[ICOM] IC706 mk11 G

Wayne Johnson vk6eh at westnet.com.au
Fri Jul 30 19:41:45 EDT 2010


Thanks to those who replied to my post.
Phil and Simon, thanks but the 2 power supplies I have tried are very 
'Stiffly' regulated, the one that the radio is connected to at present 
is sitting at 13.77 volts while on rec, with full carrier the supply 
sags slightly to 13.75 volts, and that's measured at the pcb where the 
heavy DC leads terminate.

I had already ruled out low voltage as the problem occurs while at rec, 
ie tick, tick, tick of the small relay and no display etc.  When the 
radio is operating normally all functions work with out any problems, it 
seems as though the switch on relay is failing to latch properly, or to 
be more correct, comes out of latch when the condition starts. When this 
happens there is no or incorrect voltage supplied to the logic circuitry 
ie through the relay contacts (About > 3-5 volts) and the front panel 
switch fails to even stop the ticking by attempting to turn off  :-(   
Substituting my own 706 remote head changes nothing so it's not the 
switch on the head.

Phil, thanks and I did remove the PA pcb and resolder the DC lead 
termination but alas NG!
I will now do a bit of circuit tracing to see what supplies the 
'holding' voltage to the relay and to try to ascertain why it's not 
holding. At present as soon as I connect the supply to the connector at 
the rear it starts tick, tick, tick Grrrrrr!

Anyway it's work in progress, thanks once again and I'll let the 
reflector know when I sort it out.


Cheers
Wayne
VK6EH


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