[Amps] Amplifier lifetime

[Jim Thomson]

Date: Thu, 5 Oct 2017 08:59:49 -0600
From: Jim Garland <4cx250b at miamioh.edu>
To: Manfred Mornhinweg <manfred at ludens.cl>, amps at contesting.com
Subject: Re: [Amps] Amplifier lifetime

<Hi Manfred,

<I've got an NCL-2000 that has a similar history to yours. Like you, I 
seldom use it, but think it is a well-designed amplifier and arguably 
the nicest styling of any amp before or since. Replacement tubes are a 
problem, of course, but I've got a couple of spares on hand. As I 
recall, the bias circuit is quite clever and, with updated components, 
works very well.

Interestingly, my NCL-2000 blower is rather quiet and has never posed an 
irritation. I'd be interested in hearing comments on that issue from 
other owners.

One design issue I've never liked with the amp is the T/R relay, which 
uses a 6VAC coil. This rules it out for use with modern transceivers, 
unless one uses an isolation circuit. In my station, I use my StationPro 
controllers for my amplifiers, which can accommodate any AC or DC 
antenna, so that isn't a problem

73,

Jim W8ZR

###  6 vac X 2.828 =  17 vdc.  Use a 12 vdc vac relay, problem solved. 
Im sure the oem blower could be replaced with one of the myriad of blowers
out there from ebm papst, or Dayton.  The newly re-designed dayton blower line up
draws just half the current of the old versions.   New version all use ball bearings. 
Old versions use sleeve bearings.  Then there is Kooltronics and a bunch of other blower
makers as well.   They should be good for 40 K hrs. 

Jim   VE7RF