A possible..possible..usually but not always fix...is to suck out the original phone line and use it to pull in Cat 5 or Cat 6 network cable., then hook the Cat 5 or Cat 6 up as you had the original phone wire. Its quite good at filtering out a lot of EMI. Not perfect of course..but actually quite good.
Hit up one of the network guys you see running around in the Network/Telephone service trucks for a partial box. Tell em a sob story and give him a $5 and they will generally cough up a decent quantity.
Most phone system guys have gone over to Cat5/6 now days for phone system wiring, least in the L.A. area where Crom knows what is running in the cable next to his.
The stuff used to be expensive, and now days by the box is nearly the same price as regular 4 pair phone cable.
Sometimes...if you have a 60 cycle hum on your phone..if you have the multiple conductor cable with the blu/white, or/white etc pairs..if you take an unused pair and run a jumper to a GOOD earth ground..it may knock out a bunch of the hum as well. Only ground the cable pair on ONE end. Never on both. Ground loops are another bitch of a subject...sigh
Gunner, Sr. Engineer for a data/communications company in another life....who still keeps his hand in the biz.
Gunner
"If thy pride is sorely vexed when others disparage your offering, be as lamb's wool is to cold rain and the Gore-tex of Odin's raiment is to gullshit in the gale, for thy angst shall vex them not at all. Yea, they shall scorn thee all the more. Rejoice in sharing what you have to share without expectation of adoration, knowing that sharing your treasure does not diminish your treasure but enriches it."
- Onni 1:33