[SOLVED] DECT dongle DD10K - bad performance in combination to T41S + W60P

[Babylonia]

I just purchased a Yealink T41S desk phone + DECT dongle DD10K.
It do function as a DECT connectivity by the also purchased W60P base station and two sets of W56H handsets.

Although do get audio jamming / interference when using the intercom functionality by connection to the W56H handsets and talking to each other.
Jamming / interference of the audio only is heard by the W56H handsets.
Sound is comparable as a kind of crackle / crisping of electric sparks, interfering the audio quality. Very annoying.

As it only is heard by the W56H handsets, it could be an interference by the microphone of the T41S.

Tested both, the voice by the phone hand bugle / horn (so by the microphone of that hand piece),
and by speaker phone (microphone behind the little hole at the underside of the T41S.
No difference.

Also tested by both W56H handsets. No difference.
Also used a connected headset to the W56H.
No difference.

As it seems that some "playing" / moving by the phone curly cord of the T41S, did have influence to the crisping audio interference, I took out the cord of the T41S, so only using by speaker phone. (The curled cord could be working as an "antenna" and giving electromagnetic interference ??).
No difference.

Testing by make a call by one SIP line out, and receiving the telephone call by another SIP line IN. (I have made up a set-up of four SIP lines within the W60P base station.
No difference.

Even have some audio interference making a connection from one W56H handset to the other W56H handset.
The main problem was however between the T41S phone (+ DECT dongle DD10K) and W56H handset.

Than took out the DECT dongle DD10K, and used the T41S phone as a stand alone VOIP phone, connected by Ethernet cable to my network.
Made a set-up by the same four SIP lines as set within the W60P.

No intercom possibility yet (not set in this combination), but at least could testing by making a call by one SIP line out by W56H handset, and receiving the telephone call by another SIP line IN of the T41S. (And vice versa).

Audio problems seems gone now. No crisping / crackle interference any-more by the audio.
As far as I tested yet, it seems the DECT dongle DD10K is not a good combination, working together to the W60P base Station.

I have some mixed feelings purchasing these phone sets, as it have not the potential what I intended to do with it.

Also I have mixed feelings by the firmware used by the W60P / W56H combination (fw version 77.83.0.25), and what is possible by the more or less comparable firmware within the T41S (fw version 66.84.0.15).

E.g. the directory / list of contacts made within the T41S, do have extra groups, and you can make a choice for using a special SIP line for calling OUT automatically, in spite a call is coming in by another SIP line.
As an extra tip for Yealink. Make those SIP line choices be available for any of the three phone numbers separately. Now I made two lines for contacts.

e.g.
John (landline) = SIP 0 (line 1)
John (mobile) = SIP 1 (line 2)

Also make a better logical numbering of those SIP lines
0 by programme code often is used for the first number,
but not logical to real life line numbers.
(Making contact lists by Excel ---> export / import CSV file).


These extra's (choosing SIP lines) are not possible "automatically" by the firmware of the W60P base Station. So if you see a call within the history, (coming in by one SIP line), and want to make a call back by the other SIP line, You have to do it manually in a "difficult" work-around, as by choosing the contact within history list, it shall take the SIP line as it was for coming in the call.

Regards.