Regarding the RF choke, you may use any coil at hand with 500uH or more. You can buy one, get it from an old TV set (peaking coil in the video amplifier) or using the full coil of a transistor radio ferrite antenna. The long rod of the last will help irradiate the RF field.
No, greatz bridge no. Look at google for "voltage tripler". 3 independent isolated diodes are needed and 3 electrolytic capacitor. 100uF @50 or 63V suffices.
This cristal may be used.
No, greatz bridge no. Look at google for "voltage tripler". 3 independent isolated diodes are needed and 3 electrolytic capacitor. 100uF @50 or 63V suffices.
This cristal may be used.
This schema will only oscillate and will put a clear carrier in the receiver. Perhaps a small amount of buzz as the ripple from the Ebb line. Enjoy radio too. I am ham from 1987.
Ok, I have old Iskra Savica radio for spares and will use ferrite antenna from there.
Will build voltage trippler.
I am happy with clear carrier for the start.
I'm a bit young (born in 95) and I was first fascinated by ham radio when I watched a movie Frequency (2000), lately I had been listening via WebSDR. It started with me being curious about UVB-76 station, later The squeaky wheel and similar stations... then I started searching "thru the dark" just moving across the band and it is addictive...
Sadly my generation has no interest in such things, not ham radio, not building audio amplifiers, nada...
I'm now 53. I started ham radio at my 16's. But law said that I am able to get my call with 18 so I used the Ham Radio Club call LU1EEE during my firsts tests. The president of such entity said me I may use it outside the activity hours of it.
I still enjoy radio and radio building restoring and modifying. There is an actual project publisher here as "Restoring and modding an old yaesu FT75B tranceiver".
Where are you from?
I still enjoy radio and radio building restoring and modifying. There is an actual project publisher here as "Restoring and modding an old yaesu FT75B tranceiver".
Where are you from?
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Joined 2009
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I bought an old HAM hf transceiver from an eBay estate sale a few years ago. It's got tube power amplifier and solid state receiver. I've never opened the box because I have no antenna. It needs a good outdoor antenna of decent size ($$$), that will survive lightning storms in the summer and ice in the winter, and there needs to be a feedthrough into my house which is not trivial and ties down where it can be used. So, no antenna. This is the single issue preventing me from doing something with it and furthering my electronics hobby into radio. I joined the local ham club but Covid came along so I never met anybody, I never received a single email or acknowledgement for joining the club either.
One idea that appeals to me is avoiding any feedthrough into the house. This would limit me to operating outside of the house which is fine on a warm and dry summer evening only or I have buy and set up a proper shack aka garden shed which is too big a commitment off the bat.
Another idea is to make a solar powered repeater and put it in the garden. I'd link to it from the house by bluetooth and avoid a feedthrough, avoid getting rf burns in the house etc. This isn't going to suit the ham transceiver I have so it'd be quite a project to start from scratch but an interesting option.
Always been interested in h.f. ham, especially building my own kit, but never got my license though.
One idea that appeals to me is avoiding any feedthrough into the house. This would limit me to operating outside of the house which is fine on a warm and dry summer evening only or I have buy and set up a proper shack aka garden shed which is too big a commitment off the bat.
Another idea is to make a solar powered repeater and put it in the garden. I'd link to it from the house by bluetooth and avoid a feedthrough, avoid getting rf burns in the house etc. This isn't going to suit the ham transceiver I have so it'd be quite a project to start from scratch but an interesting option.
Always been interested in h.f. ham, especially building my own kit, but never got my license though.
Usually you don't need an authorization to receive any signal. You can't radiate power over 100mW here, but it depends on local regulations.
And for using your receiver, you don't need an expensive one. You can build its own for a very small amount. Get a couple of good insulators like the depicted below and a piece of wire as long as you can. The longer it is, the bigger is the energy taken off the signal. Put both insulators at the ends of it; and the wire as high as you can and via a coaxial cable whose impedance is any, say, an excedent from cable TV may be, and hook them to the receiver. The live (inner wire) of the coaxial must be connected to the insulated long wire. Shield is unused at the aerial side, or ground it to a large metallic structure if close to it. Protect the joint between wire and coax from rain, moisture, dust and bugs. Take the other end of the coax to the receiver and enjoy. I really don't know if today are short wave radioststions still on air.
And for using your receiver, you don't need an expensive one. You can build its own for a very small amount. Get a couple of good insulators like the depicted below and a piece of wire as long as you can. The longer it is, the bigger is the energy taken off the signal. Put both insulators at the ends of it; and the wire as high as you can and via a coaxial cable whose impedance is any, say, an excedent from cable TV may be, and hook them to the receiver. The live (inner wire) of the coaxial must be connected to the insulated long wire. Shield is unused at the aerial side, or ground it to a large metallic structure if close to it. Protect the joint between wire and coax from rain, moisture, dust and bugs. Take the other end of the coax to the receiver and enjoy. I really don't know if today are short wave radioststions still on air.
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I'm from Europe, Slovenia.
I'm in local facebook sell / buy page, but equipment is rather pricey and mostly newer stuff... I'm more a fan of oldschool, amps, radios, cars, ... there is some soul in everything old.
I did some research about AM and I see the whole modulation with sound injection thing....
If my logic serves me right after building this circuit, I will be able to inject the sound signal somewhere in the circuit to make it transmit audio, right?
I still don't know where I would connect antenna, or will RF choke act as one?
Is there a place I could connect my oscilloscope to watch the modulation? What voltages I can expect there?
If my logic serves me right after building this circuit, I will be able to inject the sound signal somewhere in the circuit to make it transmit audio, right?
I still don't know where I would connect antenna, or will RF choke act as one?
Is there a place I could connect my oscilloscope to watch the modulation? What voltages I can expect there?
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Osvaldo - thanks!
To the original poster - why not make a synthesizer instead of a radio. I don't have any experience with them myself, but from what little I know, a synthesizer project gives you a chance to build all sorts of different tube circuit blocks such as oscillators, amplifiers, voltage controlled filters/amplifiers and other such stuff. It's the 'Jazz' of electronics projects where anything goes and everything is welcome. I have a box full of various tubes, TV tubes in particular, and I had thought about a synthesizer project as a way to put them to use. I have radio tubes, multi-grid tubes, diode-triodes, pentodes, power pentodes, all sorts of tubes. What I'll do with a synthesizer after making it I have no idea - give it to my kinds probably as some kind of cool device with glowing tubes!
To the original poster - why not make a synthesizer instead of a radio. I don't have any experience with them myself, but from what little I know, a synthesizer project gives you a chance to build all sorts of different tube circuit blocks such as oscillators, amplifiers, voltage controlled filters/amplifiers and other such stuff. It's the 'Jazz' of electronics projects where anything goes and everything is welcome. I have a box full of various tubes, TV tubes in particular, and I had thought about a synthesizer project as a way to put them to use. I have radio tubes, multi-grid tubes, diode-triodes, pentodes, power pentodes, all sorts of tubes. What I'll do with a synthesizer after making it I have no idea - give it to my kinds probably as some kind of cool device with glowing tubes!
Hy,
I might look into it one day, but mostly is my personal preference, radio is something I want to learn for some time.
It is not a common practice to inject any signal directly to the oscillator unless you expressely wan to modulate it in frequency FM. In any case you will have a phase modulated one PM that currently it is of little use.
I sincerely don't know about your skill in electronics rhus where to continue or stop your project.
I sincerely don't know about your skill in electronics rhus where to continue or stop your project.
https://www.diyaudio.com/community/threads/high-audio-quality-am-tuner.292628/page-8
https://www.diyaudio.com/community/...vintage-ft75b-tranceiver.391905/#post-7167013
Dou you have a 250~300VDC power supply and a small choke of say 10Hy?
https://www.diyaudio.com/community/...vintage-ft75b-tranceiver.391905/#post-7167013
Dou you have a 250~300VDC power supply and a small choke of say 10Hy?
Ok, got it.
Well about my skills...
To describe it as fast as possible...
I started as a kid, making battery fans and lights, swaping speakers in radios, opening up everything electrical and carefully putting it back together while parents were at work 🙄. So it's not new to me.
Last few years I had spent building / fixing / restoring IC amplifiers.
I also did some work with microcontrollers... My last project was adding usb / bluetooth player to stock BMW e39 Becker tape radio... alot of coding, i2c, can communication...
I was also working as a car electrician...
It's like that... as long as I have the schematic I will build it, to fix it I may need some help from time to time if things get complicated. But if one would say design me a schematic... well in most cases I would be in a dark.
I have a lot of practice, but not much theory.
I don't have the PSU, but I could make one using isolating transformer, capacitors, diodes.... if this is enough.
I must look in my parts collection for choke... there should be something.