[Amps] Attenuator needed

[Larry]

Vic,

I think you just got a bad resistor. I've been using similar resistors 
(from digikey) for my attenuators up to 100 watts and 144 MHz with no 
issues at all. You can see photos of one of them on the 3-500 amp topic 
on my web page.

73,

Larry - W7IUV
central WA - DN07dg
http://w7iuv.com



On 15-Nov-10 12:38 PM, Vic K2VCO wrote:
> I made a 6 db attenuator for the input of my grid-driven amplifier in order to bring the
> drive requirement up a bit and to provide a better SWR for the exciter during tuning. I
> used some film resistors from Mouser. I suspect that these have a low voltage rating,
> because one of them shorted after a few minutes of 10-meter operation. They didn't show
> any sign of heating, so I think it was a voltage/frequency issue and not simply overheating.
>
> Anyway, I need a 50-ohm attenuator that can dissipate about 40 watts and can be used at
> HF. Anything from 3 to 6 db will work. I had a Henry solid-state amp that had a couple of
> these, which bolted to the heat sink. Does anyone know where I can buy such a thing, or
> how to make one from reasonably priced parts?