[time-nuts] schematics for a HP117a please

paul swed paulswedb at gmail.com
Sun May 2 17:17:21 UTC 2010


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
bad...
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.

Regards

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
>
> ==============
>
>
>
>
> > Just picked up 2 units at a flea market today.
> > Would like to fire them up without smoke. :-)
> > Would appreciate schematics if the are out there.
> > My search so far is 0
> > Thanks
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