[Central-Electronics] 600L Question

[Robert Nickels]

On 10/7/2011 7:04 PM, Donovan W. Case wrote:
> I keep looking at the 45uF / 1800V oil-filled cap thinking
> that would be a tough one to find today, but perhaps there are other parts I
> should be focusing on that are prone to failure in a 600L?
>
Donovan,

Congrats on the 600L - it's a fine piece of equipment and dependable, in 
my experience.   I suspect that oil-filled cap will be working long 
after most of our are gone - I've yet to come across one that has failed 
(unlike electrolytics and other types).

I think the best advice is to really understand what the 600L can do, 
and treat it gently.   To me that includes making sure it sees a proper 
50 ohm match, the line voltage is within the design range, and that you 
don't overdrive it.   (I use an attenuator even when driving it with my 
Retro-75 QRP AM rig just to keep the 813 happy).   Of course a scope is 
the best way to make sure you're putting out a good clean signal.

While it works well, the power relay control circuit isn't easy to 
figure out, and can be frustrating to troubleshoot.  Several I know of 
have replaced the electrolytic caps, either to fix a problem or on 
general principles, but that's about it.   The only other problem I've 
had was a mechanical one - the spring that applies tension to the 
armature of the latching type Guardian overload relay failed, making the 
relay trip when it shouldn't.   Fortunately it was an easy fix once I 
realized what the problem was.   Treat the relays with great care as 
they're hard to find, and be sure to use a proper contact burnishing 
tool if cleaning is done.

A number of years ago I was a 600L for sale that had the optional 
antenna switch mounted on the rear.  This switch was coupled to the 
bandswitch to automatically select the right antenna for each band, 
another little feature that Central Electronics had before anyone else.

73, Bob W9RAN