Longwave and pF

So I would like to use the SStran AMT3000 in the longwave band, to achieve this C30 a 180 pF capacitor must be changed to a slightly higher value.

The pll with 180 pF cap installed will only allow the amt3000 to go as low as 350 KHz, anything lower and the pll won't lock on to say 170 khz.

So i did a search for a 190 pF capacitor, hmm wasn't many to choose from, so what gives?
Should i search again or is there a value slightly higher than 190 pF?

I am sure the part exists, maybe google isn't my friend anymore.

My idea is to transmit on 170 KHz LW using the SSTran even though the FCC rules allow for 1 watt, i would be happy with the 100mW -+ into a 50 foot vertical.

And I would have the Talking House 5 handle 1620 KHz duties.

I am wondering if it would be better to install a mica compression trimmer cap with a value range of 190 pF to 760 pF. The original cap is ceramic.