Question How to rendezvous radar?

[x170doom]

2 things here:
1: the lm rr self test checklist after undocking has you enter v63 and then pro to get f 04 12. The pro seems to be spurious.
2. How does one perform a manual lock on with the rr?

 

[x170doom]

Could really use some help. Since i cant find any info on how to manually lock the rr

 

[Miriam]

Well, my checklist here has the PRO after the F 04 12. Which mission, anyway? Every mission has its own checklist, so we'd need to known that.
Manual lock-on...well, for what? For checkout, for keeping the CSM tracked during descent or for the really "hard stuff" when the LGC has failed during rendezvous?

 

[x170doom]

The mission is apolllo 11. And the manual lock on is called for during a rr self test shortly after undocking. The sequence in the checklist is

V68e
Pro
F04 12
Rr manual lock on

This is what caused the confusion as the lock on process isn't explained

 

[Miriam]

Ah! That's rather a reasonabilty test. The idea is to lock on the CSM shortly after undocking and compare the LM readouts with the CSM VHF ranging. And yes, the PRO is wrong there. It rather should be:
V63E
F 04 12
verify that R2 = 00001
RNDZ RDR - SLEW
Manual lock on CSM
RNDZ RDR - LGC
PRO
PRO
16 78
R1 = range (.01 NM)
R2 = range rate (fps)
R3 = TFI (not relevant here)
...and then follows the rest of the cl.
Locking on the CSM shouldn't be too hard, as it's not too far away and the antenna is in the 'up' position. Just slew around a bit, when the AGC meter goes up, switch to LGC and the radar itself will do the rest.

 

[MrFickles]

Shortly after undocking and after the visual inspection, LM +X should be facing the CSM and be 'upside down'. Manually slew the RR to PY 0,0 and you should get a good signal strength. At this point, you can switch to AUTO TRACK and it should lock.

 

[x170doom]

Ah. I might not be able to lock it then since the sm sep burn was quite quick after undocking (~3 mins) and it's quite a distance away. Am i okay just to skip the rest of this test

 

[Miriam]

Yeah, that's a gotcha. I usually lock on the CSM as soon as I can after undocking and keep it locked by switching to AUTO TRACK. The LGC does not issue the auto track discrete all the time, so it's better to keep what you got once you have it.

 

[rcflyinghokie]

The mission is apolllo 11. And the manual lock on is called for during a rr self test shortly after undocking. The sequence in the checklist is

V68e
Pro
F04 12
Rr manual lock on

This is what caused the confusion as the lock on process isn't explained

Just FYI the checklist has a V63, not V68 there.

Also, as this is exactly from the real procedures, "RR Manual Lock-On" is all that exists in the actual doc, but @Miriam perfectly explained what it entails. Just bore sighting the RR on the CSM slewing for max signal and then move to LGC and let it hold lock.

 

[rcflyinghokie]

Shortly after undocking and after the visual inspection, LM +X should be facing the CSM and be 'upside down'. Manually slew the RR to PY 0,0 and you should get a good signal strength. At this point, you can switch to AUTO TRACK and it should lock.

+Z facing the CSM