Why would a DECT Panasonic cordless phone keep losing the wireless link?

Any idea why fully-charged DECT Panasonic cordless phones would keep losing their wireless link lately?

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They're not at all far (fifteen feet) from the base and, this loss of signal only started happening about a year ago (the phone is probably about three or four years old).

So, something clearly aged (but the batteries show as fully charged and I've changed them between handsets anyway).

The error I keep getting (on multiple handsets) is: No Link. Reconnect base AC adapter.

This happens after, say, a few minutes of talking time, but, it's erratic. Sometimes I can be on the line for an hour before it happens; other times it happens within five minutes.

What frustrates me is the lack of debugging techniques.

Reconnecting the phone to the charger doesn't change anything; nor does placing each of the handsets back into the mother phone to reinitialize them.

Here's the DECT Panasonic KX-TG6441 phone & handsets:

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Here's the model number plate:

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Googling for that error message, I see it's pretty common; but I already tried the little that Panasonic suggests:

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The outlet is working fine; the phone works fine from the base; it's just the handsets that keep losing their wireless connection.

Anyone else resolve this problem before? Any debugging hints?

Reply to
Danny D'Amico
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Have you added anything like a wireless router for the internet ? Sometimes phones and other wireless devices will interfear with other.

Reply to
Ralph Mowery

Since it happens with multiple handsets, it's a fair assumption that all of the handsets did not simultaneously fail. Therefore, whatever is wrong is at the base unit.

Clue. The transmit power of the base is only about 10 mw of RF. It doesn't take much to ruin that. I suggest you open up the base unit, and see if there's anything amiss inside. Look for loose screws, corroded connections, bad connectors, critters, liquid spill residue, mechanical damage, cracked PCB, bad solder connections, bad crimps, and a bad standby battery. The last is a bit problematic as I don't know if that model uses a battery to retain the settings and messages, or if it uses flash ram. If you find a battery, test it. If not, don't worry about it. Also, if it uses the same charger as the remote chargers, try swapping the charger. If you only have one charger, measure the voltage under load or just replace it.

These days, everything is throw away and few devices are made to be repaired. If you can find a schematic, it will be both a bonus and a miracle.

Only one charging base?

Yes, but not on a Panasonic phone. I think it was a Uniden. It turned out to be corrosion residue caused by an unreported milk shake spill several months previously. The outside had been wiped clean, but the inside was a mess. On an other phone, it was a loose screw and lug to the antenna wire causing an intermittent antenna connection.

Tear it apart and look inside.

Reply to
Jeff Liebermann

Sounds like interference.

I recently switched to a high-power router and Wi-Max wireless internet. One or both drove my 2.4GHZ wireless phone crazy. Hardly worked at all, even up close. I powered up the spectrum analyzer. Yep they were right on top of one another. I switched to a DECT phone, which, as I recall, works on different frequencies. Problem got a lot better. I still can't stand too close to the router.

Reply to
mike

Yes. There is lots of WiFi in the house.

There are also other cordless bases and phones on other lines, e.g.,

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For example, this Panasonic KX-TG6671 seems to work just fine though:

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Reply to
Danny D'Amico

Hi Jeff,

Googling, it says the error indicates the base station loses its power, but, that's just not happening, at least not from a loose power cord.

The reason I know that's not happening, other than it's not, is that not all of the handsets fail at any one time. Only one handset fails at a time.

So, if it was the base failing (which is what the error indicates), then all the handsets should fail simultaneously, I would think.

Reply to
Danny D'Amico

As someone suggested, I guess it could be my 2.4GHz WiFi antenna that is causing problems; but why would that be intermittent?

This is likely. The error indicates a lack of power at the base, but, there isn't any overt lack of power at the base.

This makes a lot of sense - and it's a good idea, especially since the error indicates a lack of power at the base.

I'll try that and re-test & report back.

Reply to
Danny D'Amico

It could be. There's a lot of WiFi floating around my house these days.

I had to look up WiMax:

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I hadn't thought of aiming my spectrum analyzer inside (mine is pointed outside). What I may try is setting up a spectrum analysis where I run a 1000 frames without any devices plugged in, and then another

1000 frames with all my WiFi devices plugged in to see if there is a big difference.

I don't know what frequency DECT works on, but, two of my four phone bases are DECT.

Reply to
Danny D'Amico

Nope. If it's a loose antenna connection on the base, the handsets close enough to get a minimal signal from the base would still work, while those far away would loose the signal.

Reply to
Jeff Liebermann

Hi One base and many handsets? Then logic tells me radio in the base unit is suspect. Or turn all handsets but one and try. By any chance checked the wall wart for the base unit? We have multi handsets but they are divided between two different base units. If some thing goes wrong easy to trouble-shoot

Reply to
Tony Hwang

In the USA:

1920 to 1930 MHz. 5 channels, spaced 1.728 MHz apart. 4 mw average tx power. 100 mw maximum.

In the USA, there's no GAP support, which means that phones from different manufactories not only will not talk with each other, but also can interfere with each other. You might try your problem phone with the other DECT phones and base turned off.

Reply to
Jeff Liebermann

This is a good observation.

I picked up the Panasonic KX-TG6441 "Operating Instructions":

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And the "Installation Manual" for the Panasonic KX-TG6441:

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The frequency range is *below* the 2.4GHz WiFi range: Frequency Range = 1.92 GHz to 1.93 GHz

And the claimed RF Transmission power is 115 mW (max.).

Reply to
Danny D'Amico

There are three kinds of interference that can happen in this case.

The first is direct interference, where your WiFi unit operates on 2.4gHz and your cordless phone also operates on 2.4gHz. The old 2.4gHz phones did not listen for activity on a channel before transmitting on it, and often would wipe out Wifi.

The newer DCT phones listen, but there is only so many channels and eventually they overlap.

Since 2.4gHz is 1/2 of 5.8 gHz, the second harmonic of WiFi can interfere directly with 5.8gHz phones and so on.

The second is intermodulation, where two signals combine and the difference or sum causes interference. Not likey in this case.

The third is desensitization, where a strong signal on a relatively near frequency overloads the receiver in a device. So a WifI router can cause DECT phones to stop receiving, even though WiFi is 2.4gHz and DECT is 1.7gHz.

That's why you can't talk on the DECT phone near your WiFi device.

It's very likely that the OP is experienceing desensitazation or direct interfernce.

Another thing they can try is to move the base station. Especially if it is sitting next to another wireless device.

Geoff.

Reply to
Geoffrey S. Mendelson

It may not be YOUR WiFi that is causing it. Unless you live in a single family house about 1/2 km from anyone else and a road, you could have problems with interference from other WiFi devices, cordless phones, cell phones, and so on.

I live in a steel and poured concrete building, and away from the center of it (I'm on a middle floor), say my bedroom, I can only "hear" my Wifi. In my living room which is in the center, I can "hear" 8 unprotected WiFi networks, and a few protected ones. It's a miracle I can use my WiFi there.

Geoff.

Reply to
Geoffrey S. Mendelson

"Geoffrey S. Mendelson"

** That some new kind of math ???

ROTFL

... Phil

Reply to
Phil Allison

You're spending too much time analyzing the problem, and not enough time testing.

Why hasn't someone suggested changing the WiFi channel? That's a great place to start testing.

Reply to
William Sommerwerck

*The last time my Panasonic phone did that, I replaced the batteries with new ones. Problem went away. If yours are four years old I would think that it is time for a battery replacement. Home Depot has them and I think Wal-Mart does also.
Reply to
John Grabowski

If they're 2.4 Ghz, wifi could be interfering too much.

Reply to
Jeff Urban

Our Panasonic DECT phones are on 1.9GHz, I'm almost certain -- not on the common 2.4GHz WiFi frequency.

Perce

Reply to
Percival P. Cassidy

DECT phones are on 1.9gHz (1.7 in Europe), DCT phones at 2.4gHz.

They are similar, and of course, incompatible.

Geoff.

Reply to
Geoffrey S. Mendelson

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