[Elecraft] Trying to get help, one more time...

[W3FPR - Don Wilhelm]

Michael,

An 8R voltage of 6.43 volts is an indication of something wrong there - it
should be about 7.5 volts, no lower than 7.35 volts.

Have you checked the input voltage (emitter) to Control Board Q2? (should be
8 volts unless the regulator output is low) and the base voltage (should be
about 0.7 volts below the emitter voltage) - if both those conditions are
true, the trnasistor should be conducting properly.  Is the voltage at the
drain of Q4 close to zero volts?  If not, Q4 is not conducting properly -
check the gate, it should be at least 4 volts (normally almost 5 volts).
You may have something drawing too much current from the 8R line or Q2 or Q4
may be bad.

73,
Don W3FPR

> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net]On Behalf Of Michael L.
> Hasenfratz Sr.
> Sent: Saturday, April 16, 2005 3:37 AM
> To: elecraft at mailman.qth.net
> Subject: [Elecraft] Trying to get help, one more time...
>
>
>
> 	Does anyone (i.e. Elecraft) know the Auxbus protocol? And
> is the spec
> available?
>
> 	I beleive, in trying to find out why the 8R voltage is at
> 6.43v, I blew the
> MCU (controller board) AuxBUS output.
>
> 	I only see pin 40 drop a few tens of millivolts during a band change
> request.
>
> 	The IOC starts and stops the clock on power up, no relays
> change and that's
> all the RF board does.
>
> 	Info 080 is displayed during powerup and on a band change request.
>
> 	That says the IOC or the AuxBUS is in trouble.
>
> 	Since I didn't get any response for my last question, I'm
> hoping this one
> is more interesting to the readers.
>
> 73's de Mike WA6FXT
> // wa6fxt at arrl.net
> // mikeh at tothe.net
>
>
>
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