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Higher shunt capacitance in the control-grid circuit.

The 10-meter coil will probably need a couple fewer turns for two tubes than for one. The lower bands might need the shunt cap for that band reduced some.

The lower the band frequency the less difference this will make. The 80-meter input for the Pride is untuned, consists of a choke coil. The shunt capacitance the radio will be feeding into has such a high reactance at 3.5 MHz that a coil to cancel it out is not needed to obtain a good input match. Odds are this rule holds for the two-tube setup.

An antenna analyzer on the input once it's tuned up will reveal where the frequency where the input SWR dips to its lowest.

73

[QUOTE="nomadradio, post: 840943, member: 22"] Higher shunt capacitance in the control-grid circuit. The 10-meter coil will probably need a couple fewer turns for two tubes than for one. The lower bands might need the shunt cap for that band reduced some. The lower the band frequency the less difference this will make. The 80-meter input for the Pride is untuned, consists of a choke coil. The shunt capacitance the radio will be feeding into has such a high reactance at 3.5 MHz that a coil to cancel it out is not needed to obtain a good input match. Odds are this rule holds for the two-tube setup. An antenna analyzer on the input once it's tuned up will reveal where the frequency where the input SWR dips to its lowest. 73 [/QUOTE]

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