[time-nuts] Dead 5065A - Some comments - Some questions... (III)

[paul swed]

Ulf
I suspect we are the same "Get it done". Not a science project. Though
science comes into it.
I just find the various new devices may be more easily obtained. L&Cs are
getting hard to come by.
So far I don't have failed FETs or anything else. But that day will come.
Regards
Paul

On Wed, Aug 26, 2020 at 3:14 AM Ulf Kylenfall via time-nuts <
time-nuts at lists.febo.com> wrote:

> Paul,
>
> A 60 MHz xtal oscillator divided by 12 and comparedwith the incoming 5
> MHz. Then there is this thing
> how to acheive a good symmetrical FM injecting
> the 137 Hz signal without affecting the loop filterparameters.
>
> Keeping the original design with modern typesof semiconductors is less
> work/effort, provided that the
> unit keeps working...
> The A7 original design used a non selective2nd harmonic detector. And uA
> 709's.That one was easy to motivate an upgrade.
>
> I am a bit lazy otherwise.
>
> As mentioned, the semiconductors that have failed
> in A3 were all dated 1968.
> At the time without knowing the exact types of the JFET'sI replaced them
> with 2N4416 only to discoverthat that was the type HP specified in a
> laterrevision of the A3.
> Best Regards
> Ulf Kylenfall
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