RSA 3303A software options

[Dw11in]

I have a RSA 3303A that has TekRSA version 4.20.009, in this software I see

Option 21 Advanced measurement suite (not present)
Option 10 Audio distortion analysis (not present)

Currently I have a software key on the back which lists standard with no options.

Having interest in option 10 it looks like I think I will need a software key to unlock this option. Does anyone know how to obtain the software key? Thanks

[G0HZU]

I think this uses a similar key code system to the Tek 5000 series of scopes.

Here's a typical example of a key I found on the web for option 02 for an RSA3308A with SN B010201.

RSA3308
SN B010201
OPTION 02
372KA-BSM34-UNJ4Q-UZ2KN

The system for the Tek 5000 is discussed here:
https://www.eevblog.com/forum/repair/tektronix-tds5054b-record-length/75/

[squadchannel]

I validated using my machine's serial number, but it should be 21 (and 02?), yet it reports 01.

other serial numbers I found online also completely different results.
3756T-T7AUK-JB5C7-BYMLF(21) -> 01
37D73-8SK6M-U3MU6-SYJJN(21 02) -> 03

Decompiling the RTSA software might reveal something. 

[tv84]

Code: [Select]

License: 372KA-BSM34-UNJ4Q-UZ2KN
Extracted: B9 E3 04 02 5C 59 4B 86 B4 93 17 27 06
Decrypted: 1C 14 AA 36 48 00 00 EC 94 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
CRC16: 94EC   CRC OK
InstrumentID: 00004836AA14 
Options Mask: 2

License: 3756T-T7AUK-JB5C7-BYMLF
Extracted: B9 6F 1E 63 07 32 A1 B0 45 0F 76 A9 02
Decrypted: 1C 98 F0 16 9D 00 00 22 F4 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
CRC16: F422   CRC OK
InstrumentID: 00009D16F098 
Options Mask: 1

License: 37D73-8SK6M-U3MU6-SYJJN
Extracted: B9 8F 9E 3D 4C 7C C9 BC 24 87 16 21 06
Decrypted: 1C 78 F8 48 9B 00 00 E6 C5 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
CRC16: C5E6   CRC OK
InstrumentID: 00009B48F878 
Options Mask: 3
I wonder how these InstrumentIDs are calculated... 

You're confusing things. The Options designations (numbers) have nothing to do with the mask bits:

Mask: 01 - Option 21
Mask: 02 - Option 2
Mask: 04 - Option 10
...