Re: Bitx40 - Not Transmitting #bitx40help #bitx40

Timothy Fidler
 

Gary , JG has done a v good job of pointing out where you are at the moment. My tuppence worth and this is not very systematic is that if relay K1 has failed or the PTT line is not getting earthed properly  then you would see Rx and no Tx.  This could be from the relay not getting power or the relay failing in the coil (or mechanically) or  one of the components across the relay coil being in partial short and stealing power from the coil (unlikely as for this to be valid there would have to be a common decent resistance somewhere to cause the voltage to pull down.... but then this is all magic - it worked, it don't work. Electrons have changed their mind) .   You could first check power is avail to the relay K1 (not K2)

http://www.hfsignals.com/index.php/2017/11/23/bitx40-circuit-description/

And if it is then put a screwdriver on the case and to your ear  and listen to  hear it pull in as PTT goes low.  (this crudity  avoids probing the PCB too much ) .  My guess is it may not.  If it does then you need to check the Tx  line is getting power.  If yes, then it was a good idea at the time and the best idea is to fish around on the site in particular the repository run by Mike to see where the list of voltage test points and voltages is.  Mostly these relate to uBitx but you might find a Bitx40 one.   Good luck 

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