Test Equipment Anonymous

Now that the warmer weather is here the migrating hummingbirds will soon arrive. In my area typically at the end of April and beginning of May. As you may or may not know hummingbirds are only found in North and South America and nowhere else. Only one species, the Ruby Throated Hummingbird, is found in my area. So it's time to put out the feeder. Currently empty but I will fill it this weekend. The nectar is a simple solution of 1 part sugar to 4 parts water. Last year I had numerous hummers come to feeder and chase and fight with each other since they are highly territorial. And Harley went nuts watching them.




In other warm weather activities the Civic has been uncovered, taken out for a run, and the oil changed. I do try to run it at least once a month in the Winter if the roads are clear and dry. To the left is Blondie's Accord. I changed the oil in her car yesterday. Always take care of her car first so you can't be accused of favoritism. And yes, I still do my own oil changes.



And TE content. I discovered that the B Sweep in my Type 535A quit working. So when I get a chance I'll dig into that.

I presumed humming birds were tropical. Then I was amazed to see them outside the work cafeteria in Palo Alto.

Sweet little things, but then so are the few remaining garden songbirds here.

SWMBO is keen on watching birds, so we have bird feeders in the garden. We also have cats. And cats like to kill birds. On the other hand, birds are astonishingly inefficient at eating from a bird feeder, dropping four seeds for every one they eat, so the dropped seeds attract rodents. Which the cats kill. So, I suppose that if you don't want extra mice/rats from feeding birds, you have to have cats and accept that some birds will fall prey to the cats. I lifted the first feeder from 5ft to 6ft after Binx proved that she could leap 5ft vertically and catch a bird when she was young. Less of a problem now, but she seems particularly offended by pigeons and has dragged three through the cat flap.

tggzzz wrote: ↑Tue Apr 14, 2026 10:15 pm I presumed humming birds were tropical. Then I was amazed to see them outside the work cafeteria in Palo Alto.

Sweet little things, but then so are the few remaining garden songbirds here.

Most species of hummers are strictly tropical but some do migrate in the Spring/Summer to as far north as Alaska.

EC8010 wrote: ↑Tue Apr 14, 2026 10:31 pm SWMBO is keen on watching birds, so we have bird feeders in the garden. We also have cats. And cats like to kill birds. On the other hand, birds are astonishingly inefficient at eating from a bird feeder, dropping four seeds for every one they eat, so the dropped seeds attract rodents. Which the cats kill. So, I suppose that if you don't want extra mice/rats from feeding birds, you have to have cats and accept that some birds will fall prey to the cats. I lifted the first feeder from 5ft to 6ft after Binx proved that she could leap 5ft vertically and catch a bird when she was young. Less of a problem now, but she seems particularly offended by pigeons and has dragged three through the cat flap.

Seeded bird feeders are not allowed here for that reason of the mess they make. Hummer nectar feeders don't have any dropping.

I did some checking and it turns out that the hummingbirds have been spotted in my area (Lower Hudson Valley). So I filled the feeder today with the sugar solution.

They flap their wings at the astonishing rate of 50Hz to 80Hz. It is audible but doesn't sound like a transformer hum. More like a buzz.

MED6753 wrote: ↑Wed Apr 15, 2026 5:44 pm They flap their wings at the astonishing rate of 50Hz to 80Hz. It is audible but doesn't sound like a transformer hum. More like a buzz.

I can imagine the pressure increases linearly as the wing moves in one direction, and decreases linearly as it moves in the other. At the transition there could be a whipcrack effect as the wings suddenly reverse, which would cause a sudden spike.

I hypothesise such triangle wave with transition peaks would have a lot of harmonics, which would sound buzzier.

tggzzz wrote: ↑Wed Apr 15, 2026 7:17 pm

MED6753 wrote: ↑Wed Apr 15, 2026 5:44 pm They flap their wings at the astonishing rate of 50Hz to 80Hz. It is audible but doesn't sound like a transformer hum. More like a buzz.

I can imagine the pressure increases linearly as the wing moves in one direction, and decreases linearly as it moves in the other. At the transition there could be a whipcrack effect as the wings suddenly reverse, which would cause a sudden spike.

I hypothesise such triangle wave with transition peaks would have a lot of harmonics, which would sound buzzier.

Only an engineer could come up with that reasonable hypothesis. I commend you Sir.

MED6753 wrote: ↑Wed Apr 15, 2026 7:42 pm

tggzzz wrote: ↑Wed Apr 15, 2026 7:17 pm

MED6753 wrote: ↑Wed Apr 15, 2026 5:44 pm They flap their wings at the astonishing rate of 50Hz to 80Hz. It is audible but doesn't sound like a transformer hum. More like a buzz.

I can imagine the pressure increases linearly as the wing moves in one direction, and decreases linearly as it moves in the other. At the transition there could be a whipcrack effect as the wings suddenly reverse, which would cause a sudden spike.

I hypothesise such triangle wave with transition peaks would have a lot of harmonics, which would sound buzzier.

Only an engineer could come up with that reasonable hypothesis. I commend you Sir.

If there was a reasonable audio file of the sound, Audacity could act as a scope and spectrum analyser. Tests are better than hypotheses

tggzzz wrote: ↑Wed Apr 15, 2026 7:47 pm

MED6753 wrote: ↑Wed Apr 15, 2026 7:42 pm

tggzzz wrote: ↑Wed Apr 15, 2026 7:17 pm

I can imagine the pressure increases linearly as the wing moves in one direction, and decreases linearly as it moves in the other. At the transition there could be a whipcrack effect as the wings suddenly reverse, which would cause a sudden spike.

I hypothesise such triangle wave with transition peaks would have a lot of harmonics, which would sound buzzier.

Only an engineer could come up with that reasonable hypothesis. I commend you Sir.

If there was a reasonable audio file of the sound, Audacity could act as a scope and spectrum analyser. Tests are better than hypotheses

Found one. Want to give it a try?

https://www.youtube.com/watch?v=0vgRYTPV9qU

Edit....looks like some audio files here...

https://pixabay.com/sound-effects/search/hummingbird/

tggzzz wrote: ↑Wed Apr 15, 2026 7:17 pm

MED6753 wrote: ↑Wed Apr 15, 2026 5:44 pm They flap their wings at the astonishing rate of 50Hz to 80Hz. It is audible but doesn't sound like a transformer hum. More like a buzz.

I can imagine the pressure increases linearly as the wing moves in one direction, and decreases linearly as it moves in the other. At the transition there could be a whipcrack effect as the wings suddenly reverse, which would cause a sudden spike.

I hypothesise such triangle wave with transition peaks would have a lot of harmonics, which would sound buzzier.

Dunno. I'd guess that like Frisbees they rely on non-linear effects. It shouldn't hard for someone afflicted with GAS to capture the sound and display it on a scope and see what an SA made of it. The wing isn't going to be a perfectly rigid lamina. It also has feathers.

There are hovering insects that make a distinctive noise. I can pick up mosquitos very easily. There are also humming bird moths which I've seen a few times. I wasn't aware of any particular sound they made.

When the technology became available to look into bat echo location, it turned out that they'd been all over the problems radar researchers had been struggling with.

MED6753 wrote: ↑Tue Apr 14, 2026 9:49 pm Now that the warmer weather is here the migrating hummingbirds will soon arrive. In my area typically at the end of April and beginning of May. As you may or may not know hummingbirds are only found in North and South America and nowhere else.

I assumed they were found throughout the tropics, but it turns out not.

https://en.wikipedia.org/wiki/Hummingbird

There are similar but unrelated things called Sunbirds in Africa, Eurasia and Australasia. Convergent evolution.