[amsat-bb] Re: accidental satellite ops
gzook at yahoo.com
Thu Sep 17 15:19:07 PDT 2009
I went back in my copies of the AMSAT Newsletter (I have virtually all of them starting with Volume I, Number 2, dated October 1969 - I joined AMSAT the 2nd month of the organization's existence) and the only mention of a waiver was that due to the control requirements that a waiver was requested for OSCAR I through OSCAR VII. Volume V, Number 1, March 1973, page 19, describes the frequency selection for the OSCAR VII transponders and the mention is made that the life expectancy was 3 years. But, there was no mention of a waiver due to the frequency selection.
Volume V, Number 4, December 1973, has a lengthy article on the capabilities of OSCAR VII. Again, no mention of a waiver because of the frequency selection. On page 18 of that issue there is an announcement of Notice of Inquiry from the FCC concerning rules for the newly proposed Amateur Radio Satellite Service.
Volume VI, Number 2, June 1974, has AMSAT's official response to the Notice of Inquiry by the FCC starting on page 8.
Remember, before the establishment of the Amateur Radio Satellite Service there was nothing in the FCC regulations concerning the frequencies even suggested, let alone required.
These days 47 CFR Part 97 Section 97.207(c)(2) specifies, among other frequencies, 144 MHz to 146 MHz and 435 MHz to 438 MHz as the allowed frequency segments for satellite operation. But, prior to either late 1974 or early 1975 there were no specified frequencies for satellite operation. Of course the frequency range of 144 MHz to 146 MHz definitely encompasses the "weak signal" portion of the 2-meter band. The 435 MHz to 438 MHz segment is well above the present "weak signal" portion of the 70 cm band.
It is my opinion that the segment around 432.150 MHz was chosen because the vast majority of operators that had 70 cm capabilities were operating very near this segment and therefore no additional transmitting equipment would have to be acquired. Also, most 432 MHz operators also had 2-meter capabilities and could easily "hear" the downlink.
AMSAT 239 / LM 463
--- On Thu, 9/17/09, kl7uw at acsalaska.net <kl7uw at acsalaska.net> wrote:
Actually, AO-7 was placed in the narrow-band (CW/SSB) subband back when it was launched. AS I recall a waiver was sought to do this. So AO-7 is, in fact, in the wrong frequency allocation for satellite operations. Perhaps Tom Clark or one of the other old hands that were involved when AO-7 was built/launched can better state this (I was a member of sbms that built the 2.3 GHz transponder that was never allowed activation).
As far as attracting new satellite operators, there is an even chance since the operator already is in possession of CW/SSB equipment that is required for AO-7. Basically, they would need proper antennas and learning about tracking issues (times, freq. Doppler, etc.). Also that the input is inverted so one tranmits LSB to hear USB. Most of the weak-signal group (CW/SSB) are pretty savy bunch, so it remains whether it would interest them.
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