[R-390] Mason Labs R-390A?

[Bill Guyger]

Go to YouTube and search “Apollo Comms” there’s a team of guys who are restoring / resurrecting actual Apollo S band radios and the telemetry and voice modules. 

They’re getting them fully functional, and they have a ridiculous collection of RF test gear to play with. 

The radio gear has been in storage since Apollo days, and the hermetically sealed aluminum boxes were still pressurized with Nitrogen. NASA didn’t spare any money on making these things environmentally resistant.

Bill AD5OL  

Sent from my iPhone

> On Jan 30, 2022, at 9:29 PM, Tisha Hayes <tisha.hayes at gmail.com> wrote:
> 
> Some people romanticize the idea that the R-390A was used to listen to
> Apollo moon landings but the reality was different;
> 
> The Apollo missions primarily operated in the S-Band (around 2.1 GHz) with
> some backup capability at 296.9 MHz. If you dig in the references you will
> see that the Gemini capsules did have HF capability at 15.016 MHz but it is
> not documented if it was ever used. By Apollo the references to the 15.016
> MHz system was dropped but maybe it was something available as a
> post-splashdown SAR/recovery unit in addition to the 296.9 (and maybe
> 243.0) aviation-type radios.
> 
> In the S-Band the system operated off of a PM (like FM) carrier with
> sub-carriers for voice and telemetry. Some of the sub-carriers could be
> turned off and the main carrier was also used for position/ velocity
> tracking with a pretty high degree of accuracy.
> 
> At one time I thought that the capability of putting an external oscillator
> on an R-390A might have something to do with compensating for doppler shift
> (from spacecraft motion) but it makes more sense that it would be used for
> high-stability operations with HF RTTY/Data on fixed or maybe even
> shipboard operations. During Apollo, NASA had lots of tracking stations on
> land and at sea.
> 
> *Ms. Tisha Hayes*
> 
> *AA4HA*
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