[ARC5] Hewlett Packard Signal Generator HP-606B - Removing screws

[D C *Mac* Macdonald]

Xcelite makes several hex wrenches in 7/64 " size. 
The 99-PS-60 set contains both 7/64 AND 9/64. 
The small short set (forget the set number) has
the 7/64 as one of the eight bits in the set. 
 
Quite a few other tool suppliers have these. I 
suspect you can even get them in the "T-handle"
style. 
 
I did not intend to mislead when I "GUESSED" that 
the know screws MIGHT be Bristol/spline. 
  
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* k2gkk at hotmail.com * 
* (Since 30 Nov 53) * 
* Oklahoma City, OK * 
* USAF, Ret (61-81) * 
* * * * * * * * * * * 
 
 
 
> From: 1oldlens1 at ix.netcom.com
> To: arc5 at mailman.qth.net
> Date: Thu, 1 Mar 2012 18:50:58 -0800
> Subject: Re: [ARC5] Hewlett Packard Signal Generator HP-606B - Removing screws
> 
> 
> ----- Original Message ----- 
> From: "Leslie Smith" <vk2bcu at operamail.com>
> To: "ARC-5 List" <arc5 at mailman.qth.net>
> Sent: Thursday, March 01, 2012 4:28 PM
> Subject: [ARC5] Hewlett Packard Signal Generator HP-606B - 
> Removing screws
> 
> 
> > Hello Group,
> > I have a 1960's vintage signal generator I wish to use to 
> > calibrate my
> > ARC-5 "command" radios.
> > The model: HP-606B.
> >
> > At the moment it's un-servicable or SNAFU.
> > To get inside the RF cage I need a special tool (an allen 
> > key or hex
> > key) on a long shaft.
> > Normally this is supplied by HP, with the instrument, but 
> > alas ....
> >
> > I am unable to find the correct size allan key.
> > 1/8 is too big, and 3/32 is too small.
> > 3 mm is too big and 2.5 mm is too small.
> > Beyond that I WILL need the correct size on an extended 
> > shaft (may have
> > to drill & silver solder a shorter key onto an extension).
> >
> > Perhaps it's 2.54mm or 0.100 inches?
> > Help! <- almost begging!
> >
> > 73
> >
> > -- 
> > Leslie Smith
> > vk2bcu at operamail.com
> >
> 
> The screws are standard size allen heads 6-32 x 3/8.
> Shield box screws have No.6 outside tooth lock washers on
> them, the ones that go on the mounting brackets have No.6
> flat washers. Some units have split lockwashers. The wrench
> is a special and are often missing. It is 0.1087 across the
> flats. This is a standard size, 7/64".
> I made a usable wrench from a long handled T wrench by
> cutting off one side of the T. I think the standard Xcelite
> wrench with extender will also fit, perhaps it takes two
> extenders. I have a vague memory I used an Xcelite at -hp-
> in preference to the long L wrench although I kept a spare
> in my kit. The only screws you really need the long wrench
> for are the ones in-between the shield box and power supply
> although its pretty handy to have for the others too. The
> sets are available via the web from a lot of places. I got a
> set at a decent price from Amazon. They are expensive but
> are very useful. You _may_ have to get an extra extender.
> You need a wrench about ten inches long.
> 
> 
> --
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com