[ARC5] ARC-5 Screws

[Kenneth G. Gordon]

On 9 Mar 2012 at 17:50, Mike Morrow wrote:

> Well, that's close.  

I thought as much: I was working from memory of several NIB receivers I 
have had over the years.
 
> For all of the classic MF/HF command set gear, to remove *any*
> component (cover, bottom plate, adapter panel, etc.) the associated
> screws must be *completely* removed.  The only "loosen and slide"
> fasteners are on the Western Electric VHF gear, especially the
> R-28/ARC-5.
> 
> The receivers use nickel-plate screws for:
> 1.  The front adapter panel (4)
> 2.  The bottom plate (14)
> 3.  The tube cover  (8)

What this means is that any part that must be removed for routine service is 
held on with nickle-plate (I thought that plating was cadmium) screws, 
whereas those parts that are not normally removed are held with black 
screws.

Also, I must take a little bit of exception to your statement that none of the 
screws must be loosened to remove a part: in fact, I have found that the 
black screws MUST be loosened a bit in order to get the tube-cover off 
without bending it. Perhaps those were simply over-tightened by a later 
user...

>     Note:  There are also 15 black screws on the periphery of this
>     cover. ONLY the 8 plated screws must be removed.  The black screws
>     do NOT need even to be loosened in order to slide the cover off. 

In my experience, that is not necessarily true. :-)

> All screws should have an internal tooth washer around them.

Yes. I figured that out. And NOT finding those on even one screw would 
indicate to me that someone had had them out.

> True.  The ARA/ATA, SCR-274-N (regardless of finish), and AN/ARC-5
> sets all follow the convention described above.
> 
> It makes sense.  And it's a clue for determining that a ham may have
> tried improving one of these units when this convention has not been
> followed, assuming that more than one in ten screws have even been
> re-installed.
> 
> What doesn't make sense is why so many of these damned little screws
> were used at all.  

Well, **I** think they are pretty in that use! Makes it look somewhat like a 
riveted boiler on a steam engine or the rivets in an airplane. :-)

This is why I always replace ALL the proper screws when I work on any of 
these receivers or transmitters. I like the finished look.

> I mean...19 just for attaching the transmitter
> cover!  Oddly, the sensible folks at Western Electric, which
> eliminated some of A.R.C.'s worthless pre-war extravagance, did *not*
> get rid of this nonsense except for its native design for the VHF sets
> (R-28 and T-23/ARC-5). 
> 
> > Dave or Gordon or Mike might have exact details.
> 
> I'm not the Mike to whom you refer, but I'll jump in anyway. :-)

Actually, yes you WERE the "Mike" to whom I was referring! You have 
proven repeatedly in the past to have an immense knowledge (or a big 
library) of historical facts that I find very fascinating and useful.

I was hoping you would jump in here, and you did. Thanks.

I guess in order to make it more clear, I should have said: "Dave or Gordon 
or Mike or Mike..." (Hee hee!) :-)

Ken W7EKB