Need a quartz crystal: 1595 to 1610 kHz

[Tio Pedro]

Looking for a 1595 to 1610 kHz crystal for a receiver
project. Anyone have one in the junkbox forsale?

Pete

[s***@trailing-edge.com]

Post by Tio Pedro
Looking for a 1595 to 1610 kHz crystal for a receiver
project. Anyone have one in the junkbox forsale?

1.8432 MHZ crystals are popular today for baud rate generators.

If you can fiddle your IF frequencies around you may find 1.8432MHz a
superior choice today. 1.6 or so MHz was commonly used in dual-
conversion ham/SW receivers (e.g. HBR-14) in the 50's and 60's but
they extended the MW band in NA since then and you'll probably find
all sorts of AM broadcasters around the original project's IF
frequency.

Tim.

[Tio Pedro]

v1.8432 MHZ crystals are popular today for baud rate generators.

If you can fiddle your IF frequencies around you may find 1.8432MHz a
superior choice today. 1.6 or so MHz was commonly used in dual-
conversion ham/SW receivers (e.g. HBR-14) in the 50's and 60's but
they extended the MW band in NA since then and you'll probably find
all sorts of AM broadcasters around the original project's IF
frequency.

Tim.

The original design used 1600kc and 100kc first and second IFs,
but I was going to go with 1625kc and 85kc to make use of
surplus command RX IF coils. This
pretty much follows the scheme used in Ted Crosby's original HBR
designs... However, I was able to locate a pair of xtals for a half-lattice
xtal filter at 1680kc (Heathkit HR-10) which I'm now going to
use in the first IF. I don't want to abandon a significant investment
in the 85kc transformers, which already have a significant L/C
ratio... So the option is finding a near 1600kc rock...

Pete

[s***@trailing-edge.com]

Post by Tio Pedro
The original design used 1600kc and 100kc first and second IFs,
but I was going to go with 1625kc and 85kc to make use of
surplus command RX IF coils.

Pete -
If you can move the 1600kc IF up to 1928 kc, either by tuning them
or by changing the tuning capacitance, then you'll avoid the issue of
AM broadcast stations leaking through into your 1625 kc IF. How do I
know about that leak through? I have an HBR-16!

There is a *LOT* of wiggle room in those IF transformers.

Tim.

[Tio Pedro]

<***@trailing-edge.com> wrote in message news:d2d7db02-079a-4bfb-9ee5-
There is a *LOT* of wiggle room in those IF transformers.

Tim.

Not much wiggle room in the 85kc command set transformers :) Not much
of an issue with the 1st IFs though.

The problem is using the existing half-lattice xtal filter
pair from the Heath HR 10. I'd like to
use them in the first IF. I hear what you're saying though.

[s***@trailing-edge.com]

Post by s***@trailing-edge.com
There is a *LOT* of wiggle room in those IF transformers.
Tim.
Not much wiggle room in the 85kc command set transformers :) Not much
of an issue with the 1st IFs though.
The problem is using the existing half-lattice xtal filter
pair from the Heath HR 10.  I'd like to
use them in the first IF. I hear what you're saying though.

Now I see, you want to build an HBR but have no wiggle room for the
first IF because you want to put an already existing crystal filter
there. Kinda nullifies the purpose of the 85kc IF you don't need it
for selectivity, doesn't it?

You know, at those low frequencies you can just build a LC oscillator
and get decent stability. Like the HBR BFO, for example. It's gonna be
far more stable than the VFO is on 15M :-).

Tim N3QE.

[Tio Pedro]

<***@trailing-edge.com> wrote in message news:f5f7cbd9-5349-4c5e-a427-***@e18g2000yqo.googlegroups.com...


Now I see, you want to build an HBR but have no wiggle room for the
first IF because you want to put an already existing crystal filter
there. Kinda nullifies the purpose of the 85kc IF you don't need it
for selectivity, doesn't it?

Tim N3QE.

Think of it as a "roofing filter" to protect the first mixer.

Half Lattice isn't going to do much
for stop band attenuation or spurious responses out of passband.
The IF transformers will clean that up and hopefully improve
the overall slope. The HBR design is a dated and a compromise.
Its hard to know where to stop, or begin. The 85kc IF transformers
should give a tighter BW than the cheesy Heath filter.

Pete k1zjh

Pete
T

[Michael Black]

Post by s***@trailing-edge.com

v1.8432 MHZ crystals are popular today for baud rate generators.

If you can fiddle your IF frequencies around you may find 1.8432MHz a
superior choice today. 1.6 or so MHz was commonly used in dual-
conversion ham/SW receivers (e.g. HBR-14) in the 50's and 60's but
they extended the MW band in NA since then and you'll probably find
all sorts of AM broadcasters around the original project's IF
frequency.
Tim.
The original design used 1600kc and 100kc first and second IFs,
but I was going to go with 1625kc and 85kc to make use of
surplus command RX IF coils. This
pretty much follows the scheme used in Ted Crosby's original HBR
designs... However, I was able to locate a pair of xtals for a half-lattice
xtal filter at 1680kc (Heathkit HR-10) which I'm now going to
use in the first IF. I don't want to abandon a significant investment
in the 85kc transformers, which already have a significant L/C
ratio... So the option is finding a near 1600kc rock...
Pete

Find a crystal that's a multiple of the desired frequency, and divide
it down. Of course, that wouldn't have been done decades ago, but you
could do it as a start and then go traditional when such a crystal
washes up.

Or go whole hog and build a PLL synthesizer to get the desired frequency
from a standard frequency crystal. Overkill, but you could even then
make it tuneable for some nifty design feature.

Not traditional either, but more akin to what you might have seen
back then, get two crystals that beat together to generate the desired
frequency, and then filter the output well.

Michael

[Jeffrey D Angus]

Post by Michael Black
Or go whole hog and build a PLL synthesizer to get the desired frequency
from a standard frequency crystal. Overkill, but you could even then
make it tuneable for some nifty design feature.

My favorite was I needed an oddball crystal to get an old Motorola
stripline receiver working on VHF. So I used an HP synthesizer. The
old rack mount about 21" tall that weighs about 200 pounds with 100
or so push buttons on the front panel.

Jeff

[Tio Pedro]

Post by Jeffrey D Angus

Post by Jeffrey D Angus
My favorite was I needed an oddball crystal to get an old Motorola

stripline receiver working on VHF. So I used an HP synthesizer. The
old rack mount about 21" tall that weighs about 200 pounds with 100
or so push buttons on the front panel.
Jeff

Probably an old Sensicon with 23 zillion tubes...

[Bill Jeffrey]

Post by Jeffrey D Angus
My favorite was I needed an oddball crystal to get an old Motorola
stripline receiver working on VHF. So I used an HP synthesizer. The
old rack mount about 21" tall that weighs about 200 pounds with 100
or so push buttons on the front panel.
Jeff

I remember that synthesizer (though not the model number)! We used one
in about 1975 as the core of a fast-tuning communications jammer. As I
recall, its claim to fame was that it had a computer interface, and
would tune and settle in less than a microsecond. No PLL here - as I
recall, it used some sort of direct, and very complicated, mixing
scheme. Heady stuff for those days. So was the computer that drove it!

Bill

[Jeffrey D Angus]

Post by Bill Jeffrey

Post by Jeffrey D Angus
My favorite was I needed an oddball crystal to get an old Motorola
stripline receiver working on VHF. So I used an HP synthesizer. The
old rack mount about 21" tall that weighs about 200 pounds with 100
or so push buttons on the front panel.
Jeff

I remember that synthesizer (though not the model number)! We used one
in about 1975 as the core of a fast-tuning communications jammer. As I
recall, its claim to fame was that it had a computer interface, and
would tune and settle in less than a microsecond. No PLL here - as I
recall, it used some sort of direct, and very complicated, mixing
scheme. Heady stuff for those days. So was the computer that drove it!
Bill

Here we go:
http://www.hpmemory.org/news/5100/hp5100_page_00.htm

Ahhhh, now THERE is a boat anchor.

There's one for sale at the surplus place for $150.

Jeff

[Tio Pedro]

Post by Jeffrey D Angus

Post by Jeffrey D Angus
My favorite was I needed an oddball crystal to get an old Motorola
stripline receiver working on VHF. So I used an HP synthesizer. The
old rack mount about 21" tall that weighs about 200 pounds with 100
or so push buttons on the front panel.
Jeff

I remember that synthesizer (though not the model number)! We used one in
about 1975 as the core of a fast-tuning communications jammer. As I
recall, its claim to fame was that it had a computer interface, and would
tune and settle in less than a microsecond. No PLL here - as I recall, it
used some sort of direct, and very complicated, mixing scheme. Heady
stuff for those days. So was the computer that drove it!
Bill

http://www.hpmemory.org/news/5100/hp5100_page_00.htm
Ahhhh, now THERE is a boat anchor.
There's one for sale at the surplus place for $150.
Jeff

Indeed. With that noise floor, you didn't need to get too
close to what you needed to jam either. Not a first choice
for IMD or LO phase noise RX measurements either :)

Pete

[Tio Pedro]

"Michael Black" <***@ncf.ca> wrote in message > Find a crystal that's a
multiple of the desired frequency, and divide

Post by Michael Black
it down. Of course, that wouldn't have been done decades ago, but you
could do it as a start and then go traditional when such a crystal
washes up.
Or go whole hog and build a PLL synthesizer to get the desired frequency
from a standard frequency crystal. Overkill, but you could even then
make it tuneable for some nifty design feature.
Not traditional either, but more akin to what you might have seen
back then, get two crystals that beat together to generate the desired
frequency, and then filter the output well.
Michael

I'm surprised no suggested going with a free-running oscillator, and
having it track the variable BFO for bandpass tuning :)

I think I located the crystals I need, so extreme measures won't be
needed. Although I did see 3.2mc xtals were readily available, and
began to try and think of a mixer configuration that would work with
a 2X LO.

Pete

[DaveM]

Post by Michael Black
multiple of the desired frequency, and divide

Post by Michael Black
it down. Of course, that wouldn't have been done decades ago, but you
could do it as a start and then go traditional when such a crystal
washes up.
Or go whole hog and build a PLL synthesizer to get the desired frequency
from a standard frequency crystal. Overkill, but you could even then
make it tuneable for some nifty design feature.
Not traditional either, but more akin to what you might have seen
back then, get two crystals that beat together to generate the desired
frequency, and then filter the output well.
Michael

I'm surprised no suggested going with a free-running oscillator, and
having it track the variable BFO for bandpass tuning :)
I think I located the crystals I need, so extreme measures won't be
needed. Although I did see 3.2mc xtals were readily available, and
began to try and think of a mixer configuration that would work with
a 2X LO.
Pete

Sorry to come into this thread so late, but I had forgotten about Surplus Sales
in Nebraska. I found your 1600 KHz crystal at
http://www.surplussales.com/Crystals/Crystals-2.html, part # (CRY) 001.6000

Hope you haven't ordered something that's not exactly what your designing for;
this one seems to be exactly what you are looking for.

[Tio Pedro]

Post by DaveM

Post by Michael Black
a multiple of the desired frequency, and divide

Post by Michael Black
it down. Of course, that wouldn't have been done decades ago, but you
could do it as a start and then go traditional when such a crystal
washes up.
Or go whole hog and build a PLL synthesizer to get the desired frequency
from a standard frequency crystal. Overkill, but you could even then
make it tuneable for some nifty design feature.
Not traditional either, but more akin to what you might have seen
back then, get two crystals that beat together to generate the desired
frequency, and then filter the output well.
Michael

I'm surprised no suggested going with a free-running oscillator, and
having it track the variable BFO for bandpass tuning :)
I think I located the crystals I need, so extreme measures won't be
needed. Although I did see 3.2mc xtals were readily available, and
began to try and think of a mixer configuration that would work with
a 2X LO.
Pete

Sorry to come into this thread so late, but I had forgotten about Surplus
Sales in Nebraska. I found your 1600 KHz crystal at
http://www.surplussales.com/Crystals/Crystals-2.html, part # (CRY) 001.6000
Hope you haven't ordered something that's not exactly what your designing
for; this one seems to be exactly what you are looking for.
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters
in the address)
Life is like a roll of toilet paper; the closer it gets to the end, the
faster it goes.

[Tio Pedro]

"DaveM" <***@comcast99.net> wrote in message > Sorry to come into
this thread so late, but I had forgotten about Surplus Sales

Post by DaveM
in Nebraska. I found your 1600 KHz crystal at
http://www.surplussales.com/Crystals/Crystals-2.html, part # (CRY) 001.6000
Hope you haven't ordered something that's not exactly what your designing
for; this one seems to be exactly what you are looking for.
--
Dave M

I was lucky enough to find both a 1590kc and 1605kc
FT-243 style crystals from a group member. I guess I'm all set...

Pete