Author Topic: RF-Protection filter for DSL-Modems  (Read 3312 times)

dk3pz

  • Newbie
  • *
  • Posts: 14
    • View Profile
    • QRZ.COM
    • Email
RF-Protection filter for DSL-Modems
« on: 2013-02-05, 21:06:52 »
For AVM Fritz!Box I have to use PIN 4 and 5 from RJ45 for the DSL Signal.
Is there a strapping area for configuration inside of the filter box ? 73, Hans

sm2o

  • Administrator
  • Hero Member
  • *****
  • Posts: 2505
    • View Profile
    • sm2oan
    • Email
Re: RF-Protection filter for DSL-Modems
« Reply #1 on: 2013-02-05, 22:25:50 »
Hi

The phone line is connected to the two pins in the middle of the connectors. It's the same pins as in   in your fritzbox, but the connector is RJ12 (4/6 modular) not 8 pin so you need to change cables or at least connectors.

73 de mike

dj0qn

  • Hero Member
  • *****
  • Posts: 1883
    • View Profile
    • DJ0QN / K7DX
    • Email
Re: RF-Protection filter for DSL-Modems
« Reply #2 on: 2013-02-06, 00:15:52 »
Mike,

Since the Fritz!Box has a >50% market penetration in Germany, we should quickly have a simple
example of what one must do to hook this up. A link to the right cable or adapter at Conrad or
Reichelt would probably be best. If anyone can take a look, that would be great.

73,
Mitch DJ0QN / K7DX

sm2o

  • Administrator
  • Hero Member
  • *****
  • Posts: 2505
    • View Profile
    • sm2oan
    • Email
Re: RF-Protection filter for DSL-Modems
« Reply #3 on: 2013-02-06, 06:59:26 »
I had no idea about it, all modems I have seen have RJ12 connector. What kind of connector is the fritzbox, using in the wall end of the cable ?

Maybe this is what is needed both, from wall/splitter to the filter and from the filter to the modem ?


http://www.conrad.de/ce/de/product/922652/VERBINDUNGSKABEL-RJ45-AUF-RJ11-3M

/mike
« Last Edit: 2013-02-06, 07:45:46 by sm2o »

dk3pz

  • Newbie
  • *
  • Posts: 14
    • View Profile
    • QRZ.COM
    • Email
Re: RF-Protection filter for DSL-Modems
« Reply #4 on: 2013-02-06, 08:36:32 »
Hi Mike and Mitch,
tnx fr quick answer.
fritzbox is equipped with RJ45 at the DSL input; it is very useful because you can take a cat6 cabel for the connection which is much better than the original line cable. A cableoffer from your side would be fine to keep the length as short as possible ! 73, Hans

dj0qn

  • Hero Member
  • *****
  • Posts: 1883
    • View Profile
    • DJ0QN / K7DX
    • Email
Re: RF-Protection filter for DSL-Modems
« Reply #5 on: 2013-02-06, 11:32:53 »
Also from my side thanks, Mike, that looks correct.

One would need two of these cables for connecting to an analog line, one on each side of filter.

For an ISDN connection, it is a bit more complex, because you must use the Y-cable that AVM
supplies with the Fritz!Box. In that case, you would need one of these cables between the filter and
splitter. To connect the Y-cable to the filter, you need some sort of adapter that accepts the RJ45
from the Fritz cable on one side and an RJ12 on the other side.

I could not find such an adapter on the Conrad web site, however I remembered that the standard
RJ45 receptacles usually accept an RJ12 connector as well. Therefore, I believe that a standard RJ45
coupler will do the trick. Just plug the Fritz RJ45 plug on one side and use any standard RJ12 analog
telephone cable on the other side (or of course a 2nd cable as above would work as well). In case you
don't know what I mean, here is an example:
http://www.conrad.de/ce/de/product/922723/WESTERN-ADAPTER-64-SW
No guarantee that this will work, but I believe it will. I can try it some day with my ISDN line and Fritz!Box
when I can borrow a filter.

73,
Mitch DJ0QN / K7DX