Re: [time-nuts] Cutler NAA on 24.0kHz....
www.glkinst.com/test-equipment/manuals/Tracor900A.pdf
On Fri, Aug 15, 2014 at 4:49 PM, paul swed paulswedb@gmail.com wrote:
David
Yes I have seen various comments and documents describing MSK that way.
But have to say the tracor 900 does not use that method to establish a
reference.
Its a few opamps perhaps one side acting as a phase delay summing with the
original and hitting a BPF. all of that running at 100Hz center frequency.
Through this magic the 900 could use NAA as a phase tracking reference.
Its as if its a classic phase doubler. The documentation almost speaks to
that.
Its seriously simple.
Regards
Paul.
WB8TSL
On Fri, Aug 15, 2014 at 4:31 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 03:09:23PM -0400, paul swed wrote:
I had discounted it because of the lack of info and totally unclear how
to
get rid of the FSK. MSK is FSK just with a very narrow shift. Also the
effects of the fsk on the carrier. Hmmm glad I am typing this.
It may be that the mark or the space is indeed exactly the true carrier
and
that op amp circuit is notching out the shifted carrier. I will bet
thats
the trick!
MSK is a kind of continuous phase differentially coded PSK in
which the carrier phase smoothly shifts either EXACTLY plus 90 degrees
or EXACTLY minus 90 degrees in EXACTLY one symbol time - in the MSK
variety of PSK the transmitted carrier phase never stays the same as the
it was the last symbol time. When transmitting steady mark there are a
series of these shifts plus 90 degrees (hi frequency mark) one after the
other, and when transmitting steady space there is a series of minus 90
degree shifts.
Obviously a steady negative phase shift is what is produced by
a signal below a center "carrier" frequency and a steady positive
phase shift by one above that frequency. Thus the isomorphism with
filtered FSK.
Effectively a QPSK (multi-arm Costas type) tracking loop should
be able to track a MSK signal just as if it was a filtered QPSK signal
with only 90 degree and minus 90 phase shifts each symbol time and
generate
a phase continuous recovered carrier.
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole
- in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
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Yes I can see on page 2 of the pdf thats the trick. Its a non costas loop
trick.
"The action of the MSK card doubles the phase shift".....
So it is the classic double the frequency stateless carrier recovery. that
may drop phase due to noise.
Regards
Paul
WB8TSL
On Fri, Aug 15, 2014 at 4:52 PM, paul swed paulswedb@gmail.com wrote:
www.glkinst.com/test-equipment/manuals/Tracor900A.pdf
On Fri, Aug 15, 2014 at 4:49 PM, paul swed paulswedb@gmail.com wrote:
David
Yes I have seen various comments and documents describing MSK that way.
But have to say the tracor 900 does not use that method to establish a
reference.
Its a few opamps perhaps one side acting as a phase delay summing with
the original and hitting a BPF. all of that running at 100Hz center
frequency.
Through this magic the 900 could use NAA as a phase tracking reference.
Its as if its a classic phase doubler. The documentation almost speaks to
that.
Its seriously simple.
Regards
Paul.
WB8TSL
On Fri, Aug 15, 2014 at 4:31 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 03:09:23PM -0400, paul swed wrote:
I had discounted it because of the lack of info and totally unclear
how to
get rid of the FSK. MSK is FSK just with a very narrow shift. Also the
effects of the fsk on the carrier. Hmmm glad I am typing this.
It may be that the mark or the space is indeed exactly the true
carrier and
that op amp circuit is notching out the shifted carrier. I will bet
thats
the trick!
MSK is a kind of continuous phase differentially coded PSK in
which the carrier phase smoothly shifts either EXACTLY plus 90 degrees
or EXACTLY minus 90 degrees in EXACTLY one symbol time - in the MSK
variety of PSK the transmitted carrier phase never stays the same as the
it was the last symbol time. When transmitting steady mark there are a
series of these shifts plus 90 degrees (hi frequency mark) one after the
other, and when transmitting steady space there is a series of minus 90
degree shifts.
Obviously a steady negative phase shift is what is produced by
a signal below a center "carrier" frequency and a steady positive
phase shift by one above that frequency. Thus the isomorphism with
filtered FSK.
Effectively a QPSK (multi-arm Costas type) tracking loop should
be able to track a MSK signal just as if it was a filtered QPSK signal
with only 90 degree and minus 90 phase shifts each symbol time and
generate
a phase continuous recovered carrier.
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole
- in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On Fri, Aug 15, 2014 at 04:56:01PM -0400, paul swed wrote:
Yes I can see on page 2 of the pdf thats the trick. Its a non costas loop
trick.
"The action of the MSK card doubles the phase shift".....
So it is the classic double the frequency stateless carrier recovery. that
may drop phase due to noise.
Needless to say one can track the recovered carrier with a very
narrow loop which will not slip in phase easily during a fade.
I believe you found that simply using it to clock a flip flop
wasn't reliable... but a narrow carrier tracking loop tracking it would
be...
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."
On Fri, Aug 15, 2014 at 04:56:01PM -0400, paul swed wrote:
Yes I can see on page 2 of the pdf thats the trick. Its a non costas loop
trick.
That PDF is returning a 404 for me at the moment...
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."
Not sure whats up with the link when I click it I get the download. Its a
2.5MB file
http://www.glkinst.com/test-equipment/manuals/Tracor900A.pdf.
Try his main page http://www.glkinst.com
I did see the info there also.
Browsers we luv'em.
Regards
Paul.
WB8TSL
On Fri, Aug 15, 2014 at 6:20 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 04:56:01PM -0400, paul swed wrote:
Yes I can see on page 2 of the pdf thats the trick. Its a non costas loop
trick.
That PDF is returning a 404 for me at the moment...
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole -
in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Not sure whats up with the link when I click it I get the download. Its a
2.5MB file
http://www.glkinst.com/test-equipment/manuals/Tracor900A.pdf.
Try his main page http://www.glkinst.com
I did see the info there also.
Browsers we luv'em.
Regards
Paul.
WB8TSL
On Fri, Aug 15, 2014 at 6:20 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 04:56:01PM -0400, paul swed wrote:
Yes I can see on page 2 of the pdf thats the trick. Its a non costas
loop
trick.
That PDF is returning a 404 for me at the moment...
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole
in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
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On Fri, Aug 15, 2014 at 03:39:07PM -0700, Pete Lancashire wrote:
URL ok from here
The text of the original post had "*"s in the URL... which
didn't work so well...
Partly pilot error here...
Works OK without the "*"s
-pete
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."
Whats interesting is I had never heard of the 900 till I started looking at
NAA and msk.
Regards
Paul.
On Fri, Aug 15, 2014 at 6:43 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 03:39:07PM -0700, Pete Lancashire wrote:
URL ok from here
The text of the original post had "*"s in the URL... which
didn't work so well...
Partly pilot error here...
Works OK without the "*"s
-pete
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole -
in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Oh Ebay has one for sale for the person that just needs one. Todays buy now
$1693 plus shipping.
There you go a deal a day. I think not.
regards
Paul
WB8TSL
On Fri, Aug 15, 2014 at 7:48 PM, paul swed paulswedb@gmail.com wrote:
Whats interesting is I had never heard of the 900 till I started looking
at NAA and msk.
Regards
Paul.
On Fri, Aug 15, 2014 at 6:43 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 03:39:07PM -0700, Pete Lancashire wrote:
URL ok from here
The text of the original post had "*"s in the URL... which
didn't work so well...
Partly pilot error here...
Works OK without the "*"s
-pete
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole
- in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Did check NAA and its banging into Boston. Had to put 40 db anttenuator
inline to make it reasonable. Using the wwvb antenna. Most likely would do
just fine with 6 ft of wire. Ok only had 4 ft of wire and its there. Could
really use 10-12ft. :-) So maybe my fillings won't pick it up.
Regards
Paul.
WB8TSL
On Fri, Aug 15, 2014 at 7:51 PM, paul swed paulswedb@gmail.com wrote:
Oh Ebay has one for sale for the person that just needs one. Todays buy
now $1693 plus shipping.
There you go a deal a day. I think not.
regards
Paul
WB8TSL
On Fri, Aug 15, 2014 at 7:48 PM, paul swed paulswedb@gmail.com wrote:
Whats interesting is I had never heard of the 900 till I started looking
at NAA and msk.
Regards
Paul.
On Fri, Aug 15, 2014 at 6:43 PM, David I. Emery die@dieconsulting.com
wrote:
On Fri, Aug 15, 2014 at 03:39:07PM -0700, Pete Lancashire wrote:
URL ok from here
The text of the original post had "*"s in the URL... which
didn't work so well...
Partly pilot error here...
Works OK without the "*"s
-pete
--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston,
Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole
- in
celebration of what could have been, but wasn't and is not to be now
either."
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
On 15 Aug 2014 at 20:57, paul swed wrote:
Did check NAA and its banging into Boston.
2 Megawatts to that antenna should show VOLTS at your place.
We used that station for many years for VLF propagation research in
Missoula, Montana. It banged in 24/7/365. Still does, except when its down
for maintenance.
So did Jim Creek (of course) and NWC in Australia, and a station whose call
I have forgotten in the Canal Zone.
Back in 1973.
Ken W7EKB
Ken
At least last night NAA was running just fine using a fluke 207 and 4 ft of
wire.
The antenna is behind a metal rack that shields it in NAAs direction. I did
that test out of curiosity.
Granted its 2 MW but then again the antenna is at best 50% efficient.
Who knows maybe they have sections of the antenna down for maintenance.
Regards
Paul
On Fri, Aug 15, 2014 at 11:22 PM, Kenneth G. Gordon <
kgordon2006@frontier.com> wrote:
On 15 Aug 2014 at 20:57, paul swed wrote:
Did check NAA and its banging into Boston.
2 Megawatts to that antenna should show VOLTS at your place.
We used that station for many years for VLF propagation research in
Missoula, Montana. It banged in 24/7/365. Still does, except when its down
for maintenance.
So did Jim Creek (of course) and NWC in Australia, and a station whose call
I have forgotten in the Canal Zone.
Back in 1973.
Ken W7EKB
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
I would be very surprised if the NAA antenna was 50% efficient (transmitter RF to radiated power)…..
Given that it’s already up and running with good signal levels, that’s not a big deal.
Bob
On Aug 16, 2014, at 10:24 AM, paul swed paulswedb@gmail.com wrote:
Ken
At least last night NAA was running just fine using a fluke 207 and 4 ft of
wire.
The antenna is behind a metal rack that shields it in NAAs direction. I did
that test out of curiosity.
Granted its 2 MW but then again the antenna is at best 50% efficient.
Who knows maybe they have sections of the antenna down for maintenance.
Regards
Paul
On Fri, Aug 15, 2014 at 11:22 PM, Kenneth G. Gordon <
kgordon2006@frontier.com> wrote:
On 15 Aug 2014 at 20:57, paul swed wrote:
Did check NAA and its banging into Boston.
2 Megawatts to that antenna should show VOLTS at your place.
We used that station for many years for VLF propagation research in
Missoula, Montana. It banged in 24/7/365. Still does, except when its down
for maintenance.
So did Jim Creek (of course) and NWC in Australia, and a station whose call
I have forgotten in the Canal Zone.
Back in 1973.
Ken W7EKB
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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and follow the instructions there.
Bob
The fact is its on the web. :-)
I was surprised that the documents said that also given most LF Ham systems
are very inefficient given what we have to work with in $ and space. But
then again its no an amateur installation. With 16 X 825 ft towers and
miles of wire over salt flats and water. Matching systems that are like a
Frankenstein movie.
Regards
Paul
WB8TSL
On Sat, Aug 16, 2014 at 11:33 AM, Bob Camp kb8tq@n1k.org wrote:
Hi
I would be very surprised if the NAA antenna was 50% efficient
(transmitter RF to radiated power)…..
Given that it’s already up and running with good signal levels, that’s not
a big deal.
Bob
On Aug 16, 2014, at 10:24 AM, paul swed paulswedb@gmail.com wrote:
Ken
At least last night NAA was running just fine using a fluke 207 and 4 ft
of
wire.
The antenna is behind a metal rack that shields it in NAAs direction. I
did
that test out of curiosity.
Granted its 2 MW but then again the antenna is at best 50% efficient.
Who knows maybe they have sections of the antenna down for maintenance.
Regards
Paul
On Fri, Aug 15, 2014 at 11:22 PM, Kenneth G. Gordon <
kgordon2006@frontier.com> wrote:
On 15 Aug 2014 at 20:57, paul swed wrote:
Did check NAA and its banging into Boston.
2 Megawatts to that antenna should show VOLTS at your place.
We used that station for many years for VLF propagation research in
Missoula, Montana. It banged in 24/7/365. Still does, except when its
down
for maintenance.
So did Jim Creek (of course) and NWC in Australia, and a station whose
call
I have forgotten in the Canal Zone.
Back in 1973.
Ken W7EKB
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
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and follow the instructions there.
On 16 Aug 2014 at 11:33, Bob Camp wrote:
Hi
I would be very surprised if the NAA antenna was 50% efficient (transmitter RF
to radiated power).....
According to this:
http://www.scribd.com/doc/145116437/THE-BIGGEST-LITTLE-ANTENNA-IN
-THE-WORLD-US-Navy-s-VLF-antenna-at-Cutler-Maine
The company which designed and built the dual trideco antenna system at
Cutler had to guarantee >50% radiation efficiency, and they achieved an
antenna radiation efficiency of 74.9% when using the 6 panel trideco.
When I read this, I was truly amazed.
Although, this site:
http://www.navy-radio.com/commsta/cutler.htm
does say that with 2 MW input, the ERP is 1 MW, which would indicate at
least 50% radiation efficiency.
I am still amazed.
Given that it´s already up and running with good signal levels, that´s not a big
deal.
Very true indeed.
Ken W7EKB
On 16 Aug 2014 at 10:24, paul swed wrote:
Ken
At least last night NAA was running just fine using a fluke 207 and 4 ft of
wire. The antenna is behind a metal rack that shields it in NAAs direction.
Ha! At VLF you could probably bury your antenna in a grounded, steel pipe 4
feet into the ground and still hear NAA.
I
did that test out of curiosity.
I LOVE curious... :-)
Granted its 2 MW but then again the antenna is at best 50% efficient.
See previous post.
Who knows maybe they have sections of the antenna down for maintenance.
The reason NAA has a double trideco is so they can continue to transmit
with one section down for maintenance.
It turns out that Cutler has a much-bigger-than-usual problem with lightning...
Ken W7EKB
Kenneth on the opamps that is correct.
But I put little U's to indicate phase. They actually represent the top
half of the input cycle.
In the top path it inverts once
The bottom path twice.
So that makes the top 180 out and the bottom in phase with the original.
However the 2 X RC sets the bottom path at I believe 180 degrees from the
input.
The final RC in the top and bottom path account for opamp filter delay and
note they are equal.
So thats has me scratching my head as to how this removes the MSK and
leaves a carrier that can lock.
One of the classic approaches to recover carrier or get rid of BPSK
modulation is to simply double the incoming carrier. Works great if you
don't loose the signal.
But I do not see this circuit doing that.
Regards
Paul
On Sat, Aug 16, 2014 at 12:20 PM, Kenneth G. Gordon <
kgordon2006@frontier.com> wrote:
On 16 Aug 2014 at 11:33, Bob Camp wrote:
Hi
I would be very surprised if the NAA antenna was 50% efficient
(transmitter RF
to radiated power).....
According to this:
http://www.scribd.com/doc/145116437/THE-BIGGEST-LITTLE-ANTENNA-IN
-THE-WORLD-US-Navy-s-VLF-antenna-at-Cutler-Maine
The company which designed and built the dual trideco antenna system at
Cutler had to guarantee >50% radiation efficiency, and they achieved an
antenna radiation efficiency of 74.9% when using the 6 panel trideco.
When I read this, I was truly amazed.
Although, this site:
http://www.navy-radio.com/commsta/cutler.htm
does say that with 2 MW input, the ERP is 1 MW, which would indicate at
least 50% radiation efficiency.
I am still amazed.
Given that it´s already up and running with good signal levels, that´s
not a big
deal.
Very true indeed.
Ken W7EKB
time-nuts mailing list -- time-nuts@febo.com
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and follow the instructions there.
On 16 Aug 2014 at 13:35, paul swed wrote:
Kenneth on the opamps that is correct.
But I put little U's to indicate phase. They actually represent the top half of
the input cycle.
Yes, I saw those, but unless I am mistaken, you didn't add a "U" after the
second opamp, which would have returned the phase to the input's.
In the top path it inverts once.
I see twice: once through the first op amp and again through the second one.
The second one then outputs to the IF.
Anyway, to me, it is a very interesting and simple circuit.
I LIKE "simple". I am a great believer in the KISS principle.
Ken W7EKB