Got a used 238 tuner. What size external cap do you use to extend range
on 160?
Each of the internal caps that get selected by the switch are 470 pf, so you
get a little less than 2,500 pf will all of them engaged and the variable
cap (500 pf) at full. To give the maximum range, you would put a 2,000 pf
cap external, but a smaller one will work in most cases.
That is a good answer. Though, depending on the 160 meter antenna you
are trying to match, you may not need it at all. If you have a 160 meter
antenna with a "not too high" SWR, say perhaps 2:1 or less, and you are
using the 238 to get it just right for your transmitter, it will
probably do it without the added capacitance. I have a 238, without the
external capacitor, and have been able to tune any 160 meter antenna I
have tried so far. I do attempt to build my antennas for a fairly low
SWR without the tuner though.
DE N6KB
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