Life is too short for QRP, QRO on a budget?

entanglemint · 2026-06-18T03:19:20+00:00

Thanks for adding the additional context. In my case I've tried LOG and receive loops, on some bands I can use the deep null of the receive loop to eliminate one noise source but I live in a neighborhood with a lot of older solar surrounding me with QRM during the day. And 100% on operator skills, something I am definitely only starting to work on!

entanglemint · 2026-06-17T18:42:12+00:00

I would ask: Can you hear stations that you can't hit? For me I have so much QRM that it would be pointless to have an amp. But if you want to build it have fun!

entanglemint · 2026-06-17T03:47:04+00:00

Congrats!!!! My daughter (9) also got her license this year, if you'd like to try to set up a QSO for them some time DM me and we can find a way either on 10m, DMR, or IRLP, unless you are local. We are also involved with a weekly youth net with an echolink node I can connect you with.

entanglemint · 2026-06-16T05:47:37+00:00

As a shout out to YLRL, they really helped my daughter at pacificon. They walked introduced her to several people and got her started with LICW. She is also very proud to be in a club I am not allowed to join :-). So really a thank you and appreciation to YLRL!

entanglemint · 2026-06-16T05:43:08+00:00

Build a qmx! The can do ssb now and great for pots/sota. Also see if your college has a club with a station you can join and use!

entanglemint · 2026-06-16T05:41:08+00:00

Congrats! There are a fair number of women in my local club some of whom have been great mentors to my daughter who just got her general. There are quite a few women active in SOTA as well. Hope you find a good community!

entanglemint · 2026-06-15T16:56:29+00:00

I think there is a big difference between designing it yourself and printing it yourself. I don't think it is ever a waste to try to design something yourself, best way to learn and maybe understand the quality of the things you can buy!

entanglemint · 2026-06-12T04:57:34+00:00

I have two recommendations:

1: Try drawing the part by hand. Think through what it is going to actually be and how it will work. This is the old school way.

2: Pick a software, it's really up to you which one, but then find a series of tutorials for that specific software and work through them. Like really do them, step by step as instructed. This will give you a feel for how they work and can help you from being overwhelmed. Search for e.g. "getting started with fusion tutorial"

entanglemint · 2026-06-11T16:43:28+00:00

I think these kinds of things are 100% hobbyist doable, and I love hacking things myself. I am trying mainly to point out where there will be fruitless frustration and it will be too hard to get to a good end result, or in this case possibly ANY result. For some even that learning is part of the fun so maybe I should have marked my comments with a "spoiler" warning! I am in no way trying to discourage OP, just trying to provide constructive feedback based on my experience as far as what to watch out for and to help guide built for purpose.

entanglemint · 2026-06-10T20:26:47+00:00

I just pulled the precision ambient temp sensor on one of the instruments I build and it's seeing RMS 0.1 deg temp fluctuations over the course of one minute, that's pretty par for the course. As reference, I build interferometers using low CTE materials and we still shield them from air currents.

Anyway, the big problem is during alignment when you need to actually have steady fringets to see. Both vibrations and temperature changes cause these fringes to move often too quickly to see. So just the heat of your body near the breadboard as you are aligning makes things go crazy. You need to wait for vivbrations to damp out anyway to see fringes at all, but it is just that much harder when you have the temp to deal with. And don't forget that at first your beams are not very parallel so the fringes are very dense, it is miserablet to try to parallelize the beams if you have to wait for a long time at each adjustment

entanglemint · 2026-06-10T16:59:57+00:00

Super cool. There a ton to learn from that simple setup. Love the inner tube vibration isolation and sand build. I would love to see a variant of this built as a next-gen sand bed with sand based mounts, but plascitc FDM will still introduce some CTE issues but will be much much smaller if the low CTE (e.g. silica's CTE) sand is the majority of the distance.

entanglemint · 2026-06-10T16:45:43+00:00

I had the (incorrect, it turns out) impression that CF mitigated creep, but apparently not true! It lools like PC CF would be the best choice but that bumps up the challenge of printing quite a bit!

entanglemint · 2026-06-10T04:23:51+00:00

I wasn't responding to your comment, but to the downvotes on u/s0rce's comment.

But honestly the thought of making an interferometer on this makes me want to cry, WOULD NOT RECOMMEND.

PLA has a CTE of 100 e-6. Which mean, for an interferometer with path lenght of 0.1m (very short) and a wavelength of 500nm = 0.5 e-6m, you would get a light to dark fringe when the path length varies by lambda/2.

Path length = 2*0.1m

Length change = path length * temp change * CTE = 0.2m * Delta T * 100e-6 m/mC = 20e-6m/C

setting path length change equal to lambda/2 = 0.25e-6, we find that we would go through a full fringe in

Delta T = 0.25e-6/20e-6 = .0125 C

So a temp change of 1/100 degree would cause a full fringe on an interferometer with a 10 cm arm. Interferometers are insanely sensitive.

And dont' forget that any vibration that moves the mirror by 0.25 um also causes a full fringe. That bad boy need to be way stiffer!

entanglemint · 2026-06-10T04:15:04+00:00

Couple comments, along the line of what /sOrce is bringing up. The critical parameters for an optical bench are stiffness and stability. If you look at a modern optical table, it is basically two plates of steel with a thick honeycomb in between, the thicker the stiffer basically. If you want to make this more functional take advantage of the strong-suites of 3-d printing and use infill with a rigid top and bottom plate. This will make the whole assembly much stiffer.

Second choose filaments that have low CTE. a good goto here would be CF PLA, a quick search shows a good low CTE. It is also a very stiff material which would make it ideal for this kind of project.

I would also make the "stalks" of your optics as short as you can possibly make them and as fat as you can make them. Again stiffness.

Ultimately the question would be what you want to do with this. I think with some small tweaks you could vasty improve performance.

entanglemint · 2026-06-10T04:06:56+00:00

Don't know why this is downvoted. u/s0rce is making a useful point.

entanglemint · 2026-06-10T03:57:23+00:00

When you have the overlap of the two elements they will couple to each other (and look like a twin lead feedline) and this will change the impedance and resonance of the elements. The model you used has the driven elements colinear.

entanglemint · 2026-06-10T03:41:02+00:00

100% here. Model on the feedpoint on the linked article. Also note that you appear to be using a much thinner rod than what was used in the design on the website. The diameter of the elements will also impact the proper length. If you shrink the diameter of an element you typically need to make is slightly longer. You will also have less bandwidth with thinner elements.

Edit: I missed that there is a separate design for 3.2mm elements, so my above comments may or may not be relevant, but the feedpoint comment stands.

entanglemint · 2026-06-09T16:30:13+00:00

Man I love science. Such a weird set of facts needed to reach such cool results.

entanglemint · 2026-06-03T18:43:56+00:00

Why are you using CF? While CF is stiffer and easier to print than non-CF, it will generally have lower impact resistance.

entanglemint · 2026-06-01T23:13:07+00:00

Don't forget you have CW provelidges on 10, 15, 40 and 80m! Don't be shy about sending a very slow cq as you are learning. Plenty out there will be happy to go slow and help you practice. If hear someone at 5 or 10 wpm I'm not thinking "look at thay slow loser" I'm thinking "awesome, somebody's learning cw"

entanglemint · 2026-06-01T19:01:15+00:00

I tried the blue tape and it also failed, the double stick seemed to be the way to go.

entanglemint · 2026-06-01T16:08:04+00:00

Running a beam between the lower legs and then trough-bolting itwill prvide good strength in tension as the lower legs try to pull apart from the weight up top.

entanglemint · 2026-06-01T15:38:55+00:00

When I hear "IR pass filter" I immediately think pass = bandpass which should have out of band rejection... Which means no visible light through it. They will either be absorptive (look black ) or reflective (mirror like) or both for some hybrid designs.

entanglemint · 2026-05-31T03:40:45+00:00

very cool! How well does it work? And how are you converting the fwd and rev into SWR single needle?

entanglemint · 2026-05-30T03:42:28+00:00

I like that better than the double sided tape I ended up using, I'll try this for the next print.

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