Explain This Regarding Dual Band Devices

[apostolakisl]

After a couple of years of having vague comm problems I actually decided to find and fix it. Well, I think I succeeded. I found one breaker with a couple of refrigerators on it that when I shut the breaker down, I get perfect scene test results. Yeahhh.

 

I decided to install 4 dual band devices and upgrade to a dual band PLM as part of my system robustness plan. I have 3 branch panels in the house. I put the ISY on one panel and used a hardwired phase coupler at the box to take it over to phase 2. I then took my dual band switches and identified switches that would put one of each of those 4 on each leg of the other 2 boxes. This should not really be necessary, but it should greatly shorten the length of wire the signal has to run to get to switches around the house (The master breaker panel is down by the street over 100ft away).

 

OK, now is the question. One of my scenes "dining rm" has three switches controlling the chandelier. I replaced one of those three with a dual band device. The device is directly below the plm (plm on second floor). It might be 15 feet away at most with nothing but drywall and wood in the way. That switch still fails the scene test! When I shut the breaker off to the noisy/sucker circuit, it succeeds. To me, it is as if the RF is not sending anything. It should be 0 hops to get to that switch.

 

Ideas/explanations?

 

PS The switch does blink when I do the "4 tap" on the PLM

[Brian H]

I know the antenna in the 2413S is a vertical one so it sends and receives in a horizontal plane.

Not sure about the Dual band Switch you added. If it also sends in a horizontal plane. The switches RF is not going down to hit the 2413S antenna.

 

Also if the Switch is in a metal electrical box. It can modify the RFs sending and receiving path.

 

What model Dual band Switch? I have some internal photos from the FCC site and it may show the RF antenna.

 

How about the other way around with the communications test. If you start it on the switch in question. Does the PLM indicate it is seeing the RF?

 

My 2413S has a poorer receive than my 2443 Access Points. If I start the test on the PLM. One Access Point sees it. If I start the test on the same Access Point. The PLM does not see it.

[Teken]

After a couple of years of having vague comm problems I actually decided to find and fix it. Well, I think I succeeded. I found one breaker with a couple of refrigerators on it that when I shut the breaker down, I get perfect scene test results. Yeahhh.

 

I decided to install 4 dual band devices and upgrade to a dual band PLM as part of my system robustness plan. I have 3 branch panels in the house. I put the ISY on one panel and used a hardwired phase coupler at the box to take it over to phase 2. I then took my dual band switches and identified switches that would put one of each of those 4 on each leg of the other 2 boxes. This should not really be necessary, but it should greatly shorten the length of wire the signal has to run to get to switches around the house (The master breaker panel is down by the street over 100ft away).

 

OK, now is the question. One of my scenes "dining rm" has three switches controlling the chandelier. I replaced one of those three with a dual band device. The device is directly below the plm (plm on second floor). It might be 15 feet away at most with nothing but drywall and wood in the way. That switch still fails the scene test! When I shut the breaker off to the noisy/sucker circuit, it succeeds. To me, it is as if the RF is not sending anything. It should be 0 hops to get to that switch.

 

Ideas/explanations?

 

PS The switch does blink when I do the "4 tap" on the PLM

 

I can tell you from personal experience that *IF* noise / signal suckers are present. All the dual band devices won't make a difference in making a switch, outlet, sensor, operate 100%. As discussed in another thread you and I had about how to test, and how to confirm *IF* the RF portion does in fact take over when a PLC can not.

 

My personal experience is that it can very from OK, marginal, to nothing.

 

I can safely state this as fact in my own environment as I was able to reproduce these results by using a MP3 charger, and a laptop charger for my netbook. In each case the RF was not able to bridge the comm issues.

 

To be fair to all parties: All of the dual band devices are installed into metal J box's. The reality is that this sort of thing should be taken into consideration anyways, regardless of plastic or metal J box's being used. I was able to move a spare dual band PLM around the house to confirm opposite legs, or same circuits.

 

As others have indicated, you can make a dual band device do the bridging test, but the reverse is not always true of the PLM?? Even though my Insteon network is rock solid, I take some of this so called dual band mesh network stuff with a grain of salt.

 

My position remains the same: Identify all known noise / signal suckers. Bridge both legs of the single phase circuit of the electrical system with in the home. Ideally as close to the main panel as possible. From there, ensure a even distribution of all AP devices so the longest direct line of sight is less than 50 feet.

 

Lastly, deploy dual band devices in all four corners of the home, levels, and areas with physical barriers . . . Of the 35 installs I have been part of, these basic rules and guide lines have not once left me high and dry at all.

 

The most time consuming, and hard part in all of this HA lifestyle has been making the user accept that a bulk of their costs will be in filtering, and removal of devices in their life / home environment.

 

Teken . . .

[gatchel]

The most time consuming, and hard part in all of this HA lifestyle has been making the user accept that a bulk of their costs will be in filtering, and removal of devices in their life / home environment.

 

Teken . . .

It would only take a manufacturer that would actually develop and test a quality product BEFORE releasing it to the masses.

 

We'll probably never see it happen. There is such a thing as 100% but to a manufacturer 90% to 95% is acceptable.

[Brian H]

Teken; Thanks for your valuable findings. My install is quite small so somethings I have never seen full hand.

I also believe Dual band can help in some instances, but is no Magic Bullet to fix everything.

[apostolakisl]

To clarify,

 

Both the PLM and dual band switches are brand new from SH. I bought them on that 20% sale last week.

 

The switch is not in a metal box. As I mentioned, just drywall and some wood and about 15 feet (and a little plastic). And the unit blinks when I set the plm into 4-click test mode. It has to be that the unit would only blink if it were getting RF. I can't prove this, but it just would seem rediculous to have it blink if it were not getting RF signal on a test of the RF system. I suppose it could be proven by putting the switch inside a faraday cage, but I don't have one.

 

It is my opinion that a dual band device should work 100% regardless of PLC issues if it is in RF range. Isn't that the point?

 

I don't know for sure what a "scene test" does. It appears to send a command to each device with a 1 hop limit and then test if it gets a response. I should think that RF or PLC wouldn't matter. If the switch and PLM are in direct RF range, it should be zero hop both ways.

[Teken]

And the unit blinks when I set the plm into 4-click test mode. It has to be that the unit would only blink if it were getting RF. I can't prove this, but it just would seem rediculous to have it blink if it were not getting RF signal on a test of the RF system.

 

It is my opinion that a dual band device should work 100% regardless of PLC issues if it is in RF range. Isn't that the point?

 

One would think, this would be a very easy test to perform and then confirm. As you clearly see this is not a easy task to be 100% certain.

 

Also, as far as I am aware the blinking on any dual band device only indicates opposite legs, or same legs. It does not how ever state 100% fact that the communication is indeed RF, and is being bridged via RF.

 

Teken . . .

[LeeG]

There is a PLM serial command specifically for initiating a Scene. The ISY supplies the Scene (Group) number and nothing else. Everything associated with the Scene protocol is executed by the PLM. This includes sending the initial Group Broadcast to all devices simultaneously as well the follow-up Group Cleanup Direct messages sent to each Responder linked to the Scene. Also all retries, bumping of the maximum hop count on each subsequence Group Cleanup Direct when the previous fails to get a Responder device ACK. All of this is driven by the PLM firmware, independent of any ISY action.

 

Normal Scene control when initiated from a Program or Admin Console is done using a different PLM serial command that explicitly sends a Group Broadcast message created by the ISY rather than the PLM.

[Brian H]

I believe the communications test does check for an RF signal.

I have a 2413S and a 2443 on the same branch circuit. One in the back of the house the other in the front. With a straight line between them front to front orientation.

If I start the test from the 2443 and look at the 2413S. It flashes red as it is on the same phase.

If I hold a piece of aluminum foil in front of the 2413S. It stops red flashing and goes to solid green.

[LeeG]

Teken

 

What is in the Smarthome documentation that indicates it could use a powerline signal for the 4 tap test?

 

Lee

[apostolakisl]

And the unit blinks when I set the plm into 4-click test mode. It has to be that the unit would only blink if it were getting RF. I can't prove this, but it just would seem rediculous to have it blink if it were not getting RF signal on a test of the RF system.

 

It is my opinion that a dual band device should work 100% regardless of PLC issues if it is in RF range. Isn't that the point?

 

One would think, this would be a very easy test to perform and then confirm. As you clearly see this is not a easy task to be 100% certain.

 

Also, as far as I am aware the blinking on any dual band device only indicates opposite legs, or same legs. It does not how ever state 100% fact that the communication is indeed RF, and is being bridged via RF.

 

Teken . . .

 

How would the unit know if it were on the same leg or opposite leg if it weren't receiving both RF and PLC?

 

Aluminum foil test. Ahhh, the poor man's faraday cage. I like it.

 

Seems like that would confirm RF must get through for the 4-tap to work.

 

Which brings me back. How could a scene test between a dual band plm and dual band switch within RF range ever fail?

[Teken]

And the unit blinks when I set the plm into 4-click test mode. It has to be that the unit would only blink if it were getting RF. I can't prove this, but it just would seem rediculous to have it blink if it were not getting RF signal on a test of the RF system.

 

It is my opinion that a dual band device should work 100% regardless of PLC issues if it is in RF range. Isn't that the point?

 

One would think, this would be a very easy test to perform and then confirm. As you clearly see this is not a easy task to be 100% certain.

 

Also, as far as I am aware the blinking on any dual band device only indicates opposite legs, or same legs. It does not how ever state 100% fact that the communication is indeed RF, and is being bridged via RF.

 

Teken . . .

 

How would the unit know if it were on the same leg or opposite leg if it weren't receiving both RF and PLC?

 

Aluminum foil test. Ahhh, the poor man's faraday cage. I like it.

 

Seems like that would confirm RF must get through for the 4-tap to work.

 

Which brings me back. How could a scene test between a dual band plm and dual band switch within RF range ever fail?

 

That is my key point. The device is confirming same leg, or opposite leg via PLC. The only true test I would accept is IF there was a wireless AP or similar device which replied back in kind.

 

There is no Insteon document that states that I have read that says RF is sent by itself. Only that it is sent simultaneously (together) with PLC.

 

Now it does state that it does exchange RF to powerline, and the other way around.

 

Which, in this case is clearly not helpful, or even in play here to assist the signal to carry forward to the next dual band device.

 

I have tested this same behavior over 34 times tonight, and not once has the dual band mesh even helped with the new dual band KPL relay, to the opposite side. only 10 feet away.

 

All the while my mp3 charger was plugged in.

 

Really?? Dual band?? Simultaneously?? Where is it??

 

At the end of the day my belief is that the primary signal is being carried via PLC, and the RF portion really is not at play as some would expect, or suggest otherwise.

 

Teken . . .

[Teken]

Teken

 

What is in the Smarthome documentation that indicates it could use a powerline signal for the 4 tap test?

 

Lee

 

The SH documents that using a AP will couple / bridge both legs via RF wireless signal. If so, why then will it not talk to another dual band device only 10 feet away??

 

If this is only via RF using a AP, than my expectation would be that the AP with its higher power output and free air would communicate to the other device(s) with out falter.

 

My limited testing tonight negates this RF mesh aspect as being at play here.

 

Teken . . .

[Brian H]

I got out my hand held scanner and tuned it to 915MHz and didn't hear any signals from my V2 Access Points or 2413S PLM.

Then I went to the FCC site and found out those modules use 914.940MHz.

My scanner only does 12.5MHz spread in the 900MHz band so it picked 914.9375.

I could hear the data burst while doing varied things.

Now the RemoteLinc I have was not heard at 914.9375MHz but was at 915.000MHz. Which is what the FCC said it was.

[Teken]

I got out my hand held scanner and tuned it to 915MHz and didn't hear any signals from my V2 Access Points or 2413S PLM.

Then I went to the FCC site and found out those modules use 914.940MHz.

My scanner only does 12.5MHz spread in the 900MHz band so it picked 914.9375.

I could hear the data burst while doing varied things.

Now the RemoteLinc I have was not heard at 914.9375MHz but was at 915.000MHz. Which is what the FCC said it was.

 

What does this limited testing indicate to you?

 

Teken . . .

[IndyMike]

Very interesting subject....

 

I would, however, suggest that we do not fully understand how RF transceivers perform when confronted with both Powerline and RF communications. Unfortunately, this may also vary with the firmware/hardware of the device in question.

 

The following are the results of tests that I've performed over the "years". Take them with are grain of salt as they are hardware version specific. Newer unit revisions could easily perform differently.

Data Point 1: Rev 1.0R Accesspoints - Linking test

1) With my passive coupler installed my Accesspoints fail the phase test regardless of where they are installed. I have all of my circuits mapped and know exactly what outlets are on which phase.

2) Removing the coupler allows the accesspoints to "somtimes" indicate they are on the opposite phase. If a 220V device is on, they will always indicate the same phase.

3) Installing the devices on the same phase with filters between them will cause them to indicate the OPPOSITE phase.

 

Conclusion - The AP's are performing a powerline signal level test. If they can communicate on the powerline, they will indicate they are on the same phase.

 

Data point 2:Rev 1.5 2457D2 - Dual band LL Linking

1) Devices correctly indicate the opposite phase regardless of whether my coupler is installed (or 220V devices are on).

2) Devices correctly indicate the same phase even when one is filtered.

 

Conclusion - The DB LL's are comparing the powerline vs communication phasing. They correctly deduce the opposite phase regardless of loads or filtering.

 

Data Point 3: Isolated Dual Band PLM Test - 2413S V1.0

Isolated my ISY PLM on a doubled filtered power strip.

1) Verified total communication loss with no "other" RF device installed.

2) Verified 100% communication with a V1.0 accesspoint on the opposite phase. Ran my house for weeks in this configuration (i.e. I forgot about it).

3) The RF only configuration does result in a 1 HOP loss in communications.

 

Conclusion - the Dual Band PLM is capable of operating in a RF only mode.

 

Data Point 4: 2477D V6.0 Dual band SWL on a noisy circuit.

 

1) Existing noisy circuit using a KPL dimmer with 8 60W equivalent CFL's. The capacitive loading of the CFL's produces huge impulse spikes on the powerline. As the dim level is reduced these spikes interfere with the Insteon communication to the KPL effectively taking it offline.

 

2) Replaced the KPL dimmer with the Dual band SWL dimmer. No noticable improvement in performance.

 

3) Isolated the Dual band SWL from the powerline (RF only). Inconclusive - partial communications to device. Adding the filtering to the Dual band input increased the impulse spiking locally at the switch (higher input impedance).

 

Conclusion - Simply replacing the KPL with the dual band unit resulted in no noticeable improvement. Attempting to isolate the device resulted in increased local noise, and as such, was an invalid comparison.

 

 

Note: None of the above testing answers the question - "What does a dual band device do when it is presented with both powerline and RF communications". While my testing indicates that devices can operate in powerline only or RF only modes, there has to be a "preference" in the firmware.

 

If the transceivers firmware has a "preference" for powerline data, noise corruption of that data could easily explain the results that Lou and others have observed. This preference could easily change, or may have already changed, with firmware revisions.

[Teken]

Very interesting subject....

 

I would, however, suggest that we do not fully understand how RF transceivers perform when confronted with both Powerline and RF communications. Unfortunately, this may also vary with the firmware/hardware of the device in question.

 

The following are the results of tests that I've performed over the "years". Take them with are grain of salt as they are hardware version specific. Newer unit revisions could easily perform differently.

Data Point 1: Rev 1.0R Accesspoints - Linking test

1) With my passive coupler installed my Accesspoints fail the phase test regardless of where they are installed. I have all of my circuits mapped and know exactly what outlets are on which phase.

2) Removing the coupler allows the accesspoints to "somtimes" indicate they are on the opposite phase. If a 220V device is on, they will always indicate the same phase.

3) Installing the devices on the same phase with filters between them will cause them to indicate the OPPOSITE phase.

 

Conclusion - The AP's are performing a powerline signal level test. If they can communicate on the powerline, they will indicate they are on the same phase.

 

Data point 2:Rev 1.5 2457D2 - Dual band LL Linking

1) Devices correctly indicate the opposite phase regardless of whether my coupler is installed (or 220V devices are on).

2) Devices correctly indicate the same phase even when one is filtered.

 

Conclusion - The DB LL's are comparing the powerline vs communication phasing. They correctly deduce the opposite phase regardless of loads or filtering.

 

Data Point 3: Isolated Dual Band PLM Test - 2413S V1.0

Isolated my ISY PLM on a doubled filtered power strip.

1) Verified total communication loss with no "other" RF device installed.

2) Verified 100% communication with a V1.0 accesspoint on the opposite phase. Ran my house for weeks in this configuration (i.e. I forgot about it).

3) The RF only configuration does result in a 1 HOP loss in communications.

 

Conclusion - the Dual Band PLM is capable of operating in a RF only mode.

 

Data Point 4: 2477D V6.0 Dual band SWL on a noisy circuit.

 

1) Existing noisy circuit using a KPL dimmer with 8 60W equivalent CFL's. The capacitive loading of the CFL's produces huge impulse spikes on the powerline. As the dim level is reduced these spikes interfere with the Insteon communication to the KPL effectively taking it offline.

 

2) Replaced the KPL dimmer with the Dual band SWL dimmer. No noticable improvement in performance.

 

3) Isolated the Dual band SWL from the powerline (RF only). Inconclusive - partial communications to device. Adding the filtering to the Dual band input increased the impulse spiking locally at the switch (higher input impedance).

 

Conclusion - Simply replacing the KPL with the dual band unit resulted in no noticeable improvement. Attempting to isolate the device resulted in increased local noise, and as such, was an invalid comparison.

 

 

Note: None of the above testing answers the question - "What does a dual band device do when it is presented with both powerline and RF communications". While my testing indicates that devices can operate in powerline only or RF only modes, there has to be a "preference" in the firmware.

 

If the transceivers firmware has a "preference" for powerline data, noise corruption of that data could easily explain the results that Lou and others have observed. This preference could easily change, or may have already changed, with firmware revisions.

 

IndyMike,

 

I can confirm data points 1 & 2 as well. With respect to your last test with the dual band KPL. My limited testing last night also suggests the RF portion is either not in play. Or there are priorities in the signal transmission.

 

One would also have to acknowledge that other factors are present. One thought is that the primary signal is sent via PLC and the RF aspect is simply clever marketing. Another is that the PLC & RF are being sent, but the PLC signal is taking priority.

 

Another possibility is that given a environment with noise / signal sucker(s) as IndyMike has suggested different firmware / releases may behave exactly as advertised with respect to the dual mesh network.

 

This is why I spent the extra money and research in finding older, to newer models of the AP devices to validate said thoughts. I am currently in the mist of a six month test to confirm, validate, or disprove any of my own personal thoughts.

 

Regards

 

Teken . . .

[apostolakisl]

Data Point 3: Isolated Dual Band PLM Test - 2413S V1.0

Isolated my ISY PLM on a doubled filtered power strip.

1) Verified total communication loss with no "other" RF device installed.

2) Verified 100% communication with a V1.0 accesspoint on the opposite phase. Ran my house for weeks in this configuration (i.e. I forgot about it).

3) The RF only configuration does result in a 1 HOP loss in communications.

 

Conclusion - the Dual Band PLM is capable of operating in a RF only mode.

 

 

Indymike,

 

I do not fully understand a scene test. But, I gather that it requires no more than one hop out and one hop back to succeed. I had a scene test fail when communicating to a dual band device from a dual band plm (both brand new). The 4 tap test on the PLM did light up the switchlinc, so I am feeling confident that it did get the message. You state 1 hop loss. Should this still not pass a scene test?

 

With your PLM isolated (filtered), did you try running any scene tests?

 

Perhaps dual band devices default to plc and only do the rf after a 3 hop failure?

 

I think tonight I will plug my PLM in behind my filterlinc and see what happens.

[oberkc]

I thought the scene test had a limited (fewer than allowed under normal communication mode) number of hops, but more than one. Three is what comes to mind.

[apostolakisl]

I thought the scene test had a limited (fewer than allowed under normal communication mode) number of hops, but more than one. Three is what comes to mind.

 

Just speaking from what pops up on my screen. Usually it says "max hops" and "hops left". Max hops typically lists as "1" but sometimes it will be different. I have no idea why it would not always be the same.

[IndyMike]

Lou,

 

This is going to be a long explanation - I apologize in advance...

 

 

I do not fully understand a scene test. But, I gather that it requires no more than one hop out and one hop back to succeed. I had a scene test fail when communicating to a dual band device from a dual band plm (both brand new). The 4 tap test on the PLM did light up the switchlinc, so I am feeling confident that it did get the message. You state 1 hop loss. Should this still not pass a scene test?

 

The one hop loss was related to "queries" and "device link table reads". These typically return "2 Hops remaining out of 3 max". Using RF only I get "1 Hop remaining out of 3 max". Please also note that I have a passive coupler at the PLM. I believe this saves a hop communicating to the opposite phase.

 

With your PLM isolated (filtered), did you try running any scene tests?

 

Yes I did, and they were successful with RF only coupling. Here we need to make a distinction between "requested HOPs" and what the PLM actually sends. The following is the scene test as I understand it:

 

1) The ISY sends a "scene on command". I believe this is performed using 3 Hops (happens so quick I can't catch it in the event viewer.

2) The ISY sends a "scene off command". Again I believe this is sent with 3 Hops.

3) The ISY sends a "acknowledge" request to the scene with a Max Hop count of 1.

4) The PLM begins interrogation each member of the scene with a Max Hop count of 1. If there is no response, the PLM will retry (up to 5 times) with an Increased hop count (up to 3). This is why you may sometimes see devices responding with max hops > 1 even though the ISY specified 1.

 

I just tried the "filtered" PLM test again (to make sure I didn't dream this). I have 2 Filterlincs in-line with the PLM, and 2 DB LL's on each phase. I receive 100% on the scene test, but 4 devices came back with "max hops =2" ( indicates the PLM was executing a retry). Not too bad for 40+ devices.

 

Perhaps dual band devices default to plc and only do the rf after a 3 hop failure?

Based on the Scene test above, the dual band devices will use RF on the first hop. Not sure what they do if PLC is present (my guess is they default to PLC).

 

I think tonight I will plug my PLM in behind my filterlinc and see what happens.

 

If you want to do this, please use 2 filterlincs in series. My PLM will communicate through a single filterlinc if there is a receiver nearby.

 

Edit - Please also make sure that you have a local RF transceiver(s) on both phases.

 

Edit2 - I performed the "isolated PLM scene test" on the entire house (100% response). That's the good news. The bad news is that my better half was home (I thought she had left for shopping). Having every light, fan, and appliance turn off and on really upset her (she may have thought she was "loosing it"). I confessed my sins, but may have lost my "automation privileges" as a result. In short, I've been a baaad boy (we'll senior anyway).

[apostolakisl]

Indymike,

 

I have a hard time putting what you say together with my experience.

 

I fail a scene test to a device that is just a few feet away (dual band plm/device). When I shut off a noisy circuit, the scene passes. In my mind this means the scene test wasn't using rf or rf adds extra hops that make it fail????

 

I suppose a noisy circuit could also confuse the dual band switch such that it doesn't recognize the rf either? But then, if that is possible, what is the point in having dual band?

[Brian H]

If the noise is making the device think there is power line traffic. It may just sit there a wait.

[IndyMike]

Lou,

 

This again may be related to your specific configuration and the firmware revision of the devices in use.

 

To be clear - I have no evidence that a dual band device can overcome local noise. The one test that I performed (#4) was inconclusive.

 

What I believe I can say is that a distant device that sees "no powerline signal" can communicate reliably purely through RF. The distinction is the "no powerline signal". If a device sees a noisy powerline signal, I can't prove what a device will do. I suspect it will rely on the noisy powerline signal.

 

Indymike,

I have a hard time putting what you say together with my experience.

 

I fail a scene test to a device that is just a few feet away (dual band plm/device). When I shut off a noisy circuit, the scene passes. In my mind this means the scene test wasn't using rf or rf adds extra hops that make it fail????

 

I suppose a noisy circuit could also confuse the dual band switch such that it doesn't recognize the rf either? But then, if that is possible, what is the point in having dual band?

 

In the above, the added Hop counts due to RF should not be a cause of failure by itself. If the PLM does not see a response, it will retry (up to 5 times) with added hop counts.

 

If the PLM see's a noise corrupted Powerline response, I do not know what the outcome will be.

 

Edit - Per Brian's note, 120 - 130 Khz noise on the circuit can fool Insteon devices into thinking there is valid communications occurring. I've injected noise using a signal generator and have effectively shut down my entire system. Fortunately, you can detect this via the "flashing leds" on your plug in devices.

[apostolakisl]

If indeed noise confuses the device, it would be quite a shame. It is a v.40 on ISY and my recollection is that it was 6.? on the device. The PLM v.98. Both are the ones SH is shipping now.

 

Perhaps I could open it up and smash whatever part it uses to pick up plc and leave the rf alone. Maybe not.

 

It seems like SH would be seriously remiss if they allowed a dual band device to be screwed up by line noise. That would elliminate at least 50% of the benefit of the RF. Phase coupling and picking up non-plc devices is a much easier problem to solve other ways as compared to noise ellimination.

 

I suppose I jury rig a filter to it and see if that changes it's behavior.