[RFI] RF tight rooms - somewhat OT

[Tom Thompson]

Charlie,

It seems to me if your friend just wants to make Q-meter measurements he 
might get by with building a 5-sided aluminum box just to contain his HP 
Q-meter since he is probably making measurements in the AM broadcast 
band frequency range.  He needs to make the box big enough to maintain 
at least a coil diameter from the top of the box when the coil is 
attached to the Q-meter.  This won't be perfect isolation like a screen 
room but it will might be good enough and a whole lot easier.

Tom   W0IVJ


On 5/11/2013 9:34 PM, n0tt1 at juno.com wrote:
> Hi Gents,
>
> I know a crystal radio enthusiast in CA that lives near
> a 50KW BCB radio station.  He's been having trouble
> making Q-meter measurements on some of his hi-Q
> coils using a HP Q-meter.  He's been making
> experiments with various shielding methods
> using an AM BCB portable radio as a detector.
> He says that the best he's found so far is aluminum
> foil, as long as the "seal" is tight.
>
> To make a room that is large enough for him and a bench
> takes a LOT of foil.  The floor, ceiling, walls, floor and a
> good seal on a screened door would be needed for a
> really good RF room.  The power for the room would also
> have to be filtered or he could use a computer's UPS.  The
> shielding would be grounded, and the shielding, whether
> it's say, chicken wire, AL screen, etc would have to be
> bonded together at the corners.  Then the door would
> have to be sealed as well (maybe metal weatherstripping
> for that?).
>
> My question to the group is what, in your opinion, is the
> best/cheapest RF-tight test room he could build for himself?
> Has anyone on this list done that?
>
> 73,
> Charlie, N0TT
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