Building And Testing The Sputnik Regenerative Receiver - Step By Step

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A simple regenerative receiver designed for the 40m amateur radio band with decent receiving capabilities, the perfect project for beginners in homebrew radio receivers.
PCB Boards available for order in the blog article.
73, YO6DXE
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*** OLDER VERSION OF THE RECEIVER:
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[@VK4MUD]

Thank you so much for this project. I have my PCB from PCB Way and have nearly all the parts. The detailed video on making the inductor is just perfect. I will let you know when I have built it. 73. John VK4MUD.

[@dxexplorer]

Thanks so much John. Ohh yes please let me know how it turns out. I am building one more as we speak as a present for a kid 😁😁. Both the one I build now and the one in the video are made nearly 95% using old salvaged components 😁. 73, YO6DXE.

[@instructoruldemeditatie2367]

Although I learned to work on a prototype board or even deadbug style (I prefer the style for the speed with which you can build), it does not compare to a clean circuit, when you know for sure that the circuit is perfectly functional, and you don't have to burn your brain checking tens of times each connectionp, and much, much easier to repair in the future if necessary. Very nice! Congratulations for the step by step video!

[@dxexplorer]

Thank you so much ( multam frumos 😁 ). I totally agree with you. I was working recently on that simple transmitter I posted the video about some while ago. Initially I built it on a breadboard and it just wouldn't work. I spent two hours trying to figure out what connection I did wrong. Turns out at the end that the breadboard had bad connections. So there is two wasted hours when I could do something productive. Now I do most of the tests for all projects more like the dead bug style... then just design a PCB board and work this way from now on. I ended up spending four days to make each video I post... it became a lot like a second job... except that I work for free 😅😅😅. So yep... working fast and knowing that you have no headaches trying to figure out things is really nice. Thanks so much and I hope you have a fantastic rest of the week.

[@instructoruldemeditatie2367]

​@@dxexplorerYes,creating quality content is taking a lot of time and not many understand that.Glad to watch your video and your beautiful built reciever .With this board even a beginner can be succesful in building his own radio . A blessed day and a wonderful week to you too! 73

[@dxexplorer]

@instructoruldemeditatie2367 With the beginner in mind I made this receiver... simply because I was a beginner when I started the KZbin channel and made the first video... and it helped me learn a lot. I also have my amateur radio license thanks to this receiver too. Just because I had enough of just listening and wanted to be able to transmit as well. Now I have the license and no free time to stay on radio. How funny is life hahaha. 73.

[@4L1LAT]

Now that's better 😁 it came out beautiful, thank you for video and 73!

[@dxexplorer]

I also love it hehe. And love the fact that is so easy to just solder the components and no need to deal with the PCB making part. So much easier for me now. 73, YO6DXE.

[@adanlewis7489]

Very nice Ciprian! My Sputnik PCB is on the way

[@dxexplorer]

Yuhuuu... I also just finished building a second one ... present for a kid. Works like a charm 😁😁. Let me know how yours turns out and if you have any issues. It helps me put more info on the blog. 73, YO6DXE.

[@mikej-38qso22]

As promised and a good demo video! the Toroid coverage is just what I was looking for, now I understand the placement of the windings. 73 Mike K7AJQ

[@dxexplorer]

Excellent... really glad it makes sense. I really hope the video helps people understand easier than just the drawing from the blog. If you want to cover from 7.0 to 7.3 maybe put 38 turns and lower the value of C16 ... I just can't tell how low as I never tried but maybe around 68pF. If that still doesn't do the job then maybe the easier way is a Varicap with a little more capacitance than the 1N4001 diodes I usually use or even the BB105 I used in the one from the video. I think that is what I used I can't remember for sure.

[@QRP.lifestyle]

Very nice receiver

[@dxexplorer]

Thanks so much David. I put on the "to build" list the one you sent me yesterday as well 😁. 73 buddy, YO6DXE.

[@MatthiasLenardt]

Finally you found out that the frequency counter really works with some turns on the main coil as the company mentioned. On your counter video you said it wouldn't work. Good to know. Much love, Matthias

[@dxexplorer]

Ohhh no no... this is a modified one. The original as it is as a kit... that one won't work. The modified version is transforming the crystal tester into a preamplifier. 73, YO6DXE.

[@MatthiasLenardt]

​​@@dxexplorer ​Thank you so much for your answer. What a pity, I wanted to buy this kit. Can you give me any information where I can find the modification? That would be a show. I really wanted to use this kit in several experiments. Thank you in advance. Much love, Matthias ( DL1NDG 👋 )

[@dxexplorer]

@MatthiasLenardt Yes I was just about to put one more comment with the link haha. Just so I don't put two links... if you search in my videos... there is a direct conversion receiver for the 80m band. In that video I am using another type of frequency counter and I like it more. That one does not need a preamplifier or any modifications and is a lot smaller. 73, YO6DXE kzbin.info/www/bejne/ZnPboYCja7h_pacsi=qvJGw5aIOFDu-9JQ

[@MatthiasLenardt]

​@@dxexplorer Thank you so much. Very kind from you. Have a fabulous week.

[@dxexplorer]

@MatthiasLenardt Always a pleasure. Thank you as well and I hope your week will be just as fantastic. 73, YO6DXE. P.S. Good luck with all the projects.

[@crescencioandrade]

Amazing!

[@dxexplorer]

Thank you 😁🙏🙏 73, YO6DXE.

[@danielborsan1004]

Very nice

[@dxexplorer]

Multam mult 😁. 73, YO6DXE.

[@son3dra]

hi Ciprian, only put two varicap bb109 instead the 1n4001, makes 350khz range! fix c16 to 100pf...amazing

[@dxexplorer]

Ohhh perfect. Excellent then. Thanks for letting me know. Amazing 😁😁. 73, YO6DXE.

[@steviejanssen]

I think you have the most relaxing voice of all HAM radio operators 😁 73's ON1BSJ

[@dxexplorer]

Hahahaha... thank you. Let's say I practiced over the years doing voice over for my sailing videos in the past ( ha ). 73, YO6DXE.

[@steviejanssen]

@@dxexplorer By the way, my XYL is from Onesti, Bacau, next time we go there I'll put my Xiegu x6100 and a QRP antenna in my luggage, just started HF finally after being a 2m/70cm guy for over 30 years. Trying to get CW in my brain now 🥵

[@dxexplorer]

@steviejanssen Ohhh then I am looking forward for a QSO. Let me know. Ohh I am also learning the code now but very slow because I don't have much free time.

[@ronsingh]

Wow, great channel! Just got here via a YT recommend.I applaud you re-using as much material as possible and to that end I want to do the same with wire off of discarded transformers and inductors, but I wonder, how to determine the gauge of the reclaimed wire? Do you use a micrometer or a caliper? Thanks a bunch and I am now subscribed🙂

[@dxexplorer]

Thank you so much for the nice words. Ohh yes is fun to repurpose old jung and bring it back to life 😁. I love doing this as much as possible and always trying to combine new with old and see what I can come up with. To measure the wire... I have no clue how the tool is called in English hahaha.... its been a while since I left US so my English is getting rusty... but a micrometer would do great yes. Thank you for subscribing. 73, YO6DXE.

[@Ismad04]

Great project. I just ordered the PCBs from PCBway. Keeping my fingers crossed that I can get theradio to work. This video helps me prepare for it. Btw, your frequency counter is working now. What modifications did you make? Thanks!

[@dxexplorer]

Ohhh you will. If something don't work just send me an email and I help you figure it out. The frequency counter... I had to modify it. Here is a link to the video I watched for the instructions: kzbin.info/www/bejne/ZnPboYCja7h_pacsi=3F7Lt7HM4PfIMNDO 73, YO6DXE

[@W1RMD]

Very cool video! You make this look easy and put away a lot of fears with choosing and winding toroids and inductors that I have. The great lesson on toroids is an added bonus. I'm curious why on two different videos I've seen you solder d4's cathode closer to the circuit board? Does that effect the performance? Great looking circuit design! Thanks and 73.

[@dxexplorer]

Ohh yes the toroids are the easiest to make for me. About the diodes... no not at all... is just to save space on the board I install them vertically instead of horizontal. 73, YO6DXE.

[@sv2tcb]

The filming and editing crew should get an increase in their salary haha. Amazing video, really enjoyable to watch. I think this video would help a lot of people. A question, is there a way for me to edit the pcb and do some experiments? Thank you 73

[@dxexplorer]

If you have Eagle I guess you could. We speak on email and we will find a way. Filming crew hahaha. 😆😆😅

[@sv2tcb]

@@dxexplorer if it is free, i will download eagle and start using this software.73

[@dxexplorer]

@sv2tcb sounds great buddy. 73

[@sv2tcb]

@@dxexplorer i will send you a voice mail

[@dxexplorer]

@sv2tcb I will send you an email )))

[@DoniSouzazs]

I built 2 recent versions and also made my own version using a fet transistor and had better results.

[@dxexplorer]

FET's are always more superior than BJT's... unfortunately not always easy to find on junk boards like BJT's... and because the project was more inclined for kids and beginers... 2N2222 or any other similar transistor was the best choice. I also have one with a FET and is way better. Coming soon with that one as well ))). 73, YO6DXE.

[@CanabraGalhardo]

Top heim estou com uma versão dessa que o Doni desenvolveu logo irei montar

[@dxexplorer]

@CanabraGalhardo Ah, isso é ótimo. Eu sei sobre o que você está falando. Deixe-me saber como funciona e se você gosta. Não é um receptor com resultados surpreendentes, mas é bom o suficiente e muito divertido de construir e aprender com o processo. 73, YO6DXE.

[@ozarktreasures8044]

Interesting. Which transistor did you replace with the FET, and how did the GDS leads correspond to the EBC connections on the board?

[@dxexplorer]

I didn't... this particular schematic is strictly with NPN transistors.

[@danamarcy5414]

Thanks Ciprian. I managed to get PCBway to process my order. Thanks in Advance Dana VE6KBI in Canada

[@dxexplorer]

Ohhh glad to hear that. Let me know how it works after you receive it. Yesterday I just built one more as a present for a kid. So far both worked like a charm. Except a bad potentiometer. Not sure what they do these days but the quality of the components is a disaster. 73, YO6DXE.

[@danamarcy5414]

Hi Ciprian. I received my order today- looks very nice. Do you have a preferred supplier for parts? Mouser/Digikey or other? VE6KBI in Canada.

[@dxexplorer]

@danamarcy5414 I must make you laugh, but the best supplier for me is the junkbox 😅😅. 99% of the components I use are old parts recovered from old boards. I need to keep building more while spending less. If the components are good I see no reason why buy new ones. But for brand new parts... I would say that any of the well known suppliers must be ok. The only one I stay away from are the stores that sell components really really cheap. I learned my lesson and I know now that those are some fakes and whatever I buy has nothing to do with what is written on them 😅. Glad you like the board... I hope it also works 😅🙈. I am excited and I can't wait to hear how it sounds. 73, YO6DXE.

[@son3dra]

hi Ciprian, I wanted to replace the coil with the toroid, but the number of turns for L2 is 32 (as on your page) or 36 as you say in the video?

[@dxexplorer]

I use 32 turns... for the T50-2 ( red ) or 36 for T50-6 ( yellow ). But it depends also on the manufacturer of the toroids... some are not so "original" so the number of turns may need to be adjusted so you don't mess with the capacitors. Usually I put 34 and then take one turn out at the time until it resonates on the right portion of the band. Most of the time using the toroids from my friends at roWaves was easy because it works with 32 turns right away no need to tweak anything ))).

[@son3dra]

Hi Ciprian, great work! I received the PCBs yesterday and started assembling Sputnik. A curiosity... what did you use to unravel the PCB? Thanks again

[@dxexplorer]

Ohhh that is great. I sent the boards I had to some friends and they also started building it. I didn't understood the question ? What do you mean reveal the PCB ?

[@son3dra]

@@dxexplorer Sorry, I meant what do you use to design PCBs? Because I use kicad but I don't like its footprints and the pads it uses

[@dxexplorer]

@son3dra Ohhh now I understand hahaha. Originally I started making designs using Express PCB. I created a custom components library just as I liked them. The problem was that I could not export Gerber files. So I moved to Eagle and started over with all the designs. I also created a custom components library so the boards I design will be easy to make at home using the toner transfer method. For this all components are having bigger pads than normally and also the traces are thiker.

[@user-gn6xj8tg1p]

Cool

[@dxexplorer]

Thanks so much. 73

[@son3dra]

hi Ciprian, Sputnik assembled and working! Could you give me the link with the modification to the crystal tester to work well as a frequency meter? Thank you

[@dxexplorer]

Ohh yes of course. If is the same as the one I used in the video... here is the link to the video with the modifications that have to be made. The crystal tester won't work anymore as it will become a preamp after the modifications. kzbin.info/www/bejne/ZnPboYCja7h_pacsi=kaTprHF2750F7UqH If you look back on the videos I posted... you will find a video about a direct conversion receiver for the 80m band. In that video I am using another frequency counter. That one works with ought any modifications.

[@son3dra]

@@dxexplorer thank you very much

[@dxexplorer]

@son3dra Always a pleasure. 73, YO6DXE.

[@badgerchillsky535]

I have a question. Watching you build the coil I was wondering, do the slight overlaps in your windings affect the calculations? Would it be better for the wire to enter the tube on the same line? Or does it matter that there is an overlap?

[@dxexplorer]

You talk about the PCV coil ? Probably yes there may me a slight difference from the calculations in the way I am making the coil. But also too small to affect anything. I always build them like this as they seem really need and stable on the PCB board when installed ))). Honestly I think no matter how well we make them, there will never be two identical ones just because of the way we make them... but they are pretty close )). 73, YO6DXE.

[@ozarktreasures8044]

Would it be possible to make plug in coils for different bands, or would the capacitance of the tuning circuit prevent that?

[@dxexplorer]

The can be done yes. As example let's say the variable capacitor is about 20pF. In our case the diode tuning I think is around 9pF. We can make plug in coils using a combination of the coil, C15 and C16. These will for them coil plug and can be changed for diferent bands.

[@ozarktreasures8044]

@@dxexplorer So C15 and C16 will become part of the removable coil assembly?

[@dxexplorer]

​@@ozarktreasures8044​@ozarktreasures8044 Yes because they will be band specific. One is to adjust the receiver in the right portion of the band... and the ceramic one the bandspread capacitor.

[@dxexplorer]

@ozarktreasures8044 send me an email when you have time... there is a contact form on the blog. And this coming week when I have a little time I will explain a little more in detail.

[@migalito1955]

I think I might order the kit you posted recently. I just bought a RS 918 so it may have to wait till December. 73 Kc2wvb

[@dxexplorer]

I am waiting until there are a few more available so I can also order one for a giveaway here on the channel at 5K. Would be nice i think. For me I like using recovered parts ))). 73, YO6DXE. And good luck building it. Let me know how it goes ( when the time comes no rush ).

[@migalito1955]

@@dxexplorer Yep, I hear you on salvaged parts. I build a lot of furniture and even one stringed instrument with salvaged wood. I have 40, 15 & 10 meters. Someday we ought to see if we can hear each other on one of the trio. Wish I had 80 meters but not yet....

[@dxexplorer]

@migalito1955 well at least I have 40m out of those three )). I only have the tr(u)SDX at the moment to play with, so 80, 60, 40, 30 and 20m.

[@migalito1955]

@@dxexplorer Ok, me too I am only Qrp although I do have one of those osg-50 small amps. I bought it for very little and have only tested it using just 0.8 watts input to see what it would output. It output 28 watts on 40 meters at that level of input. To get such a low level input I only used 9 volts with at max 2 amps to power an HF Signal's bitx-40. The bitx-40 is normally around 5 watts and I do like having 20 watts if ever really needed. As far as I am concerned 20 is all you ever really need and often less. My 15 meters comes from the 40 meter inverted V I use. 15 is resonate on the 40 meter antenna and works really well. I use a very low inverted V and its pretty NVIS. I had to use the folded dipole design for each element using speaker wire because near the ground impedance decreases and the folded dipole transforms, depending on wire spacing, a lower impedance up to 50 ohms. The speaker wire spacing gave me a perfect 50 ohms, but having the peak of the V only 12 foot above the ground I doubt that I could hit Europe, but 15 on the same antenna might not have such a steep take off angle and actually cross to Europe.

[@son3dra]

Hi Ciprian, I was playing with Sputnik to change the working frequency (I wanted to go to 9610KHz and listen to "objective DX" on Sundays). While with your values on 40m I had a range of 200KHz, on 9MHz I was unable to go beyond 40KHz of frequency range with C16 133pf and L2 14 turns (L1 always 8 turns). As tuning diodes I used 1N4007 which should have the same capacity as the 1N4001. Suggestions to make frequency and bandwidth switching more flexible? Thank you

[@dxexplorer]

I don't know if I understood right.. but you got it tuned in 9MHz... but you need to cover more bandwidth with the same diodes ? If yes... then the trick I made on the 80m band in order to cover the entire band was to calculate the resonant circuit with a higher value of the inductor and smaller capacitance in parallel. The disadvantage is that at times is not as stable in frequency. Another option it would be to calculate everything for 10MHz for example... and in parallel with the trimmer capacitor, to also use a variable capacitor. But then the diode tuning becomes more like fine tuning. Let me know...

[@son3dra]

@@dxexplorer Exactly, since on 7MHz the bandwidth is about 200KHz, I expected that even on 9MHz it would be larger than the 40KHz I have. I'll make do with 40KHz...I don't want to lose stability. After all, it's just an experiment

[@son3dra]

With 40KHZ I cover the 9610KHz that interested me 🙂

[@dxexplorer]

@son3dra Is diferent yes. From what I noticed is that depending on the band... to cover all the bandwidth we need there has to be a ratio between the inductance and the parallel capacitor. It is fun to experiment, but sometimes it also comes with a lot of headaches hahah. I know what I am saying. I think the easiest solution would be just to replace the diodes with some varicap that has more capacitance at the 9v we have there in the circuit. I actually want to test a few at some point when I have the time and see how much I can cover with one high capacitance varicap.

[@son3dra]

@@dxexplorer in fact I was thinking of the same thing, that is, using varicaps instead of normal diodes or trying to look for diodes with a larger residual capacity. Anyway, thanks for your availability. And if it works on Sunday, I'll post the video of listening to the show.

[@hobo1uk]

Hi. Diode 4 = ? is this to be installed on the latest PCB-Board if so what is it ? 73.michael.M7MZX

[@dxexplorer]

Hi Michael... is optional. It does deems to help a little in frequency stability... but is not a must. Is a 9.1 Volt Zener diode. 73, YO6DXE.

[@musasugen2364]

what should be the diameter of the wire wound on t50-2 ?

[@dxexplorer]

Anything between 0.3mm to 0.4mm would do. As long as it fits. I think I used 0.35mm if I remember well. I take the wire out from the secondary of old transformers.

[@user-ec6th3ch2m]

what is that frequency measuring device?

[@dxexplorer]

Here is a video about it: kzbin.info/www/bejne/nX-xg6F6qt96htksi=bV9zW4zyrSwT8ujP But in order to work with this receiver I had to do some modifications to it.

[@skr4021]

Bro which site u're using for coil inductance calculator

[@dxexplorer]

Coil32 for the PVC pipe coil, or toroids.info for the toroid version. The finished coil will never have the calculated value of course... but you will be close enough.

[@skr4021]

@@dxexplorer 73❤️

[@MrTauron77]

Az LM386-os IC esetén a 2-es 4-es lábra én 220 nF míg a 3-as 4-ed lábra 1 nF kondenzátort kötnék, úgy is használható lesz a vevő?

[@dxexplorer]

I don't know i never tried. Technically what you do to the audio amplifier should not affect the receiver side. But you have to be careful with the LM386 as it has the bad habit of going into self oscillation depending on the configuration used.

[@RA-Arg]

Perfect explanation! greetings from Argentina! LU8ARM

[@dxexplorer]

Glad you like it and thank you for watching. Greetings from Romania. 73, YO6DXE.

[@ranbirbhattacharyaranbir]

Sir,What is the gauge and mm of antenna wire.

[@dxexplorer]

You can either use any random wire that is at least 8-10m long as antenna, or an active mini-whip antenna, or I will leave you a link to another video about a prope EFHW for the 40m band... a cheap version: kzbin.info/www/bejne/ZpLUY2ednLGZj68si=bnYW8_264t36UXJC

[@musasugen2364]

hi sir What value diode can I use instead of bb405?

[@dxexplorer]

I used a lot two 1N4001, 1N4002, 1N4004, 1N4007... try one of these. Is just a little less capacitance but not much.

[@musasugen2364]

thank you very much for the information

[@dxexplorer]

@musasugen2364 Always a pleasure my friend. 73, YO6DXE.

[@why.k5max]

I want to ask if I need to install a 470pf capacitor on C11, will it have an effect if not installed?

[@dxexplorer]

Ohhh yes it has big effect. That is part of the oscillator circuit so with no 470pF capacitor the circuit will not work at all. 73, YO6DXE ( If you don't have a 460pF capacitor you can try 500pF or 1nF for now as a temporary solution and see if it works. It should but the results won't be so great. You can then replaced it later when you have the right value. )

[@why.k5max]

@@dxexplorer Yea, I don't have stock for 470pf, what if I use 1nf, what should I change? coil or something else?

[@dxexplorer]

@why.k5max No need to change anything else, is just that the oscillator may not perform so great. Basically it will affect the regeneration of the receiver.

[@lampyelektronowe]

👍

[@dxexplorer]

🙏🙏

[@danielborsan1004]

frecventmeter where we buy?

[@dxexplorer]

The one in the video is not so good ... it works but it also comes in a kit and you must put it together and also make modifications in order to het it to work properly. Email me please and I will send you a link to the one I usually use... not the one in the video. So far I found it on AliExpress... still trying to find someone in Romania that sells them. No luck so far.

[@cioboatamarian]

Salut! Găsesc sa cumpar kitul? Mulțumesc!

[@dxexplorer]

Salut Marian. Era la un moment dat un nene pe eBay de mi-a cerut voie sa vanda kit-ul. Nu stiu daca o mai fi ca ba era ba nu mai era si am scos link-ul din articol. Poti sa cauti un pic pe Google. Daca nu doar placute PCB direct de la PCBWay, sau au optiunea de a-l cumpara gata montat de ei, apoi trebuie doar reglat. Uite am gasit link-ul de la nenea de mi-a cerut aprobare sa-l vanda: www.ebay.co.uk/itm/296473243274

[@captmohelsaadany6751]

👍👍👍👍❤️❤️❤️❤️❤️

[@dxexplorer]

Thanks buddy. 73, YO6DXE.

[@DarrenSteele-mx3ks]

I was excited to start UNTIL you started to measure your windings with some device I had never seen before and also you are adjusting trimmers well I have "knowledge" of electronics maybe even soldering but that was WAY too much for me so I'm scared now to build this lol

[@dxexplorer]

Hahaha... is not as hard as it looks. The device ( nanoVNA ) I am not even sure it gives me the exact inductance, but at least I have an idea. If you build the coil as in the video you should have no problems at all. Is important to respect the number of turns and the diameter of the wire and the coil ( in case you use the PVC pipe version ). But you can always email me when you go trough that process and I can help you out to tune it etc.

[@DarrenSteele-mx3ks]

@@dxexplorer Hey thank you!😊

[@dxexplorer]

Always a pleasure. 73

[@musasugen2364]

İ have this frequency meter how can i connet frequency sputnik

[@musasugen2364]

Frequency meter have - + in pin İ connect - and in pin but i dont see Amy Frequency i have same frequency meter

[@dxexplorer]

I can't remember if I spoke about it in the video or in the blog article... the frequency counter needs some modifications in order to work. Here is a link to a video that I used to make the modifications. We basically transform the crystal tester into an RF preamp. kzbin.info/www/bejne/ZnPboYCja7h_pacsi=peMFYZ9S2lwwfAdv

[@dxexplorer]

P.S. The + and - won't matter anymore as you can connect the frequency counter anyway to L3 as there is no polarization there.

[@multilecful]

Can we have a surface mount version please? 😂😂😂

[@dxexplorer]

This is the best joke you posted on the channel so far 😅😅😅😅. But you know ? I should try at some point just for the fun of it. It will be a board with nothing and some potentiometers 😅😅😅. It could be interesting 😅.

[@medi40]

The postage is very expensive to order.

[@dxexplorer]

Depends what option you pick. And I guess it depends what is available for each country. I think they have cheap options too... it just takes longer to arrive.

[@medi40]

​@@dxexplorer I see. I think ordering the pcb would be great for a bunch of friends.

[@dxexplorer]

@@medi40 Yes... you took the words out of my mouth hahaha. In one order you receive 5 boards... so you can split the costs of everything including postage and whatever custom taxes you may have to pay with four other friends. Unless you are selfish and you want all five boards for you hahaha. But yes thats the best way... sharing the cost with others too. You can even order more boards... maybe like ten... the postage is the same.

[@medi40]

​@@dxexplorerOn many occasions I did 10 pcbs with postage just for €5.

[@son3dra]

i'm your evangelist 😁 @stefanohomebrew

[@badgerchillsky535]

I have a question. Watching you build the coil I was wondering, do the slight overlaps in your windings affect the calculations? Would it be better for the wire to enter the tube on the same line? Or does it matter that there is an overlap?

[@badgerchillsky535]

And to make sure I’m making sense 😅 The coils begin and end directly above where the wires first enter/exit the bottom of the tube. The first coil ends up with a slight overlap and the second comes up a little short. Would that account for the difference in your final values? And does this difference affect the overall performance?

[@dxexplorer]

@badgerchillsky535 Haha. Yes yes I understood. I replied in the other comment ))).