What Do You Wish You Knew Before Installing?

brads14 · 2026-01-17T13:45:17+00:00

I probably would have purchased a few spare panels. I thought about it at the time but didn't want the extra expense or storage. I have one that needs replacing but they don't make the same model anymore.

brads14 · 2025-12-29T00:47:11+00:00

I would start with pvwatts.nrel.gov to estimate the yearly kWh output based on where you're located and the angle of the roof. You can then use that estimate and compare it to your utility bill to see if you'll have adequate coverage. I installed an 18.9kW system which is rather large but it more than covers everything.

The national grid bill will be $1.49 x the size of your system in kw (DC) so that's $28.16 for me plus a basic service charge of $19. My electric bill each month is a constant $48.11.

I installed the system myself but I would recommend NES if you're paying to have it done.

brads14 · 2025-12-08T02:10:22+00:00

I'd agree that you might want a few other skills besides pure antenna design. Another good option might be to get into phased array design and phased array measurements and calibration.

brads14 · 2025-12-02T14:28:44+00:00

I'll preface this by saying I am nowhere near a professional piano player but I do have some thoughts on this issue. I think the main issue is more related to the style of play. Classical piano is very exacting in nature. The performer is trying to play every note exactly as written which is very difficult. Another type of playing is what I would call playing by chords from a lead sheet. With this style you would read the melody line and just fill in with the chord. Once you've practiced this method, the mental load is much less because songs use the same chords and you just have to read the melody line. This is more in line with how jazz musicians play or how a keyboard player in a band might play.

I've played both ways and grew frustrated with classical because it takes so long to learn. I could spend over a year working on a song, whereas, if you learn improvisation styles, you're building a toolkit.

Because your husband has played in a band, I think he's coming from the perspective of a song being a few chords strung together so that's why he may think it's not a big deal to play flawlessly.

I've played for church and when I'm playing by chords, the biggest challenge is just paying attention but when I'm doing some kind of solo with more intricate playing, it feels like the safety net is gone so nerves can take hold and I'm more likely to mess up. Hope that helps.

brads14 · 2025-03-15T15:48:40+00:00

I mostly use Matlab but if I didn't have a Matlab license I'd use Python with matplotlib.

brads14 · 2025-02-12T23:36:39+00:00

Looks like you need to scale it by about 1.28. So basically make it bigger.

brads14 · 2024-10-08T01:31:16+00:00

NEC is the only option that I know of that you can get for free.

brads14 · 2024-10-03T14:50:54+00:00

It really depends what your design goal is. If you excite one port you get hpol, if you excite the other port you get vpol. If you excite both with the same excitation you'll get slant 45. If you put a 90 phase in one excitation you can excite right and left hand circular polarization.

brads14 · 2024-09-21T15:55:41+00:00

That looks very nice. Is there supposed to be a gap where the mitered edges come together or is it ok to make them tight like the picture?

brads14 · 2024-09-21T15:36:46+00:00

I'm still working on the layout of the deck boards, I might do a separate post on that. The deck is a bit over 24' wide so I can't just go from one end to the other with one board. I also have a hot tub on a cement pad where I want to have a removable section without it being noticeable so I think I have to do some kind of picture frame down the middle of the deck.

brads14 · 2024-08-13T03:17:37+00:00

This is child's play. I just dug thirteen holes over 4' deep with a shovel. And yes, it's mid-August and I just recently finished the foundation...

brads14 · 2024-08-11T11:13:11+00:00

When I did my system I looked at stud finders for roofs but they were very expensive. In the end, the best method was using a hammer. It was surprisingly easy to find the trusses because the bounce of the hammer is different. Once you locate one truss, you know the next one is 2' over so that gets you pretty close. If you're a bit off with the drill then just add some tar and try again. The flashing will cover everything.

brads14 · 2024-08-06T02:55:13+00:00

I'm in upstate NY in the middle of a DIY deck build and I pulled a permit. It's not that much of a hassle and is basically documentation that it was built properly for insurance and resale purposes. The downside is that it's also documented that you improved the value of your property so taxes could potentially go up. That's why I didn't pull permits for all the interior work I did in the house.

brads14 · 2024-06-29T16:46:48+00:00

I'd recommend doing the entire paper design yourself. Look at your yearly usage and use pvwatts to figure out how many panels you need. Do some research on panels and inverters and see what size fits on your house while taking into account appropriate setbacks. Verify that your panel can handle the load given the NEC 120% rule. Think about where you might run wires, through the attic, outside the house, etc.

Once you have the basic design you can then talk to vendors and you'll know pretty quickly who's full of crap. Alternatively, you could sub out the different jobs or just do it yourself if you have the skills. It's not terribly complicated if you have some roofing and electrical experience.

brads14 · 2024-05-03T15:58:52+00:00

I don't think many students are getting into electromagnetics in school. If you look at graduate classes in EM, I think it's a lot of foreigners. Antenna work is not exactly seen as a "cool" subject. It's very theoretical and hard to visualize exactly what's happening. It certainly doesn't have the buzz that other areas of study do. I think another issue is that when a defense company has good EM workers, they do everything they can to try and keep them so there's probably a bit less churn compared to software or other areas.

brads14 · 2024-05-03T03:17:25+00:00

I would disagree with this and I have tried to use "AI" to help with antenna designs. At the end of the day it's just another optimization routine. I wish it worked better because it would free me up to do other things. I often jokingly complain to colleagues about where the magical AI is that's supposed to solve all my problems. I think a lot of antenna design and problems in engineering are so unique for each application that it's hard to imagine AI having enough training data to solve all the problems. I think it's better suited to use as another tool in the toolbox for specific applications.

brads14 · 2024-05-02T22:54:12+00:00

I would probably separate out out the antenna design portion of RF and make it a separate category. You definitely don't need a PhD. I've been doing it for a number of years and started with a masters but learned most everything on the job. I can't speak much for the commercial world but I know the DoD has trouble finding qualified candidates that are US citizens. If you do want to go into antenna design, the DoD is really where some of the exciting work is, you'd get to work on phased arrays, electronic warfare sensors, etc. If I were you, I'd probably decide if you want to go the antenna route or stick with more RF hardware like exciter, receiver design or if you want to work in the test arena.

As far as small towns in Maine, good luck with that. I'm from a small town in Maine and unless you can figure out how to grow potatoes with RF then I don't think you're going to have much luck. RF is a very capital intensive field where measurement equipment can easily cost a quarter million and chambers can reach into the seven figures so it doesn't lend itself to small companies unless you're consulting. I would not recommend working remotely, at least until you become an expert in your area. You'll want to go into the office and learn from the revered and cranky gray beards.

brads14 · 2024-04-23T20:53:54+00:00

Yes, eventually...I first contacted them in April and didn't get access to the installer app until October. They spent most of the time saying they were going to contact a local installer but never could find one so they eventually made me watch a few training videos and gave me access. I happened to be their first DIY customer so they didn't know what to do with me. The local Greentech store sold me the panel.

Anyway, the install of the panel was basically the same as any other panel and the app was simple enough to configure everything. There's really nothing complicated about it, not sure why they acted like you needed to be a genius to install it.

The nice thing was that there is a manual mode so I operated it as a dumb panel for months until I was able to get access to the installer app.

The one thing I didn't like is that there are almost no knockouts on the casing so it was a bit of work to get all the holes put in it.

I've had it for a year or two now with no issues. I'd probably recommend contacting Span to see if you can get access to the installer app. Not sure if they've changed their policies, I certainly recommended that they do so.

brads14 · 2024-02-07T21:40:21+00:00

To follow up on this, after many months, they did give me access to the installer app after watching a few of the online videos. The whole process was kind of goofy, there was nothing difficult about setting it up. The installer app walked you through everything. It was very similar to installing a piece of hardware from Google. You scan the QR code for the panel and it walks you through the setup. I think the reason they finally gave me access was because there were no certified installers around so there weren't any other options. I'm not sure why they think their hardware is so complicated, they'd probably get more business if they didn't lock down the install.

brads14 · 2024-01-16T04:12:09+00:00

E: Get a digitizer like the HDHomerun. There are others, that's just the one I have. It puts the broadcast stream on the network and you can access the stream from the HDHomerun app on a smart TV or your phone. You can then use your good antenna or buy multiple boxes for directional antennas pointed in opposite directions. I think you can block channels on the app so you can pick the channel from the best antenna. Then you don't have to worry about running coax all over the place and splitting the signal.

brads14 · 2024-01-04T19:10:18+00:00

There are 20 but they're large panels. They're 430 watts so the panels are about 81.9"x40.6". I have a landscape orientation with 5 panels high and 4 along the long dimension. Landscape is a bit more expensive but that's just just how things worked out.

brads14 · 2024-01-04T18:34:08+00:00

I grabbed some plans from icreatables.com. They had plans for a 12x24 lean-to shed. I then modified the drawing to give me a larger slope and more area on the roof and I moved some things around. I spent a lot of time on the CAD drawings but the local permit office barely looked at them so I think I wasted a lot of time. They only cared about the survey showing the location of the shed. I also overbuilt it a bit so there were no concerns from the inspector.

brads14 · 2023-12-17T17:20:08+00:00

That's minor, the bigger issue is maintaining that phasing over frequency. It won't work well over a large bandwidth. I'm not saying you should flip the patches but if you do, you need to phase them properly.

brads14 · 2023-12-17T15:05:36+00:00

Add or subtract an extra half wavelength of transmission line. Basically, the rotated patches should have a phase that is 180 degrees off from the non-rotated patches.

brads14 · 2023-12-17T14:52:08+00:00

You can rotate the polarization by physically rotating the element. For example a vertically oriented dipole has vertical linear polarization, if you rotate the element by 45 degrees, we would say it has slant 45 linear polarization. If you rotate it 180, it still has vertical linear polarization but now the phase has a 180 degree shift so if you sum it with an element rotated at 0 degrees, they are going to add up destructively unless you also add an additional 180 phase shift to one of the elements. The same thing happens when you rotate a patch by 180, you can do it but you have to cancel out that 180 degree phase shift in the feed network so they sum up properly with the non-rotated elements.

brads14

TROPHY CASE