[AMRadio] WTB: WRL Globe King 500-C (or A)

[Donald Chester]

>From: Charles Ring <charlesr at infonline.net>
>
>It's conventional plate modulated AM and fit for continuous duty - what is 
>to dislike about it?

I never owned one, but I have kept a couple of them on the air for friends.

I dislike the under-rated components in the rf final, and the under-rated 
modulator.  Neither transmitter would ever make more than 85% positive peak 
modulation no matter what we did.  The final amp runs too much plate voltage 
compared to the modulater (1800 volts on the final, 1250 on the modulator, 
as I recall).

Anothe dislike (that is easy to fix) is the "couplettes" they use between 
audio stages that make the audio sound like sideband.  I yanked all those 
out and replaced them with conventional r-c interstage coupling circuits, 
resulting in much improved audio.

Many Globe Kings I hear on the air have hum on them.  I suspect it is a vfo 
problem causing 60 or 120 Hz frequency or phase modulation of the carrier, 
since I have heard users say they replaced the filter capacitors and the hum 
did not change.  The ones I worked on didn't have that problem.

I think the earlier Globe King 400's with the plug-in coils and pushpull 
triode final is a much better transmitter.

Don K4KYV

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