[time-nuts] 6CW4 Nuvistors on eBay...

Burt I. Weiner biwa at att.net
Sun May 2 20:14:22 UTC 2010

For what it's worth, I just took a look and found a bunch of 6CW4's 
on eBay.  See:


Burt, K6OQK

>From: paul swed <paulswedb at gmail.com>
>Subject: Re: [time-nuts] schematics for a HP117a please
>Thanks everyone.
>Indeed the nuvistors will be a challenge.
>Don't know if between the 2 recvrs I have enough or if they are good or
>But if need be a bit o redesign may be in order.
>I am currently using a fair size copper tune loop/preamp on a tracor 599H.
>So thats a good start. But I will dig in and see whats cooking (Or not)
>Noticed one has the creeping ground lug oxidation. Time for a drill.
>On Sat, May 1, 2010 at 1:02 PM, J. Forster <jfor at quik.com> wrote:
> > Have you tried Dave at Artek Media?
> >
> > A couple of things on the 117A:
> >
> > The antenna is a roughly 1 meter diameter loop, but has a very frequency
> > selective pre-amp built in. Early versions used two Nuvistors and a 60 KHz
> > mechanical filter. Later versions used FETs I think. The amp in the unit
> > also uses three Nuvistors. These devices are getting scarce and expensive.
> >
> > The coax between thr receiver and antenna has DC on it to power the loop
> > preamp.
> >
> > The paper for the stripchart is getting hard to find also.
> >
> > FWIW,
> >
> > -John

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
biwa at att.net

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