[TenTec] Low power output on Argonaut V

[Dr. Gerald N. Johnson]

On Mon, 2007-07-30 at 16:26 +0100, Bob Towers wrote:
> Some time ago the power output on my Argonaut V dropped to nearly zero 
> on all bands.
> 
> TenTec say the most likely cause is
> 
> a) one or more of the switching diodes in the LPF circuits
> or
> b) blown finals
> 
Open switching diodes in the LPF circuits could lead to blown finals by
letting the transistors develop excess voltage when not loaded. An open
makes a high SWR for the transistors.

> I rarely ran it at more than 10W and was always pretty careful about 
> running it into high SWRs.
> 
> The rig is well out of warranty and getting it to TenTec across The Pond 
> and back is pretty expensive, so I'm wondering whether to find and fix 
> the problem myself.
> 
> I've recently built a K2, so I'm not too scared of complex PCBs.
> 
> Has anyone fixed a similar problem themselves? If so, any help would be 
> much appreciated.
> 
> 73
> 
> Bob Towers
> MM0RKT
> 
73, Jerry, K0CQ