"Anomaly is probably the signature of the difference between the marches of the astronomical clock of the orbit and the atomic clock inside the ship."

Interesting, I'm still hoping that the anomaly has a lot to do with the heliosheath/heliopause and who knows even the termination shock (that may even show more of an anomaly?!!)

[The Pioneer anomaly is not actually a measure of how far the Pioneer probes did or didn't travel.

Instead, scientists bounced microwave signals off each probe and noticed an unexpected drift in the Doppler frequency as the probes got farther away. The technique is akin to noting the sound change in a siren as an ambulance races first toward you, and then away from you. The Doppler effect is a shortening or lengthening of sound waves (or microwaves, or any waves) forced by an object's movement.

The drift showed that the Pioneers were being accelerated toward the Sun (or, rather, decelerated in their movement away from the Sun) by a tiny but inexplicable amount. The level of drift is equal to a gravitational effect 10 billion times weaker than the pull of Earth.

Though tiny, the signal is clear, other scientists agree.]

[Despite 11 years of devotion to the mystery, Turyshev is the first to admit that the "most obvious explanation" would be an unknown onboard effect. Perhaps excessive internal heat or leaks of propulsion gas are providing a wee bit of thrust that adds up over the years.]

From: Space.com.

I think we've heard most explanations by now (including the link you cited above!). They even mentioned our sun's eleven year cycle as the reason... the contraction and expansion of the heliosphere during the sun's eleven year cycle).

I hoped that the Voyagers would have given some answers by now.

I'm betting on the shock from the heliosphere to interstellar space, but, we'll see.

Thanks for your interest on this, LJK and for all the links you've shared with us.