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"Bill Janssen" wrote in message ... Steve Nosko wrote: I was not referring to the outer reaches of the two large faces as in; is the face flat or curved in some way. I understood what you meant. Just never considered that important. Maybe that is something I missed. Bill K7NOM Unfortunately, Dad went in the blink of an eye. I'm glad for him, but I didn't have the chance to talk, ask questions or say goodby. -- Steve N, K,9;d, c. i My email has no u's. |
H. Peter Friedrichs wrote:
Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - |
H. Peter Friedrichs wrote:
Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - |
In article , Mike Coslo
writes H. Peter Friedrichs wrote: Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - I was in the Xtal business for 20 years so can answer individual questions. WWII and before Xtals were flat plates and vibrated to the edges in "air gap" holders. after 1950s centre plated crystals were ideally dead at the edges. If you want to lap frequencies up a VCO tuned comms receiver can pick up the broad band noise generated and centered on the crystal frequency. Above assume shear mode AT type or Z cut plates. -- ddwyer |
In article , Mike Coslo
writes H. Peter Friedrichs wrote: Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - I was in the Xtal business for 20 years so can answer individual questions. WWII and before Xtals were flat plates and vibrated to the edges in "air gap" holders. after 1950s centre plated crystals were ideally dead at the edges. If you want to lap frequencies up a VCO tuned comms receiver can pick up the broad band noise generated and centered on the crystal frequency. Above assume shear mode AT type or Z cut plates. -- ddwyer |
ddwyer wrote:
In article , Mike Coslo writes H. Peter Friedrichs wrote: Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - I was in the Xtal business for 20 years so can answer individual questions. WWII and before Xtals were flat plates and vibrated to the edges in "air gap" holders. after 1950s centre plated crystals were ideally dead at the edges. If you want to lap frequencies up a VCO tuned comms receiver can pick up the broad band noise generated and centered on the crystal frequency. Above assume shear mode AT type or Z cut plates. The Crystal grinding shop in the Washington DC Navy Yard (1947) had a National HRO receiver connected to the rough grinding machine. They picked up the noise to tell how near to the finished frequency they were. They then went to hand grinding to finish. I have a chunk of Quartz from that shop. Bill K7NOM |
ddwyer wrote:
In article , Mike Coslo writes H. Peter Friedrichs wrote: Michael, I'm interested in "extreme" homebrew for its own sake. I simply like it. http://www.mindspring.com/~pfriedr/b...ry/gallery.htm http://www.mindspring.com/~pfriedr/b...ry/gallery.htm Very enjoyable Site, Peter! - Mike KB3EIA - I was in the Xtal business for 20 years so can answer individual questions. WWII and before Xtals were flat plates and vibrated to the edges in "air gap" holders. after 1950s centre plated crystals were ideally dead at the edges. If you want to lap frequencies up a VCO tuned comms receiver can pick up the broad band noise generated and centered on the crystal frequency. Above assume shear mode AT type or Z cut plates. The Crystal grinding shop in the Washington DC Navy Yard (1947) had a National HRO receiver connected to the rough grinding machine. They picked up the noise to tell how near to the finished frequency they were. They then went to hand grinding to finish. I have a chunk of Quartz from that shop. Bill K7NOM |
In article , Bill Janssen
writes Steve Nosko wrote: "H. Peter Friedrichs" wrote in message hlink.net... Hello, All: Rumor has it that QST featured an article in a January/1930 or January/1935 issue on the subject of homebrew transmitter crystals - how cut, lap, and mount them. If anyone has QST on CDROM for those years, I'd sure appreciate if you could take a look. Remove XXX's and ZZZ's if you wish to reply directly, and thanks. Pete AC7ZL Pete, I have my Dad's grinding stuff, but don't do it. One thing to keep in mind, and I don't know the details, but remember that the crystal activity is effected by the edges. Grinding the edges is one of the more esoteric aspects. The trick isn't the edges but keeping the two surfaces parallel and flat. The procedure is to grind a little and check the activity. If it is down try to grind the center or edges and check again. If it gets better then go back to to grinding and trying to keep it flat. Anyway that is the method I used. Bill K7NOM Large pieces of natural quartz usually from Brazil are getting rare as quarts gravel/pebbles are now used as feed material for re-growth on a seed plate in autoclaves. If large slices in the Y direction are required (SAW DELAY LINES) growth in this direction is so slow that the seed has to be from a slice of natural. Hence big natural pieces are valuable. -- ddwyer |
In article , Bill Janssen
writes Steve Nosko wrote: "H. Peter Friedrichs" wrote in message hlink.net... Hello, All: Rumor has it that QST featured an article in a January/1930 or January/1935 issue on the subject of homebrew transmitter crystals - how cut, lap, and mount them. If anyone has QST on CDROM for those years, I'd sure appreciate if you could take a look. Remove XXX's and ZZZ's if you wish to reply directly, and thanks. Pete AC7ZL Pete, I have my Dad's grinding stuff, but don't do it. One thing to keep in mind, and I don't know the details, but remember that the crystal activity is effected by the edges. Grinding the edges is one of the more esoteric aspects. The trick isn't the edges but keeping the two surfaces parallel and flat. The procedure is to grind a little and check the activity. If it is down try to grind the center or edges and check again. If it gets better then go back to to grinding and trying to keep it flat. Anyway that is the method I used. Bill K7NOM Large pieces of natural quartz usually from Brazil are getting rare as quarts gravel/pebbles are now used as feed material for re-growth on a seed plate in autoclaves. If large slices in the Y direction are required (SAW DELAY LINES) growth in this direction is so slow that the seed has to be from a slice of natural. Hence big natural pieces are valuable. -- ddwyer |
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