[Milsurplus] Mercury Comms

[J. Forster]

I was involved in unmanned space stuff a few years later. In general, NASA and
the prime spacecraft contractor would not have had the detailed schematics of
the modules they used.

Each box, like a transmitter or subcarrier oscillator or commutator, would have
had a set of specs and a pinout in an ICD (Interface Control Document). System
specs were likely based on IRIG (Inter Range Instrumentation Group) specs.

As to whether it had tubes, most likely yes. The low level stuff could have been
transistorized, the final stage or two tubes, the DC/DC converters were
certainly solid state. Also, remember, these boxes were not developed in a day.
Design and acceptance testing typically took a couple of years, so the designs
were late 50s. There was a rush to get the vehicles off the ground, so they
likely used stock missile or drone parts, or proven USAF hardware,  as much as
possible. There was a thriving business in that area in those 'good old days'
-John


David Stinson wrote:

> I looked into this several years ago, hoping to get technical details
> about the HF equipment in Mercury.
> After politely, repeatedly trying to explain
> the difference between a "block diagram" and a "schematic diagram,"
> I concluded that I'd have to go
> to one of the museums and get permission for a personal examination
> in order to determine if this 1963 spacecraft used any vacuum tubes
> in its comm gear; that's not likely to happen.
> Have any of you had any luck getting componant-level details?