Discontentment at RF Central

Several years ago, I worked for a TV station in Miami that had gotten a bunch of Eurotek microwave STL and ENG link radio units out of the Sprint/Nextel MMDS rebanding deal. Apparently, at the time, Sprint’s tradeoff to get the spectrum was that they had to provide new 2 ghz microwave ENG gear to any TV station whose stuff would have been obsoleted by the new bandplan. Some stations got a different one, others got the Eurotrash, I mean, Eurotek.

We had quite a few of them, all in relatively non-critical service. One of our older engineers there was trying to keep them all alive but his success was limited as the 2 ghz and particularly the 7 ghz units liked to lose reference oscillators which were made of pure Unobtainium.

The units had constant cooling issues that led to a lot of power supply and amplifier failures too.

I mean, don’t get me wrong, it was a kinda cool platform for its time… all modular and a 1U mainframe could contain any mix of transmitters (upconverters), receivers (downconverters), power amplifiers, ASI stream multiplexers or demultiplexers, and can even interleave general purpose data over the connection and make it available via standard Ethernet ports on either end.

Unfortunately it’s about like most other Italian RF gear I’ve worked on, which is to say……. questionable garbage.

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So the Eurotek adventure of the last few days began at this receiver. The picture was frozen on screen and several days old on the ASI demodulator in the studio racks, so I went out there and looked at the receiver frame and found it just strobing and chirping due to a bad power supply. Easy peasy, we had spares, it’s all good right?

Never trust a capacitor fart.

With a good spare PSU in the frame it booted up as shown above… showed a good signal strength… good modulation error rate, SNR, all that….. no transport streams in the ASI stream. Huh.

So we took a drive up to Sutter Buttes where the other end of that link resides, and found the transmitter/repeater frame up there not working, smelling burnt, and just generally unhappy. Upon switching it off and back on again it lost output completely. (This was later revealed during bench testing to be the result of the 6-7 ghz upconverter spewing out a sweeping distorted signal around 4 ghz, which was pissing off the power amplifier on the way out.)

Sutter Buttes is a weird and interesting site. It’s on a unique geological feature – the smallest mountain range in the world!! The road up there messes with your perspective and has some of the steepest weirdest little switchbacks I’ve ever seen, including one where you basically get a cul-de-sac to turn around in to continue. It’s paved, but SUPER NARROW. In this video you can see the road in much better condition than it is now (it’s being repaired). This video is not actually supposed to exist and it’s my understanding that some very angry phone calls and emails were thrown around after it was discovered on YouTube, but it hasn’t been taken down either. So, uhhhh— enjoy?

If you’re curious as to how to visit the more interesting, roadless portion of the Sutter Buttes, guided hikes are available. Due to the fact that most of the range lies on a variety of private properties (mostly cattle ranches), you must have permission to go up there.

Now, as for that transmitter site, it’s… quite simply one of the weirdest damn things I’ve ever seen. There’s what looks almost like a tiny village of little buildings up there with narrow boardwalks connecting them together. The really strange adventure starts at the end of the road seen in that video — the deck you’re looking at is actually a boarding platform for a tiny incline railway. The track goes up at about a 45 degree angle and the car (not seen there) has a wedge shaped base so its floor remains level as it goes up and down. The car is hauled up and down by a winch at the top. Due to heavy cloud cover, I was unable to take any useful pictures at the site. Also due to said heavy cloud cover, the little cart simply ASCENDED INTO CLOUDS in a truly amazing way. Whaaaaaaaaaaaa

The site is visible about halfway through this video:

So anyway, we just had to take the EuroTrash down the mountain with us and I’ve been completely unable to successfully resurrect it in the workshop.

Nice soldering, pastabag
An upconverter and a PA
fgsfds
fgsfds

 

Needless to say I’m entirely unimpressed.

As for the title of this post— I think RF Central, based out of Pennsylvania, are the US distributors for the EuroCrap gear. They also make some other devices that I… uh… am not entirely… or even slightly… fond of. Thanks to their purchase of IMT / VisLink, they are also the proud distributors of some of the late Microwave Radio Company’s, uhhhhhh, wonderful, gear, such as the MRC Strata, which…. aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.


I had to replace a burnt wire inside this and hesitate to even imagine how much DC current flows to run that stupid mess.

What’s inside that box:


Neat purple anodized PA heatsink, but……. the only way they could have made this unit any more service-resistant would be to pot the whole damn thing in glue. Inaccessible screws galore…. and it has the distinction of being built inside a plastic weatherproof box similar to a Pelican case, then having the case’s weather resistance subsequently destroyed by sticking cooling fans and non-bulkhead connectors through it!

The module at upper right is a weird DC converter puck that seems to be ubiquitous in the Eurotek / RF Central gear. The board at lower right is the incredibly high tech means of setting the transmitter power – a Mini-Circuits voltage controlled RF pad.

I dunno. Maybe I should just be glad that having to repair these things long out of warranty is good for job security. 😀

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