I recently (Jan 2012) acquired a MacBook Pro (MBP) running 10.7.4 and an AirPort Express. I also have an old PPC G4 tower (Digital Audio model) running 10.4.11. The OS software on both machines is totally up to date. AirPort Utility on the G4 is 5.4.2

Question

I recently (Jan 2012) acquired a MacBook Pro (MBP) running 10.7.4 and an AirPort Express.  I also have an old PPC G4 tower (Digital Audio model) running 10.4.11.  The OS software on both machines is totally up to date.  AirPort Utility on the G4 is 5.4.2 and on 6.0 on the MBP.  I bought a used AirPort card for the G4, I believe it is 802.11b compatible, and the wireless data rate is specified at 11 Mbps.  Being a newbie to wireless, it took me many days to get these two machines to link up.  This network is not connected to the internet, and there no other networks in the vicinity.
My last problem to solve is the very slow file transfer speeds between the two machines. The transfer time seems to vary depending on which machine I use to initiate the transfer, and which direction the transfer is going.  For example: If I initiate the transfer from the G4 and send a 5.4MB file to the MBP it takes 1:32 (min:sec), while the same file going from the MBP to the G4 takes 27 seconds.  On the other hand if the transfer is initiated on the MBP, going from the MBP to the G4 takes 2:56, while going from the G4 to the MBP takes 1:59.  I realize that these times are not actual wireless transfer times but includes the entire transfer process.
Both machines and the AirPort Express are within a 4-foot radius.  Both machines are set to radio channel 2.  The AirPort Express is set for 802.11n(802.11b/g compatible) with WPA/WPA2 Personal wireless security.
Any help would be appreciated.
CEU2

Answer 1

BDAqua,
Thanks for the response.
Apple has used the term "Digital Audio" to identify this machine.  System Profiler has the following information:
Machine Name:          Power Mac G4
  Machine Model:          PowerMac3,5
  CPU Type:          PowerPC G4  (2.1)
  Number Of CPUs:          1
  CPU Speed:          800 MHz
  L2 Cache (per CPU):          256 KB
  Memory:          768 MB
  Bus Speed:          133 MHz
  Boot ROM Version:          4.3.3f2
  Serial Number:          XBxxxxxMK9
  Sales Order Number:
Yes, I could connect them by ethernet if all I wanted to do was transfer files, but I would like to network them so I could use wireless internet.  The machines are not always so close together, I did that to simplify the testing.  With the very slow transfer speeds I am reluctant to move ahead with the internet step. 
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