u/newtonsecond — reddlx

TV Broadcast Antenna Anatomy [OC]

Found a broadcast TV antenna laying on the ground when I was exploring a tower farm. It's 45 feet tall (or long), weighs about 4000 pounds, and rated for at least 675 kW ERP per FCC filings (probably about 50 kW TPO).

The image you (probably) see in the preview is the RF input with a large center conductor and air as the dielectric. I go through the other parts of the antenna in my video.

This antenna was made in 2018 and only used briefly. Watch to find out why!

youtube.com

u/newtonsecond — 20 hours ago

▲ 47 r/glitchart+3 crossposts

Compressing music using image formats (PNG, GIF, JPG)

This a fun little DSP-related project I put together. Based on Portal Runner's universal file converter. GIF sounds the weirdest!

youtube.com

u/newtonsecond — 1 month ago

▲ 42 r/cellmapper

C-Band Spectrum Analysis (3700-4000 MHz)

Spectrum analysis of 3700-4000 MHz in Montgomery County, PA with carriers labeled.

It seems like Verizon is operating a 100 MHz channel (3700-3800) and perhaps a 60 MHz channel (3800-3860). However, what I find odd is the heavy utilization between 3840-3860 MHz. Is this some sort of network slicing or datacasting that I am seeing?

Similarly, AT&T appears to be operating an 80 MHz channel (3860-3940) with heavy utilization between 3900-3905 MHz.

Unsurprisingly, no T-Mobile to be found despite them having 40 MHz in my county.

I would appreciate if any experts could pipe in on the portions with heavy utilization. Thank you!

u/newtonsecond — 2 months ago

▲ 3 r/Septa

Auto reload threshold of $10 lower than trip cost

I just purchased and set up a SEPTA Key card. I noticed the auto reload feature has a threshold of $10 that cannot be changed. The site also says auto reloads can take up to 24 hours.

What happens if I take a round trip on the regional rail (Zone 3 - $15.50)? Will SEPTA allow the balance to go negative until the auto reload completes, or will I be unable to complete my trip?

I found a post about this problem on the Philly subreddit but it was from 8 years ago. I'm sure someone here has a more recent experience regarding what happens. Thank you!

reddit.com

u/newtonsecond — 2 months ago