[Amps] Henry hum on transmitted signal

[r-emails at n5ot.com]

I see there was no content in my messages the first time around.  I'm 
not sure what the problem is, but the workaround is to use a different 
email program.  Here's what I wrote:
- - - - - - - - - - - - - - - - -
Greetings,

I have a Henry 2K-4A console, and when I use it on the air, a few people 
have told me my signal is not pure.  One described AC hum on both sides 
of my signal frequency.  Another friend said I had "sidecars."

My conclusion is I need to replace the big (oil-filled) capacitor in the 
power supply.  I have a friend with an older Henry, I think it was a 
2K-3 console, who had a similar-sounding issue, and he says he changed 
his big capacitor in the power supply, but it didn't really fix the 
problem.  He sold the amp and I got the capacitor that didn't fix his 
problem.

Two questions:

1. Am I looking in the right direction or the wrong direction?  Any 
other PS due diligence I need to do?  Any Henry 2K-4A-specific anecdotes 
in the brain trust?

2. My Henry has the factory capacitor from the 1970s, which is 20uf @ 
5000 volts.  The replacement I have says "replacement for Henry 
capacitor" but the values are 16uf @ 7500 volts.  It's close to the same 
physical size but not exactly the same size.  It has a 2019 date stamp.

Guidance appreciated.

73 - Mark N5OT