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[JeffVolp]

Now that there are a bunch of XTBM signal meters in the field, I'm getting reports that X10 filters are actually lowering signal levels.  While I first thought that maybe this was a measurement error, I did confirm it myself.

With the house being driven by the new XTBR repeater, I monitored the signal level on my weakest X10 circuit.  Then I connected several different X10 filters to an adjacent receptacle on that circuit.  I also used two different values of capacitors for examples of typical signal suckers.  The test was repeated several times.  Here are the results:

   4.35Vpp – signal level with no filter
   4.35Vpp – signal level with X10 XPPF filter plugged in
   3.75Vpp – signal level with Leviton 6287 connected to the receptacle
   4.07Vpp – signal level with X10 XPF black lead connected to the receptacle
   4.19Vpp – signal level with X10 XPF red lead connected to the receptacle
   3.75Vpp – signal level with 0.1uF connected across the receptacle
   1.99Vpp – signal level with 1.0uF connected across the receptacle

Note that there was no effect at all from the X10 XPPF low-pass filter.  Its highest break frequency is 26KHz, so it will be well down at 120KHz.

Both the Leviton 6287 and the XPF are notch filters.  The schematic of the 6287 shows it is tuned to the high side of the X10 carrier frequency, which is why it does present some loading to X10 signals.  However, with its internal 1.0uF shunt to neutral, it is a very effective noise attenuator.  This X10 XPF is apparently tuned closer to the X10 carrier frequency, so it presents minimal loading.  However, tolerance of the components can shift the notch frequency.  So other samples of the same filters could produce different results.

In summary, the X10 XPPF should present negligible loading of the X10 signal.  Notch filters, such as the XPF, AF120, AF300, and 6287, may present some loading, depending on how closely they are tuned to the 120KHz X10 carrier frequency.

Jeff

[Brian H]

Thank you very much for the data on filters. Helpful from me.

I thought the XPPF and Leviton 6287 where basically the same with different labels. Looks like this is not true.

Also the XPPF; though rated at five amps; seems to get very warm with a five amp resistive load. I started melting the coil bobbins in a five amp test on one.

[JeffVolp]

I thought the XPPF and Leviton 6287 where basically the same with different labels. Looks like this is not true.

Also the XPPF; though rated at five amps; seems to get very warm with a five amp resistive load. I started melting the coil bobbins in a five amp test on one.

They are totally different animals.  The 6287 is essentially a "mini" version of the XPF.

The XPPF has three 115uH inductors in series with the load, and the 6287 just two 7.0uH inductors.  It takes far fewer turns for 7.0uH, so those inductors have much lower resistance, resulting in less heating.  They may also be wound with heavier wire.  All the higher current filters are notch filters so they can use low value inductors in parallel-resonant traps.

Jeff

[Brian H]

  Fading memory at work.
6288 and XPPF look the same 

[JeffVolp]

6288 and XPPF look the same 

Yes, the ones I opened up were virtually identical.

Jeff

[-Bill- (of wgjohns.com)]

JeffVolp,

Better late than never!  A helpful from me too!