Hello

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Make a search for VLF gear, it is for 137 KHz but should be no problem
for redesigning to 160 KHz.

Regards Max

1750 meter projects..
 

Hello

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Make a search for VLF gear, it is for 137 KHz but should be no problem
for redesigning to 160 KHz.

Regards Max

Nothing40 ) writes:
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience.I don't have much experience with RF
electronics,and have been working my way into this "grey area/black
magic" ;-) I have built a few FM transmitters,amplifiers,etc..
(I'm really proud o the FM amp I built,1 watt from a 6AK5,First RF
project I have built from scratch that worked!)

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Thanks a bunch! Patrick.

I think you will rarely see a receiver for this band.

There is no, or virtually no, commercially made transmitters for
this frequency and power, so you don't have much choice but to
build. Plus, a transmitter is nice and simple, so you might
as well build it.

But due to the very low allowed power, and the low frequency of
the band (and associated inefficiencies of the antenna), you really
need to go with a good receiver. So I'm sure many would use an
existing receiver that happens to cover the frequency, with it's
good selectivity and features.

If their receiver doesn't cover the band, then they'd add a converter.
I have no idea what's on the web, but there have been a number of converters
for this band described in the magazines over the years.

People building receivers are likely building something really high
performance, maybe moving away from the common receiver schemes in order
to get the most performance for the limited conditions. I'm sure such a
receiver was described in the late Communications Quarterly in an early
issue. Unless you are willing to put in a lot of effort, duplicating
such receivers are not the route.

That said, many converter schematics can be used, so long as
you change the crystal frequency and the front end tuned circuits.
Decades ago, a common LF converter was a single transistor in
a pierce oscillator/mixer combination, and no tuned circuit (or a simple
low pass circuit) at the antenna. Likely not great performance, but
a way to get started and little to go wrong.

And just about any simple receiver design could be used to get
a simple 1750 meter receiver. Pick one with decent selectivy, and
then again modify the local oscillator and front end tuned circuits.

Michael VE2BVW

Nothing40 ) writes:
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience.I don't have much experience with RF
electronics,and have been working my way into this "grey area/black
magic" ;-) I have built a few FM transmitters,amplifiers,etc..
(I'm really proud o the FM amp I built,1 watt from a 6AK5,First RF
project I have built from scratch that worked!)

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Thanks a bunch! Patrick.

I think you will rarely see a receiver for this band.

There is no, or virtually no, commercially made transmitters for
this frequency and power, so you don't have much choice but to
build. Plus, a transmitter is nice and simple, so you might
as well build it.

But due to the very low allowed power, and the low frequency of
the band (and associated inefficiencies of the antenna), you really
need to go with a good receiver. So I'm sure many would use an
existing receiver that happens to cover the frequency, with it's
good selectivity and features.

If their receiver doesn't cover the band, then they'd add a converter.
I have no idea what's on the web, but there have been a number of converters
for this band described in the magazines over the years.

People building receivers are likely building something really high
performance, maybe moving away from the common receiver schemes in order
to get the most performance for the limited conditions. I'm sure such a
receiver was described in the late Communications Quarterly in an early
issue. Unless you are willing to put in a lot of effort, duplicating
such receivers are not the route.

That said, many converter schematics can be used, so long as
you change the crystal frequency and the front end tuned circuits.
Decades ago, a common LF converter was a single transistor in
a pierce oscillator/mixer combination, and no tuned circuit (or a simple
low pass circuit) at the antenna. Likely not great performance, but
a way to get started and little to go wrong.

And just about any simple receiver design could be used to get
a simple 1750 meter receiver. Pick one with decent selectivy, and
then again modify the local oscillator and front end tuned circuits.

Michael VE2BVW

Patrick,

Check out this link:

http://www.lwca.org/

Regards,
Jim Candela
WD5JKO


"Nothing40" wrote in message
om...
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience.I don't have much experience with RF
electronics,and have been working my way into this "grey area/black
magic" ;-) I have built a few FM transmitters,amplifiers,etc..
(I'm really proud o the FM amp I built,1 watt from a 6AK5,First RF
project I have built from scratch that worked!)

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Thanks a bunch! Patrick.

Patrick,

Check out this link:

http://www.lwca.org/

Regards,
Jim Candela
WD5JKO


"Nothing40" wrote in message
om...
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience.I don't have much experience with RF
electronics,and have been working my way into this "grey area/black
magic" ;-) I have built a few FM transmitters,amplifiers,etc..
(I'm really proud o the FM amp I built,1 watt from a 6AK5,First RF
project I have built from scratch that worked!)

Any schematics,links,suggestions on circuits,antennas,etc,etc would be
great!

Thanks a bunch! Patrick.

If you can find them one of the best sources for the 1750m band was Ken Cornell's "The Low & Medium Frequency Radio
Scrapbook". There were 4 editions, that I know of, from 1975 to 1982. They were a collection of circuits from everyone
that was experimenting at the time. Ken has long become a 'silent key' and so there hasn't been a new edition out in a
long time. Check around, you might find some available, they're well worth having.
73
Richard WB8KRN

If you can find them one of the best sources for the 1750m band was Ken Cornell's "The Low & Medium Frequency Radio
Scrapbook". There were 4 editions, that I know of, from 1975 to 1982. They were a collection of circuits from everyone
that was experimenting at the time. Ken has long become a 'silent key' and so there hasn't been a new edition out in a
long time. Check around, you might find some available, they're well worth having.
73
Richard WB8KRN

----- Original Message -----
"Frank Gilliland" Wrotee:

Is this band still allocated for low power experimental use without a
license?

Yep, limited to 1 watt power input to the final, and the total
antenna/ground
system is limited to 50 feet.




Yes, the Transmit is limited to that power and antenna. However, the Rx
is not and I'd use a fairly large antenna or tuned antenna loop with a FET
follower at these frequencies.

For the rest of the Rx, a converter is a good way to go and the FET will
give a low enough output impedance for a regular mixer of some sort.

Jim Pennell
N6BIU

----- Original Message -----
"Frank Gilliland" Wrotee:

Is this band still allocated for low power experimental use without a
license?

Yep, limited to 1 watt power input to the final, and the total
antenna/ground
system is limited to 50 feet.




Yes, the Transmit is limited to that power and antenna. However, the Rx
is not and I'd use a fairly large antenna or tuned antenna loop with a FET
follower at these frequencies.

For the rest of the Rx, a converter is a good way to go and the FET will
give a low enough output impedance for a regular mixer of some sort.

Jim Pennell
N6BIU

In . net, "Jim Pennell"
wrote:


----- Original Message -----
"Frank Gilliland" Wrotee:

Is this band still allocated for low power experimental use without a
license?

Yep, limited to 1 watt power input to the final, and the total
antenna/ground
system is limited to 50 feet.




Yes, the Transmit is limited to that power and antenna. However, the Rx
is not and I'd use a fairly large antenna or tuned antenna loop with a FET
follower at these frequencies.

For the rest of the Rx, a converter is a good way to go and the FET will
give a low enough output impedance for a regular mixer of some sort.

Jim Pennell
N6BIU


I've played around on this band for a few year now, and I've noticed a few
things. It doesn't seem to matter what receiver you use because the noise on the
band is almost always much higher than the receiver's front-end noise. Increase
the receiver's sensitivity and you increase the noise. Instead, work on the
receiver's selectivity. Or send the audio output from the receiver into your
computer's sound card and use one of those great FFT programs designed for
weak-signal work. Do that and you can see signals well below the noise floor.

As far as antennas are concerned, loops are popular but there are plenty of
other options. Remember that the band is for experimentation, and part of the
fun comes from experimenting with different antennas. But even with all the
noise on the band, you can still work 20+ miles CW with nothing more than a wire
in the tree and any old receiver that will tune the band.






-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

In . net, "Jim Pennell"
wrote:


----- Original Message -----
"Frank Gilliland" Wrotee:

Is this band still allocated for low power experimental use without a
license?

Yep, limited to 1 watt power input to the final, and the total
antenna/ground
system is limited to 50 feet.




Yes, the Transmit is limited to that power and antenna. However, the Rx
is not and I'd use a fairly large antenna or tuned antenna loop with a FET
follower at these frequencies.

For the rest of the Rx, a converter is a good way to go and the FET will
give a low enough output impedance for a regular mixer of some sort.

Jim Pennell
N6BIU


I've played around on this band for a few year now, and I've noticed a few
things. It doesn't seem to matter what receiver you use because the noise on the
band is almost always much higher than the receiver's front-end noise. Increase
the receiver's sensitivity and you increase the noise. Instead, work on the
receiver's selectivity. Or send the audio output from the receiver into your
computer's sound card and use one of those great FFT programs designed for
weak-signal work. Do that and you can see signals well below the noise floor.

As far as antennas are concerned, loops are popular but there are plenty of
other options. Remember that the band is for experimentation, and part of the
fun comes from experimenting with different antennas. But even with all the
noise on the band, you can still work 20+ miles CW with nothing more than a wire
in the tree and any old receiver that will tune the band.






-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----

Frank Gilliland wrote in
:

"Transmitter for the Neglected Band" and "Tuner for the Neglected
Band", both written by Jim White/W5LET, were in the Jan and Feb 72
editions of Popular Electronics, respectively. You can probably find
those issues on film at your local public library. Both are tube
projects. The tuner (receiver) is some kind of funky TRF/superhet
hybrid, and is tuned by adjusting four compression trimmers (IOW, the
tuning is virtually fixed).


Ah, that's the one. I remember it well. With the plethora of digital radios
that tune down to 150 kHz these days, the rx wouldn't even be a
consideration.

Frank Gilliland wrote in
:

"Transmitter for the Neglected Band" and "Tuner for the Neglected
Band", both written by Jim White/W5LET, were in the Jan and Feb 72
editions of Popular Electronics, respectively. You can probably find
those issues on film at your local public library. Both are tube
projects. The tuner (receiver) is some kind of funky TRF/superhet
hybrid, and is tuned by adjusting four compression trimmers (IOW, the
tuning is virtually fixed).


Ah, that's the one. I remember it well. With the plethora of digital radios
that tune down to 150 kHz these days, the rx wouldn't even be a
consideration.

Roy Lewallen wrote in
:

You can get information about copyrights at http://www.uspto.gov.
There's no doubt that the original copyright is still in force, since
the term of a copyright is much longer than 30 years. (They've changed
it recently -- I think it was from 75 to 125 years, under the urging of
Disney, whose early copyrights were expiring.) Unless sold, a copyright
owned by an individual becomes part of a deceased's estate, so if the
author held the original copyright, it's probably owned by the author's
heirs. If it was held by Ham Radio magazine, it might be owned by CQ,
who took over Communications Quarterly, the successor to Ham Radio; or
the ARRL, who took Communications Quarterly over from CQ. Or possibly
Craig Clark, who bought the Ham Radio Bookstore from Ham Radio years
ago. Or, the author might have had an agreement with the publisher to
have the copyright revert back to him from the publisher after some
period, in which case the heirs have it.

Of course, you can copy small portions for various uses under the "fair
use" doctrine. But copying the whole thing would almost certainly be a
copyright violation.

If you're really interested, I'd recommend seeing a qualified attorney
before you proceed. I'm not one, and what I say shouldn't be taken as
legal advice.



Here's what I don't understand about copyright law. If a hobbyist wants to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

Roy Lewallen wrote in
:

You can get information about copyrights at http://www.uspto.gov.
There's no doubt that the original copyright is still in force, since
the term of a copyright is much longer than 30 years. (They've changed
it recently -- I think it was from 75 to 125 years, under the urging of
Disney, whose early copyrights were expiring.) Unless sold, a copyright
owned by an individual becomes part of a deceased's estate, so if the
author held the original copyright, it's probably owned by the author's
heirs. If it was held by Ham Radio magazine, it might be owned by CQ,
who took over Communications Quarterly, the successor to Ham Radio; or
the ARRL, who took Communications Quarterly over from CQ. Or possibly
Craig Clark, who bought the Ham Radio Bookstore from Ham Radio years
ago. Or, the author might have had an agreement with the publisher to
have the copyright revert back to him from the publisher after some
period, in which case the heirs have it.

Of course, you can copy small portions for various uses under the "fair
use" doctrine. But copying the whole thing would almost certainly be a
copyright violation.

If you're really interested, I'd recommend seeing a qualified attorney
before you proceed. I'm not one, and what I say shouldn't be taken as
legal advice.



Here's what I don't understand about copyright law. If a hobbyist wants to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

Need to apply the "Reasonable Man" theory. If it would be reasonable for
the copyright holder to profit, then he has been damaged. A copy,
distributed to a limited audience, for scientific use probably would fall
under a "fair use" exception. A "I have found this wonderful item, and
here it is" distributed to persons who would have purchased the item had it
not been distributed would be infringement. The subtle differences is why
we have courts, and a legal system.

--
73 es cul

wb3fup
a Salty Bear

"donut" wrote in message
...
Roy Lewallen wrote in
:

You can get information about copyrights at http://www.uspto.gov.
There's no doubt that the original copyright is still in force, since
the term of a copyright is much longer than 30 years. (They've changed
it recently -- I think it was from 75 to 125 years, under the urging of
Disney, whose early copyrights were expiring.) Unless sold, a copyright
owned by an individual becomes part of a deceased's estate, so if the
author held the original copyright, it's probably owned by the author's
heirs. If it was held by Ham Radio magazine, it might be owned by CQ,
who took over Communications Quarterly, the successor to Ham Radio; or
the ARRL, who took Communications Quarterly over from CQ. Or possibly
Craig Clark, who bought the Ham Radio Bookstore from Ham Radio years
ago. Or, the author might have had an agreement with the publisher to
have the copyright revert back to him from the publisher after some
period, in which case the heirs have it.

Of course, you can copy small portions for various uses under the "fair
use" doctrine. But copying the whole thing would almost certainly be a
copyright violation.

If you're really interested, I'd recommend seeing a qualified attorney
before you proceed. I'm not one, and what I say shouldn't be taken as
legal advice.



Here's what I don't understand about copyright law. If a hobbyist wants
to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

Need to apply the "Reasonable Man" theory. If it would be reasonable for
the copyright holder to profit, then he has been damaged. A copy,
distributed to a limited audience, for scientific use probably would fall
under a "fair use" exception. A "I have found this wonderful item, and
here it is" distributed to persons who would have purchased the item had it
not been distributed would be infringement. The subtle differences is why
we have courts, and a legal system.

--
73 es cul

wb3fup
a Salty Bear

"donut" wrote in message
...
Roy Lewallen wrote in
:

You can get information about copyrights at http://www.uspto.gov.
There's no doubt that the original copyright is still in force, since
the term of a copyright is much longer than 30 years. (They've changed
it recently -- I think it was from 75 to 125 years, under the urging of
Disney, whose early copyrights were expiring.) Unless sold, a copyright
owned by an individual becomes part of a deceased's estate, so if the
author held the original copyright, it's probably owned by the author's
heirs. If it was held by Ham Radio magazine, it might be owned by CQ,
who took over Communications Quarterly, the successor to Ham Radio; or
the ARRL, who took Communications Quarterly over from CQ. Or possibly
Craig Clark, who bought the Ham Radio Bookstore from Ham Radio years
ago. Or, the author might have had an agreement with the publisher to
have the copyright revert back to him from the publisher after some
period, in which case the heirs have it.

Of course, you can copy small portions for various uses under the "fair
use" doctrine. But copying the whole thing would almost certainly be a
copyright violation.

If you're really interested, I'd recommend seeing a qualified attorney
before you proceed. I'm not one, and what I say shouldn't be taken as
legal advice.



Here's what I don't understand about copyright law. If a hobbyist wants
to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

Every once in a while I point out what the copyright or patent law says.
I almost always get responses from people who feel they should be able
to do something other than the law states -- for example, a lot of
people feel that they should be able to build a patented item for their
own personal use, while the law specifically forbids it. Or photocopy a
book that's out of print. And so forth. I think most people don't really
want to know what the law says -- they'd rather keep their notion of
what they think it should say.

I don't make the laws. I don't enforce them. And, shoot, I'm not even
qualified to say what they are or what they mean. Anyone really
interested in learning what the laws say can go to http://www.uspto.gov
or a bunch of other authoritative sources. Better yet, see a qualified
attorney, who can also tell you how they're enforced. Then do whatever
it is your conscience (or rationalization) lets you do. Most people are
probably going to do what they want anyway, no matter what the laws say,
and come with reasons to justify it.

Want to know why the law says what it does? Ask your congressperson.
Have a complaint? Tell your congressperson. But be warned -- people who
like sausages or have respect for the law shouldn't look too closely at
how either is made. And it ain't pretty.

Roy Lewallen, W7EL

donut wrote:

Here's what I don't understand about copyright law. If a hobbyist wants to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

Every once in a while I point out what the copyright or patent law says.
I almost always get responses from people who feel they should be able
to do something other than the law states -- for example, a lot of
people feel that they should be able to build a patented item for their
own personal use, while the law specifically forbids it. Or photocopy a
book that's out of print. And so forth. I think most people don't really
want to know what the law says -- they'd rather keep their notion of
what they think it should say.

I don't make the laws. I don't enforce them. And, shoot, I'm not even
qualified to say what they are or what they mean. Anyone really
interested in learning what the laws say can go to http://www.uspto.gov
or a bunch of other authoritative sources. Better yet, see a qualified
attorney, who can also tell you how they're enforced. Then do whatever
it is your conscience (or rationalization) lets you do. Most people are
probably going to do what they want anyway, no matter what the laws say,
and come with reasons to justify it.

Want to know why the law says what it does? Ask your congressperson.
Have a complaint? Tell your congressperson. But be warned -- people who
like sausages or have respect for the law shouldn't look too closely at
how either is made. And it ain't pretty.

Roy Lewallen, W7EL

donut wrote:

Here's what I don't understand about copyright law. If a hobbyist wants to
photocopy out of print work for his own use, or even to redistibute to
others with like interests, how is it a copyright violation unless he
either profits from it, or deprives the legal owner of the copyright from
profit?

I understand the concept - I just don't understand the way the law is
applied these days.

In article ,
Nothing40 wrote:
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience. [snip]

A transceiver for this "band" was in the SEP 94 issue of 73.

I'd always wanted to put together a regen for this band. Regenerative
detectors are at their best when they are rather tightly coupled to
antennas that are electrically short. One reality of 1750 meters is
that any antenna one man can lift is bound to be "electrically short".
--

R F Wieland Newark, DE 19711-5323 USA 39.68N 75.74W
Icom R75 Heathkit GR-81 Inverted-L in the attic
Reply to wieland at me dot udel dot edu

In article ,
Nothing40 wrote:
Hey Gang..

I have recently become interested in the 1750 meter band (160-180
khz).I have been searching the net for
information,circuits,reports,anything I can find!
I plan on homebrewing a TX/RX pair,once I do a little more research. I
have found a few Schematics,and plans for a couple different
transmitters,and antenna's,but no plans for recievers. Can anyone help
me out? I'd prefer to go the homebrew route,mostly for experience,and
for a learning experience. [snip]

A transceiver for this "band" was in the SEP 94 issue of 73.

I'd always wanted to put together a regen for this band. Regenerative
detectors are at their best when they are rather tightly coupled to
antennas that are electrically short. One reality of 1750 meters is
that any antenna one man can lift is bound to be "electrically short".
--

R F Wieland Newark, DE 19711-5323 USA 39.68N 75.74W
Icom R75 Heathkit GR-81 Inverted-L in the attic
Reply to wieland at me dot udel dot edu

Regenerative detectors are at their best when they are rather
tightly coupled to antennas that are electrically short.
=============================

What gave you that idea?
---
Reg

Regenerative detectors are at their best when they are rather
tightly coupled to antennas that are electrically short.
=============================

What gave you that idea?
---
Reg