Hammond box to shield Eros guts?

milosz · 3037

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Offline milosz

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on: July 03, 2011, 11:44:38 PM
I read somewhere that the Eros is sized in a way that allows a Hammond box (chassis / case / enclosure WHATEVER- ) to be bolted to the underside somehow to act as a shield.

I live in a high RFI location.  I should probably shield everything. Aside from the strong field at 89.7 MHz from the radio station antenna on the roof of the building (yes, really) there's all those rays that the CIA uses to read our minds, not to mention the aliens from Epsilon Eridani-IV and their probes, Google's scanning schemes and who knows what all....

Anyway, what Hammond enclosure works with the Eros - what model#?, and how is it mounted?  

Maybe I'll buy two, and put one on my head..... probably work better than the aluminum foil fedora I currently use......

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ft1.gstatic.com%2Fimages%3Fq%3Dtbn%3AANd9GcRM7HbBQR86kyiFccx6b7hnzX1UbL66WuWiG6umX3OMs_lo37dG3g%26amp%3Bt%3D1&hash=a339c048ba0dfd27a8c73543bb7f1fcdb86c7fe6)

« Last Edit: July 03, 2011, 11:47:13 PM by milosz »



Offline milosz

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Reply #1 on: July 05, 2011, 11:18:41 PM
No reply? 

No one knows which model of Hammond enclosure is supposed to work as an internal shield for the Eros?



Offline Grainger49

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Reply #2 on: July 06, 2011, 12:39:52 AM
I contribute it to the holiday weekend and summer doldrums combined.



Offline Doc B.

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Reply #3 on: July 06, 2011, 08:18:27 AM
When we designed the initial Eros layout we picked a die cast Hammond box whose width and length fit over prototype preamp circuit layout. Sorry to say that I don't have a number handy, but it's just a little narrower than the 8" wide plate and just big enough front to back to fit over the preamp part of the circuit, but not the regulator. A look at the possibilities shows there might be something in the 1550 or the 1590 series (1590 E maybe?) that could work. In that iteration the preamp used some short bypass electrolytics on the PC boards that would fit inside the box. Those turned out not to work and we had to go to a taller capacitor that makes fitting the box over everything a real hassle, so we left the holes off the chassis. In practice we haven't found a need for the box in the environments it has been used, but I haven't used one near a transmitter other than the cell tower that is about 75 yards from our metal office building. The EF86s may be the most sensitive part of the circuit in terms of RF pickup anyway, so the box might not make that much difference. I would suggest taking a ruler to the underside and looking at the Hammond spec files before you order. You might have to reconfigure the caps at the edge of the PC boards to get them to fit.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline milosz

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Reply #4 on: July 09, 2011, 12:07:26 AM
Oh, good.  That might fit my head, too!  ;-)



Offline Grainger49

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Reply #5 on: July 09, 2011, 02:07:15 AM
I meant to comment on the head gear in my first post.  Aging eyesight that I have I had thought it was gray hair until I read closer then looked closer. 

I think you will need a bigger box for your head.