There are several major practical problems for radio here. I live below two mountains, and even though I don't live in the valley, there are forest covered peaks 20-35m higher within 200m of the mansion, which is not optimal for signals going north or west. Except to the east or south, I can not count on using the ground wave, ie the part of the radio energy that travels along the earth's surface. To get around that problem, hopefully the better radios will be sensitive enough that I can use NVIS for normal use. NVIS stands for Near Vertical Incidence Skywave, and is basically as good as it gets in a mountainous environment, because the radio energy is sent in a high angle upwards and the upper ionosphere acts as a reflector and sends the signal back down, and I hope to reach about 400km, day and night. The biggest signal loss is the ionospheric bounce, not the distance since that is open sky, so 10km or 400km is not that big of a difference when it comes to NVIS. I just need a sensitive enough receiver and a powerful enough transmitter that I can handle that path loss. A pretty good analogy for how the ionosphere can be for radio waves, is like using a diving mask in a swimming pool and looking at the surface from below and out to the sides. At a certain angle, there is a full light reflection and you can no longer see through the surface and instead see back down into the pool, and even if you look towards the surface above, you can see a faint reflex of yourself if the roof is darker in an indoor pool.
The ionosphere works a bit in the same way for radio waves depending on frequency, time of day, sunspots, auroras, etc etc. It gets very complicated. This is a high latitude of 58 degrees north, and I'll probably need to transmit to slightly higher latitudes, so the maximum usable frequency (MUF) during the day for the ionospheres 'F' layer may not even reach 7.2MHz which would be nicer to build and would have meant shorter antennas, so a lower frequency is better like around 5MHz. At the same time, the sun during the day creates the ionospheric 'D' layer which attenuates lower frequencies a lot, so 3.6MHz is not optimal either, and the antenna length for a 3.6MHz dipole is almost 40 meters, which is a bit too long for my ship due to Lateen sails poking out upwards to the sides, etc. The ships is also half that length, so it can be an 'interesting' antenna solution on the ship, and not just pulling up a wire in a mast or simple line from the mast down, or between the two masts. Sure, the antenna doesn't have to be a dipole, but in general, a larger tuned antenna is better than a small tuned antenna.
Another major problem is the so-called skin effect. A solid conductor that conducts current creates a magnetic field around it, and when the frequency increases, a magnetic field is also created in the middle of the conductor so no current goes there, and the higher the frequency, the bigger the problem. This is the skin effect, and named so since only the 'skin' of the conductor is used. So lower frequency would be much better, preferably below 0.5MHz, but I need to use several multiples over that to get manageable antenna length and work with the ionosphere. At such a 'high' frequency as 3.6MHz, the skin effect will be large as only the outermost 35µm actually conducts the signal, so even if the wire is 3mm in diameter, only the outermost 0.035mm of the surface conducts the signal. 99.9% of the copper wire is just unnecessary weight and cost, and could have been a pipe. It could be insulating plastic with a 0.035µm copper layer on the outside.
In addition to using coaxial cable for higher frequencies, the common way to reduce the problem in ordinary low frequency cables such as to headphones, is to use many many thin small conductors that are lacquer insulated and intertwined in something called Litz wire. However, it is impossible to make something that good here. I will need to buy and combine more of the thinnest copper wire due to the skin effect in the antenna's copper wire, but I will not be able to get as many strands as I want in the antenna feed. If I need 30 meters of antenna conductor between the radio and the antenna, just four strands becomes 240 meters of handmade wire for each conductor. The skin effect is a big problem, so I should stay on low frequency just because of that, and also high signal voltages that are less affected by 'resistance' compared to high current signals. Sure, I could make a coaxial cable in the form of a tube with a copper rod internally held in the middle of the tube using glass or earthenware spacers, but that's not a flexible solution, and will be cumbersome with impedance matching, but impedance matching always need to be done every time the signal changes 'circuit', and different antennas and feeds have different impedances. So, I need to match between antenna and antenna cable. Between the antenna cable and the transmitter output and the receiver input. Internally in the radio circuits.
If not everything is matched and tuned, the transmitter might output 80W, but what actually leaves the antenna is far smaller. The worse the tuning the less, so maybe only 5-20W leaves. And I expect the transmitter to output about 8-10W. It is also about reception, since it's terrible if only 1/8 of the signal the antenna receives actually makes it into the receiver. So it affects the range of the radio very much and can easily mean half the range or less if it is wrong. If both radios that are communicating with each other have the same problem, it will be much worse because it is multiplied. 1/4 leaves the antenna and 1/4 of what is received goes into the radio, ie 1/16 compared to if everything was tuned. Radio signals arn't linear and are measured in decibels, but it quickly becomes bad. This is the reason why radio amateurs are very focused on antennas, impedance matching and measuring the SWR, which is a measure to determine how well-tuned electrical signal conductors are and stand for Standing Wave Ratio. Technically, it should be a V for Voltage in front of SWR, but most people don't care to say so. Hmmm... I might be able to build a simple SWR meter.
Radio can be so simple, and so very very complicated and tricky.
So I have to accept a compromise, and 3.6MHz seems to work about as well as I can hope for with all my limitations, problems and compromises. At least during long winter nights, one or two large directional dipoles, horizontal loops or rhombic antennas should be able to provide long range when I need it, and maybe a compact loop antenna or frame antenna works when the larger antennas can not be made. The balancing of radio output-input, feed and antenna wire will be pain in the butt to do and get it tuned - but is important. I have long since realised that it will probably be a free wire ladder solution with ceramic or glass insulators of about 600 ohms impedance, and have already bought ceramic insulators for it and other stuff.
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When I inventory my electronics, I take the opportunity to disassemble Tom's Bluetooth headphones to see what useful parts it can give me. There is significantly more useful parts than I expected, and in addition to two speakers in its own suitable small acoustic plastic cases, it has four small microphones, which I think it's for actively attenuating ambient noise or some form of automatic filter calibration. Or be able to take a phone call through. There is also six small push buttons and four small blue LEDs on the motherboard. A copious amount of small capacitors and resistors, more than a hundred of each, which amaze me. I wasn't expecting this. Unfortunately, I won't be able to use most of it. Wrong values. There is also a small 3.3V switch regulator I can remove and reuse. There seem to be four diodes, one of which is more powerful, and three what I think are mosfets but I need to test them better to verify and get the data on them and follow the paths on the circuit board. The IC circuits are quite useless, although I can guess what a couple of them do and for example, I could try to reuse the headphone amplifier, but that's probably too much work. I will try to avoid fucking up what I don't need.
I am very grateful that the manufacturer made it easy for themself, and used a finished bluetooth module that has nice printed text saying what the different pins are, but it's also printed on the circuit board, so I should be able to use it with the above regulator. Maybe I should try to update my home-built speaker to Bluetooth, with pause, forward and back buttons? Wireless option would be handy.
The story has been illicitly taken; should you find it on Amazon, report the infringement.
There is also a small separate circuit board with the charge controller and two more surface mounted LEDs, red and green, which are connected to its Lipo battery cell, so that is also useful. I can build another flashlight or something very simple with this, ready for charging straight off. Just connect to USB.
Then of course some nice little screws and a whole pile of useful plastic. What I really like is that the cables between the headphones, among other things, are audio type Litz cable with many tiny beautiful strand that are individually lacquer-insulated, and the icing on the cake is the magnetic locking to make a compact unit when not on the head. Four small wonderful neodymium magnets. Together with the strands from the Litz cable, I should be able to build either four more small speakers, or four sensitive moving coil instruments. Of all the things Tom brought with him here, these 'cheap' bluetooth headphones are probably the most valuable item, which just is dripping irony considering his expensive camera with its lenses and other high tech things.
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My electrical thoughts have made me realise I can make Jane's life a little easier, better and more luxurious, and won't force her to charge her precious mobile phone in my workshop.
With Jane's permission, I try to modify her 230V charger, and when it works, I connect it to the mains power supply in her bedroom, so she can now charge USB stuff on her bed table. Jane can now charge her mobile phone or her Airpods whenever she wants, and play music etc without thinking about draining the mobile phone's battery. I should have done this several weeks ago.
Jane is ecstatic and gives me a hug followed by a really intense kiss, with enough feeling that it's damn close that I try to continue and make it more, and considering how we stare at each other? I bring Caecilia with me and leave and close the door behind us.
Deep breath.
Argh, it's getting more and more uncomfortable between me and Jane. She has a perfectly okay personality, is nice, with a sense of humor and I like her - except when she's a dumbass or teasing me. Dangerous. Especially since Kari and the others have already removed the biggest barrier. Caecilia is quick to notice and offer to fix my pants problem, and her sensual hand stroking that spot, her gaze and sensual whisper makes the problem bigger, so I lead her into the workshop to take her suggestion.
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It's nice to be able to play some music while I work, even if it's distracting when I'm not alone. There has been a small sofa in my workshop for a while just because I like to lie down and think about certain problems, and the sofa is also used by Alith, Jane or my sambos who I usually let listen to music whenever they want, even if they look funny at the speaker when some music is playing and comment most music in the background. Which can disturb my concentration, and especially if Jane tries to explain the text and asks me for help translating.
But it's cute to see Ciara sit smiling and head bobbing to things like Nilvah's 'Tekno Wily', and Xonotic 'Rise of the Phoenix'. Ciara likes several New Retro Wave synth songs because it sounds so happy and The Beach Boys for their harmonic voices, although Iselin also likes The Beach Boys. Iselin is turning to a metalhead and loves guitar solo's, although Alith doesn't seem to mind some symphony metal. Kari and Caecilia are more for music closer to what they've heard before even though they don't understand the lyric, just more powerful and impressive, like most of Malena Ernman, Sissel Kyrkjebø or like Tatu's '30 minutes', Unsun's' The Last Tears', although some of Epica and Within Temptation are also okay as well as Gregorian monks, The Hunt for Red October, Orff's 'O Fortuna', and other classical music.
Kari and Ciara look funny at the speaker during Just D's 'Vart tog den söta lilla flickan vägen'. Weird Rap really isn't something they get. I try to explain the title means 'What happened to my cute little daughter' it is a humorous text in Swedish and the men who raps wonder what happened to their cute little daughters as they now parties, travels, raids and has sex, and feels so dirty for thinking 'Oh god' when his daughter showers. The translated text is okay, but not the song and style. Most of my music is so different to them, and things like Iron Maiden, Sabaton, Metallica, most Rammstein, The Prodigy and so on are just too different. Unleash the Archers reminds Kari she have other things to do and needs Ciara's help, leaving Jane behind. Jane might not like all my music, but she enjoy their reactions and that I have it.
The music makes me miss Iselin who has almost become a metalhead. She can start headbanging and bouncing around to something like this if the song fits, and it's just the two of us. Iselin thinks it's a shame that the guards won't understand Sabaton, because she thinks they would like that they only sings about historical battles, heroes and heroism, about the good and bad sides of war. She doesn't understand the lyrics but remembers my translations very well and likes 40-1 and Purple Heart, and others like Hammerfall's 'Glory to the brave'. She does not know if they will accept the music, and I have promised she will be there when I eventually introduce it.
Jane is sketching me as I build, because radio is important, and she too can listen to music, and music is something we can talk about with modern references. La Bouche's 'Be my lover' starts playing, and Jane starts dancing to the song, and starts to mimic singing along for certain parts. Soon her paper and pen is laying on the workbench as she focuses on seductively dancing and singing in my ear, and drumming with her fingers on my shoulder. Given our shared look and the reaction before, for once it might be more than having fun at my expense. Or my thoughts just make too much of the situation. But I also know the song quite well. This is my playlist from my tablet, and I know this song well enough, and I can feel the devilish smile growing on my face.
Jane is not prepared for me to get up, stare into her eyes and rap back when the man does and even though I only know certain parts I dance around behind her, emphasizing 'getting down' in her ear and gently caressing her body sides and arms before I get around again, stare into her eyes and sing along to the ending 'oh yeah, want to be your lover'. I turn my chair towards her, sit down like a boss, and as I lean back I look her in the eyes and with a sinful smile sing along to the rest of the song.
"I hear what you say, I see what you do.
I know everything, I need to know about you.
And I want you to know that it's telling me:
You wanna be my lover?"
Jane just stands there completely petrified staring at me, while I sit there, singing along and emphasizing certain lines. It's interesting how much meaning I can hint at in just the ladadada lines, especially with a glance at her body, a little facial expression, playing with my tongue on my lips, faces and the occasional raised eyebrow etc. And I often catch her eyes still staring at me. During the final 'Wanna be my lover?' lines I just stare into her eyes, with my elbows on the armrests and with my fingers together like a movie villain, with a completely serious face.
When Usher's 'Love in this club' takes over, Jane jerks and quickly disappears from the room, completely ignoring her sketching tools. I skip to the next song, and I can not help but say 'Fatality!' when the Utah Saints' version of 'Mortal Kombat' starts playing.
Yeah, I will try to improve my horn speaker with the Bluetooth module. It will make it easier to use the speaker and I can hang it in the corner, and a cable is an unnecessary risk and can be used for other purposes. Caecilia opens the door to check if I need something or she can run a errand, so I just say it's okay, wave her off and keep working.
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Jane wants to be alone and eat in her room, so Caecilia delivers a tray. Maybe I shouldn't have done that, especially considering how the situation between us was after that kiss. I can hear the little grumpy voice in the back of my head defensively whining a 'She started it!'. I'm not really looking forward to having any kind of sexual relationship with Jane. I prefer to have her as my best friend as we both share the same huge life change, than to have her as some kind of friend with benefits. Or girlfriend. It's probably good that I avoid alcohol. Damn my morale is aiming for rock bottom, because I don't feel like a huge bastard and betrayer to Iselin, Kari and Ciara.
Honestly, it feels more like a betrayal to build and test radios without Iselin. I hardly want to officially test my spark gap transmitter and combined diode / coherer receiver, but Ciara gets to sit and press a repeating series of pulses I don't know the pattern of, but avoid '1', and I write down what I hear from the speaker, before switching to the coherer's buzzing sound that gives the same signal. When Ciara comes back and tells me that she did 4-2-5 and repeated it several times, I show the paper where I wrote down the same sequence. This is in the house where the servant system etc already works and is similar in components and appearance, and Ciara isn't good with electricity etc, so I doubt she understood what we just did. Or truly cared. We should go out and repeat this in nature with others as witnesses, but not tonight. Might as well call it a night, and cuddle with Ciara.