On May 5, 6:27�pm, N2EY wrote:

Look at the quartz crystals used in post-WW2 ham gear, and you'll see
"FT-243" and "HC-6/U" units being used extensively, while the large
round prewar types disappeared quickly. Although they seem huge today,
the FT-243 and HC-6/U holders, and many others, were miniature types
developed for military use during the war to both save space and get
more out of the limited supply of radio-grade quartz available during
the war. There were so many FT-243 units made that well into the 1990s
the surplus supply was still being used up.

For a link to MOST of the quartz crystal holders go to this link:

http://s88932719.onlinehome.us/crystal_holders.htm

[save it off-line, it was made by Brian Carling AF4K]

During WWII the USA set priorities on who should get what for raw
material, test equipment, facilities. Priority #1 was the Manhattan
Project (to develop the atomic bomb). Priority #2 was to quartz crystal
unit production with the civilian overseer being Galvin Mfg (changed to
Motorola after the war). Main reference is Galvin's own biography book
and the oft-repeated Bottoms paper (Bottoms was a participant, now
deceased) found in frequency control special interest group at the IEEE
and on several crystal companies today. Based on the Bottoms paper, USA
production of quartz crystal units from about 60 different companies
(most of them small firms) was about one million units per month in the
last three years of WWII.

The major source of natural quartz was Brasil (a neutral in WWII) and
much research and trial began after WWII to grow quartz crystals from
seed material, slightly impeded by a similar method for producing
germanium and silicon ingots of astonishing purity. Both "man-made"
efforts succeeded to make the color TV industry possible (both NTSC and
PAL systems required a quartz crystal in each set to regenerate the
color sub-carrier signal).

The "HC-" prefix to quartz crystal HOLDERS is apparently a USA DoD
designator prefix and was not used during WWII. To use those required
more refined techniques in plating electrodes on quartz, "cold-welding"
(a new technology adapted from the exploding semiconductor industry) to
those electrodes and adaptation of "microwelding" developed for vacuum
tube manufacturing (sometimes called "spot-welding" by those who haven't
done it...an "eye-opener" and "eye-closer" if done through a stereo
microscope). The vast majority of quartz crystal units made since
around 1960 have the metal holder under various "HC-" prefixes.

Semiconductor type numbers such as 1N5408 and 2N2222 are the result of
a parts numbering system developed during WW2. Ironically, the system
was developed for tubes - �think of the 2E26, 2C39, 3E29, 6C21, etc.
It was short-lived as a way to name new tube types, but lives on today
for semiconductors.

Transistors were not available until 1947 and then not in production.
High voltage breakdown silicon diodes such as the 1N5408 (3 A, 1 KV,
plastic case) would not be available until around 1960. The "1Nxxxx"
and "2Nxxxx" and (rare but there) "3Nxxxx" designations were done by the
electronics industry, not by the military. During WWII the military had
its own variation on vacuum tubes with labels of "VT-nnn" while the
electronics industry used the civilian industry designations exsiting
before USA's entry into WWII. The USA military stopped using the
"VT-nnn" designator after WWII.

Many high-power vacuum tubes used manufacturer's own part designations
which the electronics industry accepted so as to ease their own burden
in the fantastic explosion of electronics parts that began with TV set
production once the civilian 'radio' industry restarted after WWII.

Of course a lot of these developments were done by private industry,
not by military personnel. But the developments were a direct result
of military needs and funding.

Almost ALL developments in electronics began as industry projects, even
the IC. There is some controversy in the industry whether Intel or TI
made the "first IC." Intel's first IC was for an Asian customer to use
in a four-function calculator. Nearly all digital IC part numbers have
number suffixes which follow the original TI line of "54" and "74"
prefixes. Intel went on to gain a virtual monopoly on CPUs for PCs
while there is just no stopping TI to date.

While RCA Corporation developed the first CMOS junctions (and ICs), the
semiconductor industry here and in Europe developed the Advanced CMOS
juntions having idle current nearly down to leakage current yet with
clock speeds so high that power drain is specified by operating speed.
TTL logic structures have specified idle time current drain; Advanced
CMOS logic does not.

Major semiconductor corporations have their own part numbers for ICs,
such as the one-"chip" PLL frequency source made by Analog Devices and
favored by many QRP afficionados in amateur radio. Analog Devices grew
out of the George Philbrick company which began with vacuum tube
operational amplifier plug-ins (two tubes in a special holder which
contained the circuitry).

Addenda: I've never seen any FT-243 holder quartz crystals in USA-made
CB transceivers. There might be some among roughly a million CBs made
in the USA (millions more born off-shore). This post was done on 6 May
2010.

73, Len K6LHA