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Old January 30th 04, 01:31 AM
Frank Dresser
 
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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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