Problem Counting RR 5 Marks in LEM AGC- Apollo10

[sw34669]

tried again today same happened. got the 2 close, managed a high strength lock using slew then auto to fine tune. Both ships pointing at each other and in att hold. after 12 seconds the ticker tape range works. switch to LGC, as per checklist, signal drops to zero, LM radar gets pitched up by the computer and just stays there and loses lock. let it sit for 2 minutes .... nothing. Took out of AGC into slew, re-aquired lock, good strength, sticker tape range, back to LGC and same again.

Can the mission be performed without it or how do I fix it ?

 

[n72.75]

Which build are you on, 1600 right, and can you post a scenario?

I'm at work for the next 8 hours or so, but when I get home tonight I'll try it out in 1600 and see what might be your issue.

Thank you for your patience, you've made it really far already, and you're helping make the sim better by giving it a thorough test and asking great questions.

 

[sw34669]

Here's my save if you can see anything strange with thx

 

[sw34669]

no probs - the devil is i the detail and I appreciate the work that's gone into this, glad to help, the learning curve has for sure been steep. The point of the flight at the moment is hard work as you're doing the work of 3, at the same time pads are coming in like a deck of cards. I've tried to screenshot them as each comes in for the LM and CSM. If Indy can dump these out as a growing collection to a directory somewhere they could be printed.
I may have also found a rougue Uplink required message that doesnt start with LM: or CSM:

i was on 1600 but have updated to 1603 now
Ive also noticed that I cant get the P52 on the Lm to work correctly
not sure if i've screwed alignment/vectors up during sep
anyway - appreciate the help i'm lost in space
i read early solder joints on the RR could cause low voltage but i'm guessing you dont simualte that

 

[sw34669]

here is the same scenario a bit before, when the ships are closer

 

[indy91]

Yeah makes sense with the earlier scenario, I think the other scenario was already in P52 attitude and further in time. I think I know what the issue is, I'll try the earlier one and tell you about it.

Ok, I think you are in an undesirable attitude for RR tracking in the earlier scenario as well. Probably drifted off since the 360° inspection maneuver. In the flight plan it says you should be at 0° roll 304° pitch and 0° yaw. So go there. The RR only works if it is pointing roughly forwards or roughly backwards.

Then I need to slew the RR to point forwards and down a bit. In the scenario it was pointing backwards still, so slew it left by a lot. Then I can get manual lock-up working (if I was to switch to auto mode). For LGC auto mode you need V63 and then press PRO once to get to the next display. I think the checklist ommits that and even the flown LM Timeline Book doesn't give the PRO, which is probably why it was missed in the Checklist MFD. Then the LGC is happy to auto track the CSM.

 

[sw34669]

the voltage meter in the csm reads ~0.5v when the LM is not pointing at it (CSM rotary dials XPNDR and C)
when you spin the LM around and get a small signal on the LM signal display and switch to CSM, the XPNDR voltage shoots upto 4.5
Sort of a quantum issue, the less it's locked on, the fewer volts it gets
i used current state 6 above as they are closer
also check my alignments for the LM

 

[indy91]

Your alignment is good, at least good enough so that P52 found me star 14. If you get the 405 program alarm in P52 (check alarm type with V05 N09) just change your attitude a bit, maybe by 30°. Do a V32E to recycle and then PRO again. If you do that 1-3 times then it will definitely find two stars. Also make sure then that you are using the Front (F) detent of the AOT.

I answered your RR questions in the post above already, if you hadn't seen it.

 

[sw34669]

Yeah makes sense with the earlier scenario, I think the other scenario was already in P52 attitude and further in time. I think I know what the issue is, I'll try the earlier one and tell you about it.

Ok, I think you are in an undesirable attitude for RR tracking in the earlier scenario as well. Probably drifted off since the 360° inspection maneuver. In the flight plan it says you should be at 0° roll 304° pitch and 0° yaw. So go there. The RR only works if it is pointing roughly forwards or roughly backwards.

Then I need to slew the RR to point forwards and down a bit. In the scenario it was pointing backwards still, so slew it left by a lot. Then I can get manual lock-up working (if I was to switch to auto mode). For LGC auto mode you need V63 and then press PRO once to get to the next display. I think the checklist ommits that and even the flown LM Timeline Book doesn't give the PRO, which is probably why it was missed in the Checklist MFD. Then the LGC is happy to auto track the CSM.

I know those scanrios were off in terms of the direction of the radar they were the only 2 i had
ok in the earlier and later scenarios i spent a few hours at this last night and today and I think I was just past the point in the checklist where the v63 is and i had a very very strong signal and got the range tape fire up. The second the checklist switched from auto or slew to LGC, it automatically slewed the antenna to point straight up and lost signal.

I get the getting them aligned and the yellow light going out but it goes wrong when switching to LGC.

Where should the V63 and the additional PRO go into the checklist (at multiple points ?)

I have my scenario 6 up at the moment, both ships are pointed straight at each other and the best i can do signal wise is 1 at the lm end, i checked views fro external either end and the dish is looking straight at it.

 

[indy91]

I know those scanrios were off in terms of the direction of the radar they were the only 2 i had
ok in the earlier and later scenarios i spent a few hours at this last night and today and I think I was just past the point in the checklist where the v63 is and i had a very very strong signal and got the range tape fire up. The second the checklist switched from auto or slew to LGC, it automatically slewed the antenna to point straight up and lost signal.

I get the getting them aligned and the yellow light going out but it goes wrong when switching to LGC.

Definitely maneuver to the attitude I wrote, I think the LGC has some weird logic where it doesn't allow the RR to point to the sides, only forwards and backwards.

Where should the V63 and the additional PRO go into the checklist (at multiple points ?)

Ah that was referring to your other scenario that is later in time, you called the scenario "Moon". That one already has started V63 but then you need to PRO so that the LGC mode for the RR properly works.

I have my scenario 6 up at the moment, both ships are pointed straight at each other and the best i can do signal wise is 1 at the lm end, i checked views fro external either end and the dish is looking straight at it.

Hmm, maybe you have side lobe acquisition? The RR signal strength has multiple peaks. Here a page from the AOH Volume 2:

What you want is the center peak, which should give about 3V signal strength. So you might have to slew the RR manually a bit further in some direction. In the right attitude in your scenario 6 I only needed to adjust the "pitch" angle (up and down) of the RR for this, with "yaw" of the RR being 0°.

 

[sw34669]

ok here's where i've got to last night and today in this scanario attached. I have a signal , i can move around a little to make it batter and the light goes out and the range tape is active on auto.

The minute I switch to LGC it goes wrong , the dish moves to point upwards
I also tried starting V63 before and pressing pro then LGC same thing happens

the file i've attached, how do i get that into V63 mode with the checklisted switch at LGC

 

[sw34669]

i'm not having an issue getting the initial signal, as i said, it's when LGC is selected
I tried hitting PRO and it just the same

 

[sw34669]

ok, current state 6 1 2 If i pitch down to 225, the LGC mode eventually locks, but not at 306 (windows forward)

 

[indy91]

Ah that's a fun issue. You don't have the RR pointing properly. From pointing directly forward it is basically 180° rotated in trunnion (180° slewed to the right) and then slewed down as far as it goes so that it somewhat is pointing forwards. That's not a normal control mode for the RR and I wonder if auto tracking should even work with this. You can tell it's wrong because that pointy end of the RR which is housing the RR gyros (among other things) is pointing up. So for the LGC to track anything left/right and up/down are basically switched. It can not deal with that.

In that "state 6 1 2" scenario, look at V16 N72 which shows the RR angles. It is 180° and 210°. You want close to 0° for both of those. You can accomplish that by slewing left and up for a while until you reach 0°. Then try again with the acqusition.

 

[n72.75]

Also, as far as the LEB gauge on panel 101 in the CSM

A: power received by the csm (2.1v = -122 dBm, which is the minimum)
B: automatic gain control voltage.
C: frequency lock voltage (0.5v in "seek" mode when it's looking for a signal from the LM, 4.5v when it's locked onto the LMs radar)

 

[sw34669]

also just noticed 0 it will hold but as soon as i pitch up again to 260+ it breaks off (there should be enough pitch in the radar)

 

[sw34669]

Ah that's a fun issue. You don't have the RR pointing properly. From pointing directly forward it is basically 180° rotated in trunnion (180° slewed to the right) and then slewed down as far as it goes so that it somewhat is pointing forwards. That's not a normal control mode for the RR and I wonder if auto tracking should even work with this. You can tell it's wrong because that pointy end of the RR which is housing the RR gyros (among other things) is pointing up. So for the LGC to track anything left/right and up/down are basically switched. It can not deal with that.

In that "state 6 1 2" scenario, look at V16 N72 which shows the RR angles. It is 180° and 210°. You want close to 0° for both of those. You can accomplish that by slewing left and up for a while until you reach 0°. Then try again with the acqusition.

I still don't understand what you mean here , you said eariler to point at 0 , 306 , 0 . that didnt work so i put it down to 0 , 225 , 0 and got lock (roof towards CSM)
my actual attitude in the 6 1 2 above is below ...... not sure where you saw 180/210 of course the fdai is in orbital but my roll is 0 .... again, as per where the checklist had me set it and where you suggested.
scenario 6 1 2 has the LM pointing it's roof at the CSM, is this not correct ?
my patience just drained away

 

[indy91]

You are confusing the attitude of the LM with the angles of the rendezvous radar. Your LM is oriented correctly in the scenario. Your RR is not, it is flipped around in a way where it doesn't work. Look at Verb 16 Noun 72, that shows you the trunnion and shaft angles of the rendezvous radar. They are about 180° and 210°. If they would be close to zero then they would be pointing forward in the correct way. You have to look at V16 N72, slew the RR to close to 0 in the way I described in the previous post and try again with acquiring the CSM. Here I made you a picture:

I hope that helps understanding the issue.

 

[Lupus_Vulpes]

Haha, the dish was "upside-down" basically

 

[sw34669]

so, after further investigation, there's a ghost signal (reflection) that when switching to LGC caused the computer to twist the dish around like that. After reading about the gearbox inside and how it's controlled , I get this now and how it's needed for aligning. What I found is slewing further up I found the real CSM signal. This, locks well in manual/auto or LGC mode. Each time I aligned the dish correctly forwards, the LGC algo seemed to go crazy.
Small gotchas like this are hard to find when you're low hours

Once this was fixed, I have actually made it down to the surface without death 748m over-shoot but still alive. I have even managed a p57 or two. The Checklist MFD is perfect for the first p57 after landing.

After doing a number of approaches i'm still struggling a bit to get the alt's converged and end up hot and high, not by much. A detailed look at the process talks about dropping the thrust to 10% until converged. Any advice here.

The other area is the TLAND AGS variable needed (LM Epoch). I found that RTC MFD / Utils / LGC will calculate 2 of them, but, not sure what to enter here.