Value chain · CLM-1050
In plain terms
The interference limit Raytheon measured its tubes against is given as a CCIR requirement but never traced to a CCIR document, and one page even gets its units wrong by a factor of a thousand.
The claim as recorded
The -154 dBW/m2 per 4 kHz that Raytheon's 1981 magnetron study uses as "the CCIR requirement" for both noise (Table 6-1) and harmonics (Table 8-1) is cited to no CCIR report, recommendation or year on any of the nine pages that name CCIR, is printed once as "-154 dBm/meter2/4 KHz" (8-6) where the tables print dBW, and does not appear in the 1980 JPL report at all; it is the same uncited figure the solid-state study uses (CLM-1003), so the programme's two Raytheon transmitter studies share a design limit whose origin neither states.
Evidence behind this: T3, an absence of citation in two reports, named as such.
Scope and limits
An absence of citation in two reports, not evidence that no CCIR basis exists; CLM-0989 records a "-180 dBW/m2/Hz for S-band" general flux limit and CLM-0988 Report 224-4's radio astronomy thresholds, and -154 dBW/m2 per 4 kHz is neither. Whether it derives from a fixed-service or space-service power flux-density limit of the period is not settled here. Against CCIR 224-4's -247 dB(W/(m2 Hz)) (CLM-0988) the apparent gap of 93 dB is 36 dB of reference bandwidth (4 kHz against 1 Hz) and 57 dB of a different criterion; neither figure is a misprint, both having been read at zoom-6 crops (ver-clm1050-recheck.md).
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.107 / 6-1: "a sufficiently high safety factor over the present CCIR noise requirements". Table 6-1 (PDF 110 / 6-4), render read: "SAFETY FACTOR OVER CCIR REQUIREMENTS (-154 DBW/M2/4 KHz)". PDF p.166 / 8-6: "density levels that are equal to or less than the CCIR requirement of -154 dBm/meter2/4 KHz". Table 8-1 (PDF 167 / 8-7), render read: "CCIR REQUIREMENT DBW/M2/4 kHz (8) ... -154". Probe: regex "Report \d{3}|Rec\.|Recommendation" over SRC-560 prose: zero; "CCIR" on PDF pp.13, 22, 23, 107, 108, 110, 166, 167 only; "-154" and "CCIR" in SRC-559: zero.
Basis: dBW/m2 per 4 kHz
Related records
- Answers question
- QST-017 not published in this release
Cite this
energyaperture.com/c/clm-1050
CLM-1050, Energy Aperture, as of 1981-02.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-559
- CLM-1044In 1980 the quiet oven magnetron was already beyond the instrument's reach: at least 155 decibels below carrier per hertz away from the...CLM-1045Raytheon's own numbers had the klystron just failing the interference limit at the band edge and the magnetron clearing it by 45 decibels...CLM-1047The oven magnetron's second harmonic came out about 70 decibels below its carrier, a tuned stub took another 40 off, and the antenna's own...CLM-1048A cheap oven magnetron run cold and hard converted 81.7 per cent of its DC input to microwaves, measured carefully by heating water...CLM-1049The fifty-year magnetron rests on a cathode that runs cool because the tube heats it only as much as it needs, on tube-life curves from...
- Also from SRC-560
- CLM-1043With the heater off and a tuning circuit on the cathode, one hand-picked oven magnetron was as quiet as the instrument could measure: about...CLM-1045Raytheon's own numbers had the klystron just failing the interference limit at the band edge and the magnetron clearing it by 45 decibels...CLM-1046The number Raytheon wrote into the design table for the satellite tube was about fifty times noisier than its best laboratory reading...CLM-1047The oven magnetron's second harmonic came out about 70 decibels below its carrier, a tuned stub took another 40 off, and the antenna's own...CLM-1048A cheap oven magnetron run cold and hard converted 81.7 per cent of its DC input to microwaves, measured carefully by heating water...CLM-1049The fifty-year magnetron rests on a cathode that runs cool because the tube heats it only as much as it needs, on tube-life curves from...
- Also from SRC-561
- CLM-1003For a transmitter built from millions of small solid-state amplifiers instead of tubes, the 1980 study worked its noise budget down to the...