[Milsurplus] ARC-2: Smart People Needed

[Ian Wilson]

I set up a quick simulation, but had to guess at the component values.

Dave - what value are the capacitors across the IF coils (alternatively,
what
inductance are the coils)? I am assuming a frequency of 1.25MHz approx.

My simulation says reducing the coupling capacitance makes very little
difference (since tube plate looks like 500k ra and 7pf output capacitance
(plus strays)), I wouldn't have expected the coupling cap to make any real
difference.

The BW did go up fractionally but nothing you'd notice.

This situation usually means that the model doesn't represent the true
situation. I only modeled one stage (not that that would change anything
dramatic). So please send component value(s) and I will take another look.

73, ian K3IMW




On Wed, Apr 2, 2014 at 8:43 AM, David Stinson <arc5 at ix.netcom.com> wrote:

>
> ----- Original Message ----- From: "Ian Wilson" <ianmwilson73 at gmail.com>
>
>
>
>  Are the IFT primaries and secondaries coupled by both magnetic (proximity)
>> coupling and capacitive coupling (the 5pF caps) or only by the caps?
>>
>
> The schematic shows both windings in a single shield
> but if you look at the coil rack itself, the primaries and
> secondaries are completely shielded from one-another
> in individual metal cans.  The only coupling, unless there
> is some residual magnetic through the open ends of
> the shield cans, is through the 5 pFd cap.
> The later AN/ARC-2A manual shows
> the correct shielding.   Maybe disconnect the 5 pFds
> and see if there's enough residual coupling to
> do the job?
>
>
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