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Re: scope?

 

On Monday 30 December 2024 01:23:05 pm wn4isx via groups.io wrote:
Sight unseen, could the BNC be a reverse BNC?
One where the nominal female has a male stinger?
I've ran into them in the oddest places. The FCC requires reverse BNCs, TNCs, and SMAs on WiFi transceiver and some part 15 900MHz equipment.
They are also used on equipment where a manufacturer wants to lock you into using their connectors.
Nope.

--
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
Re: scope?

 

On Monday 30 December 2024 01:36:25 pm John Kohlbach via groups.io wrote:
Hi Roy, could this be the beastie?

Cheers, John VK4ATU
Without even looking at the link, I'd say probably. A bit of poking around tells me that this thing is commonly referred to as a DSO-138. The two numbers I ran across are apparently two versions of the kit, one with just the main chip soldered, the other one with all of the surface mount parts soldered The unit I have is completely assembled.

Apparently it's good to about 200KHz bandwidth, so I guess it's okay for audio work and some arduino stuff. But that's okay, I have a nice Tek scope on my bench for when it's needed (and I don't remember the last time I turned it on).

There appear to be a lot of people selling these. And one company has a newer version out that's supposed to be better. Finding a case has been another thing entirely, it looks like I'll be getting one from china by way of ebay for not very much money.

So it looks like I have a new toy here. Dunno when I'll do much of anything with it, though. I haven't yet fired it up. I guess we'll see...

--
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
Re: scope?

 

Hi Roy, could this be the beastie?
?
Cheers, John VK4ATU
Re: scope?

wn4isx
 

Sight unseen, could the BNC be a reverse BNC?
One where the nominal female has a male stinger?
I've ran into them in the oddest places. The FCC requires reverse BNCs, TNCs, and SMAs on WiFi transceiver and some part 15 900MHz equipment.
They are also used on equipment where a manufacturer wants to lock you into using their connectors.
?
Re: scope?

 

Photo?

Ken W7EKB

On 30 Dec 2024 at 11:39, Roy J. Tellason, Sr. via groups.io wrote:

I was given this little thing a while back, haven't done anything
with it yet...

There's this board, no particular identifying marks on just what it
is. The oddest BNC I've ever seen on top, some switches down the
left side that seem to be for selecting sensitivity and coupling,
some DC input connectors on the top to power the thing, five buttons
labeled OK, +, -, SEL, and RESET. A couple of pin headers and a USB
micro connector on the bottom. A plug-in board labeled "2.4" TFT LCD.

Two bits of paper came with it. One is labeled Oscilloscope DIY Kit
User Manual but it seems to be assembly instructions. This bears the
numbers 138803K and 13804K, no indication as to which unit I have
here. The other paper has "How to Use" calling out the "Display and
Controls". And some stuff about "probe calibration". On the back of
that one are schematics that are barely readable. With a magnifying
glass I see them showing power input as "9.39V". (!) Apparently some
of this thing runs at 3.3V also.

There's no case, though I'm told that one is available. Not told
where, though.

Have any of you guys run across anything like this? I'm a little
dubious as to how useful this thing might turn out to be, haven't yet
gotten around to digging out an appropriate wall wart to power it
up...


--
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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scope?

 

I was given this little thing a while back, haven't done anything with it yet...

There's this board, no particular identifying marks on just what it is. The oddest BNC I've ever seen on top, some switches down the left side that seem to be for selecting sensitivity and coupling, some DC input connectors on the top to power the thing, five buttons labeled OK, +, -, SEL, and RESET. A couple of pin headers and a USB micro connector on the bottom. A plug-in board labeled "2.4" TFT LCD.

Two bits of paper came with it. One is labeled Oscilloscope DIY Kit User Manual but it seems to be assembly instructions. This bears the numbers 138803K and 13804K, no indication as to which unit I have here. The other paper has "How to Use" calling out the "Display and Controls". And some stuff about "probe calibration". On the back of that one are schematics that are barely readable. With a magnifying glass I see them showing power input as "9.39V". (!) Apparently some of this thing runs at 3.3V also.

There's no case, though I'm told that one is available. Not told where, though.

Have any of you guys run across anything like this? I'm a little dubious as to how useful this thing might turn out to be, haven't yet gotten around to digging out an appropriate wall wart to power it up...


--
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
Re: Latching Relay Drivers

 

¿ªÔÆÌåÓý

Sound's like a great way to go!.
You may find it a easier go to start with Microchips evaluation kit for the AVR-1 product...it will greatly speed your development time by relieving you of tedious hardware design/debug just to get started.



On 12/30/2024 6:01 AM, SheldonD via groups.io wrote:

After much research looking at "single momentary input toggle output" latches based on the 74hc74, inverters, 2In Nand, mosfet / bjt, and variations of other flip flops, I have decided using gates for this little project is absolutely for the birds. Time for this old dog to learn some new tricks.

Found TinyAVR212 / ATTiny212 at a cost of sub 50cents in qty, half that using knock offs. 8pin package, can (theoretically) get 3 latches out of 1 package though only 2 can be interrupts.

Re: Latching Relay Drivers

 

After much research looking at "single momentary input toggle output" latches based on the 74hc74, inverters, 2In Nand, mosfet / bjt, and variations of other flip flops, I have decided using gates for this little project is absolutely for the birds. Time for this old dog to learn some new tricks.

Found TinyAVR212 / ATTiny212 at a cost of sub 50cents in qty, half that using knock offs. 8pin package, can (theoretically) get 3 latches out of 1 package though only 2 can be interrupts.

The 8- and 16- channel relay boards I have been considering have a big brother in form of opto-coupling. Sweet! As long as can sink 25ma-ish current, will be golden. Gone will be the several square inches for ic area and associated discrete. Might need a n-mos follower, but may be able to work around it.

Discovered some variations of the T latch I was looking for, is created from SR, JK, and D ff. Essentially tying Q' to input via AND creates. Since T input wasn't going to be used, it would have been tied high, so direct connect of Q' to T was viable. Then just strobe the clock. Did utilize CLR' function (certain packages) through resistor / cap for power-on Q of 0. Debounce was increased to 500mS (for noise and transients) or so before I realized I can invert the clock. That solved a few problems. Found packages with active low clocks, eliminated noise and transient problems. Had some timing issues, solved with Schmidt trigger on clock. Found a blown diode on bridge in my power supply causing an excessive amount of ripple. Was likely contributing to timing issues as well.

Could have continued doing all of that, or accomplish similar function with (anticipated) a few lines of code and possibly a single 8 pin package for 3 latches.

Yup, time for school. New tricks to learn.

~SD
Re: testing for mixer saturation without datasheet purely lab reading

 

Hello, I am using this mixer as a phase detector in a PLL? used? in down converting.
I got a matlab plot of the Error voltage as a function of frequency(A and B pint in the diagram).
from this error signal I need to know what controller to do.
How can I know that my mixer is acting good as a phase detector when I look at the error function diagram?
Thanks.

/g/electronics101/photo/296358/3865523?p=Created%2C%2C%2C20%2C2%2C0%2C0
?
Re: A short discussion and a couple of USB questions

wn4isx
 

In my situation, just about the time I was ready to order an analyzer software package the company came out with V2.0 drivers which solved the problem.?
?
Re: A short discussion and a couple of USB questions

 

On Saturday 28 December 2024 03:15:39 am wn4isx via groups.io wrote:
A lifetime ago I intercepted RS-232C data from a data terminal to satellite control system to "Roll my own
terminal program." I'd hoped USB would allow similar data sniffng, but you clearly have to know exactly what you are doing to examine the data packets between a PC and device.
It was? a useful lesson in the limits of my knowledge.
Have you looked at that little analyzer that I mentioned a while back? Check out sigrok.org, the thing cost me under $20 and has a *LOT* of different protocols that the software (pulseview) understands. The video at details what the thing can do in one specific instance, I2C. Take note when he hits the dropdown that allows you to select which protocol you want, USB is in there.

Mine is a different brand than the one he got, but it's otherwise the same. Yes, you can do USB sniffing to find out what's going on.

You should get one of those. :-)


--
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
Re: A short discussion and a couple of USB questions

 

On 28 Dec 2024 at 10:34, Gooey via groups.io wrote:


Ken:

Does this help?
Look at the fifth image in the description.
Yes. It does. That photo tells me that what I am trying to work with is a HighSpeed cable, and
that what I need is a simple standard cable.

That photo is exactly the same as the cable I am working with. There are two "extra" pairs of
shielded wires included in that cable. Although I don't know this (yet) for certain, I suspect
those are wired in parallel with other standard wires, possibly the data cables.

I'll find out soon enough.

I will also go to one of the local "surplus" stores and try to find a standard low-speed cable.

Thank you for the photo.

Ken Gordon W7EKB



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Re: A short discussion and a couple of USB questions

 

Ah USB 3 has the same 4 wires as USB 1 & 2 plus 4 extra ie 2 twisted pairs, sort of thing used for differential and screened too ie very high speed.
A short discussion and a couple of USB questions

 

Ken:

Does this help?
in the description.





--
G.T.


--
G.T.
Re: A short discussion and a couple of USB questions

wn4isx
 

I meant to add, are you sure you have genuine USB chips? There are a lot and I mean many counterfeits on the market that almost work right. Look up USB FTDI fake or counterfeit.chips. The fakes can cause all sorts of problems, And they show up in respected units.
?
I think there are programs to examine your chips to determina "Real/fake."
??
Re: A short discussion and a couple of USB questions

wn4isx
 

My primary radio and lab PC are HP Elitebooks and each needed to communicate with USB devices, SDR radio, USB oscilloscope, a USB capable DVM. The PCs are on a narrow shelf with no room for regular USB-A connectors so I purchased 6" USB extensions off Amazon (or Ebay, it's been 4 years).
I needed a USB breakout box so I used one of the spare 6 inch extensions, cut it in "half" and wired it to a scrap piece of Veroboard with turrant style "pins"
The grounds and V+ go to single pins, the data V-/V+ go side by side pins located 1/10" appart with solid 22AW tin plated copper wire. This way I can look at the normal data on a scope, and, if needed, intercept it.
?
I was hoping to troubleshoot a Bearinger USB audio interface that will occasionally get confused and lock up.
?
Clearly I don't know enough and the plan was a bust, but these cables had
Shield (aka drain)
Black V-
Red V+
Twisted pair
Black Data V- Standard is green?
White Data V+ Standard is white
?
This is similar to what I found.
?
You might want to try another cable, go a used thrift store, you can pick up USB cables for a dollar or less.
?
A lifetime ago I intercepted RS-232C data from a data terminal to satellite control system to "Roll my own
?terminal program." I'd hoped USB would allow similar data sniffng, but you clearly have to know exactly what you are doing to examine the data packets between a PC and device.
It was? a useful lesson in the limits of my knowledge.
?
I eventually learned the original drivers for the USB audio device were buggy, V2.0 solved the problem.
?
?
USB won't tolerate much extra electrical imbalance and, if the motherboard is set up to use the data lines backwards, the pull up resistors might cause trouble.
Intel has several detailed papers on USB
?
?
USB 3 wiring is very diferent from USB 2
I've never messed with the wires in a USB 3 cable.
You can generally use USB 2 cables on a? USB 3 port but not always. My wife's Dell Opttrash Windows 10 PC has 2 USB 3 ports, one works fine with USB cables, the other only works with USB 3, the user manual doesn't mention this and Dell tech support is non-existent.
??
?
?
?
A short discussion and a couple of USB questions

 

¿ªÔÆÌåÓý

Hello:

I am Ken Gordon, am now 82 years old, and have been involved in electronics since I was 13 years old in 1956.

So, recently I have been involved in "Elmer-ing" a good friend who is not particularly adept at electronics.

I have been helping him get his ham station operable on digital modes. He bought a new Acer laptop to use for these modes. While trying to get Fldigi installed, we discovered that his Acer laptop's USB ports' two data lines are reversed from all others we have dealt with up to this time: i.e. Data - (minus) and Data + (plus) are "reversed" in his new machine.

This, apparenty, doesn't matter when those lines are used for USB devices such as a mouse or a USB powered CD drive, but that DOES matter when those data lines are used to pass audio to/from the computer to the digital interface (in this case either a SignaLink or a DRA device).

I thought it might be easiest for me to make him a short jumper cable out of a short USB extension cable by cutting it, and "cross-wiring" those two data lines.

However, upon opening the cable, I find not 4 (or 5) wires, but a total of 11, 3 of which are obviously grounds.

I have not yet been able to "ohm-out" the wires vs connections since I must make a needle-point adapter for my VOM, but in the meantime, here are the wire colors.

First, separate black, white, green and red. These should be the standard + and - 5 V and Data + and Data -

But there are two "bundles" of other wires, These "bundles" contain a slim bare wire and two other thinner wires, pink and purple in one "bundle" and blue and yellow in the other.

Might anyone here have a clue as to what these are, or how they are wired?

Ken Gordon W7EKB

Virus-free.
Re: testing for mixer saturation without datasheet purely lab reading

wn4isx
 

Can't answer the first question but as for the second.
Monitor the output with a spectrum analyzer, take care to protect input!
Increase drive level until more drive doesn't cause a corresponding increase the output.
For instance, at some point, say a 2dB increase on the input for a 1dB increase in output.
You've reached the compression.
Be extremely careful not to overload the input to the spectrum analyzer!!!!!!!
I fried a nice Tektronix back in school. To be fair, I was following the exact instructions of the professor, he neglected to place an attenuator in line.
?
Don't let the magic smoke out.
testing for mixer saturation without datasheet purely lab reading

 
Edited

Hello,I have the following old mixer called TXF-18075 which I want to test for saturation and power levels in down converting mode.

I dont have any datasheet only this brief table I found.Unlike amplifier A mixer needs two input powers the RF and LO.

How can I see In my lab two things:

1.What is the needed LO power?

2. How can I see mixer saturation using lab equipment?

Thanks.
/g/electronics101/photo/296358/3870599?p=Created%2C%2C%2C20%2C2%2C0%2C0
Re: "Higher Superstition: The Academic Left and Its Quarrels with Science" (book title)

wn4isx
 

Consider
"A pair of Maher¡¯s speeches have been making the rounds on social media, and not without good reason. In her talking points, Maher says that? is a stuffy, antiquated, and culturally-constructed notion that must give way to the mature, enlightened view that there are ¡°many truths.¡± This is pure subjectivism of a rather bland and unsophisticated flavor. I¡¯ve definitely tasted more gourmet (though still poisonous) versions of this stale philosophical dish."

?

?
Hum, when I add 2 and 2 I get 4, not sure how there can be various versions of that truth....
I guess the designers of the collapsed Florida bridge followed the many versions of the truth.
?
I suspect technical types and non technical types will always be on opposites of a big divide.
My wife is an artist, more conservative then me [Yea hard to believe], she's also very savvy technical, rebuilt her own VW engine, on her own except for boring the block for the crankshaft (which is the standard way).
She's into quilting and has learned to not bring up any technical anything at quilting circles...
"Most women there treat logic like works of Satan."
?
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