[Amps] SB-220 Improvements

[Trevor Pitman]

Hello Group,

I am currently modifying an SB-220 for use on 6 meters by changing the 10 meter section as per the QST article (SB-220 0N 6 METERS) and leaving the rest of the amp band positions unchanged on HF.

Having read the previous posts on directly grounding the grids, I look for assistance with the following questions.

1 What is the best solution, directly ground the grids or leave them as original.

2 Should the grids be left original, what about applying the parasitic mods to the grids as per the other        QST article (IMPROVING THE HEATHKIT SB-220 AMPLIFIER) and what effect if any does this change have on 6 meter operation.

3 If the grids are directly grounded, should the input be changed to a L/C network or left original.

4 If the input is changed to a L/C network what is the coil/cap value for 6 meters. 

5 Can anyone advise on the recent January QST article on these changes.

Thanks in advance for assistance
Trevor
VK3VG