Adret 4101A, the DCF77 and a good antenna
Hey time-nuts people,
First of all, let me start by saying that I follow the time-nuts mailing
list for some time and it's a great source for trading experiences. Perhaps
you can help me on this one.
We have in our laboratory, in Portugal (near Lisbon), an Adret 4101A
Frequency Receiver Standard, and we are trying to pickup the DCF77 signal
from Frankfurt, Germany. I wasn't sure if the unit was working properly (it
seems quite old), but by injecting directly a 10mV 77,5 kHz sinusoidal
signal in the BNC antenna input I got the "level" and the "locked" green
leds to lit (it seems good news).
However, I believe that the DCF77 arrives very weakly in Portugal, and I
thought on constructing a passive or active, but very simple antenna to
connect to the Adret 4101A.
Do you have any experience on this equipment (we don't have the manual, just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for a
antenna that could be very sensitive to this signal?
Kind regards, and thank you in advance,
[1]
http://www.adret-electronique.fr/appareils_adret_metrologie/4101a/4101a.pdf
Marco A. Ferra wrote:
Do you have any experience on this equipment (we don't have the manual, just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for a
antenna that could be very sensitive to this signal?
If you want to buy it ready made :
http://www.wellbrook.uk.com/ALA1530plus.html
If instead you are prepared to do some building yourself :
http://phk.freebsd.dk/loran-c/Antenna/
But there are a lot of other interesting projects on Internet.
Use Google and you will have just the embarrass of choosing...
Alberto I2PHD
In message A8E32C24B29949D7A964468AF3722BDD@escaleno, "Marco A. Ferra" writes
:
Do you have any experience on this equipment (we don't have the manual, just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for a
antenna that could be very sensitive to this signal?
Check the www.vlf.it page, they have many good antenna designs for
receiving difficult signals.
Poul-Henning
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Marco, have you considered that HBG on 75.0kHz might be stronger with you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used to
be able to lock to MSF when it was at Rugby a few years ago.......I havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If the
noise is not a problem these receiver will often work well on a resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip design
for a very simple active low frequency antenna. This is used all round the
world for receiving weak amateur signals on 136kHz ....it is broadband up to
about 500kHz, and down to 40kHz Japanese frequency standard transmissions.
It is so small you can experiment to find the best quiet position. At LF the
secret is the higher the better.
Alan G3NYK
----- Original Message -----
From: "Marco A. Ferra" maferra@gmx.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Tuesday, October 20, 2009 10:27 PM
Subject: [time-nuts] Adret 4101A, the DCF77 and a good antenna
Hey time-nuts people,
First of all, let me start by saying that I follow the time-nuts mailing
list for some time and it's a great source for trading experiences.
Perhaps
you can help me on this one.
We have in our laboratory, in Portugal (near Lisbon), an Adret 4101A
Frequency Receiver Standard, and we are trying to pickup the DCF77 signal
from Frankfurt, Germany. I wasn't sure if the unit was working properly
(it
seems quite old), but by injecting directly a 10mV 77,5 kHz sinusoidal
signal in the BNC antenna input I got the "level" and the "locked" green
leds to lit (it seems good news).
However, I believe that the DCF77 arrives very weakly in Portugal, and I
thought on constructing a passive or active, but very simple antenna to
connect to the Adret 4101A.
Do you have any experience on this equipment (we don't have the manual,
just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for
a
antenna that could be very sensitive to this signal?
Kind regards, and thank you in advance,
[1]
and follow the instructions there.
Alan Melia wrote:
Marco, have you considered that HBG on 75.0kHz might be stronger with you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used to
be able to lock to MSF when it was at Rugby a few years ago.......I havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If the
noise is not a problem these receiver will often work well on a resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip design
for a very simple active low frequency antenna. This is used all round the
world for receiving weak amateur signals on 136kHz ....it is broadband up to
about 500kHz, and down to 40kHz Japanese frequency standard transmissions.
It is so small you can experiment to find the best quiet position. At LF the
secret is the higher the better.
The TDF 162 kHz is a 2 MW transmitter which is even closer...
A bit tricker to retriev the timing signal thought, but this is assuming
the signal can be freely selected.
The HBG transmitter is going off-air (for good) in a not to distant future.
Cheers,
Magnus
Hi Marco,
That looks like a really nice receiver. It is a little numb as far as
sensitivity goes, but there are reasons for such. At those low frequencies
atmospheric noise will certainly be quite high. So, one way to to handle it is
to put the signal preamp out at the antenna, usually a magnetically shielded loop
similar to the loop used with the Hewlett Packard 60 KHz receiver loop antenna.
The loop also acts as an extremely narrow filter.
I wonder if the manufacturer still exists ? If so maybe they could be of help as
they may still have parts and hopefully their active loop antenna that went with
that receiver.
Otherwise, you would have to build your own antenna. I highly suggest looking at
designs on the WEB, as others have suggested, concerning magnetically shielded
loops as they help with rejecting local noises.
Good luck with your project !
Bill....WB6BNQ
"Marco A. Ferra" wrote:
Hey time-nuts people,
First of all, let me start by saying that I follow the time-nuts mailing
list for some time and it's a great source for trading experiences. Perhaps
you can help me on this one.
We have in our laboratory, in Portugal (near Lisbon), an Adret 4101A
Frequency Receiver Standard, and we are trying to pickup the DCF77 signal
from Frankfurt, Germany. I wasn't sure if the unit was working properly (it
seems quite old), but by injecting directly a 10mV 77,5 kHz sinusoidal
signal in the BNC antenna input I got the "level" and the "locked" green
leds to lit (it seems good news).
However, I believe that the DCF77 arrives very weakly in Portugal, and I
thought on constructing a passive or active, but very simple antenna to
connect to the Adret 4101A.
Do you have any experience on this equipment (we don't have the manual, just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for a
antenna that could be very sensitive to this signal?
Kind regards, and thank you in advance,
[1]
http://www.adret-electronique.fr/appareils_adret_metrologie/4101a/4101a.pdf
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 Magnus I was not sure whether the 4101A would go up that far. I had not
noticed the news about HBG. That is a disappointment, particularly with the
number of "radio clocks" around in "domestic" use, and from the "Land of
Clocks" too.
Someone mentioned a screened loop in copper pipe. Screening loops at this
frequency gives little advantage and the extra stray capacitance can degrade
the performance. An open loop works just as well (and is much easier to
build for a trial) the problem usually comes from common mode pick-up on the
feeder to the receiver. This is often best combatted by careful balancing,
or transformer isolation.
Alan G3NYK
----- Original Message -----
From: "Magnus Danielson" magnus@rubidium.dyndns.org
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Wednesday, October 21, 2009 1:30 AM
Subject: Re: [time-nuts] Adret 4101A, the DCF77 and a good antenna
Alan Melia wrote:
Marco, have you considered that HBG on 75.0kHz might be stronger with
you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used
to
be able to lock to MSF when it was at Rugby a few years ago.......I
havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If
the
noise is not a problem these receiver will often work well on a
resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip
design
for a very simple active low frequency antenna. This is used all round
the
world for receiving weak amateur signals on 136kHz ....it is broadband
up to
about 500kHz, and down to 40kHz Japanese frequency standard
transmissions.
It is so small you can experiment to find the best quiet position. At LF
the
secret is the higher the better.
The TDF 162 kHz is a 2 MW transmitter which is even closer...
A bit tricker to retriev the timing signal thought, but this is assuming
the signal can be freely selected.
The HBG transmitter is going off-air (for good) in a not to distant
future.
and follow the instructions there.
Hello all:
In Portugal,HBG is much fainter than DCF77. The distance is almost the same
and the power is much less (20 kW vs 50 kW). In the Porto region,
DCF77 is stronger than all the others: MSF60, HBG75, etc. However,
since we are almost at the range limit, sometimes the signal is not
enough to provide a good tracking.
I am in Brazil till the end of November. When returning at home in Santo
Tirso, Portugal, I hope to put in this page a phase comparaison record of
DCF77 against Thunderbolt.
Best regards,
Antonio
CT1TE
Quoting Alan Melia alan.melia@btinternet.com:
Marco, have you considered that HBG on 75.0kHz might be stronger with you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used to
be able to lock to MSF when it was at Rugby a few years ago.......I havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If the
noise is not a problem these receiver will often work well on a resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip design
for a very simple active low frequency antenna. This is used all round the
world for receiving weak amateur signals on 136kHz ....it is broadband up to
about 500kHz, and down to 40kHz Japanese frequency standard transmissions.
It is so small you can experiment to find the best quiet position. At LF the
secret is the higher the better.
Alan G3NYK
----- Original Message -----
From: "Marco A. Ferra" maferra@gmx.com
To: "Discussion of precise time and frequency measurement"
time-nuts@febo.com
Sent: Tuesday, October 20, 2009 10:27 PM
Subject: [time-nuts] Adret 4101A, the DCF77 and a good antenna
Hey time-nuts people,
First of all, let me start by saying that I follow the time-nuts mailing
list for some time and it's a great source for trading experiences.
Perhaps
you can help me on this one.
We have in our laboratory, in Portugal (near Lisbon), an Adret 4101A
Frequency Receiver Standard, and we are trying to pickup the DCF77 signal
from Frankfurt, Germany. I wasn't sure if the unit was working properly
(it
seems quite old), but by injecting directly a 10mV 77,5 kHz sinusoidal
signal in the BNC antenna input I got the "level" and the "locked" green
leds to lit (it seems good news).
However, I believe that the DCF77 arrives very weakly in Portugal, and I
thought on constructing a passive or active, but very simple antenna to
connect to the Adret 4101A.
Do you have any experience on this equipment (we don't have the manual,
just
a brochure with a few pages [1]), the DCF77 signal itself or an ideia for
a
antenna that could be very sensitive to this signal?
Kind regards, and thank you in advance,
[1]
and follow the instructions there.
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.
A FCUP utiliza o sistema open source de webmail Horde/IMP (www.horde.org)
Visite: http://www.fc.up.pt/ http://info.fc.up.pt/
Most of the LF receivers of this type need an active antenna.
10 mv injected is a huge signal compared to what you might receive perhaps
10 uv as a guess.
I have a fluke and a singer for 60 khz wwvb in the US and use a loopstick
and preamp using a mpf102 and follower transistor. Believe there are far
better options today.
On Tue, Oct 20, 2009 at 5:27 PM, Marco A. Ferra maferra@gmx.com wrote:
Hey time-nuts people,
First of all, let me start by saying that I follow the time-nuts mailing
list for some time and it's a great source for trading experiences. Perhaps
you can help me on this one.
We have in our laboratory, in Portugal (near Lisbon), an Adret 4101A
Frequency Receiver Standard, and we are trying to pickup the DCF77 signal
from Frankfurt, Germany. I wasn't sure if the unit was working properly (it
seems quite old), but by injecting directly a 10mV 77,5 kHz sinusoidal
signal in the BNC antenna input I got the "level" and the "locked" green
leds to lit (it seems good news).
However, I believe that the DCF77 arrives very weakly in Portugal, and I
thought on constructing a passive or active, but very simple antenna to
connect to the Adret 4101A.
Do you have any experience on this equipment (we don't have the manual,
just a brochure with a few pages [1]), the DCF77 signal itself or an ideia
for a antenna that could be very sensitive to this signal?
Kind regards, and thank you in advance,
[1]
http://www.adret-electronique.fr/appareils_adret_metrologie/4101a/4101a.pdf
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.
Am Wednesday 21 October 2009 01:16:55 schrieb Alan Melia:
Marco, have you considered that HBG on 75.0kHz might be stronger with you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used to
be able to lock to MSF when it was at Rugby a few years ago.......I havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If the
noise is not a problem these receiver will often work well on a resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip design
for a very simple active low frequency antenna. This is used all round the
world for receiving weak amateur signals on 136kHz ....it is broadband up
to about 500kHz, and down to 40kHz Japanese frequency standard
transmissions. It is so small you can experiment to find the best quiet
position. At LF the secret is the higher the better.
I may very well be mistaken (and do hope so indeed), but isn't HBG about to be
shut down quite soon? Maybe that i'm mixing that one up with another one
though.
BTW, is there such a thing as a comprehensive page on frequency standard
transmissions on the web? That Japanese 40kHz sounds quite interesting...
And as far as i recall, reception of those LF signals is supposed to be better
at night as there probably is less man-made noise and better propagation.
HTH,
Florian
There is a good list of time signals on the web site of the BIPM:
http://www.bipm.org/jsp/en/TimeFtp.jsp?TypePub=scale#nohref
in the "Time Signals" in the Scales division of the FTP server of the Time,
Frequency and Gravimetry section. The most recent is dated 2008.
Regards,
Jean-Louis Oneto
----- Original Message -----
From: "Florian Teply" usenet@teply.info
To: time-nuts@febo.com
Sent: Wednesday, October 21, 2009 6:05 PM
Subject: Re: [time-nuts] Adret 4101A, the DCF77 and a good antenna
Am Wednesday 21 October 2009 01:16:55 schrieb Alan Melia:
Marco, have you considered that HBG on 75.0kHz might be stronger with you
from Switzerland??. In a lab or other complex quite often with off-air
standards the problem is local noise. I have a friend in Porto who used
to
be able to lock to MSF when it was at Rugby a few years ago.......I
havent
asked since it moved north to Anthorn but I suspect he uses GPS now. If
the
noise is not a problem these receiver will often work well on a resonable
wire antenna which is fairly easy to rig. Or see the PA0RDT MiniWhip
design
for a very simple active low frequency antenna. This is used all round
the
world for receiving weak amateur signals on 136kHz ....it is broadband up
to about 500kHz, and down to 40kHz Japanese frequency standard
transmissions. It is so small you can experiment to find the best quiet
position. At LF the secret is the higher the better.
I may very well be mistaken (and do hope so indeed), but isn't HBG about
to be
shut down quite soon? Maybe that i'm mixing that one up with another one
though.
BTW, is there such a thing as a comprehensive page on frequency standard
transmissions on the web? That Japanese 40kHz sounds quite interesting...
And as far as i recall, reception of those LF signals is supposed to be
better
at night as there probably is less man-made noise and better propagation.
HTH,
Florian
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.
----- Original Message -----
There is a good list of time signals on the web site of the BIPM:
http://www.bipm.org/jsp/en/TimeFtp.jsp?TypePub=scale#nohref
in the "Time Signals" in the Scales division of the FTP server of the
Time, Frequency and Gravimetry section. The most recent is dated 2008.
Regards,
Jean-Louis Oneto
Dear Jean-Louis and all the others, thanks for all the input.
In fact I have considered other time stations, but the precision of the
DCF77 (if I'm not mistaken is plus/minus 2*10^-12) and the HBG (the same
precision) made them very good candidates. The active antenna is probably a
good investiment (Conrad or custom made), since the unit itself is located
inside a building with many equipments generating alot of electrical noise.
I will also try tomorrow a loop antenna. Just for the sake of it, I have an
old radio at home that have an antenna like that and I will see if that
works.
Regards,