FTP weirdness

Background:

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System is Power 6, V5R4, QCCSID = 65535
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PC 5250 5.9 session configured to use Host code-page 37:

Display Job Definition Attributes
Job: XXXXXXXXXX User: WINBLOWS Number: 161946

Job switches . . . . . . . . . . . . . . . . . . : 00000000
Inquiry message reply . . . . . . . . . . . . . . : *SYSRPYL
Accounting code . . . . . . . . . . . . . . . . . :
Print text . . . . . . . . . . . . . . . . . . . : ' '
DDM conversation . . . . . . . . . . . . . . . . : *KEEP
Break message handling . . . . . . . . . . . . . : *NORMAL
Status message . . . . . . . . . . . . . . . . . : *NORMAL
Device recovery action . . . . . . . . . . . . . : *ENDJOBNOLIST
Time slice end pool . . . . . . . . . . . . . . . : *NONE
Print key format . . . . . . . . . . . . . . . . : *PRTHDR
Sort sequence . . . . . . . . . . . . . . . . . . : *HEX
Library . . . . . . . . . . . . . . . . . . . . :
Language identifier . . . . . . . . . . . . . . . : ENU
Country or region identifier . . . . . . . . . . : US
Coded character set identifier . . . . . . . . . : 65535
Default coded character set identifier . . . . . : 37
Character identifier control . . . . . . . . . . : *DEVD
Job message queue maximum size . . . . . . . . . : 64
Job message queue full action . . . . . . . . . . : *PRTWRAP
Allow multiple threads . . . . . . . . . . . . . : *NO
Auxiliary storage pool group . . . . . . . . . . : *NONE
Spooled file action . . . . . . . . . . . . . . . : *KEEP

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When prompting the CHGFTPA command, I see:

Change FTP Attributes (CHGFTPA)
Type choices, press Enter.

Autostart servers . . . . . . . AUTOSTART > *YES
Number of initial servers . . . NBRSVR > 3
Inactivity timeout . . . . . . . INACTTIMO 300
Coded character set identifier CCSID 00819
Outgoing EBCDIC/ASCII table: TBLFTPOUT
Outgoing EBCDIC/ASCII table . *CCSID
Library . . . . . . . . . .
Incoming ASCII/EBCDIC table: TBLFTPIN
Incoming ASCII/EBCDIC table . *CCSID
Library . . . . . . . . . .
Initial name format . . . . . . NAMEFMT *LIB
Initial directory . . . . . . . CURDIR *CURLIB
Initial list format . . . . . . LISTFMT *DFT
New file CCSID . . . . . . . . . CRTCCSID *CALC
Subsystem description . . . . . SBSD QSYSWRK
Library . . . . . . . . . . . QSYS

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Question:

When I interactively run an FTP script from the Power system to do an MGET
from a Sterling Integrator FTP server, I notice that the file(s) received
get tagged with CCSID(500).

Given the above information, why is the system determining that CCSID(500)
is the correct CCSID to use? I would expect CCSID(37)...

Regards,
sjl