Nick, this is actually quite informative teardown! Thank you for your time and for doing this. Thumbs up from me. It is, like you said, a good quality switched mode power supply that sends DC (21v 1.2A) toward the satellite head using the antenna signal cable. The main element inside the metal cube is a capacitor allowing the RF signal (AC) ranging 2-2150 MHz to pass thru all the way but blocking DC from going toward the TV set's end. It's just a clever way of using the same coaxial cable for RF signal (AC) and DC power needed at the dish, hence "power inserter." BTW, Laptops usually need around 3+ Amps, so 1.2 from this one would not be sufficient.
For those who may be interested in a little more tech info: One can measure the value of the coupling capacitor that blocks DC, but passes RF, without prying open the metal box. The value is 0.01uF. Signal loss is very low at TV frequencies. The later model, PI21R3-16 uses a different RF enclosure with a hole in the side (!), so I would conclude that the shielding is not as good as the dash -03 model. Capacitor value is 0.01uF. The PWM IC that does the switching magic is unmarked. If the device were known, it would be straight-forward to adjust the output voltage and repurpose the power supply. That being said, the dash -03 model lends itself to an easy mod whereby a TO-220 style three-terminal regulator IC can be affixed to the ground screw on the metal inserter box. Unsolder the red wire from the feedthru and wire in the IC. Many CATV/TV drop amplifiers operate on 12V (some recommend 15V, but I've found that they work just as well on 12V). With a 12V regulator, the heat dissipation with a 200mA load is about 2 watts and the metal box makes a great heat sink.
If i put longer wires and put a red and black clamp on it could it be used to charge up a car battery. Just being curious cause I have one and im tempted to try experiment with it.
My swm box just went out(since 10/2016) Someone told me if I can get it apart w/o damaging it to, replace the fuse!? I have it apart now but, which one is the fuse and, how many fuses are there!? Awesome video. Thanks so much.
I don't know which model you have, but if it's the same or similar to mine, there are no fuses, or at least none that are easy to find or replace. Thanks! And no problem.
Use a pair of pliers and you can unscrew the F-connector posts. you will destroy the threads and trash it but it will let you peek inside a bit, also you could carefully cut the glue around the back and pry the back off. in some 2 way splitters there is very little inside them other than a few resisters.
+canoestothemoon none that I can think of, but I haven't done much digging. Could reuse the power supply without the adapter box for something like a laptop that uses that voltage or something similar.
Aside from repurposing the power supply like he said, I would try repurposing the "potted" F-type connector piece. It's a bias tee. So if you apply a DC voltage across the red and black wires, it will bias the SWM port while the IRD port will not have any DC bias.
There is laid back and carefree, and then there is lazy and I don't give a f* about your time. I don't know which the host was trying for, but I think it comes off as the latter. Since I am learning about these today, I'll share some of what I've gleaned so far. As expected, the magic happens in the unopened metal box. It is called a bias-t. It supplies power to the LNB at the focus of the satellite dish while keeping the 21 volts DC out of the receiver and keeps signal from leaking into the power supply. Since capacitors resist DC but pass AC, capacitors are used to keep unwanted DC out of the set top box or radio equipment. Since inductors (coil or wire) work the opposite way, inductors keep the AC satellite signal from going into the switching power supply (and noise from the power supply out of the signal) but allow DC to pass into the line to power the LNB. Since the real world is more complicated than my explanation, inductors and capacitors are imperfect and to a degree that somewhat depends on the frequency of the AC, several inductors and maybe capacitors are generally used to ensure proper blocking, and avoid unwanted resonances. Since the frequency is high, around 2 gigahertz at that point, the parts can be pretty small, maybe just copper traces on a circuit board that act like coils or wire, and use the board or air as a dialectic in a capacitor--but I don't know enough to know if that might be done in this case which is part of why I really wanted to see inside that thing. Maybe a bit off topic, but the LNB can do quite a lot. In older systems a combination of voltage and the presence or absence of a 22KHz "tone" sent down the line from the receiver put the LNB into different modes, mostly frequency range and switch between right and left polarization reception. It also down converts the satellite frequencies from around 10-20 gigahertz to around 2 gigahertz, and amplifies the signal. However, the power injector in the video is for a newer technology called SWiM or SWM which does the old stuff and more using protocols I haven't found anything about so far. Added features include tuning in a narrower frequency range corresponding to specific satellite transponders and I don't know what else. I'd like to know the protocols and more to see if I can hack together a really crappy radioastronomy telescope and/or just mess with picking up man-made signals on my SDR radio that are otherwise too high for me to tune in. Also interesting to me, if I understand it correctly, the LNB and radios, down-convert high frequency signals by mixing in a known high frequency signal. The two combine to create a lower beat frequency. It is similar to what you hear when two slightly out of tune musical instruments try to play the same note--it kind of gets louder and quieter in pulses as the tones interact constructively and destructively. That pulsing is the down converted signal. I attempted to do something like that to listen to the ultrasonic calls of bats. I heard something, but honestly, it sounded like shit, so maybe I don't know jack, or maybe I was just hearing bats cussing me out for making annoying sounds.
Are the input and output of the power inserter completely isolated, or should you be able to get some continuity. My TV is out I checked the solid wire connection between the 2 and get nothing.
Change your title to "power supply babbling" because that's what your video is. 6minutes without any teardown of the actual rf, just rambling on about the power supply. what a bloody waste of time.
LOL. I will.....Its not hard to figure out. Its funny to me the lengths people will go to become completely unhinged on a video that you never asked for personally and just because it did not help you out with whatever it was you were so desperately needing to find out it may have helped someone else, well, like me, I found out exactly what I came here to find out. With my small amount of knowledge I was able figure out other questions I had after watching the video. Which you too can find by reading the other comments posted below one being from Karl Heavy Marx. That poster goes into a depth that I would not have even thought about but somehow it too answered a question I formulated after pondering a recycle purpose for this box I found in the trash. Anyways if I could type a specific amount of words for you to read that would equate to wasting 6 more minutes of your bloody time I would. However I do not know the time it takes you to read words typed out on a page. I couldn't possible account for the variables of your getting salty and bent, ready to launch a counter jab ad homenem. Who knows you may be one of those people who will come back with that whole I didn't waste my time to read that novel of a response as it wasn't worth my time, but you secretly did read it, you just didn't want me to know how far you got in this scalding from a complete stranger on a web of public squares full of drags. So there's that. I thought your reply was a bit harsh and you could use a pint to cool down that temper of yours. Good day. 3 years later.
Nick, this is actually quite informative teardown! Thank you for your time and for doing this. Thumbs up from me. It is, like you said, a good quality switched mode power supply that sends DC (21v 1.2A) toward the satellite head using the antenna signal cable. The main element inside the metal cube is a capacitor allowing the RF signal (AC) ranging 2-2150 MHz to pass thru all the way but blocking DC from going toward the TV set's end. It's just a clever way of using the same coaxial cable for RF signal (AC) and DC power needed at the dish, hence "power inserter."
BTW, Laptops usually need around 3+ Amps, so 1.2 from this one would not be sufficient.
I came to find out
How you hook this up to Box
This did not help me
For those who may be interested in a little more tech info:
One can measure the value of the coupling capacitor that blocks DC, but passes RF, without prying open the metal box. The value is 0.01uF. Signal loss is very low at TV frequencies.
The later model, PI21R3-16 uses a different RF enclosure with a hole in the side (!), so I would conclude that the shielding is not as good as the dash -03 model. Capacitor value is 0.01uF.
The PWM IC that does the switching magic is unmarked. If the device were known, it would be straight-forward to adjust the output voltage and repurpose the power supply. That being said, the dash -03 model lends itself to an easy mod whereby a TO-220 style three-terminal regulator IC can be affixed to the ground screw on the metal inserter box. Unsolder the red wire from the feedthru and wire in the IC. Many CATV/TV drop amplifiers operate on 12V (some recommend 15V, but I've found that they work just as well on 12V). With a 12V regulator, the heat dissipation with a 200mA load is about 2 watts and the metal box makes a great heat sink.
If i put longer wires and put a red and black clamp on it could it be used to charge up a car battery. Just being curious cause I have one and im tempted to try experiment with it.
My swm box just went out(since 10/2016) Someone told me if I can get it apart w/o damaging it to, replace the fuse!?
I have it apart now but, which one is the fuse and, how many fuses are there!?
Awesome video. Thanks so much.
I don't know which model you have, but if it's the same or similar to mine, there are no fuses, or at least none that are easy to find or replace. Thanks! And no problem.
Thank you very much for your reply.
You're absolutely welcome.
Use a pair of pliers and you can unscrew the F-connector posts. you will destroy the threads and trash it but it will let you peek inside a bit, also you could carefully cut the glue around the back and pry the back off. in some 2 way splitters there is very little inside them other than a few resisters.
Thanks! I'll try that! I was probably going to do a followup soon.
just found one of these while scrapping tonight. Are there any known hacks/ repurposed applications for this device?
+canoestothemoon none that I can think of, but I haven't done much digging. Could reuse the power supply without the adapter box for something like a laptop that uses that voltage or something similar.
Aside from repurposing the power supply like he said, I would try repurposing the "potted" F-type connector piece. It's a bias tee. So if you apply a DC voltage across the red and black wires, it will bias the SWM port while the IRD port will not have any DC bias.
Now I'm even more clueless Holy fuck
There is laid back and carefree, and then there is lazy and I don't give a f* about your time. I don't know which the host was trying for, but I think it comes off as the latter. Since I am learning about these today, I'll share some of what I've gleaned so far. As expected, the magic happens in the unopened metal box. It is called a bias-t. It supplies power to the LNB at the focus of the satellite dish while keeping the 21 volts DC out of the receiver and keeps signal from leaking into the power supply. Since capacitors resist DC but pass AC, capacitors are used to keep unwanted DC out of the set top box or radio equipment. Since inductors (coil or wire) work the opposite way, inductors keep the AC satellite signal from going into the switching power supply (and noise from the power supply out of the signal) but allow DC to pass into the line to power the LNB. Since the real world is more complicated than my explanation, inductors and capacitors are imperfect and to a degree that somewhat depends on the frequency of the AC, several inductors and maybe capacitors are generally used to ensure proper blocking, and avoid unwanted resonances. Since the frequency is high, around 2 gigahertz at that point, the parts can be pretty small, maybe just copper traces on a circuit board that act like coils or wire, and use the board or air as a dialectic in a capacitor--but I don't know enough to know if that might be done in this case which is part of why I really wanted to see inside that thing.
Maybe a bit off topic, but the LNB can do quite a lot. In older systems a combination of voltage and the presence or absence of a 22KHz "tone" sent down the line from the receiver put the LNB into different modes, mostly frequency range and switch between right and left polarization reception. It also down converts the satellite frequencies from around 10-20 gigahertz to around 2 gigahertz, and amplifies the signal. However, the power injector in the video is for a newer technology called SWiM or SWM which does the old stuff and more using protocols I haven't found anything about so far. Added features include tuning in a narrower frequency range corresponding to specific satellite transponders and I don't know what else. I'd like to know the protocols and more to see if I can hack together a really crappy radioastronomy telescope and/or just mess with picking up man-made signals on my SDR radio that are otherwise too high for me to tune in.
Also interesting to me, if I understand it correctly, the LNB and radios, down-convert high frequency signals by mixing in a known high frequency signal. The two combine to create a lower beat frequency. It is similar to what you hear when two slightly out of tune musical instruments try to play the same note--it kind of gets louder and quieter in pulses as the tones interact constructively and destructively. That pulsing is the down converted signal. I attempted to do something like that to listen to the ultrasonic calls of bats. I heard something, but honestly, it sounded like shit, so maybe I don't know jack, or maybe I was just hearing bats cussing me out for making annoying sounds.
Are the input and output of the power inserter completely isolated, or should you be able to get some continuity. My TV is out I checked the solid wire connection between the 2 and get nothing.
Los que hablamos español👁️👄👁️
Change your title to "power supply babbling" because that's what your video is. 6minutes without any teardown of the actual rf, just rambling on about the power supply. what a bloody waste of time.
LOL. I will.....Its not hard to figure out. Its funny to me the lengths people will go to become completely unhinged on a video that you never asked for personally and just because it did not help you out with whatever it was you were so desperately needing to find out it may have helped someone else, well, like me, I found out exactly what I came here to find out. With my small amount of knowledge I was able figure out other questions I had after watching the video. Which you too can find by reading the other comments posted below one being from Karl Heavy Marx. That poster goes into a depth that I would not have even thought about but somehow it too answered a question I formulated after pondering a recycle purpose for this box I found in the trash. Anyways if I could type a specific amount of words for you to read that would equate to wasting 6 more minutes of your bloody time I would. However I do not know the time it takes you to read words typed out on a page. I couldn't possible account for the variables of your getting salty and bent, ready to launch a counter jab ad homenem. Who knows you may be one of those people who will come back with that whole I didn't waste my time to read that novel of a response as it wasn't worth my time, but you secretly did read it, you just didn't want me to know how far you got in this scalding from a complete stranger on a web of public squares full of drags. So there's that. I thought your reply was a bit harsh and you could use a pint to cool down that temper of yours. Good day. 3 years later.
Worthless
Duh