ange-ftp and passvie mode

[Harry Putnam]

My ftp client defaults to passive mode.  The -p flag sets passive
on, so I see no way to start the client with passive off.  Other than
giving the PASV command once it is started.

I have one host that is different from any others I use.  That host
won't work with ange-ftp.  It does work with the command line ftp
client if I switch off passive mode.

So... What is the easiest way to switch off passive mode when using
ange-ftp? That is, how can I pass a command to my ftp client when
calling it with ange-ftp?  None of the M-x ange-ftp-<spc> completions
look like they do that.

Currently, calling ange-ftp on this particular client just hangs and
never gets to a password prompt.

  /ftp:reader@MY_HOST:/

Just hangs.

That same syntax works on all other hosts I've tried.