POTS line CallerID Problem

[tstuart]

We have 4 lines all with CallerID connected to a high end piece of equipment. 2 of the lines pass CallerID without issue, while the other 2 do not.
We were able to fix one of the lines by putting 300 Ohm resisters on each wire in one of the non working lines. However we still have one line that will not pass callerID to our equipment. We tried 100 Ohm upto 2k on the non-working line and had no luck!
CallerID does pass to a consumer phone, and to a cheap callerID box. For this reason we cannot get TELUS to look at the line. Even if we paid all they do is hook a cheap callerID box to the line as a test. They have checked the programming and said all is right in the world.
Does anyone know of any tests I could try, or a company I could hire to test the lines properly?
These are straight POTS lines.
We have ruled out our equipment, if we connect one of the known good lines callerID works just fine! The missing callerID follows the line...

[mitigator]

Tstuart if your line is a "hot Line" ie very close in the City to the Telephone Central Office typically a line less than 3 dB Circuit Loss, then you will need to Pad the Line Down which is what it looks like your trying to do with those Resistors. At MTS we used a Device called an "OPTO-TECH 97A5 Adapter which inserted a 4 dB Pad in series (with modular telephone Jacks in and out) with the Device you are trying to get to work. Not sure if Opto-Tech is still around but you can try Google. They made Pads from 1 dB up to 8 dB. Try that for now - hope this helps.

[hugh]

Who knew? Mitigator thanks for the very informative reply. It's always great when readers help others.

[timmaywpg]

If you have no luck finding the opto-tech attenuator, I can also recommend Mike Sandman's attenuator products http://www.sandman.com/attenuate.html.

[mitigator]

Thanks Hugh, (I worked a lot on Caller ID problems & Telephone Problems in the past). Timmaywpg, in my opinion those products by mike sandman in Chicago are a bit too bulky and very pricy ie $24.00 US dollars each. What Business & Local Customers need for these type of problems is something light, portable, and easily inserted in series with a device, ie Fax, or Modem etc and most importantly a lot cheaper than mike's solution. The Opto - Tech 97A5 Adapter meets all these requirements (if they are still in production).

[mbhydro]

Here is the web link to the Opto - Tech attenuator pad devices.

They are now made by Wilcom. http://www.wilcominc.com/Item.cfm?ProdID=103

[Jake]

Could you also attenuate the signal with a device with a high load number?

[mitigator]

Mbhydro, wow has the price of the Wilcom 97A5 Attenuator ever gone up, they used to be around $8.00 each but now $35.00 - unbelievable!!

Jake the Load Number of the device should not matter for the 97A5 Adapter. Load Number does limit the number of devices ie phones allowed on a Telephone Line to allow the Phones to be able to Ring. Depending on the Device you are trying to attenuate a Load Number of up to 100 would maybe cause Ringing Problems, but most of todays Electronic Phones, Faxes, etc have a Load Number well under 10 and most under 1.0. Also Ringer Equivalence Number (REN) is usually stamped on the back of most Phones or Devices and the Max REN allowed is 5.0 on a line, - this is equivalent to a load number of 100.