Len,
I am sorry if I have angered you. Please don't take my postings as a personal attack. That was certainly not my intent.
In order to produce a circularly polarized radiation pattern over a wide beamwidth the two linear antennas would need to lie in the same plane within a tenth of an inch or so. If the two antennas are offset more then they could still produce CP, but their CP axial ratio would fall off rapidly as one moved off axis, quickly deteriorating back to linear. This is because of the change in path length from the rx antenna to each of the linear tx components.
I design antennas for a living so I have seen quite a bit in my 36 years of antenna design. But I have been wrong before, so I apologize if I am. Can you please provide a link to Andy's statement saying they are circularly polarized?
And yes, you are right, I have been sloppy with my terminology in my previous posts. I talked of signals becoming weak, but the true indicator of a good signal is the checksum. Checksum errors tend to occur on the weaker signal, but there no doubt are exceptions.
I don't know why the designers might use a separate antenna for telemetry rather than multiplexing the main antenna. Perhaps to reduce cost? Or to reduce insertion loss? Or to improve reliability? It was just a guess.
Anyway, I am drifting way off topic. I suggest we continue this discussion by PM if you care to.
73,
w2anz