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![]() "tommyknocker" wrote in message ... Note that these are *amateur* callsigns, not standard (commercial) four letter signs. These stations were likely legally considered on the same level as hams with fleawatt tx's because there was no provisions in federal law to license commercial stations on SW-the "domestic broadcasting" ban that's been talked about so much in this group. It's my understanding the old callsigns with a 'X' in them were experimental broadcasters. The early TV and FM stations also had them. Over the years I've seen articles on old SW transmitters, as well as looked at some tube era ham level SW tx's. It seems that ALL SW tx's were crystal controlled until the 1960s, when transistorization made tunable transmitters possible. A lot of these Third World stations that stay on the same freq for decades, and whose transmitters can be tracked from owner to owner by freq usage, are one crystal setups. I suspect that the crystals in these tx's were (and are) sort of hardwired in like the early tube computers had one "program" that could only be changed by rewiring. I'm sure the crystals were socketed. The early crystal circuits usually had a reletively high power crystal oscillator, in order to reduce the number of stages. Cracking the crystal was a risk. Also, the crystal may drift in frequency after it was manufactured. Putting the crystal in a socket and having at least one spare was prudent. Here's more than most anyone wants to know about the early crystal industry: http://www.corningfrequency.com/library/vbottom.html Frank Dresser |
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