[ACARS] ACARS Receiving

[Carlos Abreu]

Hi List

Could anyone help me with the following problem (?):

Since a 1999 I monitorize ACARS 24H per day, I live less than 10 miles from
Lisbon International Airport (Portela LPPT/LIS), normaly I pick up around
2000 messages (and sometimes 3000 & more) using a Notebook Toshiba Satellite
4070 CDT connected to a Radio Shack PRO-29 scanner, a Watson WRP-125
amplifier, a AOR ABF 125 filter for airband and a Radio Shack internal
antenna with 9 extended sections.

However during some days with excepcional summer weather like today with
clean sky, a very high temperature and no humidity my receiving messages
decrease for only an hundred or a little more than that...
All uplinks are missing (?) I jus pick up some downlinks (?).

It is a rare situation but isn't the first time it happens, I lived in a 5th
floor that in a high place that is good for reception signal, from my large
window I can see all final approach to runaway 03 from LPPT, as a ex-SITA
staff I called my friends from OPR dept and they confirmed to me that no
maintenance was made in Aircom antenna in the airport and the system was
working fine, I checked the equipment and it's everything ok, no wires were
moved, the apartment is climatizated what means no problems with equipment
performance, there�s any physical external interference...I can't undersatnd
this !!!

Can any list member give an opinion about this or shared any knowledge about
this strange phenomenon.

Many thanks in advance and best regards.
Carlos