Midwinter calling, day 45
Control
I've been trying for a while to figure out the easiest way to do some kind of remote control via radio, and what I have been thinking of is the usual carrier wave, tone coding, etc, but everything requires circuits and many valuable transistors, both to generate the tone and to receive, detect and control something from the signal. Remote control would be really useful for being able to trigger something from a distance, for a lot of things. It would be useful in our normal radios and above all the mobile radio and the mansions radio so it can trigger a bell or similar so no-one have to sit and listen all the time. Instead of just a schedule or regular check ins it would be possible to send a signal when you want to talk, much like a telephone's ring signal.
It admittedly took a while, but I realised that there is actually something I can easily use, which I have with me; standardized IR remote controls for the camera, and there are several sensors. So I was able to find four; from SDR dongle; from my modded Mobius; and two from my scrapped DSLR camera. The sensors are for IR light, but can connect to radios by removing the IR LEDs from the remote controls and putting one directly against the sensor housing. With some simple connections and power feed, I have four modules where the electrical signal that usually flashes IR LEDs is instead sent via radio and that makes the IR LED in the 'receiver module' weakly flash. Inside the IR sensor there is important filtering, detection and amplification, and it gives a pulsed signal out that normally would go to a micro processor, which I don't have. But with a couple of capacitors and a transistor on the output it will smooths out the pulse train into a stable signal that can drive something.
The disadvantage of the system is that it takes away the efficiency of pure CW radios, fucks up the bandwidth of radios, which negatively affects the sensitivity of the receiver even with adapted signal path and rise and fall time, but I could partially solve the problems with the help of it's own IF filter. This all means that I can't predict how it will affect the transmission range. Is the overall gain of the IR sensor's internal amplification and filter more than the loss in efficiency, bandwidth and filters? I hope so. But the function to be able to trigger a bell in a radio is important enough that less optimal range can in many cases be accepted. The selectivity in the normal filters I've built are 'not good', but the IR signal system's filter is even wider and tuning in exactly the right radio frequency is less important which can also help if one station is slightly badly tuned.
So I now have four remote controls circuits I will build into radios, and there will be one each in both stronger radios, but the remote control modules is not quite finished, and the third system will be in the mobile radio. The LED previously assigned as just 'On' in the front now glows much brighter when a remote signal is sent or received and a relay buzzer is triggered when a remote signal is received, regardless of what code is sent. Radios have not seen much use yet, but it works. I've also modified the Off-On switch so they have Off, On with buzzer which I call 'monitor' in Norse, and finally On without buzzer for normal radio traffic. First tests seem to indicate that this remote control system is more sensitive than the ear is to hear pure CW Norse tone, so it may be that it gives the radios longer range in not just calling the station, but also make it easier to listen and get a good copy of a weak signal. In normal mode the radios squelch mute the hissing white noise as that is annoying to listen to, but that can also mute a signal, so a new mode we will try is remote signal Norse code that effects the squelch by muting the radio noise when the signal is missing, which will mean the Norse tone mixed with normal radio noise becomes clearer when the signal is sent. Hopefully it will make it easier to just listen and writing down without having to see the flashing light signal, as listening for tone and hiss volume change is far more practical than using the relay buzzer. It remains to be tested whether it is practical or most problematic or annoying function.
I don't want to disassemble Tom's DSLR camera to strip the two sensors from it has, and haven't come up with anything else easily accessible that has one, but I may end up building inferior remote control filters detectors of transistors that fulfil the same function, but probably does not have the same sensitivity. The remote control and sensor in the SDR receiver didn't have the same carrier frequency as the others, and isn't fully compatible, but that's okay because it gives me separate remote system for a specific radio if I want, and might be the one I will install in the mobile radio. Pretty much any transistor with the right resistor-capacitor or inductor-capacitor circuit, can make an oscillator that for transmitting the remote right control frequency, because I 'only' have a total of three DSLR camera remote controls.
Looking practically on it, it is better if not all radios have a remote control system since it is not possible to choose which one to activate except that third one, so if every radio had a system all radios in monitor mode activate by same signal. It's more practical if the mansion's radio have the system so everyone can call the mansion, and the same with the ship's radio and the mobile radio. Because it's not just buzzer activation but hopefully also extra range when it comes to the ship, and means I can use the mobile radio while in company of people that shouldn't really know about radio, and the mobile radio will probably have a shitty antenna and need any boost it can get. It is also possible to have separate frequency settings for different receivers, so whoever wants to contact the mansion uses one frequency, another for the ship and a third for the mobile radio and so on. Instead of dialling a number, tune in that radios frequency and push the 'buzzer' signal. When I eventually send a ship or two on a long-distance expedition in the future, it will hopefully include two radios, just so those ships can communicate between each other and as a backup for contact back home. I'm honestly tempted to make an inferior radio with lower output power and features, which also means fewer transistors, because in many cases just longer range than line-of-sight is really useful. Both between ships, and between us if we split up in a town or something.
I have four systems, with the SDR system and its 28 button remote being the weird one, and I'm contemplating if I should use the SDR IR system for simpler Radio Control of something because I can use the 29.25MHz crystal to build a simple and compact radio transmitter, basically just the crystal, a transistor as a power stage, the remote control and a battery. The receiver can be almost as simple with a filter, mosfet, sensor and transistor output to something. I could even do some more advanced decoding if I reprogram the ATtiny85 from the Mobius to read the code and control four-five outputs, and that is basically the code in it already, so I can just open the project file, modify the code and reprogram. I can 'sacrifice' 3-6 transistors to get that RC system where the outputs can drive electromagnets or relays.
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I could even make a fancier system that activate combinations of outputs at the same time by taking advantage of the fact that even though the remote has 28 buttons, it can only send one signal at a time, not two or more, and there is a priority which button signal it sends. So normally only one output at a time can be activated. But I can get two outputs to activate simultaneously by sending a third remote signal. So instead of basically a classic plus shaped joystick on a gamepad with no option to press 'diagonally', I can make a diagonal function with four more signals. The remote has 28 buttons, so I should be able to be used 8 for a joystick, 8 more to say the receiver should also combine that joystick directs while activating the fifth output as a push button. Hopefully a couple of the remaining buttons can be used to be push buttons when the joystick is in null position, and one signal that says nothing at all is activated as a check that the radio signal from the transmitter is there. If the directional pad actually controls a vehicle, then a couple of the last buttons can be used to combine outputs that can otherwise never happen from the controller like up+down, left+right, and can do frequency control on the receiver output so that the same output goes through two or three RC filters so a low frequency signal controls one thing, while a high frequency signal activates something else, or just use diode switching on the output.
So many options. I kind of want to do that system just to see how good I can make it.
But I have electric motors.
I can build a radio-controlled model boat, and use electromagnets to pull a rudder. I can also use two electric motors and build a small radio controlled tank. I'll admit the horns in my forehead started to grow when I thought about how I deliberately can try and deceive people with a made-up sea monster or some kind of mechanical monster on land. Like a large walking insect or scorpion or something with just relatively simple cyclic leg movement and six legs. With maybe even 1-2 extra buttons to control claws or a tail. If I can make a good enough electric pump or valve, maybe a built-in flamethrower. If I hide the transmitter and antenna on my body and do the remote control in a small package, I can be pretend I control the model by voice, gestures or just with my mind, while my hand in the pocket press buttons and moving the joystick. I could actually do a 'monster on a leash' right now with a hidden joystick in the leash.
Can I build a simple receiver for the car key's 434MHz remote? Rolling code or whatever doesn't matter as it will be just 'is there a signal?', but I could probably it convert to a pure CW transmitter. Or can I make something out of the Tesla key? Even a short range of just a couple of meters would be useful, and it could be a physics experiment or something.
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Since the ship's radio will get a remote, we update the ship's radio installation with an external bell and Asta along with some of the crew help with that so Asta and they get practice for future repairs or maintenance. An signal line of painted, paper-wrapped and lacquered copper wire is pulled and fastened with insulators behind wooden veneer for extra protection, and a bell is placed under a small wooden cover outside above the deck door to the cabins so that someone is more likely to hear if the radio is buzzing, or in this case ringing. To disconnect the bell a small switch is installed on the cabin wall beside the radio so it can be switched off during use. We leave the bell plugged in while we test that it works, so the surprised sailors can hear the bell and learn what it sounds like, and know to inform Asta if it rings.
We make an improved Inverted V antenna installation on the ship, and it might not be optimal, but should be better than the loop. A better antenna is a better antenna. If this doesn't work we might literally have to go around the problem with the sails but attaching horizontal poles that simple place the antenna out over the boats side or high over the main sail, or I have to accept that one or both ends of the dipole might be moved or removed during some sailing or weather. There might just be a simple vertical antenna wire hanging from the aft mast or an inverted L antenna using the sea as the ground plane. What will be best for using ground wave or NVIS? I don't know. I'm a little worried that a wet sail can mess up the antenna's tuning, but nothing to do about it except know it might be an issue and test for it or compensate. Same with how the antenna will not be equally good in every direction so ships heading matters. We simply need to test to know which heading and tweaking the antenna is most effective in, and we will take measurements and test as the ships sail around to different locations. One test will be to sail around in a big circle somewhere a couple of days away while the mansion or ship is constantly transmitting, and by transmitting heading we should be able to hear which hearing works best and what works worst. The loop antenna will remain on the ship as a spare antenna, but it will be stored below deck. An improved 'quick' mount will be installed on the aft mast with a prepared antenna cable down to Asta's cabin, but it is not ideal if the antenna needs to be adjusted. Asta has interesting radio tests ahead of her and she is looking forward to them.
Since it was installed, the ship's crane have only been used for loading and unloading cargo, which is in port with furled sails or possibly if the ship's boat is put into the water. The crew has realised how nice a winch can be, and wants to try to save labour when sailing. So another winch is now attached to the deck for used during normal sailing. With the help of blocks and pulleys, they can winch in and handle the mainsail in a controlled manner, which helps when tacking or trimming sail. The same winch will also help to raise and lower the sail, and with the right rope course, the winch can also help with the aft sail as well, and help with the anchors. The most tiring and crew demanding work is during strong winds, and any help is good, and the winch will help make that work safer. In the future I will probably make an updated stronger winch especially for the sails if it works well. A winch is not particularly expensive, and it is quite easy to make one in wood that is not geared and just use long poles as levers, and Asta have seen one before. Just a round cylinder that pulls the ropes using with long poles as levers that are pulled out of holes and moved, and those holes also works as the lock that blocks rotation.
As we have worked we've also talk about installing lanterns, and although it is of less use when no one else is using it, it can be useful in certain occasions such as when approaching or leaving ports, or sailing together with other ships through the night. Sailing in the night is something that Asta likes when she can do it, and lanterns are important on long journeys with multiple ships which there definitely will be if my plans survive contact with reality.
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