also if a chokes rating says 60 hz can it be used at double the frequency if so what happens to the voltage and current rating and does the h rating change at all
i have a 10H @ 600mA 3100VDC 60Hz choke i was thinking about using
There is nothing critical about the frequency rating of a choke. Inductance doesn't change significantly with frequency. Some people successfully use power supply chokes as modulation reactors. I'm not sure why the manufacturer even puts a frequency rating on a filter choke.
The .15 mfd is probably OK for capacitance. The question is whether it has high enough voltage rating. The a.c. voltage rating should be somewhat more (as safety margin) than the peak ripple voltage. To be on the safe side, make it at least about 50% more than the DC power supply rating. Just any old 0.15 mfd capacitor won't do. They tend to blow up very easily. Adequate resonating capacitors are hard to find; that is the reason why resonant filter chokes are so seldom used. For a typical plate supply, that 0.15 cap would need to be rated at about 4 kv. Another problem is that capacitance may be substantially different from the nominal value. Typically, a 0.15 mfd cap may have something more like 0.2 mfd actual capacitance. For some reason, capacitance of both electrolytic and oil capacitors tends to be higher than the value stamped on the case. Be sure to measure it with a capacitance meter or bridge, or else be prepared to use trial and error if you have several suitable capacitors on hand to substitute.
The size of that choke @ 600 MA is way more than what you need for a screen supply filter at amateur radio power levels. That is more like what you would use in the main plate supply.
