With that tempco, it will drift with RF power. You'd be better off
with N750 or even better with NPO. You can buy NPOs in values under
about 75 or 100 pF in 5kV rating I think. Would take a lot of them,
but they are much more stable. The Micas would work at 160, but start
to have a lot of inductance and loss above 3 MHz. I plotted a bunch
of them (large ones with 0.01 uF for instance) with an Hp impedance
meter 5 years ago, and was amazed at how they turned into lossy
inductors above 5 MHz.
>From: 2 <2@vc.net>
>To: "Lynn" <no9z@soltec.net>, "AMPS" <amps@contesting.com>
>
>>N3300 3 amps @1mhz 400pf quantity 4 7.5kv
>>
>? Tnx. This type of dielectric is not rated for tuned circuit
>applications, however it works ok for bypass and coupling
>applications. For 1.8MHz padders, 2000v mica caps are good. See
>Cornell-Dublier Web site for the nitty gritty.
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