- Hi Ian,
--- In DVRPTR_V1@yahoogroups.com, va2ir@... wrote:
> On the topic of the board, I am interfacing the board to a Hamtronics REP-200 repeater. This is a very basic repeater with separate TX and RX boards and a simple controller (which will be disconnected).
> The TX should be able to handle the digital data and the RX board provides discriminator output up to 2V p-p.
That's ok. A DV-RPTR board can handle 3Vp-p w/o distortion. A (smaller) GMSK signal should give 0.5Vp-p if the RX receives up to 25kHz channels.
> My question: I won't be using a 9K6 connector: to key the transmitter, is the signal from the board positive or negative going? Am I best to use the keying line through a relay as I am doing now?
From DV-RPTR normally you got a Active-Low (PTT triggered -> Pin goes to ground) signal (weak high; true open collector after removing a resistor).
You have the possibility to change the DV-RPTR hardware to have a positive (PTT triggered -> Pin goes to supply voltage) signal...
This feature is needed only in a few cases (self-made TX)...
relay usage isn't needed in the case you have the same power supply (ground; not only the analog-ground line for RX/TX signals). A relay will add ~20ms (rule of thumb) additional TX-Delay.