I don't have as much respect as Ray for the GRC-14. To align the rec. you take the relevant section out, so you can reach the adjustments, and cable the section back to the mainframe. The extender cables were only issued 1:x

radios, not 1:1 and the rec. top band is 16 -32 MHz, not divided in 2 like the SRR-19. The connectors for extender cables have the blue connectors like in old v.t. Tek scopes, but i haven't pursued that. I read somewhere that this contract was given so the manufacturer didn't feel left out in the rain, maybe so. The rec. is definitely old school design compared to the Collins product R-392.