sundance-communications.com/forum Forums Other TDM Phone Systems ESI Telephones & Systems S-Class with RF Issues

I am installing an S-class at a location that has an AM radio station
next door. Three Towers surround the customer’s location. When we
put in the system we had static and crackling on all stations coming
from the speaker. When the phone goes off hook we can hear the
radio station being broadcast loud and clear. We installed .5 to 3 mhz (for am).
filters, this didn’t work. We tried installing a filter at both ends of the
station cable still no resolution. Has anyone here ever had to deal
with a situation such as this?
They have also purchased presents management
so I don’t know what is going to happen when we install the reader.

Thanks in advance for any info.

Put am filters on the co lines before they go in the
system. (Graybar has the am filters)

Had a similar situation with a Mitel SX200. It was resolved by replacing the power supply. Also, inspect your ground closely. Are you grounded to building structure? If yes then you may need to change the grounding location.

Another thought, how about phone lines at Dmark. Static there, Yes or No?

Check out mike sandman - they have a good tutorial on solving interference.

Make sure you have an isolated ground that is not shared by the AM towers and equipment. Make sure this is a 3 point ground that measure 5 ohms or less and if need - in addition to your filters use shielded cables for the CO lines and Phones.

grider there is interference at the demarc.

LaneComm what is a three point ground?

DId you check out the following tech bulletin

https://sandman.com/rfbull.html

It will cover your issue and suggested resolutions in detail.

Since you have interference at the Dmark prior to being fed into the system your probable solution is the filters previously recommended. Your ground is probably OK. I would place a call to the service provider and alert them to the problem, after all it is their responsibility to deliver you a "clean" line to work with. Who knows they might dispatch a tech with filters to install for you. Definitely bring it to someones attention such as customer contact. You are repairing someone else's problem which brings up another question. Did this customer choose a new phone system because of this particular problem or were there other factors?

John

WE INSTALLED A S-CLASS GEN II IN A AM RADIO STATION
LAST YEAR HAD REAL BAD RF ON PHONES AND FAX.WE PUT
ALLEN TEL TELEPHONE FILTER (PART NO. ATL100)ON THE
CO LINES BEFORE THEY GO INTO THE SYSTEM.ALSO RAN CAT5 CABLES TO EACH PHONE (PROBLEM FIXED).