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.

Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take them
down a few Kilocycles....Eddie

"Eddie Haskel" ) writes:
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.

Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take them
down a few Kilocycles....Eddie


Actually, considering the date of the magazine, they aren't talking
about shifting commercial crystals.

They must be talking about taking quartz, and making crystals. On
the same level as making your own capacitors. I gather it might
have been common back then. Does the date coincide with requirements
of "crystal like" stability? I can't remember when such rules came into
effect, but I can imagine it would have set off homebrewing of crystals.
For that matter, there may not have been that much choice; I have no
idea what the state of commercial crystal manufacturers were back
then. ANd considering it was the thirties, likely many hams had
no money to buy commercial crystals, but they could scrounge.

It was WWII that offered up all those surplus crystals in FT-243 holders.
If you were lucky, some would fall where you needed them. A bit less
luck, and you'd at least find some close enough to your needs that you
could grind them a bit and move them onto your frequency. With no luck,
you'd have to buy crystals.

One could reference the other thread about selecting a receiver's IF
frequency. Often, such selection resolved to what was available. If
you could buy a filter, you'd use that frequency. Likewise when hams
started making crystal lattice filters after WWII, they used frequencies
which were available (which luckily overlapped the common 455KHz IF).
Even today, the choice of frequency for a homemade crystal ladder filter
often depends on what crystals are available cheap. Not the only criteria,
but one of the criterias.

Michael VE2BVW

Michael Black wrote:

"Eddie Haskel" ) writes:

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.

Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take them
down a few Kilocycles....Eddie



Actually, considering the date of the magazine, they aren't talking
about shifting commercial crystals.

They must be talking about taking quartz, and making crystals. On
the same level as making your own capacitors. I gather it might
have been common back then. Does the date coincide with requirements
of "crystal like" stability? I can't remember when such rules came into
effect, but I can imagine it would have set off homebrewing of crystals.
For that matter, there may not have been that much choice; I have no
idea what the state of commercial crystal manufacturers were back
then. ANd considering it was the thirties, likely many hams had
no money to buy commercial crystals, but they could scrounge.

It was WWII that offered up all those surplus crystals in FT-243 holders.
If you were lucky, some would fall where you needed them. A bit less
luck, and you'd at least find some close enough to your needs that you
could grind them a bit and move them onto your frequency. With no luck,
you'd have to buy crystals.

One could reference the other thread about selecting a receiver's IF
frequency. Often, such selection resolved to what was available. If
you could buy a filter, you'd use that frequency. Likewise when hams
started making crystal lattice filters after WWII, they used frequencies
which were available (which luckily overlapped the common 455KHz IF).
Even today, the choice of frequency for a homemade crystal ladder filter
often depends on what crystals are available cheap. Not the only criteria,
but one of the criterias.

Michael VE2BVW




This was actually just before then, when crystal stability was expected
but not (I believe) required. The '33 handbook "starter transmitter"
was just a TNT oscillator connected to an antenna.

--

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

Michael Black wrote:

"Eddie Haskel" ) writes:

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.

Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take them
down a few Kilocycles....Eddie



Actually, considering the date of the magazine, they aren't talking
about shifting commercial crystals.

They must be talking about taking quartz, and making crystals. On
the same level as making your own capacitors. I gather it might
have been common back then. Does the date coincide with requirements
of "crystal like" stability? I can't remember when such rules came into
effect, but I can imagine it would have set off homebrewing of crystals.
For that matter, there may not have been that much choice; I have no
idea what the state of commercial crystal manufacturers were back
then. ANd considering it was the thirties, likely many hams had
no money to buy commercial crystals, but they could scrounge.

It was WWII that offered up all those surplus crystals in FT-243 holders.
If you were lucky, some would fall where you needed them. A bit less
luck, and you'd at least find some close enough to your needs that you
could grind them a bit and move them onto your frequency. With no luck,
you'd have to buy crystals.

One could reference the other thread about selecting a receiver's IF
frequency. Often, such selection resolved to what was available. If
you could buy a filter, you'd use that frequency. Likewise when hams
started making crystal lattice filters after WWII, they used frequencies
which were available (which luckily overlapped the common 455KHz IF).
Even today, the choice of frequency for a homemade crystal ladder filter
often depends on what crystals are available cheap. Not the only criteria,
but one of the criterias.

Michael VE2BVW




This was actually just before then, when crystal stability was expected
but not (I believe) required. The '33 handbook "starter transmitter"
was just a TNT oscillator connected to an antenna.

--

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

Eddie Haskel wrote:

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.


Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take them
down a few Kilocycles....Eddie



No, the good _really_ 'ol days of taking a chunk of quartz, whacking
pieces off of it with a mud saw, hand lapping the saw marks off and
mounting it in a home-made holder. That namby-pamby FT-243 wasn't
invented until just before WW-II.

The same magazine has an article about the blind ham who built his own
equipment. Soldering by feel. There were giants in those days...

--

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

"Tim Wescott" wrote in message
...
Eddie Haskel wrote:

Yes Mrs. Cleaver... ....Eddie



[...snip...]

The same magazine has an article about the blind ham who built his own
equipment. Soldering by feel. There were giants in those days...
Tim Wescott


O U C H !!

"Tim Wescott" wrote in message
...
Eddie Haskel wrote:

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.


Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take
them
down a few Kilocycles....Eddie



No, the good _really_ 'ol days of taking a chunk of quartz, whacking
pieces off of it with a mud saw, hand lapping the saw marks off and
mounting it in a home-made holder. That namby-pamby FT-243 wasn't
invented until just before WW-II.

The same magazine has an article about the blind ham who built his own
equipment. Soldering by feel. There were giants in those days...

--

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

"Tim Wescott" wrote in message
...
Eddie Haskel wrote:

Yes Mrs. Cleaver... ....Eddie



[...snip...]

The same magazine has an article about the blind ham who built his own
equipment. Soldering by feel. There were giants in those days...
Tim Wescott


O U C H !!

"Tim Wescott" wrote in message
...
Eddie Haskel wrote:

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.


Ah yes..the good 'ol days of grinding FT-243 Xtals with toothpaste(or
comet)to go up, and writing on the blank with #2 pencil lead to take
them
down a few Kilocycles....Eddie



No, the good _really_ 'ol days of taking a chunk of quartz, whacking
pieces off of it with a mud saw, hand lapping the saw marks off and
mounting it in a home-made holder. That namby-pamby FT-243 wasn't
invented until just before WW-II.

The same magazine has an article about the blind ham who built his own
equipment. Soldering by feel. There were giants in those days...

--

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

actually, it is a lot easier to simply etch or grind away some of the
xtal, then check it with a grid dip oscillator for sharp dip, no need to
remount and test ;-) An old Hints and Kinks IIRC. This could be really
handy if you wanted to make a xtal filter and needed to really match and
control the xtal freq offsets (what, 3.5179 Mhz xtals from TV color burst
sources?) ;-)

and how about drilling a small hold in the holder so you could tread a
small bolt to put pressure on the xtal holder plates, shifting the xtal
freq. around like a xtal controlled VFO - but only a handful of khz ;-)
Still, very solid (pun intended) freq. source that can be varied around
enough to avoid QRM at minimal cost and effort for QRPers and so on? ;-)

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 ;-)

regards bobm
--
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