[Asterisk-Users] About Grandstream ATA-286 and ring voltage

[Joshua Roberson]

If my memory serves me correct, typical analog ringing voltage is
between 90 and 95V.  the ATA-286 from grandstream will ring all of my
newer analog phones except for ones with bell ringers, which generally
require at least 75-80V.  You could always build a step-up relay that
would attach and step up the ringing voltage, but then you risk putting
too much strain on the ringing circuit of the ATA.  I'd say don't use
this device for more than anything but a newer style, digital ringing
phone.  Most fax machines look for a ringing voltage spike of about 75V,
IMMSMC.

--------
Josh Roberson
Indigent Networks
1.877.677.9647 x1
twisted at indigent-networks.com


On Mon, 2004-02-23 at 06:01, mattf wrote:
> The only adapter that I know of that allows you to modify the ring voltage
> is the Sipura analog SIP adapter. I was able to get my old fax machine to
> answer after jacking up the ring voltage to 90V. http://www.sipura.com
> 
> MATT---
> 
> 
> -----Original Message-----
> From: Nicolas Bougues [mailto:nbougues-listes at axialys.net]
> Sent: Monday, February 23, 2004 3:41 AM
> To: asterisk-users at lists.digium.com
> Subject: [Asterisk-Users] About Grandstream ATA-286 and ring voltage
> 
> 
> Dear all,
> 
> My GS ATA-286, which otherwise work well, seem to be unable to ring a
> fax (or at least, some kind of fax). The fax basically doesn't detect
> the ring.
> 
> I measured with a volt meter about 45V during the ring pulse out of
> the ATA. This looks fairly low to me (supposed to be in the 70V+
> range, isn't it ?).
> 
> The adapter works with evey kind of phone I tried, but did not work
> with two different fax machines. Am I simply out of luck with these
> fax ? Does my ATA look defective (tried two of them, however) ?
> 
> --
> Nicolas Bougues
> Axialys Interactive