AM receiver convert to ATC receiver

[Bob Monsen]

"Varactor" <Moreflaps@gmail.com> wrote in message
news:5ddef92b-5533-42f9-936f-8e27e87ca416@v26g2000prm.googlegroups.com...

Don't know abou that. When two stations broadcast over each other its
generally just distorted garbage. I speak as a pilot, not from theory.

As a pilot too, I know that if people step on each other's communications,
it ends up with distortion. Stuck mikes are always a problem. However, the
receiver isn't locked onto the stuck mike, and you hear something. ATC can
often blast over a stuck mike to get the offender's attention. Also, it is
possible for pilots to talk over other pilots at remote fields with the same
unicom frequency (very common here in California, despite the attempt by the
FAA to spread out the frequency assignments).

Anyway, enough said. I had always been told by instructors/pilots that AM
was preferred due to this effect, so I was parroting that (as they probably
were), without really examining the claim in detail. However, it does appear
to have some merit.

Regards,
Bob Monsen

 

[Tom2000]

On Sun, 20 Apr 2008 00:28:18 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

From a regen that misbehaves it certainly can.

Not to worry. That receiver wouldn't stay on any given frequency long
enough to cause problems. Might not even stay in the air band.

Tom

 

[Wayne]

"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com...

Hi all

If I change the tank circuit components (reduce the capacitance and
inductance) and change the transistors to appropriate VHF ones, will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelto,

I have tried to read and understand the posts in this thread the best I
can. Can someone tell me; Is there a problem for the aircraft industry, or
me, if I sit at the end of Regan National airport outside DC and use this,

http://tinyurl.com/3ayskq

Thanks.

Wayne

 

[Don Bowey]

On 4/20/08 11:57 AM, in article
l6udnTgHSKeUD5bVnZ2dnUVZ_tGonZ2d@comcast.com, "Wayne"
<NOwaynerr@SPAMcomcast.net> wrote:

"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com...
Hi all

If I change the tank circuit components (reduce the capacitance and
inductance) and change the transistors to appropriate VHF ones, will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelto,


I have tried to read and understand the posts in this thread the best I
can. Can someone tell me; Is there a problem for the aircraft industry, or
me, if I sit at the end of Regan National airport outside DC and use this,

http://tinyurl.com/3ayskq

Thanks.

Wayne

No. It does not use a regeneration type detector.

 

[Joerg]

Don Bowey wrote:

On 4/19/08 5:28 PM, in article
C6wOj.2082$pS4.1634@newssvr13.news.prodigy.net, "Joerg"
notthisjoergsch@removethispacbell.net> wrote:

Don Bowey wrote:
On 4/18/08 11:25 AM, in article lI5Oj.4682$iK6.2220@nlpi069.nbdc.sbc.com,
"Joerg" <notthisjoergsch@removethispacbell.net> wrote:

Don Bowey wrote:
On 4/18/08 8:16 AM, in article fuae44$6tg$1@dns3.cae.ca, "Claude"
claudec@cae.com> wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:cJMNj.6968$GE1.6102@nlpi061.nbdc.sbc.com...
Michael Black wrote:
On Wed, 16 Apr 2008, Bob Eld wrote:

"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com.
..
Hi all

If I change the tank circuit components (reduce the capacitance and
inductance) and change the transistors to appropriate VHF ones, will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelton.
Not likely. I doubt you'd ever get that circuit to work at VHF
frequencies
no matter what you did with the resonant circuit portion. There are
many
problems including wrong impedances for the various parasitic
capacitances.

Secondly air traffic stuff is FM I believe.

Military may use FM, I don't know, but airplane related communication is
unique in that it does use actual AM.

A project that saw publication a number of times in the old days took
advantage of that, a "crystal radio" that tuned VHF. It was nothing
more than a tuned circuit and a diode detector feeding an earphone, not
sensitive but useful near airports and since it didn't radiate anything,
even useable (though maybe not legally) on an actual airplane.

The description of the circuit says it's a regen receiver, and those
were never popular at VHF, I'm assuming instability came into play.
You did see superregen receivers there. Either type will radiate, and
that's not a good thing in the aircraft band.

Yes, and then you'd quickly have visitors coming with vehicles bearing
government license plates. A regen-receiver is most definitely not a good
idea in the aircraft band.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
Quite correct, it is most likely jail time where you will have hours and
hours of fun designing electronics such as movement alarms
that will detect the proximity of "fellow inmates" . Just swearing on an
ATC
frequency will net you a $2,500 fine in Canada, I can't even imagine what
they would do to you if you jammed one of their frequencies.

Claude
Montreal


One of you naysayers should estimate the amount of radiated energy from a
typical regen receiver.

Also, what is the distance from the intended regen location to the airport,
and what would you imagine the comparative strengths would be of the regen
signal and air traffic signals at air traffic receivers?

The regen receiver radiated signal would be lost in the noise.

The other party to air traffic communication are aircraft. Those happen
to roam about quite a bit

Seriously, disregarding the airstrip that's almost next to the office
here we are also roughly in the flight path for Mather Field. Altitude
above our building maybe 1500ft, give or take. If Fedex, DHL and other
pilots would report some weird shhhhht noise everytime they pass a
certain spot, guess what would happen?
I doubt that at 1500 feet the signal from a regen receiver would break the
squelch.

From a regen that misbehaves it certainly can.

Yes, just about anything and everything that misbehaves can can cause a
problem. When I lived in Ketchikan, AK, I received one of those
salmon-colored FCC QSL cards from a listening station at Point Reyes, CA due
to a misbehaving multiplier in my HT9. Got a 579 on my second harmonic.

That one would be worth placing it in a frame

Problem with homebuilt regens is that unless they have a preamp they can
easily emit lots of RF power if something goes wrong, straight out the
antenna. "Dang, why doesn't it receive anything?" ... "Hey, Joe, uncle
Leroy said the ballgame just started." ... "Ok, coming." ... Meantime
the regen is forgotten and happily keeps humming until after the
overtime. Back when I was a kid people built their own RC electronics
because the stuff from companies such as Robbe was financially out of
range for most of us. More than once have I seen someone flick that
switch on the boat, followed by other boats instantly going out of control.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Joerg]

Wayne wrote:

"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com...
Hi all

If I change the tank circuit components (reduce the capacitance and
inductance) and change the transistors to appropriate VHF ones, will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelto,


I have tried to read and understand the posts in this thread the best I
can. Can someone tell me; Is there a problem for the aircraft industry, or
me, if I sit at the end of Regan National airport outside DC and use this,

http://tinyurl.com/3ayskq

As Chris said it's a superhet. Now if the oscillator leaks and the thing
runs the usual 10.7MHz IF the oscillator could still land on an active
ATC channel. That would mean trouble.

BTW $44.95 is a bit steep. Simple airband radios can be had for less,
sans soldering.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Joerg]

christofire wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:xINOj.2155$pS4.1361@newssvr13.news.prodigy.net...
Don Bowey wrote:
On 4/19/08 5:28 PM, in article
C6wOj.2082$pS4.1634@newssvr13.news.prodigy.net, "Joerg"
notthisjoergsch@removethispacbell.net> wrote:

Don Bowey wrote:
On 4/18/08 11:25 AM, in article
lI5Oj.4682$iK6.2220@nlpi069.nbdc.sbc.com,
"Joerg" <notthisjoergsch@removethispacbell.net> wrote:

Don Bowey wrote:
On 4/18/08 8:16 AM, in article fuae44$6tg$1@dns3.cae.ca, "Claude"
claudec@cae.com> wrote:

"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:cJMNj.6968$GE1.6102@nlpi061.nbdc.sbc.com...
Michael Black wrote:
On Wed, 16 Apr 2008, Bob Eld wrote:

"Archimedes" <shelton.dcruz@gmail.com> wrote in message
news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com.
..
Hi all

If I change the tank circuit components (reduce the capacitance
and
inductance) and change the transistors to appropriate VHF ones,
will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelton.
Not likely. I doubt you'd ever get that circuit to work at VHF
frequencies
no matter what you did with the resonant circuit portion. There
are
many
problems including wrong impedances for the various parasitic
capacitances.

Secondly air traffic stuff is FM I believe.

Military may use FM, I don't know, but airplane related
communication is
unique in that it does use actual AM.

A project that saw publication a number of times in the old days
took
advantage of that, a "crystal radio" that tuned VHF. It was
nothing
more than a tuned circuit and a diode detector feeding an
earphone, not
sensitive but useful near airports and since it didn't radiate
anything,
even useable (though maybe not legally) on an actual airplane.

The description of the circuit says it's a regen receiver, and
those
were never popular at VHF, I'm assuming instability came into
play.
You did see superregen receivers there. Either type will radiate,
and
that's not a good thing in the aircraft band.

Yes, and then you'd quickly have visitors coming with vehicles
bearing
government license plates. A regen-receiver is most definitely not
a good
idea in the aircraft band.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
Quite correct, it is most likely jail time where you will have hours
and
hours of fun designing electronics such as movement alarms
that will detect the proximity of "fellow inmates" . Just swearing
on an
ATC
frequency will net you a $2,500 fine in Canada, I can't even imagine
what
they would do to you if you jammed one of their frequencies.

Claude
Montreal


One of you naysayers should estimate the amount of radiated energy
from a
typical regen receiver.

Also, what is the distance from the intended regen location to the
airport,
and what would you imagine the comparative strengths would be of the
regen
signal and air traffic signals at air traffic receivers?

The regen receiver radiated signal would be lost in the noise.

The other party to air traffic communication are aircraft. Those
happen
to roam about quite a bit

Seriously, disregarding the airstrip that's almost next to the office
here we are also roughly in the flight path for Mather Field. Altitude
above our building maybe 1500ft, give or take. If Fedex, DHL and other
pilots would report some weird shhhhht noise everytime they pass a
certain spot, guess what would happen?
I doubt that at 1500 feet the signal from a regen receiver would break
the
squelch.

From a regen that misbehaves it certainly can.
Yes, just about anything and everything that misbehaves can can cause a
problem. When I lived in Ketchikan, AK, I received one of those
salmon-colored FCC QSL cards from a listening station at Point Reyes, CA
due
to a misbehaving multiplier in my HT9. Got a 579 on my second harmonic.

That one would be worth placing it in a frame

Problem with homebuilt regens is that unless they have a preamp they can
easily emit lots of RF power if something goes wrong, straight out the
antenna. "Dang, why doesn't it receive anything?" ... "Hey, Joe, uncle
Leroy said the ballgame just started." ... "Ok, coming." ... Meantime the
regen is forgotten and happily keeps humming until after the overtime.
Back when I was a kid people built their own RC electronics because the
stuff from companies such as Robbe was financially out of range for most
of us. More than once have I seen someone flick that switch on the boat,
followed by other boats instantly going out of control.

--
Regards, Joerg


Once upon a time, before Led Zep, I built a super-regenerative receiver that
used an acorn valve for the RF gain, a 958 if I remember correctly, a
Jackson air-spaced variable capacitor with a knob connected directly to its
1/4" shaft, and a small air-spaced coil wound from chunky silver-plated
copper wire. I connected it to the 144 MHz 'ground-plane' aerial I'd
installed on a pole at the end of the garden of our family house and found I
could tune-in to BBC television sound which, in those days, was AM (possibly
around 44 MHz in Band I).

I thought this was a great facility ... until I switched the telly on
downstairs and noticed the dreadful interference on the picture of BBC1. Of
course, it was my receiver that was causing it. Then I looked outside and
realised the distance between my ground-plane and our TV aerial was greater
than the distance between it and a load of aerials on other houses. Ooops!

I think I got away with that one, but I learned a bit of a lesson about
super-regen (or just regen) receivers that have the aerial connected
directly to the detector, not via an RF amp.

At least you didn't get zinged. When I built my first receiver with
controlled feedback (to set the BW) the structure was such that the cap
for the feedback had to ride between two points on plate level. Meaning
250VDC or so. No problem I thought since the knob was bakelite and would
certainly isolate that. Fired it up, connected earth and antenna,
reached for the feedback and *OUCH*. I had forgotten the minor detail
that the bakelite knob did not have a recessed set screw.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Archimedes]

Hi Wayne

I dont see any problem using that kit to listen to ATC.
When I go to the AP on Friday, I will be there with my regen receiver
listening to ATC - and I will be 500 meters from the active runway.
Cheers


On Apr 21, 4:57 am, "Wayne" <NOwayn...@SPAMcomcast.net> wrote:

"Archimedes" <shelton.dc...@gmail.com> wrote in message

news:b3b30960-27bc-4d59-924f-4312caffe7c2@x41g2000hsb.googlegroups.com...

Hi all

If I change the tank circuit components (reduce the capacitance and
inductance) and change the transistors to appropriate VHF ones, will I
be able to pick up ATC (Air Traffic Conversations) using this
circuit ?

http://www.electronics-lab.com/projects/rf/006/index.html

Thanks
Shelto,

I have tried to read and understand the posts in this thread the best I
can. Can someone tell me; Is there a problem for the aircraft industry, or
me, if I sit at the end of Regan National airport outside DC and use this,

http://tinyurl.com/3ayskq

Thanks.

Wayne

 

[Michael A. Terrell]

Claude wrote:

While I am here , anyone out there have plans for a functional cell phone
jammer that could jamm all 4 protocols to within 50 feet or so? I have seen
theoretical papers ( Google) but would like to know if any hobbyist has
ever built a successful one?

If that is why you are here, go away.


--
http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

 

[Michael A. Terrell]

Claude wrote:

It's just for fun amongst friends, not to antagonize the general public!
Touchy touchy aren't we? I've done the spook the neighbour on the FM band
trick, it's time for the next fun packed spook.

It is illegal in every country in the world, and your little 'prank'
could cost someone their life.


--
http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

 

[Michael Black]

On Mon, 28 Apr 2008, Joel Koltner wrote:

"Claude" <claudec@cae.com> wrote in message news:fuq0g9$3j5$1@dns3.cae.ca...
Ok last post on the subject. They are NOT illegal everywhere, many
businesses and restaurants use them.

Not in the U.S. they don't... at least not without attracting a lot of legal
trouble for themselves.

And useage is no indicator of legality.

Most people who talk about wanting to jam cellphones don't have a clue
about what's involved or the rules governing the radio frequencies. Since
they don't know about the laws, if they felt a need to jam cellphones
likely they'd jump at the chance if offered a jammer. And of course, it
being illegal there are always people willing to supply the product, they
likely can make money from it. At the very least, little competition.

I don't doubt that some places in North America have cellphone jammers.
That doesn't make the legal. I have no doubt in other parts of the world
that some places use jammers; they may be "allowed" through lax laws, or
just lack of man power to track them down.

There may be places where they are legal, but having written that I find
it harder and harder to imagine it. Not because there might be some
countries in the world where they care less about radio frequencies, but
that cellphones have become so commonplace that they can't be treated like
the "wild west" of the early days of radio.

Michael