[AMRadio] WRL Globe Champion 350

[Kim Elmore]

Hello to you all,

I'm a new list member and am delighted to find such a resource.

I've been a ham for a bit over 30 years, but almost never operated AM until 
recently.  However, my Dad, W5JHJ, has been a ham since, well, I'm not 
sure.  Probably 62 or 63 years (he'll be 81 this September).  He has had 
some health problems recently and, at 80 years old, is no Spring Chicken 
anymore. Anyway, he has some pretty neat old gear that he's maintained, 
which I used when I started out 30 years ago: a WRL Globe Champion 350 
transmitter, a Hammarlund HQ-170 receiver, and a Hammarlund HQ-110 general 
coverage receiver.  All of these he's had since new (the transmitter kit 
was purchased in March, 1959).  He also has a mint condition FT-102 in 
superb condition.

He's always maintained all of the gear in good working order and when I was 
very young (before kindergarten) was quite active.  But, with family, the 
decline of AM in favor of SSB, and increasing job responsibilities, his 
activity waned. Recently, he's become interested in operating a bit.  So, 
last Saturday, we fired everything up. Aside from dirty switch contacts, we 
got it all working fine. We even made a QSO with WA5UEK, in Plano, TX, 
early Saturday evening.

However, as we tuned up the Globe, we noticed that the plate current swings 
down under modulation.  Adjusting modulation gain doesn't seem to remove 
this tendency, though it is lessened until, of course, there is no 
modulation.  I also notice very slight negative deflection of output power, 
too.  Dad doesn't recall whether this was characteristic of the rig, and no 
mention is made in the manual.  Our signal report was fine, though we were 
only a couple of S-units above the noise, so poor audio might not be noticed.

I want to understand why we're seeing the negative deflections under 
modulation.  I'd expect positive deflections, not negative ones. What is 
this telling me about the transmitter's operation?

73,

Kim Elmore, N5OP
                           Kim Elmore, Ph.D.
                        University of Oklahoma
         Cooperative Institute for Mesoscale Meteorological Studies
"All of weather is divided into three parts: Yes, No, and Maybe. The
greatest of these is Maybe" The original Latin appears to be garbled.