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DaveTLV boosted

@Surasanji Yup. It's a minimalist set up because I want to keep it as clean as I can, but I wanted to use the elements to give it some texture.

DaveTLV boosted
DaveTLV boosted

Ok, made some updates to the previous mock that I think I like enough to build.

DaveTLV boosted

sometimes people just WANT to be angry and thatโ€™s some bullshit

Not a joke, by the way. Completely serious.

Friendly reminder that DARTZ vehicles once offered seats upholstered with the foreskin leather of mink whales.

DaveTLV boosted
DaveTLV boosted

Finally completed the 6th and final directional Coupler utilizing all the tricks I learned from the series. She is beautiful isn't she.

Wanted: Butler

Role ideal for enthusiastic animal who doesn't mind wearing clothes.

DaveTLV boosted

I published the small fix when opening details of a toot (nothing was clickable). It's available in 1.65.2 #Mastalab

DaveTLV boosted

Half of the final prototype for the directional Coupler complete. Isn't she pretty!

Cat Update:

My cat is still fantastic and I love her more everyday.

This has been your cat update.

DaveTLV boosted
DaveTLV boosted

Ok, so you log into Fipamo and this is the opening screen. Thoughts?

DaveTLV boosted

Extremely cool joke Show more

DaveTLV boosted
DaveTLV boosted

@Surasanji While it does have a shield, that would be true of anything carrying an RF signal really. But yes in this situation the outside of the boxes you saw do act as shields.

But aside from that it is not a "shield" just happens to use one. The shield isnt too important for the operation other than to make the output a bit cleaner. It actually works more like a transformer.

There are many ways to build a directional coupler. In my case I'm using a circuit called a "Tandem Match" circuit. Its basically two transformers. One on the main line carrying the high power (up to 1500W in this case). That transformer is a 1:20 ration with the "1" just being the high power line running straight through the middle of the toroid, and the toroid having the 20 turns around it. this is matched on the other side with a "mirror image" between the two coupled ports (the ones where a smalls sample of the forward and reverse waves come out). In this case however the transform is reversed from the direction it was in on the main line. The two transformers balance each other such that the main power line doesn't get effected very much so the DC wont disrupt the existing signal in any meaningful way (though it will loose a tiny bit of power). The two transformers also serve to "sense' voltage and current seperately.

This then spits the waves out the two smaller ports in a rather clean way.

Now WRT shielding there is some special shielding going on here that you wont usually see. It doesnt result in the actual function but as i said just makes the signal cleaner. Youll notice in all of my designs the thick wires running through the center of each toroid has a wire mesh around the outside and is grounded ONLY on one end. In addition in the copper case based designs there is an additional vertical wall separates the two toroids, this is another level of shielding.

Also a sort of form of shielding is the fact that the two toroids are positions at 90 degree angles to each other. This eliminates some parasitic inductance (not capacitance) and prevents the two transformers themselves to affect each other as inductors would (instead of as capacitors).

It would work fine with none of this shielding it would just be less predictable (it would respond to slight changes in frequencies by slightly changing its sensitivity a bit). That because when you have two wires running near each other they accidentally create a very low value capacitor between them. This is called "parasitic capacitance" and is undesirable and causes the issues. all this extra shielding i just mentions eliminates a lot of parasitic capacitance and gives a really clean output.

Thats why i didnt go to the same lengths of shielding on the silver boxes. They were prototypes so not worth the effort. Its only on attempts at final designs (the copper boxes) I add the extra level of shielding to create a final product.

DaveTLV boosted

@Surasanji A directional coupler itself seperates out electrical waves traveling in opposite directions down a wire into the forward and reverse components so they can be analyzed. This alone is useful for things beyond just radio.

the purpose for me however is as a component to my ROES meter I've posted before. You seperate out the waves going to your antenna from your radio, and those moving from the antenna to the radio (the ones reflected back by the antenna). By comparing these two waves using specialized chips in the ROES it is possible to analyze the efficiency of your antenna as well as know what you have to do to improve your antenna system (how to get your antenna to transmit more power rather than to waste it).

DaveTLV boosted

Punisher season 2 drops tomorrow, so that means I have to binge season 1 today, right?

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QOTO Mastodon

Welcome to the QOTO instance

QOTO: Question Others, Teach Others

A Mastodon instance for scholars in Science, Technology, Engineering, and Mathematics (STEM) and all yearning to learn.

A free speech space. No censorship here.
We do not silence or block any instances.

Unique Features
  • Inline math Latex support - Use \ ( and \ ) for inline LaTeX, and \ [ and \ ] for display mode.
  • 65,535 character limit for toots (usually 500)
  • 65,535 character limit for profile bio (usually 160)
  • Full text searches - usually you can only search hashtags and usernames
  • Halcyon / Twitter clone front-end - Want the interface to look exactly like the Twitter interface? After you signed up just go here to login:
  • PeerTube - We host our own PeerTube server with open registration for up to 100MB, but all of our active users get unlimited quotas. Sign up here:
  • Professionally hosted with nightly backups
  • light modern theme with full width columns (not fixed)
  • Several extra themes - including mastodon default and mastodon default with full width columns (not fixed)

Message to New Members

Welcome to the Qoto Mastodon instance, its like twitter but better!

Please don't hesitate to Direct Message me or tag me in Toots (what we call tweets here) if you have any questions or even if you just want to chat.

If you are new to Mastodon you may want to check out this official getting started guide:

We are a free speech, no censorship zone. Feel free to talk about whatever you want, say whatever you want, as long as it is legal you wont ever get banned from the server. With that said we do have a few rules: No spam, and no using multiple accounts to circumvent personal bans.

This server isnt a typical mastodon server either. I have personally modified the code on this server to give it several unique features you wont find on other servers.

If you are new to Mastodon here is some useful info.

First off, if your coming from Twitter and you'd prefer an interface that looks exactly like twitter, then just go here and login with your Qoto credential: No need to create an account there, your account on this server will work just fine. Just enter your username in the following format @[username] so for me it would be @freemo But personally I think our default skin here is way better.

Basically Mastodon is a decentralized twitter. That means anyone can run a server (like Qoto) that people can sign up to and use just like twitter. The unique part is how the servers talk to each other.

If you want to tag someone on the same server as you then you can just do @user however if you want to specify someone on a different server you can do @user@server. If someone follows you or mentions you on any server on the internet you'll get notified right here. So my full tag is

So now a bit about the timelines, there are three (unlike twitter there is just one): Home, Local, Federated.

The Home timeline is just like what you'd expect on twitter, that is, everyone you are following.

The local timeline is any post made by anyone on your local server.

The federated timeline is what is cool. It combines the timeline of everyone on the server into one. This way you can see the posts of everyone that is followed by anyone on the server (assuming the post is public). So this timeline is a close representation of everyone on the internet who has Mastadon (though not really). Moreover we have a bot here that goes around and federates with everyone it can find, so our Federated Feed is rather robust covering thousands of instances.

Only other thing that is unique is listed vs unlisted posts. You have normal privacy settings like on twitter but you also can set a post to be listed or unlisted. If it is listed it acts just as i described. If it is unlisted then it acts just as a normal tweet would but it doesnt show up on local or federated timelines anywhere.

Also this goes without saying, but don't be racist, sexist, hateful, and don't harass people. Its a pretty shitty thing to do, don't be shitty!

The following is the list of QOTO administrators/moderators.
Note: The account listed as the administrator is NOT an actively monitored account. It was selected so as not to show favoritism among our moderator group, we are a democracy and even our administrators and moderators are held to the same high standards of decency as the rest of the community.

***We will never advertise on QOTO or sell your information to third-parties***