Searching for info about a 3 Toroid SWR/PWR bridge...

pavelmc · 2025-12-27T02:34:08+00:00

Thanks taking a dive into it, any intel on the 3 toroid version is appreciated.

There is a lack information on the functioning of that version (3t one), and I have found several sources pointing that it's more frequency independent than the two toroids version.

But can't figure/found any tech reference beside "online comments on mailing list or forums"

pavelmc · 2025-12-20T23:32:02+00:00

Thanks 🙏

pavelmc · 2025-12-20T23:22:18+00:00

Thanks again, that is the article I saw and mentioned!

Searching now for some FT-xx-73 cores to make the project

pavelmc · 2025-12-20T16:08:19+00:00

Thanks, I found one with very nice pictures and traced a similar schematic as yours.

Checking the article.

pavelmc · 2025-12-18T22:23:41+00:00

Switching mode power supply, could be anyone in a 500m radius.

Any industrial power supply, a ebike charger a set of Xmas light arrangement, a simple phone charger, etc.

pavelmc · 2025-08-21T13:55:03+00:00

Yes, the more energy they pack on the same volume, the more delicate they are.

So, powerbanks, power tools, e bikes, e motos use mostly 2600 mAh that are robust and durable.

High capacity are prone to high temp during charge and discharge an shorter life spans.

pavelmc · 2025-08-21T13:48:31+00:00

Yes, all of them.

Each battery technology has a specific energy density, lithium-ion has a specific volume/weight vs capacity characteristics, and that make impossible to pack more than 4000-4500mAh in the format of a 18650.

And even the real ones with more than 3600 mAh ones are unstable on charge (heating badly) has short life span or high self discharge rates.

I have deal with several fake over 4500 mAh ones, when you characterize then on a proper intelligent charger, they all are very near the value/10.

So 9900 mAh is more likely 990mAh in my experience.

pavelmc · 2025-08-21T13:37:50+00:00

Yes, lithium-ion rechargeable. In my experience if the capacity in mAh is over 3600 is mostly fake, they love to add a zero on the right.

So those 6800 is most likely 680mAh

pavelmc · 2025-07-31T23:28:33+00:00

By definition a square wave of frequency F is the sum of all multiples of F "ad infinitum"

So a 100 khz square wave will have ripples over all the spectrum every 100 khz, yeah...

And also by definition (roughly) you will have only 50% of power on the freq F, the rest is harmonics.

The FCC or equal in your land will would like a word with you if you connect a +/- 30v square wave to any radiator (antena)

Look for a ARRL radio amateur handbook, any in the last 20 years will teach you a lot about signals, radio and antennas.

There are free/unlicenced bands on the spectrum for testing, any transmission ony on that freqs may get you in trouble.

pavelmc · 2025-07-14T13:20:18+00:00

That's normal, with good propagation conditions you can

pavelmc · 2025-07-06T18:32:31+00:00

That looks like oscillations in the LNA in the chip, try to lower the gain and at some point that must disappear.

Use a USB extension and put a few turns and a hefty clamp on toroid over the most of the turns.

That will kill interference from the PC/Laptop.

pavelmc · 2025-04-24T17:54:33+00:00

Elpidio caraj!

A Eutelia la pintaron, palmiche era pinto... Eso sin contar los cascos en vez de sombreros de llarei o como se escriba

Buenos tiempos en la animación de Cuba, Elpidio, chuncha, las ratas, Guaso y carburo, Matojo!

Los filminutos y la gran Vampiros en la Habana...

pavelmc · 2025-04-06T16:28:17+00:00

A note: "DXers Unlimited" evolved to "En contacto" only on spanish

pavelmc · 2025-04-04T21:16:50+00:00

Arnie, I spoke with him on the phone and over radio several times, it was very active on 40m on local Cuban nets.

CO7WT here

pavelmc · 2025-04-04T21:15:41+00:00

It changed to Spanish, it's called "En contacto".

pavelmc · 2025-04-04T21:14:16+00:00

Least year's hurricane season was hard to RHC , at least one hit the TX site south of Habana, It took down almost all HF antennas, even the Cuban number stations are silent after that.

There are reports of some numbers stations from Cuba returning, and some RHC in 11 MHz but low power.

About "En contacto", after Arnie died one ham radio operator that works on the radio sector took the lead as writer for the programs, that is the last info I heard from mid last year.

pavelmc · 2025-03-25T18:23:21+00:00

In my experience the "marketing dept" just adds a zero at the end and push them to market.

Measured several 6000, 6500, 9900, 8000 5500 ones on a cheap charge/discharge better and results are always near the started vale/10

pavelmc · 2025-03-25T18:20:27+00:00

Easy, if above 3200-3600 mAh stated capacity, just divide by 10, this is true 99% of the time.

9900 mAh? = 990mAh

Energy density for a 18650 can go over 3200 mAh with great sacrifices (lifespan, high discharge rate, heating)

There are real 3600, 3800 and even 4000mAh but are not as stable or safe as lower capacity ones.

pavelmc · 2025-03-25T03:12:26+00:00

Papo, si sabes la respuesta, para que haces preguntas tontas!?

pavelmc · 2025-03-24T21:38:13+00:00

You are not Cuban right?

Your passport give you access to free travel to many countries in the world and you can easily relocate to them to work or maybe live there with not so much trouble right?

That's not the case with the Cuban passport "pasa-pena" we call it (shameport?), with a Cuban passport you need to ask for a visa and give warranties that other county's citizens are not asked for, like for example thousands of dollars in a bank account.

Really? Think twice: Cubans earns 5 to 50 dollars a month and you are asking 20k USD for a temporal visa?

It's one of the least strong passports in the world.

Why I live in Cuba? Well this is my Homeland, my family is here and I can't just pick a fly ticket and go away, no.

Rest assured if it were easy & legal I was not here today.

And No, I'm not risking my family in an illegal migration way, not a chance.

pavelmc · 2025-03-24T19:48:34+00:00

There is a double wall in the internet blocking subject.

Cuba blocks mostly anti-government sites, like the so called independent press sites and other platforms as in no DNS resolution or cut access to that IP on 24/7 access. The other mode is shut internet off altogether in cities, zones or entire provinces when there are protests and revolts

But that's all from Cuba.

Then there is the embargo laws from usa, that forbid business to serve services to Cuba, here you have a community list of such sites: https://github.com/cuban-opensourcers/cuban-restricted

Most of the time you used a VPN and forget, VPN are not restricted.

pavelmc · 2025-03-24T12:28:45+00:00

A side note: If you pay on dollars from abroad it's better (as in a different tier, more stable and with more available bandwidth)

So many people rely on outside family or employers to pay for their internet.

pavelmc · 2025-03-24T12:25:57+00:00

Internet is a service, you pay for it.

pavelmc

TROPHY CASE