[Boatanchors] Hickok 600A

[Rob Atkinson]

Jeez, just put in another 83.

https://www.ebay.com/itm/145413285090

Rob
K5UJ

On Mon, Nov 13, 2023 at 10:37 PM Jacques Fortin <jacques.f at videotron.ca> wrote:
>
> Hello Walt,
> When you mention that you have gone "solid state" is it just a pair of
> silicon diodes you used to replace the 83 rectifier ?
> A 83 drops a fairly constant 15 volt between each conducting plate and
> filament.
> To mimic a 83 behavior, you have to either add a 15V Zener in series with
> each diode or use a single 15V (5W) Zener between the center tap of the 83
> filament winding and the rest of the circuitry.
> But the biggest problem is not there: it is related to the global power
> transformer loading and the line voltage adjustment.
> Replacing the 83 with solid-state devices only also remove a 15W load from
> the transformer and this affect the calibration of the line adjustment.
> You can then use 6 x 10 ohms, 5W resistors in parallel to mimic the 83
> filament load (5V, 3A = 1.6666 ohms).
> This way, all the global calibration of the tester will be preserved.
> BTW, the 600A uses the same circuit and settings than the 533A.
> On our side of the border, the Stark 9-66A and it's "upgrade", the Canadian
> Marconi MU-101, also uses the same basic circuit with some minor changes.
> Incidentally, the MU-101 is a "solid-state adaptation" of the 9-66A.
>
> 73, Jacques, VE2JFE in Montreal
>