DECT phone connected to Hub 3.0

[Mikedp23]

Hi

Has anyone had a problem with incoming calls when using a BT 2500 DECT  connected direct to VM Hub 3.0 ? 

Mine works OK for outgoing calls but about 1/2 incoming calls we can hear the caller but they can't hear me .    If anyone had this problem and changed to a different phone ?  If yes, can you recommend a different DECT phone 

Thanks 

[goslow]

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@Mikedp23 wrote:

Hi

Has anyone had a problem with incoming calls when using a BT 2500 DECT  connected direct to VM Hub 3.0 ? 

Mine works OK for outgoing calls but about 1/2 incoming calls we can hear the caller but they can't hear me .    If anyone had this problem and changed to a different phone ?  If yes, can you recommend a different DECT phone 

Thanks 

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That model does not get stellar reviews on Amazon

https://www.amazon.co.uk/BT-Cordless-Phone-Answer-Machine/product-reviews/B00AF83IUG

From the one star reviews

"I bought this phone 18 months ago. I was initially happy with the phone however now the volume of my received calls has gone and no one can hear me although I can hear them. I tried to return it but how very convenient the guarantee is only for 12 months. Not impressed !!!"

and

"people I phone are unable to hear my conversation but I have no problem hearing them. I have had to buy another phone."

The other complaints are wide-ranging including build quality and sound quality (which seems to be a general theme with BT phones in online reviews)

Aside from BT phones, the other two brands which seem to be most used by customers on here are probably Panasonic and Gigaset.

[Kain_W]

Hi Mikedp23,

Thanks for your post and welcome back to the community.

Just from checking our forums I can see that you're currently in a PM with an agent.

To avoid any confusion, we'll allow the responses to occur from there.

Take care,

[Mikedp23]

I have advised the VM forum team of my account number   but  have had no further reply and no help that is why I went on the forum again .  I have searched the forum but cant find anyone who has replaced a phone to fix this problem and say what make/model they bought 

I simply cant afford to buy a new phone only to find it doesn't work any better . 

[Kain_W]

Thanks for the responses,

The agent may be out of office at the moment however once they're on shift they'll respond accordingly.

Regards,

[Mikedp23]

Thanks , but The phone works fine and is about 4 years old.  I already posted about the problem and you responded before  . VM say it is the REN value too low and i have to replace the phone with >1 REN .    I have today measured the voltage and currents from the phone port with my Fluke multimeter and they are :-

On  hook voltage 49.2 v DC   on hook current  0.03 mA DC 

Off hook voltage 7.8 v DC   off hook current ( with dial tone )  22.7 mA DC

Ringing voltage 54v AC   in pulses,  ringing current to two phones in parallel ( DECT and wired phone)  only 2.5 mA  AC that I can detect using the MAX capture feature 

I just  looked on the internet to see i could see what the ring current should be for a REN of one but could not find  anything . 

Any ideas what it should be ?

Thanks

[goslow]

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@Mikedp23 wrote:

Thanks , but The phone works fine and is about 4 years old.  <snip>

I just  looked on the internet to see i could see what the ring current should be for a REN of one but could not find  anything . 

Any ideas what it should be ?

Thanks

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I think you are possibly heading off at a tangent (based on dubious information from the VM telephone support line) investigating REN numbers etc.

If you are interested in the spec's though you can look at the Openreach SIN documents (no. 351 I think is the relevant one for you)

https://www.openreach.co.uk/cpportal/help/suppliers-information-notes-(sins))

and there is a simpler Sky legacy document here

https://static.skyassets.com/contentstack/assets/bltdc2476c7b6b194dd/blt55683910fd987aba/5d74dd6a288...

which are for PSTN/POTS lines (rather than VM's hybrid connection)

If I was in your situation, I think I would pop down to Argos and buy a super-simple cheapomatic corded handset (for £10 or less) and try that on your line for a period of time and see if you get the issue recurring.

I don't have a landline any more but, when I did, I always kept a very simple cheap corded handset as a spare for testing purposes in the event of any landline problems so buying one would not necessarily be money wasted.

[Mikedp23]

Thanks goslow 

I was hoping that I could prove that my installed phones ( DECT and hard wired )  were valued with a REN of 1 or better ( or not )  .  Interesting reading the links you sent  . Clearly the HUB 3.0  phone jack is intended to simulate much of  a conventional POTS line such that plugging in more less any phone that previously worked on a conventional line should work plugged into the hub. Certainly the voltages and currents I measured seem to confirm this .    I am dubious of what VM support say and what they can check remotely . Especially as he did  his remote test with out the phone ringing .  The phone(s) always rings OK it is just what happens with the Hub circuitry detecting when the phone is picked up that should trigger  establishing two way speech over the internet .   

To be honest the fault has not occurred in the last few days  ( 5 or 6 calls total only  ) but happened 3 times on the day I reported the fault .   The VM person on the forum  has now arranged an Engineer to attend next week .  Not sure what that will achieve unless they know there is an issue with these 3.0 hubs and he is going to change it  ????          Any thoughts ? 

Thanks 

[goslow · Accepted solution]

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@Mikedp23 wrote:

Thanks goslow 

<snip>  

To be honest the fault has not occurred in the last few days  ( 5 or 6 calls total only  ) but happened 3 times on the day I reported the fault .   The VM person on the forum  has now arranged an Engineer to attend next week .  Not sure what that will achieve unless they know there is an issue with these 3.0 hubs and he is going to change it  ????          Any thoughts ? 

Thanks 

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From descriptions on here, VM's approach to faults often seems to involve replacing a lot of stuff until there is nothing left to replace. Not sure how much diagnosis is involved.

If you are interested in further tech stuff, the BT document above references this

https://www.etsi.org/deliver/etsi_i_ets/300001_300099/300001/04_60/ets_300001e04p.pdf

which explains (UK) REN on bottom of page 173 and top of page 175 (based on a BT bell unit apparently). Far beyond my tech abilities.

My suggestion for testing with a simple phone is based on two things. Firstly the 'BT Duet' range has been mentioned in several recent topics as having problems via the VM hub so is not a good device to test with. Testing with a cordless phone introduces other variables into the equation such as the wireless connectivity of the cordless phones, battery charging of the devices, any calling features which may be switched on with the cordless system etc.

By using a simple corded phone, powered from the line, you have pared the connection back to as simple as it can be.

Argos sells a simple desk phone for £6.99 and a simple gondola phone for £10. As mentioned above, I used to keep a simple phone, when I had a landline, for testing if the line was having problems so I could check against my cordless phones.

When you post on here, one of the first questions VM is likely to ask is if you have tried another handset, so worth having one around IMO. If you buy a new one, there is no question of any age issues being the cause of problems.

Final thought in the connection chain would be the VM adapter. These are super-cheapo generic parts and have been the cause of connection problems in the past but, if it was at fault, I would expect your line would be disconnected altogether during a call but if VM are going to be into swapping stuff when the VM tech visits ...

Hope you manage to get to the bottom of it.

[Mikedp23]

Thanks goslow for your further advice and information . Unfortunately  my Fluke meter is not clever enough to read the current pulses when the phone rings .  to be able to do a full REN test  as shown in the BT document .  FYI  The ringing AC voltage from the Hub 3.0 does have frequency  25 Hz 

I have bought a basic corded phoneset from Argos ( REN =1) and that  is connected now  and is tested as working. The BT Duet is no longer  connected so we will see how it performs in the  next few days . I also have another RJ11 to BT jack adapter  but I am sure this isn't the issue as it is just a connection and if it was faulty the phone wouldn't work at all or the call would drop out .

I'll let you know what  happens