Low voltage vacuum tube transmitter

© Joe Sousa

My analytics data tells me my visitors love tube projects! I recently located a low voltage tube transmitter project created by the famous electronics dude Joe Sousa, who tells us:

"Following the RadioMuseum tradition of home-made AM transmiters listed at the end, I have come up with this simple single tube version. I based the design of this simple transmitter on Gammatron/Gridless-Audion operation of the 1Zh37B Russian Subminiature Tube."

Next, Joe describes his VCO tuning approach:

"A matched capacitor and ferrite stick could have been recovered from a discarded AM transistor radio. This would give a fairly accurate frequency indication. In my case, the ferrite and capacitor came from different sources."

© Joe Sousa

Joe goes on to describe his home-made chassis:

"The box is made of soft Bass wood and was bought ready-made at a local crafts store. I added the two wooden posts to support the ferrite stick, and removed the original brass clasp to fit the variable capacitor, after chiseling out the wood. The lid is kept closed with an embedded pair of neodymium magnets on one of the front corners of the box and lid."

© Joe Sousa

Joe describes his power plan:

"The picture that shows the batteries includes a 0V battery for Bplus in the form of a shorted battery clip that was recycled from a dead 9V battery. The 1.5V cell you see with a 9V clip on it is used to run Bplus at 1.5V."

Read the full article, get the schematic and full construction instructions at the fabulous Radiomuseum.org forum - go there!