Re: apollo psa test point adaptor
It’s hard to find documentation for the ground test equipment apparently. The flyable hardware is very well documented, and Mike Stewart and co. are in the process of scanning it all at NARA. I can glean a few things from the markings on your picture. The PSA, or Power and Servo Assembly, had all the analog electronics for the Inertial Measurement Units and the star alignment optics, namely the scanning telescope and the sextant and the 3 pendulum accelerometers or PIPAs. It was a very large beast having maybe 100 modules, all the DC, 800Hz and 3200 Hz power supplies for the gyros and resolvers, the servo amplifiers for the 3 axes of the Inertial Measurement Unit, and the various temperature controllers. The test points give you access to internal key test points in the PSA to such things as the inertial measurement unit 3 gimbal error signals, the Scanning Telescope and Sextant optics trunnion and shaft error, corresponding servo test inputs (so you could rotate the gimbals or the optics), all the temperature monitors (there are many). There are two types of PSAs, one for the CM and one from the LM. Yours mentions SCT (Scanning Optical Telescope) and SXT (Sextant), and only the Command Module had a sextant, so we can pretty much tell this is a command module PSA test unit. There are also two very different revisions of the PSAs, Block I and Block II. Looking at the Block II PSA description (find it in the ND-1021043 manual), it appeared to have two test connectors, J1 and J2, 61 pins each. But your tester breaks out 195 test points. The Block I seems to have more test pins, but I haven’t yet found the exact description. So my guess is that it is a Block I tester. Reading from the top: TB1 to TB5 – my guess is that this is a breakout of 5 test connectors at the back of the PSA. A guess only, I don’t have the doc to confirm it. You put a voltmeter or a signal in these pins to measure your test point of put a signal into it. Pulse Probe, Direct Probe, Buffered Probe: I don’t know. The lowest left corner seems to deal with testing the servos, 3 at a time. If you are in the ISS (inertial sensing system) position, you’d probably move the 3 gimbal servos of the IMU. If you have it in the OPT position, you’d move the 3 axes of the optics which you can see on the other buttons, the SCT trunnion and the SXT trunnion and shaft. Apparently each of them has a slow or fast setting (that’s how I read 1:1 and 1:10 markings). The large commutator in the middle marked IRIG S.F. may be referring to the Integrating Inertial Reference Integrating Gyro Scale Factor monitoring. These are resistors networks that contained the calibration of the individual gyros. Problem is, there were 3 gyros and the knob has 5 positions, so that does not make a whole lot of sense to me. If it’s indeed a Block I tester, then I have a one of the Block I PSA trays it connects to. I was planning to used with my IRIG gyro, so the tester could potentially be useful to the project, if you were to lend it to us before you modify it. But probably not essential, as we can always break out the connectors ourselves (although it would be way less cool). And playing with the PSA is probably not going to happen for a while. It would be interesting to open it up and see if we could glean more insight from looking at the innards, and thoroughly document it before you modify it, so we can at least reproduce it. Marc From: cctalk on behalf of "cctalk@classiccmp.org" Reply-To: Jon Elson , "cctalk@classiccmp.org" Date: Sunday, May 19, 2019 at 7:46 AM To: Adrian Stoness , , "cctalk@classiccmp.org" Subject: Re: apollo psa test point adaptor On 05/18/2019 10:08 PM, Adrian Stoness via cctalk wrote: anyone know where i could find manual or drawings on this im up in northern manitoba canada picked it up at a rr auction to experiment with as a audio interface not sure if the jacks on the side are the weird pins nasa had or another standard i can find? https://www.flickr.com/photos/1ajs/albums/72157705166193482 There's a switch labeled "IRIG" which stands for Inter Range Instrumentation Group, and refers to a standard for telemetry encoding. There is a standard for time code, a standard for modulating analog signas onto a bunch of FM carriers, and a standard for multiplexing several analog signals onto one FM carrier. Apollo documents are probably VERY hard to come by these days. Jon
RE: apollo psa test point adaptor
Too funny that was 73 Eugene W2HX -Original Message- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Will Cooke via cctalk Sent: Tuesday, May 21, 2019 1:58 PM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: apollo psa test point adaptor > On May 21, 2019 at 12:31 PM W2HX via cctalk wrote: > > > >BTW I got my Apollo IRIG at the same auction that Adrian got the Apollo PSA > >tester from. > > Wow, didn't know that NASA had testers for prostate specific antigen! They use them when exploring Uranus.
Re: apollo psa test point adaptor
> On May 21, 2019 at 12:31 PM W2HX via cctalk wrote: > > > >BTW I got my Apollo IRIG at the same auction that Adrian got the Apollo PSA > >tester from. > > Wow, didn't know that NASA had testers for prostate specific antigen! They use them when exploring Uranus.
Re: apollo psa test point adaptor
BTW I got my Apollo IRIG at the same auction that Adrian got the Apollo PSA tester from. On Tue, 21 May 2019, W2HX via cctalk wrote: Wow, didn't know that NASA had testers for prostate specific antigen! Sure! Didn't you see the Public Service Announcement?
Re: apollo psa test point adaptor
>BTW I got my Apollo IRIG at the same auction that Adrian got the Apollo PSA >tester from. Wow, didn't know that NASA had testers for prostate specific antigen!
Re: apollo psa test point adaptor
pritty much lol On Tue, May 21, 2019 at 9:50 AM Jon Elson via cctalk wrote: > On 05/20/2019 05:38 PM, Carl Claunch via cctalk wrote: > > On 05/19/2019 09:46 AM, Jon Elson via cctalk wrote: > >> There's a switch labeled "IRIG" which stands for Inter Range > >> Instrumentation Group, and refers to a standard for > >>telemetry encoding. There is a standard for time code, a > >>standard for modulating analog signas onto a bunch of FM > >>carriers, and a standard for multiplexing several analog > >>signals onto one FM carrier. > > In this case IRIG stands for Inertial Reference Integrating Gyroscope, > one > > of three inside the Intertial Measurement Unit of the spacecraft. > Good GRIEF! Clashing acronyms. And, NASA certainly knew > about the other IRIG, as they used IRIG standards on a lot > of telemetry and radar systems. > > Jon >
Re: apollo psa test point adaptor
On 05/20/2019 05:38 PM, Carl Claunch via cctalk wrote: On 05/19/2019 09:46 AM, Jon Elson via cctalk wrote: There's a switch labeled "IRIG" which stands for Inter Range Instrumentation Group, and refers to a standard for telemetry encoding. There is a standard for time code, a standard for modulating analog signas onto a bunch of FM carriers, and a standard for multiplexing several analog signals onto one FM carrier. In this case IRIG stands for Inertial Reference Integrating Gyroscope, one of three inside the Intertial Measurement Unit of the spacecraft. Good GRIEF! Clashing acronyms. And, NASA certainly knew about the other IRIG, as they used IRIG standards on a lot of telemetry and radar systems. Jon
Re: apollo psa test point adaptor
I do not think this is correct. The IRIG almost certainly refers to the Apollo Inertial Reference Integrating Gyro, which you can see in this video along with one of the PSA trays Adrian’s contraption is supposed to be testing: https://youtu.be/lXe2OS4nwnQ BTW I got my Apollo IRIG at the same auction that Adrian got the Apollo PSA tester from. Marc From: cctalk on behalf of "cctalk@classiccmp.org" Reply-To: Jon Elson , "cctalk@classiccmp.org" Date: Sunday, May 19, 2019 at 7:46 AM To: Adrian Stoness , , "cctalk@classiccmp.org" Subject: Re: apollo psa test point adaptor On 05/18/2019 10:08 PM, Adrian Stoness via cctalk wrote: anyone know where i could find manual or drawings on this im up in northern manitoba canada picked it up at a rr auction to experiment with as a audio interface not sure if the jacks on the side are the weird pins nasa had or another standard i can find? https://www.flickr.com/photos/1ajs/albums/72157705166193482 There's a switch labeled "IRIG" which stands for Inter Range Instrumentation Group, and refers to a standard for telemetry encoding. There is a standard for time code, a standard for modulating analog signas onto a bunch of FM carriers, and a standard for multiplexing several analog signals onto one FM carrier. Apollo documents are probably VERY hard to come by these days. Jon
Re: apollo psa test point adaptor
On 05/19/2019 09:46 AM, Jon Elson via cctalk wrote: > There's a switch labeled "IRIG" which stands for Inter Range > Instrumentation Group, and refers to a standard for > telemetry encoding. There is a standard for time code, a > standard for modulating analog signas onto a bunch of FM > carriers, and a standard for multiplexing several analog > signals onto one FM carrier. In this case IRIG stands for Inertial Reference Integrating Gyroscope, one of three inside the Intertial Measurement Unit of the spacecraft. This adapter is used to test the PSA tray (Power Sub Assembly) which had modules such as the Coarse Alignment Amplifiers that were used to drive and measure the gryos (and the accelerometers). It also drives the sextant optics for star sighting in the CM (thus you see the knobs labeled Sxt Shaft and Sxt Trun) Those same circutis would be used with the Rendezvous Radar for the PSA installed in a LM. > Apollo documents are probably VERY hard to come by these days. They are being rapidly and steadily digitized and made available. Many of the PSA schematics are now accessible. The test point adapter itself is not going to be easy to find, but you can find the wiring harness schematics that would tell you what each of your 91 leads in the connector does. Carl
Re: apollo psa test point adaptor
On 05/18/2019 10:08 PM, Adrian Stoness via cctalk wrote: anyone know where i could find manual or drawings on this im up in northern manitoba canada picked it up at a rr auction to experiment with as a audio interface not sure if the jacks on the side are the weird pins nasa had or another standard i can find? https://www.flickr.com/photos/1ajs/albums/72157705166193482 There's a switch labeled "IRIG" which stands for Inter Range Instrumentation Group, and refers to a standard for telemetry encoding. There is a standard for time code, a standard for modulating analog signas onto a bunch of FM carriers, and a standard for multiplexing several analog signals onto one FM carrier. Apollo documents are probably VERY hard to come by these days. Jon
Re: apollo psa test point adaptor
These are sturdy and notoriously expensive aerospace grade 38999 connectors. We had to slightly machine modern 38999’s male plugs to fit in these, but by in large it still fits the modern standard. I have one of the PSA trays it connects to, trying to make it work again! Nice and noble hardware it is. Marc > On May 18, 2019, at 8:08 PM, Adrian Stoness via cctalk > wrote: > > anyone know where i could find manual or drawings on this im up in northern > manitoba canada picked it up at a rr auction to experiment with as a audio > interface not sure if the jacks on the side are the weird pins nasa had or > another standard i can find? > > https://www.flickr.com/photos/1ajs/albums/72157705166193482
apollo psa test point adaptor
anyone know where i could find manual or drawings on this im up in northern manitoba canada picked it up at a rr auction to experiment with as a audio interface not sure if the jacks on the side are the weird pins nasa had or another standard i can find? https://www.flickr.com/photos/1ajs/albums/72157705166193482
