ORA-28545 config issue

followed this script to try to query postqresql from an oracle server:
https://dbaspot.wordpress.com/2013/05/29/how-to-access-postgresql-from-oracle-database/
and having some trouble.

oracle server: Database Patch Set Update : 11.2.0.4.160119
postgresql server: 9.4.6

oracle> rpm -qa | grep -i odbc
postgresql95-odbc-09.05.0100-1PGDG.rhel6.x86_64
oracle > rpm -ql postgresql95-odbc-09.05.0100-1PGDG.rhel6.x86_64
/usr/pgsql-9.5/lib/psqlodbc.so
/usr/pgsql-9.5/lib/psqlodbcw.so
/usr/share/doc/postgresql95-odbc-09.05.0100
/usr/share/doc/postgresql95-odbc-09.05.0100/license.txt
/usr/share/doc/postgresql95-odbc-09.05.0100/readme.txt

--
oracle> cat .odbc.ini
[ODBC Data Sources]
   PG_LINK = PostgreSQL
[PG_LINK]
   Debug = 1
   CommLog = 1
   ReadOnly = no
   Driver = /usr/pgsql-9.5/lib/psqlodbc.so
   Servername = pghost
   FetchBufferSize = 99
   Username = pguser
   Password = pgpass
   Port = 5432
   Database = mydb
[Default]
   Driver = /usr/lib64/liboplodbcS.so

--
listener.ora
-------------
SID_LIST_LISTENER =
   (SID_LIST=
       (SID_DESC=
          (SID_NAME=PG_LINK)
          (ORACLE_HOME=/apps/database/oracle/product/11.2.0)
          (PROGRAM=dg4odbc)
       )
   )


LISTENER =
   (DESCRIPTION_LIST =
     (DESCRIPTION =
       (ADDRESS = (PROTOCOL = TCP)(HOST = orahost)(PORT = 1521))
       (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
     )
   )

ADR_BASE_LISTENER = /apps/database/oracle/product


--

oracle> cat initPG_LINK.ora
HS_FDS_CONNECT_INFO = PG_LINK
HS_FDS_TRACE_LEVEL = 0
HS_FDS_SHAREABLE_NAME=/usr/pgsql-9.5/lib/psqlodbc.so
set ODBCINI=/apps/database/oracle/.odbc.ini

--

tnsnames:
----------
PG_LINK  =
   (DESCRIPTION=
     (ADDRESS=(PROTOCOL=tcp)(HOST=pghost)(PORT=5432))
     (CONNECT_DATA=(SID=PG_LINK))
     (HS=OK)
   )

--

listener status:
-----------------
Services Summary...
Service "PG_LINK" has 1 instance(s).
   Instance "PG_LINK", status UNKNOWN, has 1 handler(s) for this service...

(asks himself why the oracle listener needs a service...it's not
answering requests???  clueless me)

--

created db link in ora:
-----------------------
create database link PG_LINK connect to "pguser" identified by "pgpass"
using 'PG_LINK';


SQL> select count(*) from mytable@PG_LINK;
  select count(*) from circuit_tracking_event@PG_LINK
                                              *
ERROR at line 1:
ORA-28545: error diagnosed by Net8 when connecting to an agent
Unable to retrieve text of NETWORK/NCR message 65535
ORA-02063: preceding 2 lines from PG_LINK

any clue will do....