Years ago my Heathkit HW-16 transmitted on all of the harmonics. Much to my dismay I received a call from a local ham who said I was transmitting on 20M. At the time I was a Novice and that was a no no. I built a set of filters for each band that the HW-16 covered and tested. No more calls. Great.
I built only the 40m only. I couldn't get two RF chokes so I did the toroid route. The 820 pF is polystyerene film, while the two 390 pF are silver micas. I used an Altoid tin and used the whole tin as the ground; was that what you meant when you said the enclosure should be metal? I did insulate the toroids from the ground with some cork. Wish I can upload a pic. Thanks again for the video Peter. Now i'm going to build the one transistor transmitter so I'd have a signal to filter!
Years ago my Heathkit HW-16 transmitted on all of the harmonics. Much to my dismay I received a call from a local ham who said I was transmitting on 20M. At the time I was a Novice and that was a no no. I built a set of filters for each band that the HW-16 covered and tested. No more calls. Great.
I built only the 40m only. I couldn't get two RF chokes so I did the toroid route. The 820 pF is polystyerene film, while the two 390 pF are silver micas. I used an Altoid tin and used the whole tin as the ground; was that what you meant when you said the enclosure should be metal? I did insulate the toroids from the ground with some cork. Wish I can upload a pic. Thanks again for the video Peter. Now i'm going to build the one transistor transmitter so I'd have a signal to filter!
Peter you are a wealth of knowledge. vk2jcc
Hi Peter, newby question here....are the capacitors in pF? Thank you.
Yes
I am hearing fm broadcast radio in my qrp ubitx6 rig will a low pass filter stop this?
Probably.
plastic box for transmitters!!! Not good practice. nice video though, thanks