[Milsurplus] Wideband Receivers R-1039 and R-1151 ???

[mikea]

On Fri, Dec 04, 2015 at 03:15:32PM +0000, Ray Fantini wrote:
> Don't know about the NSA but NASA used lots of old Ampex and similar wide
>bandwidth analog recorders for direct capture of the downlinks from things
>like the Microdyne receivers. The oldest Microdyne I have seen are the 1100
>family but going to assume that maybe the R-1151 or 1039 may have been
>something prior to the Microdynes like those old Nems Clarke thirteen hundred
>series radios?

I don't know about the radios at the various ground stations, though I have
the E-mail address of someone who worked at the Tananarive, Madagascar (now 
Antananarivo, Malagasy Republic) Gemini/Apollo ground station; he may be able
to tell us more. 

I do, however, know about the wideband analog recorders used at the ground
stations, since we had some at the Manned Spacecraft Center, in the Data
Reduction Complex on the second floor of Bldg. 12. They were Ampex FR-1400
systems: 2" tape, 14 track, .9375 to 120 IPS in 2 speed bands. Changing from
low band to high band involved opening up the transport and shifting a belt
from one set of pulley faces to another. Frequency response in direct mode at
120 IPS was something like 400 HZ bottom, topping out at 1.5 MHz, flat within
1 dB; in FM mode, at 120 IPS, the response was DC to 400 kHz, flat within 1
dB, and it was fairly easy to get it a lot flatter.

There were 14 slots in the record electronics, each holding one of NBFM, WBFM,
or direct electronics. Ditto for reproduce electronics. 

There were 4 possible head configurations: 
o   14 track wideband
o   14 track narrowband
o   7 track wideband
o   7 track narrowband 

The wideband head stacks were very expensive and very soft; using even the
best tape available (Memorex 62J), they scalloped after about 20 hours of use,
and had to be sent back to Ampex for refurbishing. Using anything other than
Memorex 62J was prohibited, because it would sandpaper the heads down to where
the head gaps were too wide for refurbishment, and the stack would have to be
discarded. The narrowband heads were very hard and very nearly bulletproof: I
think I could have got away with running emery paper over them. 

The transport was a wonderful piece of design, implemented very nicely:
muscular as could be, as it needed to be to handle 9200-foot rolls of tape,
and very soft indeed on the tape. The guides all had air bearings, and tension
control was through feedback on the air pressure at the bearing-tape
interface. 

I loved using them, and they were *SO* easy to work on. They didn't need much
work, either: built like battleships, but by Swiss watchmakers. 

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin