I have a query relating to the tone setup on HT8o1, HT814 and HT818 ATAs.
We have a large VoIP network which replicates the UK’s Public Switched Network of the 1960/70’s using the old dialling codes to which are connected a number of former preserved old public electro-mechanical exchanges[C*NET Directory UK &a NORTHERN IRELAND NUMBER Listings (ckts.info)](https://ckts.info/directory/europe/uk/) . But everyone can’t get hold of one of those exchanges to which to connect their old rotary dial telephones hence we’ve been using HT5XX and HT7XX and GXW40XX units.
However I got in touch with Grandstream in 2020 about adding the ‘reverse’ New Zealand dialling configuration plus making it possible to add tones below 301Hz for the HT8XX range. Not long afterwards Firmware version 18.104.22.168 appeared with the ‘New Zealand dialling standard’ added.
And beneath the tone settings appeared -
(Frequencies are in (10, 4000) Hz and cadence on and off are in (0, 64000) ms)
which wasn’t on earlier editions. This tends to intimate that tones below 301Hz could be added.
After downloading this firmware I was able to get the tones below 301Hz working OK on the HT812 and two HT802’s that I’d bought.
For instance by mixing tones f1=100@-2,f2=133@-2,c=0/0; the HT802’s & HT812 give the lovely old ‘purring’ dialtone of the old Strowger exchanges.
Recently I have bought a several more Grandstream ATAs – two HT801’s plus an HT814 and an HT818. All have been upgraded to the lastest version of firmware.
Sadly the tones can be barely heard on the HT801s, HT814 and HT818 .
The HT801/814 andHT818’s all have the latest firmware as the HT802/HT812’s with identical settings but barely audible tones! The firmware is the same version (Prog 22.214.171.124) on all the ATAs – the ones’ that setup and work OK and those that don’t give the correct tones.
Anyone-one any idea why the HT802/812’s tones work fine but not the HT801, HT814/HT818. ?
Ian Jolly CNet 0352 2979