I scrounged up a frequency counter for free, and it looks to be a joy to use!
Although I do have a cheap function generator from eBay, I do not have a frequency counter. This frequency counter would come in handy!
It comes in a perfect small package with an antenna, the device, and the user manual. Unfortunately, most devices don't come with a carry case included nowadays.
On closer inspection, a small area with seven 7-segment displays is provided on the top of the unit. The mechanism of operation is surprisingly simple- the frequency counter accepts any voltage between 0.2 V and 10 V p-p and will display any frequency from 10 Hz to 24 mHz.
A view from the front of the unit. There is a port for a wall supply power (supposing the device is used in benchtop mode), a screw hole for the antenna, and a 1/4 mm jack for a signal. Hmm...
I tried screwing the antenna in and pointing the unit at various household devices. Unfortunately, the device is useless for measuring any sort of reasonable frequency with the antenna alone. Although the number displayed shifts from a number usually less than ten to a number in the hundreds or thousands when pointed about 1cm away from a person, I'm not sure if that helps me in any way! Even pointing the device almost inside of a power outlet failed to return any value near 60 Hz.
A look at the back shows that the device was made back in the good old Tandy days of RadioShack. Before it almost went bankrupt for the first time... In all seriousness, though, this product is truly a beauty of classic design.
The manual. Very retro. I'll put up a scan soon.
Another close-up of the tiny, glowing digits. Mesmerizing.
Wrapping up the device in its case. I'll post some measurement tests soon! Until next week.