[time-nuts] The "NAKED" 5065A optical unit

[paul swed]

Corby no intent to rework the bulb.
Its just I have had good success with bulbs from the FE-XXXX series when
they fail to operate by heating the bulb to re-vaporize the "Stuff" that
plates out. Wasn't sure if this would be an approach on the 5065 when that
day comes for mine.
Regards
Paul
WB8TSL

On Tue, Feb 20, 2018 at 1:03 PM, <cdelect at juno.com> wrote:

> Paul,
>
> You do NOT want to take one apart to this level!
>
> It's never going to operate again.
>
> If you look at the lamp in the PIX you will see a white coil wrapped
> around the bulb.
>
> This is the tank for the 90Mhz drive and it sits cocked at a 45 degree
> angle.
>
> The lamp assy can be removed easily via 3 small screws and repaired or
> modified.
>
> The Lamp circuit is designed to put out a bit higher RF level and once
> the lamp starts it drops down a bit.
>
> I would question re-engineering the lamp circuit as it can easily reach
> 1.5X10-13th at 100 Sec stability and 5X10-14th at 100 Sec. with the
> filter mod.
>
> Unless you have a maser or BVA to compare against how will you know if
> any modifications are going to help or hurt?
>
> The only thing I replace even if it measures OK is the 1.33K resistor as
> it will "crack" eventually and change value.
>
> A 1.3K 5% 1W metal oxide works well.
>
> Cheers,
>
> Corby
>
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