Bob Monaghan ) writes:

Wasn't there a recent historical article in QST on the role of the quartz
xtal industry in WWII, how they figured out overtone osc. issues and so
on?

Given that some sources ask $12 and up for scanner and ham crystals, these
costs add up rather fast if you need to replace a bunch of xtals in a
scanner. So the search for alternatives seems quite worthwhile ;-)

But they already figured out the solution, thirty years ago, and
it did not require going to the quarry for quartz and digging out
old QSTs. The need for a lot of crystals luckily coincided with
digital ICs, so before most people could get around to paying for
all the crystals to fill out a mult-channel unit, synthesizers came
along so you only needed one crystal. About as soon as it could be
done practically, hams built them and wrote up articles in the ham
magazines.

Anyone who decides to make their own crystals today, other than
for the sake of doing so (and I admit it would be an interesting
thing to try), will likely find they can't go for the subminiature
look, and probably will find that putting effort into building
a synthesizer still makes sense if you need more than a few
crystals.

Michael VE2BVW

Michael Black wrote:
Bob Monaghan ) writes:

Wasn't there a recent historical article in QST on the role of the quartz
xtal industry in WWII, how they figured out overtone osc. issues and so
on?

Given that some sources ask $12 and up for scanner and ham crystals, these
costs add up rather fast if you need to replace a bunch of xtals in a
scanner. So the search for alternatives seems quite worthwhile ;-)


But they already figured out the solution, thirty years ago, and
it did not require going to the quarry for quartz and digging out
old QSTs. The need for a lot of crystals luckily coincided with
digital ICs, so before most people could get around to paying for
all the crystals to fill out a mult-channel unit, synthesizers came
along so you only needed one crystal. About as soon as it could be
done practically, hams built them and wrote up articles in the ham
magazines.

Anyone who decides to make their own crystals today, other than
for the sake of doing so (and I admit it would be an interesting
thing to try), will likely find they can't go for the subminiature
look, and probably will find that putting effort into building
a synthesizer still makes sense if you need more than a few
crystals.

Michael VE2BVW


Absolutely: You should only make your own crystals for the same reasons
you'd knap your own stone tools -- to understand how it was done back in
the day, and to have some thing to show off to friends. You could get
crystals much faster by cleaning toilets at McDonald's and buying them
at $12 a pop than you could making them from scratch.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Michael Black wrote:
Bob Monaghan ) writes:

Wasn't there a recent historical article in QST on the role of the quartz
xtal industry in WWII, how they figured out overtone osc. issues and so
on?

Given that some sources ask $12 and up for scanner and ham crystals, these
costs add up rather fast if you need to replace a bunch of xtals in a
scanner. So the search for alternatives seems quite worthwhile ;-)


But they already figured out the solution, thirty years ago, and
it did not require going to the quarry for quartz and digging out
old QSTs. The need for a lot of crystals luckily coincided with
digital ICs, so before most people could get around to paying for
all the crystals to fill out a mult-channel unit, synthesizers came
along so you only needed one crystal. About as soon as it could be
done practically, hams built them and wrote up articles in the ham
magazines.

Anyone who decides to make their own crystals today, other than
for the sake of doing so (and I admit it would be an interesting
thing to try), will likely find they can't go for the subminiature
look, and probably will find that putting effort into building
a synthesizer still makes sense if you need more than a few
crystals.

Michael VE2BVW


Absolutely: You should only make your own crystals for the same reasons
you'd knap your own stone tools -- to understand how it was done back in
the day, and to have some thing to show off to friends. You could get
crystals much faster by cleaning toilets at McDonald's and buying them
at $12 a pop than you could making them from scratch.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

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

Pete
AC7ZL

"Michael Black" wrote in message
...
Bob Monaghan ) writes:

Wasn't there a recent historical article in QST on the role of the
quartz
xtal industry in WWII, how they figured out overtone osc. issues and so
on?

Given that some sources ask $12 and up for scanner and ham crystals,
these
costs add up rather fast if you need to replace a bunch of xtals in a
scanner. So the search for alternatives seems quite worthwhile ;-)

But they already figured out the solution, thirty years ago, and
it did not require going to the quarry for quartz and digging out
old QSTs. The need for a lot of crystals luckily coincided with
digital ICs, so before most people could get around to paying for
all the crystals to fill out a mult-channel unit, synthesizers came
along so you only needed one crystal. About as soon as it could be
done practically, hams built them and wrote up articles in the ham
magazines.

Anyone who decides to make their own crystals today, other than
for the sake of doing so (and I admit it would be an interesting
thing to try), will likely find they can't go for the subminiature
look, and probably will find that putting effort into building
a synthesizer still makes sense if you need more than a few
crystals.

Michael VE2BVW

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

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 , 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

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 -