Wireless Transmitter DIY Kit

I’m playing a music CD over my 1946 Sonora AM radio with this kit even as I type. Work carefully and pay attention to the diagrams showing component placement as with any analog circuit lead dress as they call physical parts orientation in a circuit is important.The results are outstanding, I found a 12SA7 glass tube works just as well as the supplied metal tube and I prefer the glass tube’s glow. Sound quality is pretty good, though if course you won’t be hearing stereo. But for a learning process and giving yourself more listening choices if you have antique AM only radios, this kit is just the ticket.

This little AM transmitter requires patience to assemble, as well as basic soldering skills, but isn't too hard if you follow the directions precisely. You may need to read up on how to interpret the printed info on the capacitors, and how to figure out the capacitance of any unmarked blue ceramic ones. My kit was missing the .047 microfarad axial capacitor, which I had to purchase separately from another supplier. I received a glass tube, which was nice. I've connected a dynamic mic to a pre-amp and simple mini-amp to the transmitter to broadcast voice. Works like a charm. I had to fiddle with the antenna setup a bit. Nice kit overall.

Worked the first time I tried it after experimenting with frequency and antenna. I'm getting about 60 feet with a 6 foot piece of wire. It didn't go 20 feet with the 6 inch wire they recommended. I might go with a longer wire yet without worrying about the FCC knocking on my door. If I get 200 foot distance, I'll be happy. Had a little difficulty identifying parts, but figured it out. I've been a Ham radio operator for over 50 years, but that doesn't make me a technician. They recommended wiring the tube socket first with the socket pins remaining straight down and soldering the components from the bottom of the socket, then mounting it on the board and finishing the wiring from the top, but I bent the pins on a 90 degree, mounted the socket on the board and wired it all from the top. It just seemed more natural to me. The frequency stability is good and I haven't had to retune the receiver at all. This was a fault I read about with the transistor transmitters. I'm old school and still like the vacuum tubes best. Most of my equipment is still vacuum tube operated. Great little product

As the pictures show, I did a little upgrade. Worked fine. Good quality parts.

I have one as a tube to tube interface device. I pipe classic radio shows from the internet archives. I tune into it with my old SX-42. Simple and easy to build. I used superglue for the tunable inductor and the peg that the tube socket sits on. Glued that on first after looking at the picture to provide a reference point.

Easy to build but the instructions are a bit confusing. Either that or my understanding was a bit confused... Be careful soldering to the oscilator coil. I burned my first one up with too hot an iron. Had to buy a new coil. After i carefully installed it though the thing fired right up and after only a little searching i found my signal. I agree these are a bit weak and i plan to add a preamp as well as a power switch. All said it was a fun build and a good little transmitter for the money.

Simple and easy to build if you take your time. I built a wood box to put it in and added a power switch and 120VAC LED assembly from Digikey. Audio power makes a huge difference in the range. I'm using an Intel NUK (streaming 40's Junction, SiriusXM) connected to a receiver with the gain turned up enough to receive throughout my house, downstairs and upstairs on 3 antique radios.

The instructions are very well written. The kit went together easily. It worked perfectly the first time I used it. I connected a karaoke unit to the transmitter and was able to broadcast music and voice very clearly. I plan to add a fused switch and a wooden case with a vented back.