Batboard

Hi I have a IFR 1900 that was working perfectly until I tried to listen on a external antenna for a "lost Link" It flashed up INPUT OVERLAD ON ANT or DUPLEX port atetion required. Since then it does this on start up. Does anybody know of a reset for this. Back to the factory is not a current option due to the freight costs. Thanks Neville

If you are getting an overload on restart, then you have blown up the front end.

You've committed a rather expensive oops. Options are going to be return to factory or to a qualified repair shop for a new front end and calibration.

Always a good practice to know what's coming down the coax before you go plugging it into your expensive box...

And just a bit of "behind the scenes" - many people wonder why we don't put some form of protection diodes in line - after all, most radios have protection diodes to give their front ends a fighting chance to survive an event like that.

When you are designing a radio that needs to only work over a limited frequency range, and doesn't have to present 50+0j ohms antenna impedance over that limited range, you can do that.

When you are designing a piece of test equipment, that needs to operate from 1MHz to 3GHz, and MUST present as close to 50+0j ohms across that whole range, adding a non-linear element like a diode really doesn't work very well.

It's best to ALWAYS hook up to the T/R (high power input) port FIRST, and then, after you have looked at the signal line for a while (to allow for intermittent transmitters like paging systems) and have a reasonable confidence you are dealing with low level signals, move to the antenna port.

thanks for the replies I guess I will need to get it fixed I normaly do not use the unit of air it is a pity I can not use it without the of air reciever Hope to be in your country later in the year ( with a carry on repair ) Thanks again for the replies Neville