No background noise on PSTN, but no caller ID either and once-a-week phantom ring here, despite trying both the grounding and the shorter 1.8m cable, though in both cases the number of CRC errors seemed to have halved and the VDSL2 throughput speeds to have slightly increased! Others apparently find the latest Beta 84-05-07 21362 (I think - something like that dated 22 Dec) firmware available from the AVM Labs English site cures the problem for them, though not for me.

So in advance of a future hoped for firmware upgrade to nail it, I'm using a workaround of a free-for incoming calls Sipgate VOIP service with a local exchange number, and call forwarding from the PSTN line to the VOIP number through my voice provider at about £1.50pm (as the call forwarding costs should fall within my monthly unused free call allowance). That should allow me to control calls on the Fritz! interface as so many cold callers these days seem to ignore the Telephone Preference Service registration.

Edited by deleted (Tue 21-Feb-12 13:57:14)

Interesting that you don't get any background noise on PSTN as the noise is definitely being generated by the Fritz!Box. Perhaps the older cable doesn't cause the noise? My Fritz!Box came with the newer cable where the voice cable terminates in a proper BT plug. Am I right in saying that the older cable spilts into two RJ45s or an RJ11 and an RJ45 and the package came with an adapter which converted RJ45 to BT? I got hold of one of the shorter cables from Amazon http://www.amazon.co.uk/Y-CABLE-FRITZBOX-VOIP-1-5-M/... However, this cable spilts into two RJ45 plugs so require adapters. I got hold of one of these http://www.amazon.co.uk/Rj45-Socket-Bt-431a-Plug/dp/... to get the telephone side of things going. Unfortunately, when the cable and adapter is plugged into the phone line, the line is constantly engaged. I guess the adapter that comes with the older cable does a bit more than the one I purchased?

Best to use the BT socket Y-cable, I think which didn't show any noise on my connection. I'm using a standard UK/American BT/RJ11 adapter (from Maplin) combined with the black RJ11/RJ45 adapter (as supplied in the original packaging with the spare German Y-cable) with the shorter 1.8m Y-cable. The black adapter is an AVM special and has a pin arrangement 1 & 8 only on the connection to the Y-cable for analogue which is important for a good matching connection. (Pins 3 4 5 6 are for an IDSN connection only which is not used in the UK). Are you also using the black cable on the Y-cable? The original grey AVM adapter doesn't work for analogue phone and isn't required in the UK.

Yer' pins have to match correctly for each connection, obvious really (but it took me a bit of experimentation to work it out).

If the BT Quiet Line test is OK on a wired phone connected direct to the socket, and you still get noise with the corded phone connected to the Fritz is it worth considering a return/exchange under warranty as defective?

Edited by deleted (Tue 28-Feb-12 16:25:12)

Just to confirm I'm using the Fritz supplied cable which requires no adapters on the Y part. It terminates with an RJ11 and a BT plug. I'd say the cable is about 3-4 metres in length. With regards to the shorter cable I bought from Amazon, the Y part has a one grey and one black RJ45 plug. The grey is labelled 'DSL' and the black is labelled 'ISDN/Analog'. I'm using the RJ45 to BT adapter on the black RJ45 plug. The RJ45 to BT adapter I bought uses only the two middle pins so I guess that's why it doesn't work. Where did you get your shorter 1.8m cable? Does it split to two RJ45s? But confused where you say you're using a BT to RJ11 adapter from Maplin - is this for voice or DSL? Does the black RJ45/RJ11 Fritz supplied adapter terminate with BT or do you then have to use an RJ11 to BT adapter to plug it into the PSTN part of the microfilter? Is it possible to get hold of this special adapter for the voice part without buying an 'older' 7390?

I've tried the BT Quiet Line Test and it doesn't indicate any problems. I guess the unit could be faulty (I don't get any noise with my Siemens Gigaset SL565 base station). However, I've seen lots of reports of people having noise on PSTN; the fix tends to involves plugging/chaining the BT plug into two microfilters which gets rid of the noise for me (but more likely at the expense of not having caller ID). Have a read of the reviews on Amazon in particular the one by 'Pete' and the comments http://www.amazon.co.uk/Fritz-7390-Wireless-Router-A... Also check out the comments on the PC Pro review http://www.pcpro.co.uk/reviews/wifi-routers/365482/a... . Perhaps there's a big batch of faulty 7390s?

I tried the beta firmware you mentioned. However, I'm under the impression this is for Annex B. I say this because once the firmware had been updated, the Fritz!Box would crash and reboot whenever it tried to connect to the ADSL. Thankfully I was able to get into the router by leaving the ADSL cable unplugged so I could downgrade the firmware to the latest 'stable' version. Anyone else had this problem?

Just in case you haven't noticed AVM have released a new beta firmware, 84.05.09-21821. I gave it a whirl last night and, without making any changes to my setup (i.e. plugging and unplugging devices), saw the reliability of caller id improve significantly. Interestingly the 'Current power consumption' figure has increased from around 33% to 44%. I would say that 95% of the test calls I made had CLIP presented properly. I haven't fully tested it yet but I imagine that I would get a 100% success rate if I plugged the voice cable into the phone line without the DSL cable which seems to be generating noise and interfering with CLIP.

I am now at the point of considering switching from my Siemens DECT base station to the Fritz. However, the background white noise problem still remains on PSTN calls unless I do the chaining filter trick but this seems to prevent caller id from working, beta firmware or not.

I wondered what would happen if I put a standard dual BT splitter (i.e. not a microfilter) into the master socket and from there plug two chained microfilters into one and a single microfilter into the other. I put the DSL cable into the end of the chained two and put the voice cable into the single microfilter. I was hoping, rather than 'double filtering' the voice part I could try doubling filtering the DSL signal. Unfortunately, I still got the same amount of background white noise on PSTN calls.

I then plugged the voice cable straight into the BT splitter and in the other side of the splitter plugged a single microfilter into which the DSL cable went. I made a PSTN call and could hear really loud AM radio/modem white noise screeches as the ADSL modem in the Fritz!Box dialled up and maintained a connection. This is the first time I've heard the Fritz!Box 'unfiltered' and it is loud. I've setup many ADSL connections and routers over the years and I've never really heard noise like this on the phone line when an ADSL modem was connected, even when a microfilter wasn't being used. I can see now why people have varying success with caller ID displaying. Those very close to the exchange will have a stronger signal which can cut through this noise. I guess I'm a moderate distance from the exchange so I have intermittent success. Those far away probably don't have a strong enough signal to cut through this noise.

Interestingly though, smurf46, you report you don't get any noise on PSTN calls on your Fritz!Box. I would really appreciate it if you could try the test mentioned in the previous paragraph? I'm wondering whether you can hear this noise with your Fritz!Box; it would be a good test in terms of whether my unit is faulty. I never asked the question but I suppose you've tried just plugging your voice cable straight into the phone line without any microfilters and tested caller ID?

In light of this, then, until AVM can come up with some kind of fix to the noise generated by the DSL part of the router, I'm passing off this role off to another device and setting up the Fritz!Box in 'cable modem mode'. I'll probably go for one of these http://www.draytek.co.uk/products/vigor120.html.

Edited by deleted (Fri 09-Mar-12 14:08:08)

Nick, not quite with you on this one as I'm on FTTC (VDSL2) and I believe you are using the Fritz! on ADSL? I've tried the use of additional filters without success.

I'm 3.4km from the exchange - 600m or so from the cabinet. I don't think distance is an issue. The analogue phone is clear (except on some mobile calls, but I believe the difficulty is at the mobile end, especially as I have a facility to run my mobile callls through the router which completely avoids the local echos, quietness and drops in the mobile signal).

I'm convinced there is no problem with the CLI signal. especially as my workaround is to use the Fritz!'s ability to forward all analogue calls to my VOIP service (as I have a "free calls" allowance from my phone provider), which then displays CLI perfectly on all calls and allows full use of the call management functions to screen calls. It therefore seems to me that it's a problem with the Fritz! decoding, as when the analogue call is sent out to the VOIP server, it (or a separate DECT phone connected to the analogue port) can decode the signal well, the Fritz! cannot due I suspect to cross-talk interference within the Fritz! from the concentration of DSL tones in the adjacent frequencies on ADSL (or in my case VDSL where I have a high concentration of tones in the lower frequency range). I'm also running the latest beta, but I'm disinclined to disable my workaround to check whether it's sorted the original issue!!

Hi all - been following this thread for a few days, thought I'd create an account and share my experiences. I also had problems with static and caller ID not working. The solution for me involved the following:

Move the Fritzbox to the master BT phone socket.
Earth the unit (from the metal casing of the LAN ports to an earthed pipe).
Make a custom cable to replace the Y-Cable that came in the box. My unit was quite old so it shipped with the long Y-cable that terminates in two rj45s.

I got the following pin out from Fritz support and made a short cable by cutting the end of a standard cat5e cable and reterminating some of the pins in a BT plug and some in an RJ11 (you obviously need the right crimp tool to do this!). I tried to keep the cables as twisted as possible and used electrical tape as a makeshift cover for the pair going to the RJ11.

I've uploaded the pin out if anyone else wants to try this:
Fritz ADSL pinout

This has got rid of the hum and I now have reliable caller id. Haven't noticed any phantom calls since doing this, but I've only had this in place for a few days...

<rant>
Have to say, the Fritz box on the whole sucks. If you turn on telnet and have a snoop about the device, they have implemented things in a weird way. The DHCP server is utterly broken to the extent that if you want to do RFC compliant DHCP you have to use something else! I've found firmware updates tend to cause router reboot loops. I used to have a script that changed my dial plan in the evenings to make use of BT free evening and weekend calls - they [censored] this when they introduced a javascript based md5 hash challenge string on the log in, so now the script is massively more complicated to comply with this. If you want a domain name other than fritz.box you have to jump through hoops. If you want true gigabit performance you have to go and disable the power saving features. Basically, if you are a network engineer this unit will frustrate the hell out of you - if you don't know what you are doing, its probably quite good.
</rant>
Anyhow - hope this is of help to someone.

Cheers
Spanner

Latest Beta firmware: 05.22-22182 BETA actually appears to resolve this issue for me. I always got the occasional number showing on incoming calls so possibly mine was marginal but was less then 10% of calls showing a number correctly, 90%+ shown as 'unknown', since loading the beta it has identified every call (only a couple of days so far but looks VERY hopeful).
Check here: ftp://service.avm.de/Beta/FRITZ!Box%207390%20int/ for latst beta.

Apologies for not responding sooner. You're right - I forgot that some people on this thread are on FTTC. I did try using another device for the ADSL modem but experienced the same problem so it seems it doesn't matter what is being used for this, the Fritz!Box voice side of things will still pick up the ADSL signal as static. I went back to using the Fritz for DSL duties and managed to reduce the amount of noise on the line while maintaining Caller ID by chaining two different filters together, the second one has less 'filtering power' which I guess allows greater signal through for CLIP to work. I then tried this setup for a few days but discovered a far worse problem than a lack of Caller ID. Almost every call made or received over PSTN had a horrible echo which began at the start and gradually faded but made the initial part of the conversation very difficult. After some research it didn't seem there was much of a fix for this.

At that point I decided to give up with using the PSTN line on the Fritz!Box and have gone to using VOIP for all calls. Like you, I have my PSTN line forwarding to my VOIP number. Caller ID is not an issue anymore and the call quality is much better.

Also confirming that the latest beta firmware worked for me: ftp://service.avm.de/Beta/FRITZ!Box%207390%20int/

I have the double ADSL filter in place, multiple hard-LAN ports in use on the router, use the default (short) supplied Y-cable, and no additional earthing solution. ...so just the firmware finally gave me CLID.

Let's hope it fixes the phantom call problem too....