[TenTec] Paragon Problem

[Mike Bryce]

Ben,

the finals and the driver transistors are all connected to the +12 volt supply directly. Although a shorted driver would more than likely smoke before the final transistor simply because the final are more robust and could take a whale of a lot of current.

That's why the ten ten power supply instantly goes into over current shut down and the smaller supply goes into current limiting.

There's the possibility that the decoupling capacitors inside the PA have failed, but that's a real stretch.

did you measure resistance between the red wire going into the PA and ground?

bet you'll see it very low, a few ohms perhaps..

mike, wb8vge

On Jul 14, 2012, at 8:20 AM, Ben Hall wrote:

> Hi Mike!
> 
> Got the covers off, unsoldered the red wire going from the final amp 
> section to the power input board and it powers up fine and I hear static 
> in the speaker.  :)  Seems to operate normally - can switch filters, etc...
> 
> I think you've hit the nail on the head!  Something is amiss in the 
> driver / final section.
> 
> Interestingly, measuring from the disconnected red wire to ground and to 
> the negative power supply input shows high resistance.  Not sure what to 
> make of that.  The thought that maybe the finals are okay and the driver 
> is shorted (only shorting the finals when power is applied) did occur to 
> me, but without a schematic I'm just guessing.
> 
> Anyone have a schematic, service manual, or parts list for a Paragon?
> 
> thanks much and 73,
> ben
> kd5byb
> 
>