Originally Posted by tylerSC
I am guessing you are trying to separate WJZ RF13 from Baltimore?
Nope. A senior living community in another market presently uses what are called "lifeline filters" to enable its non subscribers to watch just channels 2-13 for free, but their house channel is on cable channel 98, which believe it or not, is actually somewhere between the frequencies of channels 6 and 7. . When they were on franchised cable, regulation was accomplished by the cable company, which simply scrambled all of the subscription channels. Now they have stuffed twelve broadcast channels into 2-13, but those filters are long cylinders that combine a channel 13 lowpass filter with a midband reject filter that is incorporated into that filtering cylinder to eliminate cable channels 14-22 which are just below channel 7 at 120-174 MHz. Unfortunately, that filter apparently also eliminates cable channels 98 and 99, sometimes called A-1 and A-2, at 108 to 120 MHz.
In order to pass that house channel, they need to have a filter that inexpensively passes it at some frequency, and since they are trapping out the paid tier channels to about 30 non-subscribers, they need an inventory of about 50 of these filters, so I can't pay Tinlee or anyone a hundred dollars each. I yet ever visited this property but the maintenance engineer and I have done business for nearly twenty years as he has managed many other properties.
Thanks to a tip that was sent to me as a private message, I just bought enough such filters for my purposes at a close-out price, so I'm not looking for that item anymore. and I have ordered samples of two inexpensive midband reject filters to confirm that they will pass channel 98 (and do minimal damage to channel 7, as some midband reject filters are more damaging to channel 7 than are others).
But now, I do get to address another matter for this customer. Their headend was designed by a national company that did not perform a spectrum analysis for interference, and since this property is located just five miles from a broadcast tower farm, three of their co-called "clear" VHF channels must be looking like sandpaper wiped their screen on any TV where the shielding is not perfect, and since every market I have ever serviced has some bad midband channels, this customer might be best served by simply enabling the passing all twenty three channels that are below 216 MHz (2-13, 14-22 and 98), moving the three programs that are on noisy VHF channels into the midband, giving a few more "free" channels to non subscribers, like CSpan, CSpan2, maybe a free religious channel and a second house channel), and moving maybe ten channels up to vacant channel numbers above the highest channel they are using now, as there over a dozen presently unused, high numbered cable channels that have no broadcast interference in that market.