Re-use existing Panasonic DECT handsets

I have just installed freepbx and enjoying learning about VOIP. My landline ceases next year and in the meantime I plan on sourcing some cheap equipment to try things out. I already have several Panasonic DECT phones circa 2016 that work with my existing analogue DECT base station. Will I be able to use these handsets with a Panasonic KX-TGP500 VOIP DECT base? I understand full functionality will be unavailable, but wondered if:

  • Basic DECT GAP interoperability will work and be sufficient for basic functionality.
  • All necessary config can be made via HTTP interface on the KX-TGP500, rather than the actual 100% compatible Panny handsets.

Many thanks for any insight.

All you need is a cheap ata to covert your voip line back into analog …

Yes, I’m considering that option too. But I’m still interested in knowing to what extent other DECT/GAP handsets will work with a KX-TGP500.
Also, here in UK used market at any rate, there seems a prevalence of VOIP/DECT bases compared to ATA adapers.

On the Panasonic KX-TGP500 VOIP DECT, only the TPA50 remotes work. The other DECT phones you have purchased require an analog base using the method @lyndenwld has mentioned above.

I have found it is usually cheaper to buy a used TGP500 with remotes than just buying a TPA50 handset. EBay has a wealth of them. You can then keep the used base station as a spare and associate the TPA50 handsets with your existing system.

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Thanks. It seems some other DECT/VOIP bases have some compatibility with basic third party DECT handsets. I’m assuming here, possibly wrongly, that that may apply to my existing Panasonic andalogue DECT handsets.
I’m also considering gigaset N300.
For the time being, I just want some cheap second user equipment to play with before I become solely reliant on VoIP some time next year. Only thing I’ve tried so far is soft phones on android devices. That’s not gone too well so far but early days.

The Panasonic KX-TGP500 works great with FreePBX and Asterisk. I have 4 handsets off it in my install. The range and clarity are super. Setting it up on FreePBX can be a little tricky but once you figure it out, its worth the trouble.

If I plug my existing Panasonic DECT base in to an ATA, can the individual handsets registered to that base be treated as separate extensions by FreePBX?
Incidentally, I now have softphones working. It was a firewall misconfiguration.

Your analog DECT base will only support one extension off of FreePBX which will be on all the associated handsets.

The KX-TGP500 is SIP based (not analog) and can support up to 8 individual extensions off the PBX.

I have used Gigaset in the past, and they work great and are full of features. You may have more than one extension. Take a look at Gigaset COMFORT 550A IP flex.
I think it does what you need.

I have now got myself a 2 line Cisco ATA.
I also have a couple of old BT (UK) handsets I dug out, which I would like to play with. The phones have the typical removable rj11 socket and the cables are terminated the other end with a BT plug.
Rather than use an adapter, I would prefer an rj11->rj11 cable to connect them to the ATA. The only one I have in my possession right now is straight wired middle pins (3&4) only. It doesn’t work. What pins connect a UK/BT handset to an ATA FXS port and what if any crossover wires? What do I look for as far as ready made cable goes?
Many thanks.

If the connector has more than 3 and 4 connected, it is, by definition, not RJ11.

OK, thanks. The lead that works (for this old handset when connected to a BT/UK wall socket) is terminated at the phone end with a 6P4C connector (pins 2-5 are populated) and at the other end is a ‘BT plug’.
If I use the straight RJ11 (6P2C pins 3&4) I mentioned, to plug the handset in to the ATA, it appears to get no power: No dial tone and the various toggle buttons don’t illuminate if pressed.
In order to connect to the ATA, my understanding is I could buy a BT->RJ11 adapter or a new cable.
If this RJ11 lead I have is adequate and functional, I guess there may be a problem with the ATA or its configuration. What config on the cisco ATA might result in it not providing sufficient power to the handset or render the handset otherwise non-functional?

It sounds like they are using the two wire BT pinout on a 6P4C connector, in which case I imagine you would want RJ11 4 to phone 5 and RJ11 3 to phone 2.

If any other pins are needed, you will probably need the guts of a BT master socket.

Thanks @david55. So a crossover lead. These are two BT converse 200’s from around late 90s. They’re our own old phones. The leads attached to them were the original BT items to connect them to the master socket/extension.

The basic issue about extra wires is bell common, which might be needed by old BT phones. Ground is only really relevant for PABXes, as the PSTN uses time break, rather than earth, recall. If you do need bell common, you will need a master socket.

I just managed to find some more RJ11 to BT-plug leads:
One of which only has pins 3&4 populated on the 6P2C connector. Connected via this lead to the master socket, the phone does not function either.
I think I have some 6P6C connectors. I will try crimping one with the pinout you suggested.
Many thanks.

This worked. Many thanks for the help.

EDIT: Other than the handset does not ring for incoming calls :-/
Seems it does require the ring capacitor. I’ll be buying a female BT → male RJ45 adapter after all, ensuring it is one that includes the cap.
I’ve grown quite fond of these old phones since digging them out for this project!

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