Radio Technology

Collins 30L-1 Fan Modification

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The motor is old, the blades a bit out of whack, and most of the noise is really coupled to the cabinet by the decayed and ineffective rubber isolation bushings on the three-point mounting plate.

In this parsimonious approach the two rear support plate studs are coaxed slightly to fit a 60 x 60 mm 10 CFM Fulltech unit {Jameco 213867}, while on the other side the fan’s ground hole is supported by a brass strap that needs no fastening. Though not mechanically isolated, the substitute method is inherently quiet and efficient.

And if you are motivated to search for the parts, nothing prevents you from replacing the original fan and suitable gaskets for the original mounting plate.

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Cognitive Radio is Here

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The American Radio Relay League (ARRL)—the mothership for U.S. ham radio—just reported an FCC action which should interest all observers of wireless policy. Medical devices have become miniaturized to the point where they can communicate within the body. As this is indubitably noble work, they have been authorized to use certain radio frequencies. What is initially surprising is that while we would traditionally expect these devices to be given an exclusive, protected spectrum, instead they must share it with other radio services. The full story [please follow the link below] contains important details and implications for all radio operations.

http://www.arrl.org/news/fcc-grants-secondary-service-allocation-to-wireless-broadband-medical-micropower-networks

Reviewing the article for the non-ham, FCC’s main job is to prevent radio interference. It divides different radio uses into “Services.” When a Service has a secondary allocation, in most cases its receivers must tolerate and defer to signals from the primary Service, and to the extent it creates any disruption there, a secondary must cease transmission. The ARRL was concerned not just to defend its own secondary spectrum, but humanitarianly and justifiably concerned that classifying medical devices as secondary, where they might be legally exposed to significant power from primary or other secondary Services such as ham radios could be dangerous. FCC’s response was politically bold, technically profound, and its significance can not be overlooked.

The first hint comes with mention of ‘spectrum-agile radios,’ and the other shoe drops with Genachowski’s saying: “MMNs [Medical Micropower Networks] have been shown to reliably operate in spectrum shared with other services and are a model for making more efficient use of radio spectrum by using advanced technologies such as monitoring the quality of the radio link, switching frequency bands, notching out of interfering signals and error correction coding.”

I must admit, FCC seems to have caught me off-guard here by doing something extraordinarily progressive. The technology under discussion is in fact called Cognitive Radio because the radios are smart. Their design departs from the traditional hardware model; more resembling a cell phone whose features change with the application. Cognitive radios go even farther though, essentially containing knowledge of their operational purpose, context and applicable regulations (which can vary radically internationally), in addition to wide sensitivity to their electromagnetic and physical environment.

In a broader sense, Cognitive Radio is extremely important to the future of communications because it seems to be the only strategy by which regulators can quickly respond to the dynamic needs of this wireless world, as well as to be able to efficiently allocate the spectrum available for maximum advantage. Politically, Cognitive Radio stands the 1934 Communications Act paradigm on its head: instead of blocks of spectrum and disparate radios built specifically for them, we’ll have one general-purpose radio constantly redefined in real-time with its privileges and limits according to the needs of higher-priority Services. The six or ten radios per person we now have—cell phones, Wi-fi, remote controls, security systems, garage-door openers, Family, General Mobile or Citizen’s Band—are in principle replaced by one device that implements whatever radio function is needed as it is needed through software. And to preserve its battery and respect other radios it will only emit the minimum radiation required to do its job.

While to the experienced ham the concept of a Cognitive radio that might offer different features depending on when and where you are may be unsettling, in ten years it could also well be the only feasible solution to the problem of constantly increasing spectrum demand. One can also look at this evolution as reinventing and distributing for each user our beloved and forgotten, problem-solving FCC Field Engineers, albeit robotically. But, challenging questions will arise. For example, what happens to short-wave listening (SWL) and radio distance (DX) operating skills if the radios are regulated to use the most reliable routes at the least power? And when all radios (that is, phones) have adaptive emergency response capability will the traditional social justification for Amateur Radio even remain or be allowed? Finally, while dynamically inter-filling the spectrum may give more users better service through fewer, lower-power transmitters, the technique can potentially raise the population’s aggregate daily radiation exposure as it is adopted by more Services.

ARRL appropriately emphasizes that much more experimentation remains to ensure the safety of MMNs under secondary status. Both the developers and the FCC seem willing to address those challenges. And no, I don’t think my Aug 19 demand had anything to do with it. Innovative programs like this require smart people rendering considerable sustained interdisciplinary effort. That they are now willing to subject their concept to the acid-test of intimately serving life itself speaks enormously of both their commitment to an urgent new vision for radio in general, and the performance promised by Cognitive Radio specifically. I wish the entire effort good luck. Its success will profoundly affect and advance radio communications policy for the rest of the century.

Heathkit HP-23 Capacitors

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Guess what, capacitors of the same era as the Collins 30L-1 showing exactly the same signs of failure, and what replacement looks like.

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Julius Genachowski: GO AWAY!

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Genachowski’s incompetence burns brightly. As of November 18th, while national protests spread, he has spent his time in judicial retrospection—dismantling the bedrock Fairness Doctrine (among others) as suddenly discovered to be “a threat to free speech.” Yet, concerning contemporary free speech issues, his agency is vacant and aimless.

While FCC’s three-month search for BART’s plausible deniability plods, we notice throughout that challenged as they are to ensure both safety and rights, no other U.S. municipality has dared to cut cell phone service. COULD THAT BE BECAUSE RESPONSIBLE POLITICIANS—seemingly excluding BART and Julius’s FCC—KNOW IT IS AN ILLEGAL, DANGEROUS, and INCENDIARY ATTACK UPON FREE SPEECH?

Dear President Obama, I can understand why you would want FCC to just raise money through spectrum sales. But this admittedly under-funded agency is rapidly losing credibility. To say nothing of being oblivious to the challenges of civil media rights and contemporary Emergency Communications, it has so lost focus that local police agencies are now forced to do FCC’s fundamental job—and original raison d’être—of preventing interference to legitimate radio services, for example, from spreading pirate FM stations.

Apparently, Congress somewhat agrees with this criticism. Earlier this year I learned from Rep. Greg Walden’s office that Genachowski’s inexplicable performance was already under investigation by The House Energy and Commerce Committee; which just responded (Nov 16) by crafting legislation specifically targeted to increase transparency and efficiency at FCC. Thus, Mr. President, the next step needed to stem further embarrassment to your administration is for this wireless industry puppet to resign.

Collins 30L-1 Rebuild

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Every original capacitor in the power supply was visibly damaged. There is no ‘cure.’ Forget about the variac.

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Satellite 2.0

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Satellite Trailer After

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Satellite Trailer Before

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