Home |
Search |
Today's Posts |
#14
|
|||
|
|||
JAMES HAMPTON wrote:
"Lenof21" wrote in message ... In article , "JAMES HAMPTON" writes: Hello, Len That commercial license wasn't a particularly big deal, except that you were expected to memorize the "band plan", as it were, for VHF television. I had to laugh, no problem with the video or audio carrier nor the allotted 6 MHz per channel space. First question, I think, was "what is the frequency of the video carrier of channel 6 television in the United States?". Well, I guessed they couldn't all be that bad, so I flipped a couple of pages, put my finger down, and examined the question by my finger. "What is the color burst frequency?". Ah, simple. 3.58 MHz .... oops, all of the 4 answers started with 3.579 ..... NTSC color subcarrier is exactly 3.579545454545454545454545.... MHz. :-) Frankly speaking, I don't give a damn about that FCC field office test I took in Chicago in March, 1956. It DID allow me to work at some broadcast stations and earn a bit of money. I don't remember that four-part test for a 1st 'Phone as being exclusively about broadcasting. Maybe it changed later. Irrelevant. A whole lot of changes have taken place in radio and electronics in the last almost 49 years. So, I had to take it a second time and this time I simply memorized the splits and took a good hard look at how tightly various frequencies were specified. Then it was easy. I took mine just once. Everything. My "Q&A" book was a borrowed Regulations set then printed up in loose-leaf form. All I did was memorize what seemed to be important regulations. The theory I'd already learned from the military experience, high-power HF trans- mitters plus VHF, UHF, microwave radio relay. No real problem. Not exactly IEEE stuff. It was never intended to be such...any more than the amateur written test is some kind of academic accomplishment. The commercial telegraph license and radar endorsement were also not very difficult. Such brain-strainers as "why do you avoid long horizontal sections of waveguide". Why would you? :-) A commercial license is not a noble title indicating a licensee is "superior" to all other human beings (amateurs included) LOL I've never stated that nor implied it was. However, a lot of hams go on and on, terribly full of themselves, on implying that Their accomplishment is academic PhD level stuff. :-) [ ptui...] Since 1958 I've been working in the microwaves, topping out at the top of Ka Band (25 GHz) with only a brief time with some 2mm wavelength stuff where the waveguide had to be coin silver electro-deposited on a polished copper mandrel (due to RF surface conduction being too high a resistance with ordinary silver plated guide...too much loss). I think of that lil-bitty guide stuff as my "first SMT" exposure... :-) A couple good reasons why amateur operations aren't widespread at microwaves, particularly above X Band (greater than 12 GHz) are Co$t of guide, flanges, measuring equipment, and RF sources; there's no "magical" round-the-world bounce off the ionosphere as with HF; so few amateurs know what they're doing at those very short wavelengths (nearly all the present-day record setters have commercial/military microwave experience). One big plus at microwaves is that antenna gain can be terrific due to beam-forming. Very little power is needed. Sure, there's no "skip" at those frequencies, it's all line-of-sight, but eventually there's going to be humans out there, far away. HF techniques won't be good for interplanetary QSOs. :-) Hello, Len I don't know how many amateurs are going to even get much above 1 GHz. As you point out, high power is not necessary due to high gain antennas being easy to make (or, perhaps, purchase). The problem might be in the aiming. That is a big part of it. Even if a lot of hams were there, it would be pretty much a sked only comms. This leads to prospective users having a need to work in pairs or teams. It will not be about making QSO's with multiple people, you will be wanting to put your equipment together, and try it out. So right away, the users will need to be interested in mainly putting a station together and using it a few times, then moving along to the next goal. And of course, the major attraction of these GHz and up frequencies is that they DON'T go very far. You have to be the type of user that doesn't care to make long distance QSO's! Despite the ARRL's promotion and record keeping, for AIAP's these frequencies are *very* local. - Mike KB3EIA - |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
CW computer interface woes ... | General | |||
Cell phone woes | Policy | |||
Magloop woes | Antenna |