John -
Beat me to it!! :-) Been lots of meters destroyed by loosening those nuts. Key to watch for is
only ONE. Expensive meters have two, one to hold the terminal in place, the other to tighten over
the solder lug. Those two extra brass nuts would have seriously affected the slightly less than $1
production cost of those meters.
They do seem to break at the coil rather than at the bolt terminal. Hopefully Steve will get
lucky! If not, they're ALL the same meter, from to 2-A to the R-4B so donor units not that hard to
find.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
John Meyer wrote:
Steve,
If you have to work on the meter don't remove the nut on the back, unsolder the wire. Go into the
meter from the front. When you do you will see why. I made the mistake and loosened the nut which
broke a very fine wire close to the coil body.
John Meyer K8IHY
----------------------------------------------------------------------------------------------------
From: w1es1...@earthlink.net
To: drakelist@zerobeat.net
Date: Sun, 1 Jan 2012 11:04:13 -0500
Subject: [Drakelist] S-meter shorted to case.
I'm working on an R-4B and fried a resistor in the metering circuit. The 560-ohm resistor is now
measuring about 80 ohms. I thought, perhaps, the resistor had simply failed, but decided to sniff
around the circuit some more before subjecting this no-longer-obtainable meter to any more stress
(it is still indicating when I put an ohmmeter across its terminals).
Whilst metering the meter (don't you love it?), I discovered that the right-hand terminal (when
facing the back of it), was shorting to the metal case! Arrrggggghhh. I played around some more
with the insulator and torque upon the nut and have it so it's no longer shorting to the case.
When I lifted that oblong insulator to peek at the screw and where it comes through the back of
the case, it appears that it is supposed to be isolated from the case - as I would expect.
What could have caused this short? I'm very much suspecting that this could have fried that
resistor. I've eliminated the short but am uneasy because I didn't see anything that fixed it
other than re-torqueing the nut.
Anyone ever have one of these puppies apart?
73,
Steve Wedge, W1ES/4
Live free or die: Death is not the worst of evils.
John Stark.
All my computers have my signature with various pearls of wisdom appended
thereto.
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