Fly swatter ham radio transmitter

[joeqsmith]

Article on early detectors.  I've never heard of most of these. 
https://earlyradiohistory.us/1917de.htm

[joeqsmith]

Homemade detector from a glass fuse, two brass inserts and a slurry of metal.  The grill starter will trigger it from across the lab with no antenna but my transmitter, with a clip lead attached, sitting next to it, will not trigger it. 

[joeqsmith]

Housing for the aerial current and reflected power meters.   

[joeqsmith]

Using a car ignition coil to power the latest transmitter.  Using my new Tecsun PL-990 portable receiver to determine how far we are transmitting.   Also shown is a demonstration of the home made cohere.   



Old movie showing using an X-ray machine as a transmitter to signal for help.  In the movies, it messes with every radio broadcast.  It's Hollywood.. 

[joeqsmith]

Mounted the car ignition coil, timer circuit and 3X18650 battery pack. 

[joeqsmith]

Dipole, sparkgap and capacitor used to generate GHz signal. 

[joeqsmith]

To extend the Signal Hound BB60's frequency range I put together a simple down converter.   Nothing more than a DRO for the LO, a couple of filters, an amplifier and mixer. 

Shown using the LiteVNA64 with my frequency extender for a source.  This was set to 11.5GHz.   The DRO is 12.0GHz,  producing a 500MHz to the Signal Hound.   I had asked the people at Signal Hound a few times about adding support to Spike for external mixers, but sadly after all these years, they still don't have this simple feature.   The down converter, extender and Signal Hound are all locked to the GPS.  The LiteVNA was not (this was my 3.2 revision).

[joeqsmith]

I attached one of the printed horns to the down converter and made a new spark gap with a dipole that should resonate near 10GHz.   

Holding the dipole about a meter from the horn, it shows up around 11.8GHz.   It is not very clean.