Does the L4B use the Eimac tube chimney and matching tube socket?

The tube pins can get so hot the soldered connections on tubes without the
chimney/socket [i.e. Heathkit Cooling] can and do melt at 100% duty cycle at
full power.

K3HVG wrote:

FWIW, Although the Drake manual for the L4B says that tuning/operation
for CW and RTTY are the same, in one of my L4B books, there's what looks
to be a 2nd or 3rd generation copy of a Drake letter that speaks to RTTY
activity. The Drake letter recommends that the power level for RTTY be
limited to 400 watts, citing the near 100% duty cycle, when key-down. I
guess you take your pick? I run mine at about 400 watts, just to be on
the conservative side.......

John, N9JG wrote:

I have a Drake L-4B, which I purchased new in about 1975. Recently I
have started to use RTTY mode with the L-4B, and I have some concerns
about what is the safe RTTY power level for this amplifier. The Drake
easily puts out 1 kW into my antenna, but during an RTTY contest the
transmission duty cycle can approach 50%. During a long-winded rag
chew, a transmission might be as long as five minutes (just like the
old AM days!). I am reasonably certain that the L-4B (both the
amplifier deck and the PS) can withstand long transmissions at (say)
500 watts out, but my concern is with the 1000 watt level.

John, N9JG