In Maine, we spend half of our year preparing for winter, the other half living in it! I've finally taken a break from a month of doing fire wood so I can stay inside and mess with project all winter. Great looking projects! 73.-W1RMD
Many small DC relays have solid armatures, which shunt the HF ability of the choke coil (relay coil) so a good powdered iron torridal choke is recommended. I've had very good results with about 8 to 15mH for RF above 1 MHZ. Bifilar wound chokes of about that size are often found in the AC input for switch mode power supplies, if you have scrap ones you keep for parts. They are used to keep common mode noise off the AC power input. Made up a bunch of 15mH bifilar chokes for a sound system on an outdoor stage. The stage was less than 800 feet from an AM radio broadcast tower. The audio snake carrying the output of the sound console to the main PA amplifiers was picking up the radio station until the chokes were inserted in the audio signal lines.
Hi, I did the etching myself. After cleaning the board, I put on strips of tape along the entire length, leaving spaces between strips. I then used a sharp hobby knife to cut out sections of each strip so I was left with squares of tape. Then the board was etched in ferric chloride. This board will be used for many different circuit design and testing projects. One good thing about the low frequencies is for most things you don't need to be too careful about layout or lead lengths.
@@n1bug Interesting! So do I understand correctly, that no additional preparation of the blank copper is needed when etching with ferric chloride? And can I use any tape? I already thought about cutting myself some MeSquares like being sold on QRPme, but now I am intrigued by your method. Thanks
@@yofamagtfoke Just make sure the board is clean. If it is an old one with some dirt or the copper is oxidized (somewhat dark and not shiny) I first sand it with 800 or 1000 grit sandpaper, then wipe it down with isopropyl alcohol. It can be dry sanded, but I like to use wet sandpaper and some water. You can also use steel wool or a Scotch-Brite pad instead of sandpaper. I have used all of these methods with good results. If the board is new and clean you can just wipe it down with the alcohol. Try not to get fingerprints on the board while working with the tape, but if you do you can gently wipe it with alcohol again after you finish all of the tape work. I have used three types of tape, all worked for me. Masking tape (like painter's tape). Vinyl tape such as Scotch 33", Super 88 or one of the many cheaper alternatives. Brother TZ series tapes for a label maker work great also. I have a lot of that stuff so that is what I used this time, but I wouldn't buy that just for this purpose. If there is any sticky stuff left after you remove the tape, just clean it off with alcohol or another solvent. I also have another method I sometimes use to make islands on boards, using a small carbide bit in a Dremel tool to carve away copper. Maybe I should make a video showing these two board making methods? I also use MeSquares in some projects. You will see that in one of my videos quite soon!
@@n1bug Thank you for the elaboration! I will definitely try your method. I think I have also seen some content on the carbide bit-method here on TH-cam. For me as a beginner in electronics I feel that the whole process of making your own boards also teaches you a lot of things about circuity and electronics in general. So I am happy about learning from videos like yours. Sure I would also watch a whole section on board-making :-) greetings!
@@yofamagtfoke In case you haven't seen it, I posted a video showing the tape and etching method. I think I will do one on the carbide bit or diamond burr method soon.
In Maine, we spend half of our year preparing for winter, the other half living in it! I've finally taken a break from a month of doing fire wood so I can stay inside and mess with project all winter. Great looking projects! 73.-W1RMD
So true! We made it through preparation for winter again. Now we get to enjoy messing with projects. Have fun!
Many small DC relays have solid armatures, which shunt the HF ability of the choke coil (relay coil) so a good powdered iron torridal choke is recommended. I've had very good results with about 8 to 15mH for RF above 1 MHZ. Bifilar wound chokes of about that size are often found in the AC input for switch mode power supplies, if you have scrap ones you keep for parts. They are used to keep common mode noise off the AC power input. Made up a bunch of 15mH bifilar chokes for a sound system on an outdoor stage. The stage was less than 800 feet from an AM radio broadcast tower. The audio snake carrying the output of the sound console to the main PA amplifiers was picking up the radio station until the chokes were inserted in the audio signal lines.
Thanks for this information. I will see if I can find some of those and do some testing on them.
Hey N1BUG, did you do the etching of the copper by yourself or did you buy the board from somewhere? Greetings from Ger
Hi, I did the etching myself. After cleaning the board, I put on strips of tape along the entire length, leaving spaces between strips. I then used a sharp hobby knife to cut out sections of each strip so I was left with squares of tape. Then the board was etched in ferric chloride. This board will be used for many different circuit design and testing projects. One good thing about the low frequencies is for most things you don't need to be too careful about layout or lead lengths.
@@n1bug Interesting! So do I understand correctly, that no additional preparation of the blank copper is needed when etching with ferric chloride? And can I use any tape? I already thought about cutting myself some MeSquares like being sold on QRPme, but now I am intrigued by your method. Thanks
@@yofamagtfoke Just make sure the board is clean. If it is an old one with some dirt or the copper is oxidized (somewhat dark and not shiny) I first sand it with 800 or 1000 grit sandpaper, then wipe it down with isopropyl alcohol. It can be dry sanded, but I like to use wet sandpaper and some water. You can also use steel wool or a Scotch-Brite pad instead of sandpaper. I have used all of these methods with good results. If the board is new and clean you can just wipe it down with the alcohol. Try not to get fingerprints on the board while working with the tape, but if you do you can gently wipe it with alcohol again after you finish all of the tape work. I have used three types of tape, all worked for me. Masking tape (like painter's tape). Vinyl tape such as Scotch 33", Super 88 or one of the many cheaper alternatives. Brother TZ series tapes for a label maker work great also. I have a lot of that stuff so that is what I used this time, but I wouldn't buy that just for this purpose. If there is any sticky stuff left after you remove the tape, just clean it off with alcohol or another solvent. I also have another method I sometimes use to make islands on boards, using a small carbide bit in a Dremel tool to carve away copper. Maybe I should make a video showing these two board making methods? I also use MeSquares in some projects. You will see that in one of my videos quite soon!
@@n1bug Thank you for the elaboration! I will definitely try your method. I think I have also seen some content on the carbide bit-method here on TH-cam. For me as a beginner in electronics I feel that the whole process of making your own boards also teaches you a lot of things about circuity and electronics in general. So I am happy about learning from videos like yours. Sure I would also watch a whole section on board-making :-) greetings!
@@yofamagtfoke In case you haven't seen it, I posted a video showing the tape and etching method. I think I will do one on the carbide bit or diamond burr method soon.
It's much simpler with a nanoVNA...
Yes, I am sure. But I don't have a nanoVNA yet so I used what I did have.