Old gear to the rescue.

Got an email tonight from my old mentor. He's retired, but still does consulting work for a few radio stations in Florida. One of them (which was the second radio station I ever worked at) had a major failure of their main transmitter earlier today. Hal called in and walked the on-duty engineer through the process of firing up the aux transmitter. (It's slightly more of an ordeal than turning on a modern solid-state rig.) Once it was up and running, the engineer snapped a photo and sent it to Hal, who sent it to me.

https://cimg1.ibsrv.net/gimg/www.mia...af983c52f6.jpg

(This is just the upper-third of the machine. It's about 6 feet tall and 4 feet wide.)


This machine was built in 1965. In the mid 1990s, I tore it down and totally rebuilt it, including a new coat of paint. (It was originally a horrid aqua-blue color that could have only seemed reasonable on an industrial machine in the mid 1960s.) Turns out that it still works perfectly today. 53 years is a long time for a piece of electronic equipment.

Stuff like this makes me feel good.

Someone slipped off the trail yesterday and tumbled a bit.

Well, fuck.

This is what the furnace hoses leading into Dish #2 (the 12 meter primary uplink, which carries WGN America, the Chicago Blackhawks, the Chicago Bulls, and a bunch of other stuff) are supposed to look like when it's snowing:

https://cimg0.ibsrv.net/gimg/www.mia...e713c628aa.png
(2018 photo)


And this is what they look like right now, with more snow in the forecast for tonight:

https://cimg5.ibsrv.net/gimg/www.mia...07c2613318.png

This is a non-optimal scenario.

Supposed to be below zero here tonight.

If you want, i can have my SB guys drive up there and get a fire going for you to help warm things up a bit. They're getting good at it.

https://cimg4.ibsrv.net/gimg/www.mia...bef2ecfe5c.jpg
https://cimg5.ibsrv.net/gimg/www.mia...61245f389a.jpg

Holy balls, man. What happened?

All else being equal, I'd prefer that my uplink dish not look like that. Smart people who wear ties with short-sleeve shirts designed it to be curved at a rather specific radius, and I think that's probably important.

Just got off the phone with Intelsat. On the one hand, I'm used to "controlling" a spacecraft in the sense that I beam a signal to it which it then re-processes and sends back down. On the other hand, this is the first time I've ever been logged directly into the actual control system of a spacecraft (admittedly, in view-only mode).

Galaxy 14 says that we're about 1.5 dB down in receive strength, but still have a a 17.2 EBNO, which minned at 15:36 GMT (9:36am Chicago), and has been stable within a point or two since.

Thank you, Galaxy 14, for being a hell of a robust, high-gain bird.

http://dyingwords.net/wp-content/upl.../01/tech12.jpg

Must be the season for it. We had a major fire end of last month, and it still isn't cleaned up.

I read an interesting article today discussing why the Navy needs to implement software defined radios (SDR)...and most of it went over my head. But the little I remember from emag made me wonder about antenna design/limitations for these little guys. The SDR may be able to process whatever signals fed to it, but I'm under the impression the antenna is going to be the limfac.

https://cimg3.ibsrv.net/gimg/www.mia...167d7c1d50.jpg

Electric heater on tank got left on. Plastic tank, mounted with wood. No thermal limits in place.

Yeah 6 months ago we built two new tanks for them just after the fire and are currently building a SS tank for them. You'd think they'd install the tanks and be productive again.
It will probably be me week after this when i go back.

https://cimg6.ibsrv.net/gimg/www.mia...c27b66dccd.jpg

Interesting that you post this- I use an SDR dongle very similar to that one as a broadband spectrum analyzer.

For receivers, antenna design is not very critical. Yes, you can get better performance with an antenna which is specifically tuned to the frequency of interest (and we do exactly this in cases such as wireless mic receivers, microwave BAS receive antennas, etc) but modern amplifiers have sufficiently low noise and high gain that they can compensate for nonlinearity associated with antenna mismatch well enough for most casual purposes.

For transmitters, antenna design is extremely important, The antenna (or filter / combiner, in the case of shared antennas) has to be very closely matched to the frequency of the transmitter, or else large amounts of power will be reflected back from the antenna into the output stage of the transmitter. This makes them unhappy, especially at higher power levels.




Ouch.

On the plus side, gotta hand it to State Mechanical. One of the two furnaces is back online, and the snow is melting. Intselsat says we're coming back to full signal on the bird.

Very interesting. Is the SDR fed a raw signal, or is there some other processing required from the receiving antenna?

F-15C AESA radar upgrade from my last active duty base (Kadena). Unclassified source, just found from a quick google search.

https://cimg5.ibsrv.net/gimg/www.mia...edfe5ed502.jpg

Huh. We use no wood, but same scenario. Heater thermal fuse was supposedly just replaced by maintenance.

Insurance adjuster listed probable cause as improperly tightened wire nuts.
Not surprising, as our only real maintenance guy was fired for inappropriate language last month.
(go figure, the blue collar guys swear a lot in a factory)

From an RF-engineering standpoint, an SDR isn't much different from a conventional broadband receiver. They both have a tuneable filter (or switchable bank of filters) between the antenna and their input. The only "magic" part is that an SDR uses a very-high-bandwidth ADC to receive the signal and then implements the tuning and demod bits in software, rather than with resistors and capacitors and VCOs and such.

Got it. (Not really, didn't get that far in EE)

https://cimg4.ibsrv.net/gimg/www.mia...2fd3cb361b.jpg

Seriously?

I mean, I'm a director (#2 level within the company overall), and I use words such as "fuck" rather gratuitously on a daily basis, including meetings with the general manager, the HR manager, the director of operations, my own staff, the operations staff, the news director, the news staff, the stagehands, the shooters, the talent, and, well, pretty much every single person in the whole station except for the one cute redhead producer.

In Australia, EVERYONE would be fired if that logic applied here.

FYI: Aussies/Kiwis swear a LOT more than Americans in everyday speak. When I worked in the US, I became very conscious of this and adjusted accordingly. I also learned never to use sarcasm in the US because it was usually interpreted literally so people thought I was being an arsehole when it was intended as a humorous comment.