sundance-communications.com/forum Forums General General Telephone & Systems Information RFI on 4 line phones

Any time we have had RF a Sandman filter has been the cure. Good luck your going to need it.

You know, Hal, you are probably right. That reminds me of a site that we adopted with an existing Merlin Plus. They were two blocks down the street from an AM Hispanic station, plenty of party music. That was the complaint; unwanted background music.

I guess that white-brown pair being an open audio input into the set's amplifier meant that it wouldn't take much for RF to get picked up. After many years, we replaced the Merlin, but now that I think back, I'll bet that if we just put filters on the fourth pair, instead of all four, we could have saved a lot of money and frustration.

I had a noise problem on our DID's some time ago, and I found a company in Oskosh, WI called SNC Manufacturing Inc. They have a long line of noise chokes and filters.

Check them out, it worked out for me.

Well, the customer gave up too, she sent the phones back & got more of her old GE 4liners.
They don't have RFI.

why didnt you use the oppurtunity to sell her some REAL phones ?

I think Ed and Skip555 have the right idea. Sandman's filters solved my problem on a real system but they didn't help on the 4 line sets.

Had a customer with Merlin 1030 that picked up a local station only on BIS sets,( no problem with membrane ) Put an RF filter on WH/GR pair, no more music. Picked up the same station on a piece of cheap 4 conductor running the length of a warehouse with an old rotary butt set even without dialtone on the line! I've had luck using RF filters on 2 line phones, but never eliminated it completly.

On systems very near transmitters (a few hundred yards) you can have what's called a 'saturated ground field'. This means that the land itself has RFI - if you drive a ground rod a couple of feet into the ground, then 'ground' the shielded cable you just installed to try to correct the problem, it only gets worse. In this case, you need a real ground rod - at least 6 feet, the longer the better. It has to do with local soil conditions - lack of moisture, layers, etc. - sort of 'insulating' the top few feet from deeper, 'true' ground.

How come if I (as a Ham Radio Operator) come over someones phone I have to fix it. If the radio station does it, its your fault???

I think Ed need to address this when he is elected.

I couldn't agree with you more. If a plant's emissions of gases, fumes, noise, traffic or otherwise unacceptable by-products occur, they have to take the steps necessary to correct them. (Bakeries don't apply).

Why not radio stations?