "D" cell flashlight with a patent date of Sept 28, 1915. This unit uses a small silver plated "parabolic" reflector with a large glass lens. Thus began my collection of flashlights.....a collection continues to grow, I've never met a flashlight I didn't like. All of this is of historic interest and perhaps offers a view into my somewhat odd psyche, but what on earth does it have to do with Electronics 101. ? I could go into the vibrator powered electroluminescent light my dad built for me, or how my uncle replaced the vibrator with a pair of germanium power transistors, or how I made my first LED flashlight, it used red and green LEDs and either or both could be enabled, but I won't. ? [And for you with dirty minds.... https://en.wikipedia.org/wiki/Vibrator_(electronic)] ? Your portable electronic gear operates from batteries, unless you have a hand held generator or can operate off PV cells in direct sunlight. ? A friend gave me an interesting book. This book is almost mandatory for those of us who operate equipment from batteries ? Batteries in a Portable World: A Handbook on Rechargeable Batteries for Non-Engineers, Fourth Edition? ? It is available at Amazon (and at the ARRL), it is a bit expensive at about $30. ? I still distrust secondary (rechargeable) lithium batteries, but they are a factor of modern life and, unless I wish to give up my cellphone, laptop PC, portable equipment, I have no choice but to learn to live with the !@#% things. ? The book starts out with the basics of batteries and might appear too basic for a serious hobbyist, but it gets down to brass tacks with reasonably detailed information on many different types of batteries, their strengths and weaknesses. And all batteries have both. ? ??? |
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Re: inexpensive 600/600 ohm AF transformers
On Tuesday 25 February 2025 03:04:08 am Nuno T. wrote:
Such transformers, with, and without CT, can be recovered from old computer modems add-in cards.Yup, that's where I got a number of them. "Winmodems", which are absolutely useless to me. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: proper way to connect single ended to differential circuits
Hello Andy,In the attached folder there is the united circuit where the PID and the driver I chose.
I grounded one of the input legs of the differential driver.
The driver is desscribed in the link.
You said that "? A transformer is one pretty good way, but it is AC only.? A simple inverter is another"
My driver is suppose to pass a PID controller behavior. What device you reccomend to connect the two?
Thanks.
https://www.analog.com/cn/resources/technical-articles/adsl-line-driver-receiver-design-guide-part-two.html
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Re: inexpensive 600/600 ohm AF transformers
wn4isx
These were new old stock and I didn't have to desolder a bunch of transformers.
I'm as cheap as the next guy, but, at 73 I have to balance the value of my time on this side of the grass against the cost of just buying something and finishing a project that has been hanging on some design changes my friend couldn't decide on, so I decided for him, he can have someone else modify my design if he wants.
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Re: inexpensive 600/600 ohm AF transformers
¿ªÔÆÌåÓýSuch transformers, with, and without CT, can be recovered from old computer modems add-in cards. ? Nuno T. ? From: [email protected] [mailto:[email protected]] On Behalf Of wn4isx via groups.io ? First, I have no financial stake in Electronic Goldmine, I'm just a satisfied customer. ? I needed some transformers for a special project and Electronic Goldmine started offering these. ?Microtran Pico Transformer PM34-M Miniature 600 Ohm C.T. to 600 Ohm C.T. 50mW Rating"Microtran Pico transformer type PM34-M is a miniature fully encapsulated 50mW rated 600 Ohm C.T. to 600 Ohm C.T. transformer. Frequency response is ¡À2db 300Hz to 100KHz. Has 6 full length leads. Size only 0.3" x 0.4" x 0.425" tall. New" at ? https://theelectronicgoldmine.com/products/g28678 ? Full specs can be found here https://www.technicalaudio.com/pdf/MicroTran/Microtran_miniature_transformers_catalog_1974.pdf ? Electronic Goldmine offers surplus, new old stock, components and probably doesn't have oodles of these. ? 60Hz appears be just over -3dB. YMWV depending on your system. Short pulses of 1 cycle or 1kHz show minimum ringing. ? These could be ideal for coupling a computer to a ham/shortwave radio, PA, or other interface needs. ? ? -- Nuno T. |
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Re: proper way to connect single ended to differential circuits
On Sun, Feb 23, 2025 at 07:41 AM, john23 wrote:
Not enough information. ?
Depending on the differential input circuit, and on its CMRR, it may accept single-ended inputs directly.? Apply signal and ground to the differential input pins.
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There are ways to actually convert a single-ended signal into a differential pair, should that be necessary.? A transformer is one pretty good way, but it is AC only.? A simple inverter is another.? You can get more fancy about them, but these are simplest.
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Since your "diff" input circuit drives a transformer primary, it probably has excellent CMRR.
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Andy
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Re: inexpensive 600/600 ohm AF transformers
wn4isx
I gave quite a few suitable transformers of mixed heritage.
But, I was building a project for a friend and decided using the same transformers would make life easier for someone else down the line, probably long after I'm gone. I even included 4 spare transformers. |
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Re: inexpensive 600/600 ohm AF transformers
On Saturday 22 February 2025 05:52:07 pm wn4isx via groups.io wrote:
First, I have no financial stake in Electronic Goldmine, I'm just a satisfied customer.I got that when you brought it up before. I needed some transformers for a special project and Electronic Goldmine started offering these.Not bad for communications gear, but for more general audio uses that lower end of the frequency response is pretty pitiful. Electronic Goldmine offers surplus, new old stock, components and probably doesn't have oodles of these.I did take a look at their site, lots of interesting junk there. But I really need to deal with the junk I have here first, I think... 60Hz appears be just over -3dB. YMWV depending on your system. Short pulses of 1 cycle or 1kHz show minimum ringing.Noted. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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inexpensive 600/600 ohm AF transformers
wn4isx
First, I have no financial stake in Electronic Goldmine, I'm just a satisfied customer. ? I needed some transformers for a special project and Electronic Goldmine started offering these. ?Microtran Pico Transformer PM34-M Miniature 600 Ohm C.T. to 600 Ohm C.T. 50mW Rating"Microtran Pico transformer type PM34-M is a miniature fully encapsulated 50mW rated 600 Ohm C.T. to 600 Ohm C.T. transformer. Frequency response is ¡À2db 300Hz to 100KHz. Has 6 full length leads. Size only 0.3" x 0.4" x 0.425" tall. New" at ? https://theelectronicgoldmine.com/products/g28678 ? Full specs can be found here https://www.technicalaudio.com/pdf/MicroTran/Microtran_miniature_transformers_catalog_1974.pdf ? Electronic Goldmine offers surplus, new old stock, components and probably doesn't have oodles of these. ? 60Hz appears be just over -3dB. YMWV depending on your system. Short pulses of 1 cycle or 1kHz show minimum ringing. ? These could be ideal for coupling a computer to a ham/shortwave radio, PA, or other interface needs. ? ? |
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Re: CTI OCXO type OSC5A2B02
On Saturday 15 February 2025 11:26:30 am wn4isx via groups.io wrote:
I've used these in a variety of projects and never been dissapointed.I don't know specific numbers offhand, but I have a whole pile of those "canned" oscillators in various frequencies. The kind where you plug 'em into an IC socket. I assume that two opposite corners are for +5v and ground and one of the two remaining pins is the output. I'm also assuming that most of these put out a square wave, though I haven't checked. What kind of things do you find those useful for? Most of the ones I have are NOS, but I've pulled a few off of MBs and ISA video cards. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: poor/distorted tx audio
On Friday 14 February 2025 04:43:42 pm wn4isx via groups.io wrote:
I typically place a 10k metal film resistor across both primary and secondary to inhibit ringing. These values worked for me but might need to be tweaked depending on your setup.I don't recall what value my friend suggested, and it was a *long* time ago... Ringing can be extremely difficult to see on a standard, phosphor, scope, a DSO or storage phosphor scope might be required. And you'll probably never hear it because the ringing only lasts a cycle before rapidly fading to nothing.I used to see it all the time with my Tek 2246 when troubleshooting stuff like the c64. Probably because I was using the longer ground lead on my probe. It was a surprise to me that the darn thing worked at all with how dirty those signals were. This can be a real killer for modern RF data formats,I have yet to play with any of those. Hell, with no antennas up and only having one in the cars I haven't been on the air in ages. Never mind getting into all of that stuff. Oh I never meant to imply that you needed a Jensen shielded transformer, in most cases you won't, but there are ham shacks with enough magnetic field strength only a premium transformer will work and they are obscenely expensive. Hence, the "rob a bank" snark.I'll keep that in mind if I ever get any reports of hum or similar on my signal, if I ever get back on the air again. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: poor/distorted tx audio
On Friday 14 February 2025 04:32:40 pm wn4isx via groups.io wrote:
On Fri, Feb 14, 2025 at 01:55 PM, Roy J. Tellason, Sr. wrote:Okay, that makes sense...The winding are separate, one inside the other so it has shorter turns and a lower resistance, the other is outside and has longer turns so it has a higher resistance. This data can be used as your friend, feed your output signal to the higher resistance and take your signal from the lower, this way the lower resistance is shielded to some degree by the outer winding and will >probably< pick up less stray noise.I wouldn't have thought to do that, either. I'll have to check the ones I salvaged, and see what they measure. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Re: CTI OCXO type OSC5A2B02
wn4isx
On Sat, Feb 15, 2025 at 09:42 AM, Sam Reaves wrote:
I don't remember if they are square wave or sine wave but you could filter the square to a sine if needed.Epson offers sine, triangle and square wave, though not all waveforms are available on all models. They have reasonably low phase noise, I wouldn't want to use one for a VHF digital data mode, but for most applications they are very good.
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Turn around time is 1 to 2 weeks.
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I've used these in a variety of projects and never been dissapointed.
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Re: CTI OCXO type OSC5A2B02
The crystal in these has a very special cut (SC? IIRC) that has a temperature curve that is very flat in the operation area as compared to the commonly available AT cut. The parabolic curve slope broadens out as compared to the AT. This way the oven temperature control does not have to control the temperature quite as precisely to achieve?the desired results. Perhaps if you could get the appropriate crystal and knew the?oven operating temperature?it could be made to work. They are outstanding 10MHz OCXO's?if?you don't get one where the crystal has aged out of EFC range. There are programmable oscillators available from Digi-Key that they will program for you to a specific frequency. I think SITime makes them. I don't remember if they are square wave or sine wave but you could filter the square to a sine if needed. Sam Sam Sam Reaves
ARS W3OHM
Owner / Moderator of: LeCroy Owners Group on Groups.io Sencore Owners Group on Groups.io Sprint Layout Group on Groups.io?? Pulsonix EDA Group on Groups.io LPKF Owners Group on Groups.io
Electronics and Mechanical Hardware Design Engineering Manager Staff Scientist Andritz Rolls Global Research Center (RETIRED) On Sat, Feb 15, 2025 at 8:07?AM wn4isx via <wn4isx=[email protected]> wrote:
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Re: CTI OCXO type OSC5A2B02
wn4isx
A friend tried this and the answer is .... Nope.
Opening the sealed metal case is a challenge, Joey destroyed 4 before he succeeded with number 5.
Everything inside is supper small surface mount, including the crystal. And they don't use lead-tin solder, probably used silver solder.
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What frequency do you need?
Is there anyway to get it with a divide by chain or device by chain with a PLL with divide by chain for multiplication.
For instance, I needed 60Hz, so I divided down to 20Hz, used a PLL with a divide by 6 in the loop to multiply by 6 to get 120, followed with a divide by 2 to get 60Hz.
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Sam Reaves