Re: The Shapiro's experiment HOAX. A 1968 TIME article.

CORRECTION FROM PREVIOUS POST: The difference that allegedly was
measured was 1/5 msec or 200 microseconds. So, the alleged accuracy was
1.45E-07 or 0.145 ppm (in 1964!, with ad-hoc real time computers built
in that epoch.
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The Haystack radar antenna is a 120 ft diameter Cassegrain system
designed and built in the 1960s.
QUOTE:
1965- Irwin Shapiro proposed a “fourth”
test of general relativity—
measuring the general-relativity
prediction of “time dilation”
or “excess delay” up to ~200
microseconds for radio waves
that travel very near the Sun.
He suggested that radar
measurements of a planet near
superior conjunction should
double the one-way value; this
value would be compared to the
total round-trip time of up to
~1500 seconds. The first results
from a radar-echo excess-delay
experiment were obtained in 1967
using Mercury as a target
https://archive.ll.mit.edu/publications/HaystackCommemorativeBk.pdf
In the 60s it operated at 8 Ghz, with a power of about 200,000 Watts.
In a round trip of about 2 x 200 million Km, the FSPL (Free Space Path
Loss) is
FSPL(dB) = 20 log d + 20 log f - 147.55
d: distance in meters
f: frequency in Hertz
FSPL(dB) = 20 log 4E+11 + 20 log 8E+09 - 147.55
FSPL(dB) = 220 log 4 + 180 log 8 - 147.55 = 147.45
60dB have to be added due to the passive reflection in Mercury.
Received power (dBW): -207.45 + + 5.3 = -202.15 dBW
Antenna gain (at reception) = 61 dB
Beamwidth = 0.07 degrees
Received power (W): 10E-07 Watts = 100 nanowatts
Noise at reception (W, estimated) = ? nanowatts (depends on many
factors), like bandwidth, technologies, cosmic sources, etc.
https://repository.aip.org/islandora/object/nbla:307780