"JB" wrote in message
news:g_bwk.563$1a2.176@trnddc04...
The crystal
companies
could have put the big hurt on PLL or programmable dividers. I know
the real
reason crystals took a back seat, and it;s not what anybody thinks
happened.

73 OM

n8zu

It would be my guess to do away with technicians that tune up radios and
fix
things.


I've been racking my brain trying to figure out a reason.
But, I think you hit the nail on the head. It fits right in
with the obsolescence of the FCC 1st and 2nd Class
Radiotelephone tickets.

Pete

On Sep 4, 9:11 pm, raypsi wrote:
On Sep 3, 2:54 pm, Michael Black wrote:



On Wed, 3 Sep 2008, raypsi wrote:
Hey Gary,

Rocks aren't cheap hehttp://www.icmfg.com/thruhole_crystals.html
Maybe in 9 land they pave the streets with gold.
Personally I'd go with a programmable divider or PLL.

Maybe you like retro, then I'd get some old rocks the ones
you can take apart and grind them down to git's the freq's you need.

And you can't grind them unless they are quite close to the desired
frequency. Grinding by hand will be too uneven, so the crystal will
stop working if you try to grind it more than a tiny bit.

It also relies on a big stock of crystals spread around so you can
find one sufficiently close enough, something that did seem possible
in the years after WWII, but after all this time attrition may have
reduced the stock considerably.

And realistically, they also have to be bulky FT-243 holders, since
those you can open by removing screws, and the blank is held in place
with pressure. More recent holder types require desoldering the case,
and figuring out how to remove the blank and then get it back in place
when it's soldered in place (or something like that I can't remember how
the blank is connected).

One of the odd things is that if one has to buy new crystals, a
synthesizer will likely be far cheaper. In the early seventies,
synthesizers made a big splash because everyone wanted lots of channels
on 2m FM, and the need to have them ground to frequency (and to equipment)
made it all very costly, so synthesizers despite their cost and bulk
became the norm.

Almost forty years later, a synthesizer for a handful of crystals would
still be comparatively bulky, but would be even cheaper than in the early
seventies.

Michael VE2BVW

Believe it or not I was making a living sell rocks HI HI back forty
years ago.
It was like there was a freaking crystal company on every corner.
There was so
much competition back then the prices was chump change. The crystal
companies
could have put the big hurt on PLL or programmable dividers. I know
the real
reason crystals took a back seat, and it;s not what anybody thinks
happened.

73 OM

n8zu

You don't see any newbies on here making any rock controlled hets..
It's like vinyl records or CD's
they is all gone. They don't want you to know about crystals there is
to much
power in that knowledge. They want everyone dumbed down so they can be
controlled,
that's why they did away with code, nobody will ever know it ever
existed in 5 years time.

73
n8zu

The real reason for the popularity of synthesizers is cost. When you
need a new rock for every band they get costly, but a synthesizer
doesn't. This wasn't practical until chips that could do most of the
work became cheap.

The main reason for eliminating the commercial operator licenses was
cost too. Here's what happened:

There was a time, not so long ago, when there were a large number of
tasks that could only be performed (legally, anyway) by a person with
an FCC Commercial Operator license. No others need apply, regardless
of experience, education or background. Either you were a Radio
Operator of a certain class, or you weren't.

Those licenses meant that a person with a high-school education and
some smarts could have a good middle-class income if they had the
license. Not that all the jobs were easy, or that you didn't need a
certain amount of knowledge to do them, but that the Commercial
license became the equivalent of a union card, and the jobs were, in a
way, protected by FCC regulations.

In other words, the Commercial licenses protected a craft known as
Radio Operators, with a set of skills and knowledge specific to them,
and jobs only they could do.

The masters of industry didn't like that, so they prevailed on the FCC
to reduce the requirements and eliminate most of the licenses and the
requirements for tasks to be done only by Radio Operators. The jobs
went with them.

This is also why the maritime services went to satellite-based comms
rather than HF and MF radio and Morse Code - it eliminated the need
for ships to carry licensed Radio Operators.

Oddly enough, FCC still issues Commercial RadioTelegraph licenses,
both First and Second Class, though I don't know where in the USA you
can get the required experience for a First Class.

73 de Jim, N2EY

On Sep 6, 7:38�pm, raypsi wrote:

They want everyone dumbed down so they can be
controlled,
that's why they did away with code, nobody will ever know it ever
existed in 5 years time.

They didn't do away with Morse Code. They did away with the test for
it. It was done a little at a time over the past 30 years.

My personal theory on why it was eliminated is this:

Since the early 1980s, the FCC has been required to do more and more
stuff with less and less resources. So they have constantly sought out
ways to reduce their workload, particularly for radio services that
don't bring in $$, like ham radio.

That's why they turned over the job of amateur license testing to the
QPC and VECs back in 1983 or so. Instead of paid FCC employees making
up and conducting amateur license tests, unpaid volunteers do almost
all the work. It's also why they doubled the license term to 10 years
about that same time - reduces the number of renewals by half.

Reducing the number of license classes reduces the number of tests and
the number of upgrade applications to process. In the old days when
there were six license classes, a ham who went from Novice or Tech to
Extra could upgrade as many as four times. Now there are only two
steps.

Eliminating the Morse Code test means one less license test. Less
work.

But even though the last remnants of the Morse Code test were removed
back in February 2007, there are still plenty of hams using it on the
air. This past Field Day, for example, the group I went with had one
Morse Code station and three voice stations, all similarly equipped.
There were three Morse Code operators and far more voice ops, yet the
Morse Code station made more QSOs than all the voice stations
combined. This wasn't a surprise, either.

73 de Jim, N2EY

raypsi wrote:
Hey Gary,

Rocks aren't cheap he http://www.icmfg.com/thruhole_crystals.html
Maybe in 9 land they pave the streets with gold.
Personally I'd go with a programmable divider or PLL.

Maybe you like retro, then I'd get some old rocks the ones
you can take apart and grind them down to git's the freq's you need.
I recall grinding some of these to get them into the novice band back
40 yrs ago.
And putting a pencil mark on the quartz to get them to go down in
frequency.
FT243 style can be found here maybe still: http://www.af4k.com/crystals.htm


73 OM

n8zu

On Sep 2, 4:12 pm, Gary@ removenospamandputkf9cm.com wrote:
I am looking for some Heterodyne conversion crystals for a receiver I am
making.
The frequencies a 5 MHz, 7 MHz, 10.5 MHz, 13.5 MHz, 17.5 MHz and 21.5
MHz.
The variable mixing frequency will be from 3 to 3.5 MHz. I would prefer all
the same type holder.

TNX de Gary, KF9CM

You can use the same grinding powder that ATM's (amateur Telescope
makers) use to grind mirrors for grinding crystals. You want the fine
stuff #400 or finer. www.gotgrit.com has this stuff cheap.
Grind the crystal against a piece of scrap plate glass. I've had mixed
results, I've moved a few rocks a few hundred khz and I've also killed
some trying to move them just a few hundred hz.

Only grind ONE side of the rock, put a pencil mark on the other so you
don't mix this up. Wash the crystal well after each grinding session
and only handle it by the edges, you don't want your finger sweat or
oils getting on the crystal. Grinding motion should be a figure 8, use
light pressure and don't push down on the middle of the crystal, handle
by the edges while grinding.

If you do kill the crystal, you might be able to get it to start again
by light grinding using a different motion. Also try holding the
crystal vertical and grind the edges slightly. Measure the thickness
(carefully!) with a micrometer all around. If you ground a 'wedge'
shape into the rock this will also kill and and the cure is to regrind
putting more pressure on the fatter end.

I have quite a few useless FT243 rocks in the junk box, one of these
days I'll probably try moving a few of them to a more useful frequency.

BTW some of those 'useless' frequency rocks do multiply out into some
ham bands.

A few examples from my junk box:
4845khz - 29070khz (10 meters)
6050khz - 18150khz (17 meters)
6025khz - 18075khz (17 meters)
4785khz - 28710hkz (10 meters)
5300khz - 21200hkz (15 meters)

On 2 Sep, 21:12, Gary@ removenospamandputkf9cm.com wrote:
I am looking for some Heterodyne conversion crystals for a receiver I am
making.
The frequencies a 5 MHz, 7 MHz, 10.5 MHz, 13.5 MHz, *17.5 MHz and 21..5
MHz.
The variable mixing frequency will be from 3 to 3.5 MHz. I would prefer all
the same type holder.

TNX de Gary, KF9CM

The Si570 will generate those frequencies, apart from the 5 MHz.

Leon

On Wed, 3 Sep 2008, Leon wrote:

On 2 Sep, 21:12, Gary@ removenospamandputkf9cm.com wrote:
I am looking for some Heterodyne conversion crystals for a receiver I am
making.
The frequencies a 5 MHz, 7 MHz, 10.5 MHz, 13.5 MHz, *17.5 MHz and 21.5
MHz.
The variable mixing frequency will be from 3 to 3.5 MHz. I would prefer all
the same type holder.

TNX de Gary, KF9CM

The Si570 will generate those frequencies, apart from the 5 MHz.

Leon


Of course, 5MHz is the one in the bunch that is bound to be easy
to get (and if it's not, 10MHz makes it almost as easy) and
would provide the clock for the synthezier if it needs an external
one.

Michael VE2BVW

On Sep 2, 4:12�pm, Gary@ removenospamandputkf9cm.com wrote:
I am looking for some Heterodyne conversion crystals for a receiver I am
making.
The frequencies a 5 MHz, 7 MHz, 10.5 MHz, 13.5 MHz, �17.5 MHz and 21.5
MHz.
The variable mixing frequency will be from 3 to 3.5 MHz. I would prefer all
the same type holder.

Once source of crystals is eBay. Another is AF4K (google his call), he
has quite a stock in various holders.

But be prepared to pay more than a few dollars per crystal!

Actually, when you adjust for inflation, crystals cost about as much
now as they did 30-40 years ago. Three dollars back in 1965 is the
equivalent of about twenty dollars today.

You can also do things like use harmonics and overtones of the
crystals to get the higher frequencies.

--

But before you start building, I suggest you reconsider that mixing
scheme.

As I understand it, the receiver will consist of a tunable section
that covers 3 to 3.5 MHz, and a converter section which converts the
various ham bands to that tuning range.

So for 160, you would take the 2 to 1.5 MHz range, subtract it from 5
MHz, and get 3 to 3.5 MHz

For 80, you would take the 4 to 3.5 MHz range, subtract it from 7
MHz, and get 3 to 3.5 MHz

For 40, you would take the 7.5 to 7 MHz range, subtract it from 10.5
MHz, and get 3 to 3.5 MHz

For 30, you would take the 10.5 to 10.0 MHz range, subtract it from
13.5 MHz, and get 3 to 3.5 MHz

For 20, you would take the 14.5 to 14 MHz range, subtract it from 17.5
MHz, and get 3 to 3.5 MHz

For 17, you would take the 18.5 to 18 MHz range, subtract it from 21.5
MHz, and get 3 to 3.5 MHz

I guess you don't plan on 15, 12 or 10 meters.

The main problem I see with this design is on 80 meters. On that band,
the tunable frequency is too close to the band being covered, and
you'll likely have troubles with feedthrough. For example, when you
are trying to listen to a signal on, say, 3.6 MHz, the tunable section
will be on 3.4 MHz, and the front-end selectivity probably won't be
able to stop strong signals from leaking through.

I suggest you look at other heterodyne schemes, because 80 meter
operation will be compromised using the scheme you describe.

Here's one to consider, from G2DAF:

Tunable range is 5 to 5.5 MHz

For 160, you would take the 2 to 1.5 MHz range, subtract it from 7
MHz, and get 5 to 5.5 MHz

For 80, you would take the 4 to 3.5 MHz range, subtract it from 9
MHz, and get 5 to 5.5 MHz

For 40, you would take the 7.5 to 7 MHz range, subtract it from 12.5
MHz, and get 5 to 5.5 MHz

For 30, you would take the 10.5 to 10.0 MHz range, subtract it from
15.5 MHz, and get 5 to 5.5 MHz

For 20, you would take the 14 to 14.5 MHz range, subtract 9 MHz from
it, and get 5 to 5.5 MHz (Note that the 9 MHz xtal works on two bands)

For 17, you would take the 18 to 18.5 MHz range, subtract 13 MHz from
it, and get 5 to 5.5 MHz

For 15, you would take the 21 to 21.5 MHz range, subtract 16 MHz from
it, and get 5 to 5.5 MHz

For 12, you would take the 24.5 to 25 MHz range, subtract 19.5 MHz
from it, and get 5 to 5.5 MHz

So you cover 8 ranges below 25 MHz with 7 xtals

Ten meters is left as an exercise for the reader.

For the higher frequencies, harmonics of the can be used. For example,
an 8 MHz xtal could be used for 15 meters by doubling.

Here's another one:

Tunable range is 3.5 to 4.1 MHz

For 160, you would take the 2 to 1.4 MHz range, subtract it from 5.5
MHz, and get 3.5 to 4.1 MHz

For 80, the conversion section is bypassed and you use the basic
tuning range

For 40, you would take the 7.5 to 6.9 MHz range, subtract it from 11
MHz, and get 3.5 to 4.1 MHz (Note that the second harmonic of the 5.5
MHz xtal used for 160 is 11 MHz)

For 30, you would take the 10.6 to 10.0 MHz range, subtract it from
14.1 MHz, and get 3.5 to 4.1 MHz

For 20, you would take the 14 to 14.6 MHz range, subtract 10.5 MHz
from it, and get 3.5 to 4.1 MHz

For 17, you would take the 17.6 to 18.2 MHz range, subtract 14.1 MHz
from it, and get 3.5 to 4.1 MHz (Note that the same xtal that gives
you 30 meters also works on 17 meters)

For 15, you would take the 21 to 21.6 MHz range, subtract 17.5 MHz
from it, and get 3.5 to 4.1 MHz

For 12, you would take the 24.5 to 25.1 MHz range, subtract 21 MHz
from it, and get 3.5 to 4.1 MHz (Note that the second harmonic of the
10.5 MHz xtal used for 20 is 21 MHz)

So you cover cover 8 ranges below 25.1 MHz with 6 xtals. If you use
harmonics of certain xtals, those 8 ranges can be covered with just 4
xtals.

Ten meters is left as an exercise for the reader.

There are lots of other schemes.

73 de Jim, N2EY

On Sep 6, 8:31*pm, wrote:
On Sep 2, 4:12 pm, Gary@ removenospamandputkf9cm.com wrote:

I am looking for some Heterodyne conversion crystals for a receiver I am
making.
The frequencies a 5 MHz, 7 MHz, 10.5 MHz, 13.5 MHz, 17.5 MHz and 21.5
MHz.
The variable mixing frequency will be from 3 to 3.5 MHz. I would prefer all
the same type holder.
.

73 de Jim, N2EY

What you ain't got no IF?
All those fine numbers and no IF
You know what the image frequency is with no IF?

I think he can get's 12 and 15 meters.
21.5+3.39=24.89 the bottom of the 12 meter band.
21.5+3.49=24.99 the top of the 12 meter band
17.5+3.5=21.0 the bottom of 15 meters for an extra
squeeze the tuning range to 3.95 and
17.5+3,95 =21.45 the top of the 15 meter band.

Back in the day the reason for Heterodyne was simple
to get a lower frequency at which you could amplify the signal
more readily getting you more SN ratio and selectivity.


73 OM

n8zu