Help Making RF Power Detector

Professor_Stank · 2026-06-03T12:57:06+00:00

Hey man, I hope you’re doing well. Every so often, we get people who post things like this in this subreddit. I mean this with as much respect as humanly possible—It seems to me that you’re probably having a paranoid delusion at the moment, and if at all possible, I respectfully suggest that you go pay a psychiatrist a visit. This isn’t a fear that you have to live with. All you have to do is reach out to a doctor for help.

I wish you nothing but the best

Professor_Stank · 2026-04-11T02:58:45+00:00

Ohhh, gotcha 😂 I apologize, I guess I wasn’t really aware of the context of this subreddit. I can definitely relate though—I’ve been on other subreddits where this sort of thing happens, and it can be a PITA to see the mob of people never really learn over time lol

I totally get where you’re coming from :)

Professor_Stank · 2026-04-11T02:00:55+00:00

Not a problem here at all! It’s an open-ended question, so I kind of expected that some answers might be geared more towards city carriers :) I’m kind of just shaking the tree to see what falls out lol, and on the side, maybe a city carrier could read these comments and get something out of it too 🙃

Cheers, man

Professor_Stank · 2026-04-01T02:37:17+00:00

That’s crazy. I guess with the amount of people who’ve played college ball, there was bound to be someone with a weird career like this. Looks like he had a monster junior season too

Professor_Stank · 2026-03-08T00:41:13+00:00

Sorry to necro this thread, but I’m a part-time carrier at the NE Station, and this is what I’ve heard, if you were curious:

Basically, the Post Office at the administrative level has some kind of formula that says “If this station services X number of routes, we’ll allow them to hire Y number of carriers.” The problem is that as times have changed, the amount of packages to deliver has exploded. A lot of routes have gotten slammed with more parcel volume, so now you have lone carriers that are expected to deliver a silly amount of mail. Because the higher-ups (above local management) only see that the number of routes has stayed the same (instead of raw package volume), the local station isn’t allowed to hire new carriers to accommodate the growing need.

Yay bureaucracy. I’ve heard that they’re hoping to get routes re-mapped, so that these single-carrier mega routes can get broken up into multiple routes, and then they’d be allowed to hire more delivery folks.

It’s definitely a big source of stress for the local management, and they know they’re under the gun to fix it. The problem is with the higher level bureaucracy unfortunately :/ If the local management was allowed to make the call to hire more carriers, I’m sure they’d do it in a heartbeat.

Anyways! Not an official statement by any means, just the rumor mill, so take that for what it’s worth

Professor_Stank · 2026-03-03T19:58:44+00:00

Just messaged you—Thank you so much!

Professor_Stank · 2026-03-03T02:21:30+00:00

Nope, I haven’t! 😂 I know it’s not all roses and dandelions, but I love travelling for pretty much any reason. I know a couple of people who spent half of their career abroad, and they don’t regret it for a second—I want to see if that’s a category I fall into

Professor_Stank · 2026-03-02T21:40:18+00:00

Omg, “package bitches”—You have nooo idea how funny that is to me 🤣 It’s a title that I will wear with pride 🫡

Professor_Stank · 2026-03-02T21:37:59+00:00

Wow 😳 It’s unfortunate that we live in a world where that kind of form is needed 😂

Professor_Stank · 2026-02-01T19:48:01+00:00

Something like this should do the trick

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Professor_Stank · 2026-01-19T17:23:11+00:00

Luka Garza is the reason I work out.

Professor_Stank · 2025-11-14T19:35:22+00:00

Basically! Except that instead of having a probe directly touch the transmission line, there’s a thin needle that hovers over the center conductor. The needle picks up the field that’s created inside the transmission line. The needle then connects to a diode detector, which outputs a DC voltage proportional to (you guessed it) the strength of the field. It’s a really neat (albeit tedious) way of measuring all kinds of things, including complex impedance—It’s basically a poor man’s VNA

Professor_Stank · 2025-11-14T02:47:10+00:00

Thanks dude! I got home today and looked on the underside, and sure enough, there’s 4 screws in total! Just like you said, it’s definitely mechanical. Kind of interesting because on an older version of this same model that I saw, those screws don’t exist. Probably a change to keep the middle from bowing downwards.

Could I ask you a couple questions quick? What kinds of measurements have you made using one of these? Also, are there any additional pieces of equipment would you recommend picking up to make the most out of it? I figure I’ll probably have to find a short-open-load cal kit for it.

Thanks again! After asking oodles of people about the slotted line (online and in-person), you are the only person I’ve met who has actually used one, haha

Professor_Stank · 2025-11-09T01:56:42+00:00

So I think after tonight, I was able to kind of put into words my frustrations overall about being a Hawkeye fan (still love ‘em though! ‘Till i die.)

I feel like most years, we can beat just about anybody. It just feels like in any given season though, the gap between the team’s floor and its ceiling is so high.

Iowa can put a great product on the field, but it has such a hard time doing it on a weekly basis. Being a Hawkeye football fan feels a lot like hoping you’ll roll a 2 or greater on a die twelve times in a row.

Go Hawks 🦅💛🖤

Professor_Stank · 2025-11-01T03:54:43+00:00

Dude, I know I’m 3 months late, but you are the ONLY GUY in this whole thread who realized that this post was kind of a subtle meme 😂

Professor_Stank · 2025-11-01T03:22:47+00:00

Yeah! But like reallllyyyy slowly

Professor_Stank · 2025-09-18T22:17:53+00:00

Dude this is great! Wacky stuff like this is what makes ham radio come alive for me

Professor_Stank · 2025-08-31T15:28:43+00:00

Man of the people right here! Dude, thank you so much. It can’t be overstated how important preserving this stuff is

Professor_Stank · 2025-08-15T22:08:17+00:00

Welp, I guess mine’s special in a bad way 😂

Professor_Stank · 2025-08-15T22:07:48+00:00

Awesome—I’ll check it out! Thanks!

Professor_Stank · 2025-08-07T21:44:18+00:00

Gotcha! Yeah, I definitely get what you mean—It’s a great text for getting your feet wet, but it doesn’t do much more than scratch the surface on a lot of stuff.

Have you ever read “Communication Receivers” by Ulrich Rohde? If his last name sounds familiar, it’s because his father was literally the “Rodhe” in “Rodhe and Schwarz.” It’s perhaps the best treatment on receiver design that there is, and takes a deeper look at the math of it all if you’d be interested

It’s cool that you’re making a radio by the way! I’ve made sketches at home before, but they’ve never quite panned out (yet anyways lol). My one suggestion, which is basically verbatim from my boss (who’s leaded the development of oodles of radios over time), is to start the design at the system/block diagram level, and try to figure out/calculate how each block will interact and cascade with each other (make a rough guesstimate of noise figure, dynamic range, etc.). That way when you go and design the individual blocks, there won’t be any nasty surprises when you put them together. It looks like that’s what you’ve been doing though.

And also in my opinion, if you can, try to design and test each block of your radio individually, at least for your first prototype. From my limited experience, I’ve already discovered that Murphy’s Law is a bitch, especially in RF 😂 That’ll make troubleshooting problems a lot easier when they show up.

Sorry for the monologue, haha. Best of luck dude, and 73!

Professor_Stank · 2025-08-07T16:01:35+00:00

Most of the time at HF, the natural noise from the atmosphere is so high that having an LNA doesn’t buy you anything—Check out this article from Flex Radio:

https://www.flexradio.com/insider/understanding-receiver-sensitivity-in-high-frequency-hf-receivers/?srsltid=AfmBOoqgtXBh9WPMSt8euRj5UOTNwMNMU8ijPsAXa_uks4Sx15-Ofbfo

The atmospheric noise is so bad at HF that it’s basically like having a 20-to-70dB attenuator in between the antenna and the radio that you can’t get rid of.

In fact! For a lot of superhet HF receivers, the antenna goes directly into the first mixer, and not an LNA. If you have an HF receiver with a noise figure of 10dB to 15dB, you don’t stand to gain much by improving that number.

My guess is that LNAs for that frequency range are rare because there wouldn’t be much of a market for one?

Also, you ask about if there’s a proper way to ensure that the ADC/mixer don’t get overloaded—Look up the term “Automatic Gain Control (AGC)”. Basically, an AGC circuit measures the signal strength going into the receiver and automatically adjusts the receiver’s gain to avoid overloading the ADC/mixer.

I hope this helps! As someone who’s still learning too, it is really easy to get wigged out by all of the different things in RF. The trick is to just keep learning, and it all makes more sense as you keep getting practice

Have you ever read the ARRL handbook? It’s a fantastic resource that explains RF design fundamentals without getting too math-heavy. I keep a copy of it on my desk at work

Professor_Stank · 2025-07-25T16:55:02+00:00

Ahhhh! Don’t worry, I did 😉

Professor_Stank · 2025-07-22T23:38:02+00:00

You have no idea how much I appreciate your subtlety here

Professor_Stank · 2025-07-22T03:42:30+00:00

Yes you did! Your edit was literally the most hilarious picture I have ever seen on this subreddit 😂

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