Radio Amateurs have achieved the very first reception of amateur signals bounced off the planet Venus, over 50 million km away - EVE (Earth-Venus-Earth)
Peter Guelzow DB2OS, President of AMSAT-DL has provided a description of this landmark achievement.
On March 25th, 2009 a team from the German space organisation AMSAT-DL reached another milestone on its way to an own interplanetary probe towards planet Mars.
The ground station at the Bochum observatory transmitted radio signals to Venus. After travelling almost 100 million kilometers and a round trip delay of about 5 minutes, they were clearly received as echoes from the surface of Venus.
Receiving these planetary echoes is a first for Germany and Europe. In addition, this is the farthest distance crossed by radio amateurs, over 100 times further than echoes from the moon (EME reflections).
For receiving the EVE signals, an FFT analysis with an integration time of 5 minutes was used. After integrating for 2 minutes only, the reflected signals were clearly visible in the display. Despite the bad weather, signals from Venus could be detected from 1038UT until the planet reached the local horizon.
The 2.4 GHz high power amplifier used for this achievement is described in the current AMSAT-DL journal.
This represented a crucial test for a final key component of the planned P5-A Mars mission. By receiving echoes from Venus, the ground and command station for the Mars probe has been cleared for operational use and the AMSAT team is now gearing up for building the P5-A space probe.
For financing the actual construction and launch, AMSAT-DL is currently
in negotiation with the DLR (Deutsches Zentrum für Luft- und Raumfahrt) amongst others, to obtain financial support for the remaining budget of 20 Mil Euros.
AMSAT-DL wants to show that low-cost interplanetary exploration is possible with its approach.
More information and the link to the official press release [in German]:
http://www.amsat-dl.org//index.php?o...=166&Itemid=97
The EVE experiment was repeated on Thursday, March 26th for several hours with good echoes from Venus. Morse code was used to transmit the well known “HI“ signature known from the AMSAT OSCAR satellites.
73s de DB2OS
Peter Guelzow
President AMSAT-DL
Saturday, March 28, 2009
Tuesday, March 24, 2009
FCC Clarifies What Constitutes an Amateur Radio Repeater
In December 2007, Gary Mitchell, WB6YRU, President of the NorthernCalifornia Packet Association (NCPA), filed a Petition with the FCC,asking for the Commission to clarify the definition of a repeater.According to Part 97, Section 3(a)(39), A repeater in the amateurservice is "[a]n amateur station that simultaneously retransmits thetransmission of another amateur station on a different channel orchannels."
Mitchell sought clarification on the word "simultaneously," askingif it referred to the signal information being retransmitted, or tothe fact that the receiver and transmitter must both be active atthe same time while acting on the same signal information. On March23, 2009, the Commission clarified that even if there is a slightdelay between what is received and what it transmits (as in the caseof D-STAR and other digital repeaters), it is consideredsimultaneous if the receiver and transmitter are both active at thesame time.
Mitchell pointed out in his petition that while the Commission'sRules specify on which bands amateur repeaters may operate, "someamateur repeaters are operating on bands other than set forth inSection 97.205(b) with systems that are essentially voice repeaterstations, but that digitize and retransmit the user's voice, on thetheory that because there is a small delay in retransmitting thesignal of another amateur station, the signal is not'simultaneously' retransmitted and, therefore, the system is not arepeater.
"In its reply, the Commission pointed out that prior to 1994, arepeater was defined as "[a]n amateur station that automaticallyretransmits the signals of other stations." This, the Commissiontold Mitchell, was revised to clarify "that certain accommodationsfor message forwarding systems do not apply to other operatingactivities such as repeaters and auxiliary stations." The Commissionproposed to define a repeater as "[a]n amateur station thatinstantaneously retransmits the transmission of another amateurstation on a different channel or channels," but ultimately replaced"instantaneously" with "simultaneously" because commenters notedthat there is always a small propagation delay through a repeater.As one commenter explained, "The word 'simultaneously' in this casemeans that the repeater is receiving and transmitting concurrently,whereas each signal might be slightly displaced in time betweenreceive and transmit."To be able to repeat another station's transmission, the Commissionsaid that a repeater "must be able to receive a transmission fromanother station and retransmit it. Because the word 'simultaneously'in the definition is used to modify 'retransmit,' we believe itrefers to a repeater station's transmitter being active whenretransmitting the signal received by the repeater station'sreceiver from another amateur station.
We conclude, therefore, that'simultaneously' as used in the definition of a repeater refers tothe receiver and transmitter both being active at the same time.
Mitchell sought clarification on the word "simultaneously," askingif it referred to the signal information being retransmitted, or tothe fact that the receiver and transmitter must both be active atthe same time while acting on the same signal information. On March23, 2009, the Commission clarified that even if there is a slightdelay between what is received and what it transmits (as in the caseof D-STAR and other digital repeaters), it is consideredsimultaneous if the receiver and transmitter are both active at thesame time.
Mitchell pointed out in his petition that while the Commission'sRules specify on which bands amateur repeaters may operate, "someamateur repeaters are operating on bands other than set forth inSection 97.205(b) with systems that are essentially voice repeaterstations, but that digitize and retransmit the user's voice, on thetheory that because there is a small delay in retransmitting thesignal of another amateur station, the signal is not'simultaneously' retransmitted and, therefore, the system is not arepeater.
"In its reply, the Commission pointed out that prior to 1994, arepeater was defined as "[a]n amateur station that automaticallyretransmits the signals of other stations." This, the Commissiontold Mitchell, was revised to clarify "that certain accommodationsfor message forwarding systems do not apply to other operatingactivities such as repeaters and auxiliary stations." The Commissionproposed to define a repeater as "[a]n amateur station thatinstantaneously retransmits the transmission of another amateurstation on a different channel or channels," but ultimately replaced"instantaneously" with "simultaneously" because commenters notedthat there is always a small propagation delay through a repeater.As one commenter explained, "The word 'simultaneously' in this casemeans that the repeater is receiving and transmitting concurrently,whereas each signal might be slightly displaced in time betweenreceive and transmit."To be able to repeat another station's transmission, the Commissionsaid that a repeater "must be able to receive a transmission fromanother station and retransmit it. Because the word 'simultaneously'in the definition is used to modify 'retransmit,' we believe itrefers to a repeater station's transmitter being active whenretransmitting the signal received by the repeater station'sreceiver from another amateur station.
We conclude, therefore, that'simultaneously' as used in the definition of a repeater refers tothe receiver and transmitter both being active at the same time.
Friday, March 20, 2009
FCC Denies Petition to Increase Size of Amateur Radio Question Pools
In April 2008, Michael Mancuso, KI4NGN, of Raleigh, North Carolina,filed a petition with the FCC, seeking to increase the size of the question pools that make up the Amateur Radio licensing exams.Mancuso sought to increase the question pool from 10 times the number of questions on an exam to 50 times more questions.
On March19, 2009, the Commission notified Mancuso that it was denying his petition.In his 2008 petition, Mancuso claimed that the current question pool is too easy to memorize and "that there has been a significant increase in the number of Amateur Radio operators receiving their licenses over at least the last decade or more who do not appear to possess the knowledge indicated by the class of license that they have received.
Most discussion about this topic, both on the air an don Internet forums, generally refers to these widespread observations as the 'dumbing down' of Amateur Radio. It has been widely assumed that the cause of this observed situation is based upon the subject material addressed by the license examinations,that the material requirements specified for the examinations does[sic] not meet some minimum level of knowledge expected by some or many in the Amateur Radio community."
The FCC pointed out to Mancuso that each applicant for a new or upgraded Amateur Radio operator license "is required to pass a written examination in order to prove that he or she possesses the operational and technical qualifications required to perform properly the duties of an amateur service operator licensee, i.e.,that he or she is qualified to be an amateur service licensee."The Commission summed up Mancuso's petition, saying, "You argue that the current question pool size is no longer adequate, because online practice examinations enable examinees to memorize a question pool without fully comprehending the subject matter being tested.Consequently, you propose to increase the size of the question pools, in order to hinder memorization."
The Commission concluded that Mancuso did not present grounds for the Commission to amend its rules: "As noted above, the purpose of the examinations is not to demonstrate an applicant's comprehension of certain material, but rather to determine whether he or she can properly operate an amateur station. Moreover, your contention that there has been 'a significant increase in the number of Amateur Radio operators...who do not appear to possess the knowledge indicated by their class of license' is not supported by any data or facts."The FCC pointed out to Mancuso that the Commission's Rules only dictate the minimum number of questions for each question pool for the three Amateur Radio license classes.
This, the Commission told Mancuso, "does not prevent the National Conference of Volunteer Examiner Coordinators (NCVEC) from increasing the number of questions in a question pool should it decide that this is appropriate. We conclude, therefore, that the petition presents no evidence of an existing problem or other reason for a rule change."
On March19, 2009, the Commission notified Mancuso that it was denying his petition.In his 2008 petition, Mancuso claimed that the current question pool is too easy to memorize and "that there has been a significant increase in the number of Amateur Radio operators receiving their licenses over at least the last decade or more who do not appear to possess the knowledge indicated by the class of license that they have received.
Most discussion about this topic, both on the air an don Internet forums, generally refers to these widespread observations as the 'dumbing down' of Amateur Radio. It has been widely assumed that the cause of this observed situation is based upon the subject material addressed by the license examinations,that the material requirements specified for the examinations does[sic] not meet some minimum level of knowledge expected by some or many in the Amateur Radio community."
The FCC pointed out to Mancuso that each applicant for a new or upgraded Amateur Radio operator license "is required to pass a written examination in order to prove that he or she possesses the operational and technical qualifications required to perform properly the duties of an amateur service operator licensee, i.e.,that he or she is qualified to be an amateur service licensee."The Commission summed up Mancuso's petition, saying, "You argue that the current question pool size is no longer adequate, because online practice examinations enable examinees to memorize a question pool without fully comprehending the subject matter being tested.Consequently, you propose to increase the size of the question pools, in order to hinder memorization."
The Commission concluded that Mancuso did not present grounds for the Commission to amend its rules: "As noted above, the purpose of the examinations is not to demonstrate an applicant's comprehension of certain material, but rather to determine whether he or she can properly operate an amateur station. Moreover, your contention that there has been 'a significant increase in the number of Amateur Radio operators...who do not appear to possess the knowledge indicated by their class of license' is not supported by any data or facts."The FCC pointed out to Mancuso that the Commission's Rules only dictate the minimum number of questions for each question pool for the three Amateur Radio license classes.
This, the Commission told Mancuso, "does not prevent the National Conference of Volunteer Examiner Coordinators (NCVEC) from increasing the number of questions in a question pool should it decide that this is appropriate. We conclude, therefore, that the petition presents no evidence of an existing problem or other reason for a rule change."
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