[Test-Equipment] (no subject)

[Stan]

Hello,

I fixed a 3586C with a similar problem. Turns out that there's an
incandescent grain-of-wheat lamp in the rotary encoder that burns out
and causes these symptoms. The control can be easily disassembled and
the lamp replaced. IIRC, it's a 5V lamp.

Hope this helps!

Stan

-----Original Message-----
From: test-equipment-bounces at mailman.qth.net
[mailto:test-equipment-bounces at mailman.qth.net] On Behalf Of Geoff Greer
Sent: Sunday, November 21, 2004 6:24 PM
To: test-equipment at mailman.qth.net; w3sz at comcast.net
Subject: Re: [Test-Equipment] (no subject)

Hi,

  This behavior sounds like your unit is unit uses an rotary encoder
with quadrature outputs.  I've seen this 
behavior on WJ radios that use this type of encoder for tuning.  Usually
it's a problem with a lamp in the encoder.  
Hope this helps.

Geoff Greer


11/21/04 16:38:36, w3sz <w3sz at comcast.net> wrote:

>Hello, All,
>
>I have an HP3586C Selective Level Meter that I use mostly for VLF  
>listening and frequency calibration work.
>
>Today the HP3586C started misbehaving; first, the frequency tune
encoder  
>started occasionally skipping.
>That is, rotating it would produce no effect for 30-60 degrees, then it

>would work OK.  Then it
>started only tuning down in frequency, no matter which way the knob was

>rotated.  It is currently
>working properly, but it has cycled back and forth between working  
>properly and not doing so several
>times this afternoon.
>
>I did the brainless stuff like reseating the boards / modules /
internal  
>connectors with no apparent effect.
>
>As I don't have schematics I am somewhat at a loss for troubleshooting.
>
>Has anyone else noticed a similar problem with a similar HP unit and if
so  
>what was the diagnosis /
>treatment?
>
>I don't have any manuals for the unit, though today I ordered the  
>operating, calibration, and parts manuals
>on CD from http://www.fullnet.com/u/tomg/manuals.htm .  Unfortunately,

>they don't include the schematics
>and I haven't found the service manuals [parts 1 and 2] for less than  
>$180.00.
>
>Thanks in advance, and
>
>73,
>
>Roger Rehr
>W3SZ
>
>-- 
>Roger Rehr
>W3SZ
>http://www.qsl.net/w3sz
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>Test-Equipment at mailman.qth.net
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>




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