Hi,
what is the maximum rating in voltage and current for X8 in com-port?
I can read max 500mA from documentation but cant find max emitter-collector voltage.
I asume this is a NPN-transistor for pulldown/clamping (according to Susdr pro documentation), but I maybe mistaken this as a PNP for source of external relay??

My goal is to switch the PTT of a Yaesu FL2100. It needs a clamp to GND and the unloaded voltage is approx. 20V and it draws approx. 200mA when clamping the PA relay.

73
/T

I tested with 10k ohm between 13.8V(pin14) and X8 (pin13) and I can see a leakage of approx 1mA in off-state, this seems a bit high!? Is this correct?
I can see the same on X5 as a reference.
Is there a schematic on the extra control interface?

73
/T

tomas wrote: my bad, this is working correct (and it is a NPN).
But my first question is still valid regarding max ratings.

73
/T

Thomas, While I am not sure of the ratings

I can tell you that an old FL2100 is like 25 or 50 volts on the relay and is well above modern radios keying line recommendations

You should be using a buffer of some sorts
and probably should set a delay in the Keyline within the EESDR software as well

Thanks for the reply N8SDR! (I like your call sign
yeah, I did connect a relay to X8 and it works fine. However I think there is some very important info/specifications missing here and I would like to know where to find it.

73
/T

With respect, do not take chances. Email Roman at EE and he will gladly give all the info you need and then you will be sure.

g0cgl wrote: sure, I'm new to this product and will not take any chances , thats why Im asking here, but if email is the best way Ill do that(?)
...just more used to read this type of info from a interface specification.

Thanks for your feedback!
/T

I think there is a lack of clarity to the interface specification for situations when connecting a legacy amp like the FL2100 to the Ext Ctrl connector. For PTT I would use a computer com port to the amp and switch via software using TCI. However, that doesn't mean your method is unsafe (though as N8SDR stated I am sure the voltage will be far too high) and surely Roman will make it clear one way or the other for you.