Anyone ever seen one of these? I just bought it on ebay and was hoping someone somewhere might have a manual. It generally looks understandable from the pictures (It hasnt arrived yet) but there are some DB25 connectors on the rear which I'd like more information on.

Military Radio RTTY teletype An/ggm-21a Test Set Pulse Generator Sg-1186/ggm-21 a - eBay

Fast shipping. Very heavy steering box broke the box in shipping but the post office taped it up. Maybe consider better boxes. Anyway the part came in good order without damage. Part description was perfect, as used original in good condition. Direct M151A2 MUTT replacement. Price and value is unmatched compared to other sellers. Great transaction. Fast shipping. Great item. Recommend Seller ...