HT-286 -- intermitent dial tone

[msturtz]

When connecting my HT-286 directly to the "LINE" jack on my fax machine (Sharp UX355LR), the dial tone seems to come and go. I press the "Speaker" button for on-hook dial, and the HT-286 light turns green (and stays green as long as the machine is off hook). Dial tone is heard, but then briefly goes away, and then briefly comes back, etc, even before dialing...

Clearly it's a problem with the device, and not VOIPo -- It works 100% correctly when connected to a regular phone.

Any ideas?

[VOIPoTim]

Matt,

Does it have a power setting in it? I don't know what it is in the 286, but I'm pretty sure it does.

It sounds like it's just not giving out enough power for the speaker.

[msturtz]

On the second settings page, theres an impedance setting, but no power settings that I've come accross... The closest thing I can find is "Powerline Ring Tone", and "Volume Amplification". I could look up the REN of the fax machine, but I'm sure it's quite low (meaning it shouldn't require any more current than a regular phone).

I should also have stated that the fax machine can't dial, either, the ATA acts like it isn't hearing the tones.

[msturtz]

I've discovered that if I use a line splitter and connect both the fax machine *and* a regular phone, if I pick up the regular phone, all is well, but if I pick up the fax handset, it still misbehaves. Stranger still, if I pick up BOTH, it also acts up.

Any other ideas out there?

[quattrohead]

What is the REN rating for the fax machine and the HT286 ?
Perhaps the fax is over loading the ATA.

[msturtz]

The Sharp fax machine has an REN of 0.7B (not sure what the B stands for, but that's what's on the label).

The regular phone's REN is 0.1 (Panasonic 5.8GHz cordless).

I have no idea what the REN limit is of for HT-286; it has a setting for "Onhook Voltage", but the documentation shows 'Low power', and 'High power' and the device simply has a voltage selections for 18, 24, 36, 48, and 51, with 36 being the default. I've tried bumping that all the way up, and it makes no difference.

It also has an impedance setting, with 600 ohm being the default, and other options for 900, 600 + 2.16uF, 900 + 2.16uF, and a couple more obscure ones for Australia, the UK, and South Africa... I've tried those first 4 settings, and the problem doesn't change.

In practice, it might not turn out to matter, since it seems I can't fax accrss G711/uLAW anyway...