[Amps] NCL 2000?

David A. Pruett k8cc at comcast.net
Thu Oct 2 00:10:01 EDT 2003


The idea of re-tubing an NCL-2000 with Svetlana tubes is quite 
intriguing.  I would think it would be virtually certain that the 4CX400A 
would fit, since it is slightly smaller in diameter than the 8930, which is 
in turn slightly larger than the 4CX250.  While this might not make legal 
limit by the datasheets, it's probably a good match overall (plate 
dissipation, power supply, etc.) to the original 8122s.  They are, however, 
relatively inexpensive - RF Parts sells them for $140 each, and I suspect 
somebody like W4TH might beat that price.

I've had good results from the 4CX800As in my Alpha 91b, however these are 
larger in diameter and might not fit the NCL-2000 chassis layout.

Dave/K8CC


At 10:17 AM 9/30/03 -0700, Steve Katz wrote:
>Hi Rich,
>
>I'll bet the Svetlana mod would be do-able, and probably cheaper than almost
>any other mod, but I've never tried it.  Next time I have an NCL2000 on the
>bench with dead 8122s (it will eventually happen!), I'll suggest this to
>whoever owns it and would be pleased to tackle the job!  Years ago I
>modified one NCL2000 to 8874s in GG, and it worked out well but certainly
>was not cheap.  I added a tuned input board, which added about $100, not to
>mention the horrendous cost of the tubes....-WB2WIK/6
>
>"Success is the ability to go from failure to failure with no loss of
>enthusiasm." -Winston Churchill
>
> > -----Original Message-----
> > From: rlm [SMTP:r at somis.org]
> > Sent: Tuesday, September 30, 2003 9:30 AM
> > To:   Steve Katz; AMPS
> > Subject:      RE: [BULK] - [Amps] NCL 2000?
> >
> >
> >
> > >It's a very pretty amplifier that is, of course, also quite old, c. 1966
> > or
> > >so.  As such, if it has its original filter capacitors they should be
> > >replaced, along with their equalizing resistors.  The 8122 replacement
> > cost
> > >is scary, but many have converted to other tubes successfully.  ...
> >
> > EUR  Steve -- would conversion to Svetlana 4cx400s or 4cx800s be do-able?
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps




More information about the Amps mailing list