Hello,

I would like to know what is the best/safe way to have more than one PTT line on my PRO2 rig.
I am planning to add a XPhase filter and a low band HF preamplifier. Both require a PTT line to be switched off when the rig transmits.
I already have a eb104 power amplifier connected to the PRO2 with a dedicated preassebled cable.
I am wondering if I can use a static relay like the AQY275 so to have a low noise device.
I would be glad if you could also suggest any phisical components name.

Thank you very much and 73'
Enzo, iw7dmh

Hi,

in the mean time I found the project of Paul, G4DCV. http://www.g4dcv.co.uk/radio/pttbreakout.htm
Still will be glad if you could give me some feedback mostly about the "safety" aspect.

73' Enzo
iw7dmh

Hi, Enzo.
You can use the presented schematic, BUT with certain modifications:
1. Connect the base of Q1 to X8 Key (pin 13) in ExtCtrl connector via resistor R1_10K.
2. Pull +12V from pin 14 and connect to R2 resistor in parallel with PTT line from EB104 PA.
In ExpertSDR2 settings, you can adjust PTT delay.

Just FYI on our website you can find this schematic - eesdr.com/images/Document/EB300_to_ExtCtrl.pdf

Thank you very much Roman,
I'll do as you suggested

73' Enzo
iw7dmh