Brian Kantor <brian@ucsd.edu> (08/23/90)
Does anyone happen to remember the USOC or other ordering code for the widget used for bypassing phone line entry to radio transmitter buildings? Lemme spring this one on you: Ham radio repeaters on the 2m band are spaced 600 kHz between receiver and transmitter. About five miles from our repeater site is KOGO-AM, on 600 KHz. We didn't have a problem until the phone line was installed into our mountaintop site, but we've measured nearly a VOLT of 600 KHz KOGO on the phone line - seems that fifteen miles of rural phone lines will make a hell of an antenna. When combined with the very strong transmitter signal in the building, we get a mix that generates a weak carrier on the repeater station's input and it sits there and sings to itself. We've used one of the CORCOM power line EMI filters to bypass the telco line we have, but we're going to be ordering several new lines installed in the next few weeks and I'd rather have the "official" filter box if I can get it. Our installer wasn't able to find the ordering codes in his references. Thanx! Brian
brian@ucsd.edu (Brian Kantor) (08/24/90)
Many thanks to those who replied; the answer seems to be a 40BA capacitor at the protector and a 1542A inductor connecting block. Per BSP 500-150-100. Brian
larry@uunet.uu.net (Larry Lippman) (08/25/90)
In article <11242@accuvax.nwu.edu> brian@ucsd.edu (Brian Kantor) writes: > Does anyone happen to remember the USOC or other ordering code for the > widget used for bypassing phone line entry to radio transmitter > buildings? > We've used one of the CORCOM power line EMI filters to bypass the > telco line we have, but we're going to be ordering several new lines > installed in the next few weeks and I'd rather have the "official" > filter box if I can get it. Our installer wasn't able to find the > ordering codes in his references. What you want is generally referred to as a 1542AM Filter, which is used for radio frequency noise suppression on subscriber telephone lines. While this is the traditional WECO designation, the same type number is used by other telephone apparatus vendors, such as Suttle. GTE, as an example, calls it an SE1542 Suppressor Filter. This device is similar to a modular jack, but on a larger base with a potted toroidal dual-winding inductor. The modular jack version is the 1542AM, but a screw terminal-only 1542A is also available. Other vendors, such as Transcom, manufacture multiple units for simultaneous protection of several pairs. I can't easily help you with the USOC code, however. But if all else fails, and you *must* have the USOC code, let me know, since I do have a USOC handbook lying around somewhere. Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" {boulder||decvax||rutgers||watmath}!acsu.buffalo.edu!kitty!larry VOICE: 716/688-1231 || FAX: 716/741-9635 {utzoo||uunet}!/ \aerion!larry