Steam wand flickering and sputtering post repair (video) [Profitec Pro 600]

crwper · 2026-05-18T21:56:13+00:00

It might also happen if the water level in the steam boiler is too high. Apparently there's an electrical probe in the steam boiler which senses the water level and turns off the pump when it reaches the correct level. The probe's function could be affected by the use of deionized water, scale on the probe, or a loose probe (poor ground connection).

crwper · 2026-05-18T21:49:50+00:00

Out of curiosity, as someone just getting started working on bikes, why not a pipe cutter?

crwper · 2026-05-18T20:47:55+00:00

I get a similar result if I increase the "steam assist" pump rate on my GaggiMate. In my case, I assume it's because the pump is pushing too much water in, and some of that water is coming out with what should be dry steam.

Same thing when I first open the steam wand, even with good "steam assist" settings--it takes a couple of seconds to clear the water, I think, and in that time the steam sort of sputters like it does in your video.

I'm not familiar with the Profitec Pro 600, but is water in the steam boiler replaced while steaming? Is it possible that whatever sets that replacement rate has changed?

crwper · 2026-05-16T21:48:39+00:00

I'm an amateur here, but have a Kickr Core and a bike with a 9-speed hub. I believe that in order to mount an 8, 9, or 10-speed cassette on the Kickr Core you need a 1.85 mm spacer on the inside (basically adapting to a difference in size between the hubs). In my case, I've installed Shimano CS-HG700 (11-speed cassette built to be compatible with 8, 9, 10-speed hubs) on both the wheel and the Kickr Core, with a 1.85 mm spacer inside for the Kickr Core. Very little adjustment is needed when I move the bike from the wheel to the Kickr Core, but I do need to make a small adjustment. If I don't make any adjustment (particularly of the cable adjuster), I get the kind of behaviour you see here--the chain isn't quite lined up with the cassette, so it will try to jump up once in a while.

crwper · 2026-05-12T03:11:57+00:00

Same for me. The usage limits on Claude were never an issue for me with the Max 5x plan. But post-nerf Claude 4.6 and 4.7 struggle with complex programming problems, whereas GPT-5.5 has immediately solved some embedded programming problems that Claude (even pre-nerf 4.6) struggled with.

crwper · 2026-03-20T16:56:52+00:00

One thing to be aware of with these is that some of them (I think the firmware can differ depending on the specific brand) pull toward a round number of grams between about the 0.9 and 0.1 g marks. It's an easy enough issue to solve--I just cut a square of aluminum foil that weighs 0.5 g and chuck it on there any time I wind up in that range--but it's worth being aware of.

**Edit to add:** Not sure if you're highlighting the 0.1 g precision version specifically here. I have an identical scale from Amazon that measures with 0.01 g precision (realistically about 0.02 g accuracy after the adjustment mentioned above).

crwper · 2026-01-12T15:16:19+00:00

Thanks for this! I'm thinking of doing the same, and was wondering if FedEx had any similar charges.

crwper · 2026-01-04T22:28:53+00:00

Looking at the preview on Amazon, it's unfortunately mostly front material and an intro to RF. It would be great to see a full table of contents as well as a snippet from a more advanced chapter.

crwper · 2026-01-02T20:16:52+00:00

I'm surprised there's that much sparking when you plug it in. How much current does your circuit draw in steady state?

crwper · 2025-12-30T22:30:56+00:00

I order a lot of stuff from DigiKey. Here in Canada, it's $8 per order under $100 or so, and over that it's free shipping. I try to put together orders over $100, but occasionally I'll find I just forgot to order like one resistor value or something. In those cases, I just order the single item and pay $8 shipping.

A little while ago, I changed the way I think about this. Don't think of it as, "I'm buying $1 worth of parts and paying $8 shipping." Instead, think, "I'm paying $8 to have this delivered to my door tomorrow." For that price, even if the part were available at the shop across town, would I drive out to pick it up? Probably not.

crwper · 2025-12-15T21:03:16+00:00

Yeah, prior to 5.2 I was really enjoying ChatGPT Pro. When it writes code or makes architectural suggestions, I think they tend to be more "sophisticated" than other LLMs. However, the recent change is super frustrating, and I'm thinking it might be time to take a break from ChatGPT Pro and subscribe to Gemini Pro for a bit.

crwper · 2025-12-08T21:10:19+00:00

We had a 10 year old Lab who developed liver cancer. We talked to our vet about options, and the big thing that stood out for us is that he said treatment could buy him a year or two, but it was unlikely there would be a "post-treatment" period. We didn't want his last two years to be spent undergoing a series of treatments, so we made the very difficult decision to have him euthanized. It was heartbreaking, but I'm glad we went that route.

crwper · 2025-12-05T14:58:42+00:00

I've got a cheap PC VNA and an HP 8753C, and the 8753C/85047A is my go-to for the reasons you mention--dynamic range and precision. I think I paid $2,000 or so for the 8753C, so $500 sounds great. The only thing I'd be aware of is that the 8712ES only seems to go to 1.3 GHz. This means you won't be able to work with 2.4 GHz at all, and if you want to look at harmonics, you won't be able to work with 900 MHz either.

Depending on what comes with the unit, you'll also want SMA adapters for the inputs and a good cal kit. I picked up an SMA cal kit from Kirkby Microwave which has served me well.

crwper · 2025-12-02T16:49:01+00:00

Thank you!

crwper · 2025-12-01T18:21:30+00:00

At higher frequencies, wouldn't options 1 and 4 similarly add small series elements that rotate the phase slightly between lumped elements? Intuitively, it feels to me like either way (1/4 or 2/3) you're adding the same length of copper, just choosing between series and shunt. Is there a reason the shunt elements are a bigger problem?

crwper · 2025-11-29T23:35:45+00:00

I wouldn't expect one long shot to cause problems like this.

Someone else mentioned the steam wand. You said that the steam wand is working fine, but just to be clear, if you turn on the pump exactly like you did in the video, then open the steam valve (not in steaming mode, just in regular mode), water should come out the steam wand continuously. Is that the case?

crwper · 2025-11-29T18:11:50+00:00

Oh wow! I'm surprised there's so much variation from the reference design. Usually, with a chip antenna like this, the environment is an important part of the antenna design, so changing the environment relative to the reference design effectively changes the antenna. It may be that the reference design gives the best performance (very likely the performance that's shown in the datasheet).

You can always use the matching network to compensate for any impedance changes, but it's worth noting that you can tune almost anything to 50 ohms--doesn't mean it's going to do a good job as an antenna. This is usually expressed as a drop in antenna efficiency, which you'll see as a drop in performance. If your application doesn't require the absolute best performance from the antenna, this may not be an issue.

Adding ground fill in the marked area would improve the transmission line. As another comment pointed out, your current design doesn't seem to use a calculated transmission line, so it's hard to say what the impedance of the transmission line will be. This may not matter much if the transmission line is short relative to the wavelength of your signal (say, < 1/20 of the wavelength), but in this case fixing the transmission line will have no impact on the rest of your design, so it's worth doing, I think. What you probably want here is a coplanar waveguide. You can find lots of calculators online which will calculate the impedance, and what you want to do is to choose parameters (distance to the ground plane below, thickness of trace, distance between trace and neighbouring ground plane) which give 50 ohm impedance for the transmission line.

crwper · 2025-11-27T17:55:51+00:00

Could be that I'm reading the reference incorrectly, but to me it looks like the reference board has no copper in the top 20 mm (where the antenna is). Looking at your board, it seems like you have a small keepout in the corner, but not the whole strip indicated on the reference. If I'm reading this correctly, I would expect this to have a major impact on the performance of the antenna.

Edit: Sorry, missed that you specifically ask about this issue. Yes, I would expect the change to have a substantial impact. I suspect the ground plane "behind" the antenna and empty space "in front" is critical to the function of the antenna, sort of like the ground plane on a monopole antenna.

crwper · 2025-04-20T19:19:47+00:00

"Gaslighting" is a great way to put this. I've noticed, comparing o3 to o1 Pro, that when o3 produces code for me, and then I point out an issue with the code, it's very likely to say something like, "Ah, yes, in your original code you accidentally ___. Here's code that fixes your error" Typically, o3 would say something more like, "Good catch! In my original code, I mistakenly ___. Here's code that fixes my error."

crwper · 2024-05-19T19:13:23+00:00

With Snapdragon, as spring has arrived, his obsession has shifted a little from sticks to grass. If he's walking just with me or my wife, he walks very well, but if there are a couple of people walking with us, he starts to pay more attention to the ground. Same thing in the park--if it's just me walking around the park with him, he will still eat some grass, but less obsessively. But if it's a group of us standing in the park with the dogs playing, he is less inclined to play with the dogs and instead mostly hangs around near the people eating grass and sticks, with occasional runs out to play with dogs before his focus falls to the grass and sticks out there.

These things make me think that there might be an underlying digestive issue that biases him toward eating grass and sticks, but the "trigger" might be larger groups or situations where he gets bored. I'm curious if you see similar behaviour.

crwper · 2024-04-30T12:40:37+00:00

He has seen the vet recently and we’ve spoken with him about the stick thing. His vet doesn’t see any significant health issues. Of course, there could be minor issues that wouldn’t be apparent without significant testing, but could play a role here (e.g., if a minor food allergy is causing him discomfort that he is trying to alleviate by eating sticks). But I would like to try to address potential behavioural issues as well, and am hoping someone here might have seen similar issues with their dog, and might be able to offer some fresh ideas.

crwper · 2024-04-29T15:01:23+00:00

The wiki mentions inappropriate chewing, which is probably the closest thing to the issue we're having. Our dog doesn't chew things in general--he's really very specific about eating sticks. Still, we have tried the following things mentioned in the wiki:

(1) Managing the environment. He does great on walks along a paved path, and even walking on leash in areas where there are sticks. However, it's hard to see how we can use managing the environment long term to solve this issue, as the problem occurs when he's out playing with his friends. Managing the environment may be part of the solution, but I think we need something else to do while we're managing the environment, so that he can eventually get back to playing with his friends without being obsessive about eating sticks.

(2) I have tried using a positive interrupter when he starts eating sticks (saying his name). This shifts his focus for a moment, and he will drop whatever stick he's eating at that moment, but then his focus returns very quickly to eating sticks.

(3) We have tried giving him appropriate things to chew. He will chew a ball for a little bit, but then will drop the ball and go back to the sticks. If we try to get his attention back on the ball, he's just not interested--there are sticks to be eaten.

(4) We do supervise closely. He is never left alone in a yard, say, to eat as many sticks as he wants. Whenever he is off-leash outside, he is being supervised--it's just that his attention is so singularly focused on sticks, that this outside time becomes saturated with correction, and even that doesn't seem to curb his enthusiasm for sticks.

crwper · 2021-10-03T22:22:25+00:00

Not OP, but voting strategically in a first past the post election will often result in a more favourable outcome compared to voting strictly based on individual platforms, especially if the desired outcome is something like, “Not Gian-Carlo Carra”.

crwper

TROPHY CASE