new Murata dc/dc converters with a ferrite toroid embedded in the PCB

Yeah, we normally have one to three connectors. We really like U.FLs--they have a nice positive snap action, have gold contacts, cost

20 cents, are the size of a SOT23, work up to 6 GHz or so, and have next to no capacitance. Other than that, they stink.k

Cheers

Phil Hobbs

The hexavalent chrome stuff is very good, but has just about been regulated out of existence. The Cr+4 stuff sucks.

Cheers

Phil Hobbs

<snip>

B layout

"Value for money .. value for many..." says it all.

Beings the OP's "look at my cobbled together thing" serves as this thread's theme, here's another peek at my own cobbled contraption:

My webpage needs an update because this guy:

recently replaced the cheap mp3 player. The new board costs only US$3.95 and it runs circles around the old player. You can read about all of the functionality packed into one proprietary chip on my new board. For my purposes - outdoor cycle spins and dog walks - only the 3.5mm output's necessary. Connected to a Sony Walkman MJR-J10, because they reliably stay in place. A few sad old dogs whined about corded earbuds and mp3 players the last time a link to my gizmo was posted. Nonetheless, in the end, my gadget proves out as the best solution for my needs.

Danke,

They are hard to mate and un-mate.

Transmission-line transformer, stock cable assembly:

Beauty might be in the eye of the beholder, but if you lack any aesthetic sense, ugliness is a knife in your back.

Beautiful schematics and boards work better for a couple of reasons. One, they have had more time being beautified and looked at and thought about. Two, they are designed by people who really care about details.

This helps if the person who did the beautification knew what they were doing. Bringing the board proportions closer to the gold mean won't make the circuit work any better

Caring about details isn't getting the fundamentals right. John Larkin doesn't care about design details enough to have any enthusiasm for designing his own special purpose transformers to have exactly the right performance for a particular circuit. Caring about the proportions of the printed circuit board is a less profitable use of his time.

On a sunny day (Thu, 29 Sep 2022 18:08:14 -0000 (UTC)) it happened "Don" snipped-for-privacy@crcomp.net wrote in snipped-for-privacy@crcomp.net:

Ha! I have several of those ! Bought many years ago from ebay... My mp3 player however is a Creative Muvo, 10 hours on an eneloop AAA

That one is new to me... My creative muvo has been working now for almost 13 years...?

idea what I payed for it, bought locally in a store, love at first sight.

Also have a credit card size mp3 / video player from ebay and little credit card size FM radios Some came 3 for a few dollars... Al works.

Interesting links My wall clock:

Mating is easy. Unmating needs a quarter-twist of a small screwdriver under the panhandle (where the cable attaches).

One of their principal virtues is that you can sprinkle them as test points, which gets rid of the usual scope probe problems with pickup and ground inductance. They don't have to be populated in the production boards, and the footprints are small enough to ignore (usually).

Yeah, that's a cute hack I've been meaning tor try out.

Cheers

Phil Hobbs

What's wrong with just a drop of solder? Or are you changing potcores all the time?

Stripping and soldering coax is a lot of labor.

We can buy those "windings" from Digikey. Elegant.

But tx transformers make gorgeous isolated outputs

That was driven by mosfets. We'll go GaN in the future and get more speed and more voltage.

You don't have to strip semi-rigid coax, and there are crimp connectors for it, Of course it is more expensive than regular coax, but it is a lot more uniform.

The waveform looks a bit grassy. Semi-rigid coax might run a lawn-mower over it, if you did it right. Our narrowest pulse was half a nanosecond wide, back in the 1980's and only a few volts high .

On a sunny day (Fri, 30 Sep 2022 07:41:26 -0700) it happened John Larkin snipped-for-privacy@highlandSNIPMEtechnology.com wrote in snipped-for-privacy@4ax.com:

Yes, is that not more reliable? I mean connectors.. seen many problems with connectors I have some equipment with these models but did not feel reliable. Have some problem here with an USB RTL-SDR stick also the RF connector should solder it really.

Works great. Electronics needs connectors.

Cutting, stripping, soldering micro-coax is not easy or reliable.

On a sunny day (Fri, 30 Sep 2022 10:26:15 -0700) it happened John Larkin snipped-for-privacy@highlandSNIPMEtechnology.com wrote in snipped-for-privacy@4ax.com:

Well I never had a problem with RG178 putting on connectors in the right way requires more effort. Do you do this just for the looks of it?? ;-)

U.FL jumpers are very cheap and work very well. We use quite a few.

I wouldn't want to try making one by hand!

Cheers

Phil Hobbs

Didn't you say you were buying prebuilt connectorized cables? Crimping is also not easy, but with the right (expensive) equipment, it's reliable.

Coaxial cable doesn't reflow-solder nicely, even if you wanted to hand-solder, a bit of a preformed collar or wrap for the braid would be prudent. I like to whip ends with a copper strand, like it was a rope, then tin that. Works on stainless steel brake cables for the bike, too, with silver solder.

On a sunny day (Sat, 1 Oct 2022 02:04:44 -0700 (PDT)) it happened whit3rd snipped-for-privacy@gmail.com wrote in snipped-for-privacy@googlegroups.com:

Yes I have a lot of those with SMA connectors to connect things, but only one length, that length would have to be correct for his coils. He could have them made to length in China for large quantities perhaps.

Sometimes higher temperature helps 370 degrees C should work.

Nice, have not tried that. Here an example with RG178:

use that coax for about everything RF, that one makes a tuned antenna from a piece of 300 twin wire, impedance matched. But even my sat dish with rotor uses that cable, it is so thin you do not have to drill holes in the outside wall just goes through the window. that you can then close without problems... PTFE, bit harder to melt the insulation, melting point 327 degrees C, makes soldering easier.

We just buy that cable assembly for $1.54. And pick-and-place the connectors on the board. It's a cheap and easy and reliable.

But it does look cool, got to admit.

Given the need to make a custom transmission-line transformer, this is a great way to do it. This is the isolated high-voltage output option of a pulse/delay generator.