[Collins] 51J4 and AC Power gremlin questions (long post)

[Robert & Linda McGraw K4TAX]

Your wiring gremlin is a loose neutral.  It's making contact to provide 
current for the indicator and the VOM but won't carry any load.  Did you 
connect the receptacle via using the "push the wire in the hole means" or 
around a solid screw?  Bet you used the first method.  I've found many of 
these to be the source of the fault.  Check each recpt and circuit breaker 
by visual inspection, tug and wiggle the wire.  If you used the push the 
wire in the hole method Change it, put a hook on the end of each wire, put 
it under the screw and make it tight.  It will then last for years.

73
Bob, K4TAX

----- Original Message ----- 
From: "Chris Kepus" <ckepus at comcast.net>
To: <collins at mailman.qth.net>
Sent: Sunday, November 06, 2005 1:16 AM
Subject: [Collins] 51J4 and AC Power gremlin questions (long post)


>
>
> Friday evening I finally hooked up and started using my 75S3 and 51J4.
> Sadly, the beginning of my fun was interrupted by a very strange and
> bewildering power problem that I am submitting to the group in the hopes
> that someone has "been there" or "done that".  My shack wiring is two 
> years
> new, wired and inspected to code.  The power source for the circuit in
> question is a 120V 20 Amp breaker followed by a 20 amp GFCI.  The GFCI
> output feeds 7 duplex receptacles in the shack.  The circuit has been in 
> use
> over the past two years and has worked FB.
>
> Friday evening this circuit was feeding my Collins receiver "power supply"
> (a variac controlled isolation transformer) which in turn was providing
> power (and "power on" switching) for my 75S3 and 51J4.  All was well.  It
> was the first time in several years that the 51J4 was fired up.  It worked
> great.  I did notice, however, that the 3 kc filter on the 51J noticeably
> reduced the signal strength compared to the 6 kc filter (even more than 
> the
> 1 kc filter).  I also noticed that if I switched in the crystal filter to
> position 1, the signal strength increased on all the mechanical filter
> positions.  Hmmmmmm.  Why is that?  I know filters have insertion losses 
> but
> I didn't think there was that much difference between the 3 kc and 6kc
> filters.  Is this normal?  Why did switching in the crystal filter make 
> such
> a positive difference?
>
> Saturday evening, I went back into the shack to resume my play with the
> receivers.  I turned on the "power supply" but the pilot light didn't come
> on and the receivers didn't light up.  Scratching my head, I checked the
> power plug.  It was solidly in the receptacle.  I tested the GFCI and 
> cycled
> it.  It was OK.  I checked the 20 Amp breaker.  It was "ON" (normal) but I
> cycled it anyway.  But the outlet my "power supply" was using was still
> dead.  I checked for power on the circuit by plugging a lamp (with a known
> good bulb) into each of the other 6 receptacles with the same result as 
> with
> the receivers.  No power/no light.
>
> I unplugged everything that was on this circuit and then performed two 
> tests
> on all the receptacles.  For the first test, I used a plug-in circuit 
> tester
> that tells you with a three light combination if you have wired the
> receptacle correctly or if you have a problem.  All the receptacles tested
> AOK.  More head scratching.  What the heck is going on?  For the second
> test, I took my multimeter, checked all the receptacles and found 120V at
> each receptacle.  I felt better.  Where there's power, there's light! I
> plugged in the lamp and switched it on.  The light did not come on.
>
> Now I am into very serious head scratching.  What the H--- is going on?
> Determined to figure out what was going on, I moved to a set of side by 
> side
> duplex receptacles for yet another test.  I plugged in the circuit tester,
> plugged in the lamp (turned off) and connected my multimeter to the third
> outlet.  With the breaker "ON" and the lamp switched off, the circuit 
> tester
> showed AOK (wired correctly) and the multimeter showed 120 V.
>
> I then switched the lamp on.  Rats! No light...again.  But the circuit
> tester light pattern changed from AOK to a pattern that indicated the "Hot
> and Ground wires are reversed", and the multimeter reading was now "zero
> Volts"!  What???!!!  When I switch the light off, the circuit tester 
> pattern
> changed back to AOK and the multimeter showed 120V. !!  In the meantime, 
> the
> breaker did not trip.  I did bypass the GFCI but that had no effect.
>
> So in summary, when there is nothing plugged into this circuit, both the
> circuit tester and the multimeter results on each of the receptacles are
> positive.
>
> The instant a load is connected (plugged in, turned on) the circuit tester
> indicates the "Hot and Ground wires are reversed", and the multimeter
> reading shows "zero Volts"!  This result is the same regardless of the
> receptacle being used.
>
> So gents, does anyone have an idea about what is going on with either the
> 51J4 or with my wiring gremlin?
>
> Please excuse the long post,
> 73,
> Chris
> W7JPG
>
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