[App_rpt-users] Can't Change CTCSS input threshold on RTCM menu

Bryan Fields Bryan at bryanfields.net
Mon Jan 9 12:17:06 EST 2017

>> On Sat, Jan 7, 2017 at 12:39 PM, Skyler F <electricity440 at gmail.com
>> <mailto:electricity440 at gmail.com>> wrote:
>>     Unfortunately, on our CTCSS output, there is about 0.15 Volts when no
>>     signal, and 5 when there is signal. The RTCM thinks that there is Always a
>>     signal.

> On 1/9/17 10:47 AM, Tim Sawyer wrote:
> I don't think that ever got implemented in hardware... there's no DAC there. 

Top posting is improper.

Try a 10k resistor to ground on that pin.  If it's TTL logic it would make
that a hard 0 volts (or close enough to fool CMOS).  I've had to do this
before a few times.

>From when I spoke to Jim about this last he was doing menu item this for
version 2 of the voter, but I believe that project never got to production.  I
was asking for an independent setting of CTCSS level on transmit :)

If you're doing simulcast with the RTCM you'll need to sync the 9.6mhz clock
in it as well, or maybe not if you don't have a ton of overlap.

Bryan Fields

727-409-1194 - Voice

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