[ARC5] T-19 Update

[Neil]

> The proper way to check the level of drive is to measure the DC volts
> across R74, the 15K grid bias resistor. You can measure that with the
> 1625's keyed or unkeyed and it should hardly vary from one to the other.

I wrote the above but didn't make clear that I was referring to keying of
the 550VDC supply to the 1625's by contacts in the modulator, as was
done in the original configuration.
If the 1625's are keyed in the cathode leads (as many hams prefer to do),
the grid current will fall to zero each time the contacts open.

73 de Neil ZL1ANM