[Amps] Alpha 87A Power Supply Question
Gary Schafer
garyschafer at largeriver.net
Mon May 3 23:57:46 EDT 2021
To clarify, the way you describe having the amp wired you have a loop with
neutral tied to ground at the amp via the coax cables to the other equipment
that is connected properly to ground.
73
Gary K4FMX
> -----Original Message-----
> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of
> Gary Schafer
> Sent: Monday, May 03, 2021 10:47 PM
> To: w5cul at sbcglobal.net; Amps at contesting.com
> Subject: Re: [Amps] Alpha 87A Power Supply Question
>
> I think that I see your problem. The ground wire should never
> carry ANY current. It is not a substitute for neutral.
> With the old wiring system for dryers of 2 hot and neutral (3
> wires total) it had to be a dedicated circuit with no other
> connections to that line.
>
> You need the amp chassis connected to the GROUND lead only.
> All other outlets on your secondary box must have their
> grounds connected to the ground lead also. The neutral leads
> from the other outlets should go only to the neutral wire
> back to the main panel.
>
> The GROUND and NEUTRAL should be bonded together ONLY in the
> main panel, nowhere else!
>
> The amp should be wired only to L1, L2 and GROUND wire.
>
> 73
> Gary K4FMX
>
> > -----Original Message-----
> > From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of
> > w5cul at sbcglobal.net
> > Sent: Monday, May 03, 2021 9:29 PM
> > To: Amps at contesting.com
> > Subject: Re: [Amps] Alpha 87A Power Supply Question
> >
> > All,
> >
> > Just a slight correction on the Cable from the Main
> Electrical Panel
> > into the Bedroom. It is a 6/3, 6AWG with L1, L2, N & a Ground wire.
> >
> > Thank you,
> >
> > Mike
> > W5CUL
> >
> > -----Original Message-----
> > From: Amps <amps-bounces at contesting.com> On Behalf Of
> > w5cul at sbcglobal.net
> > Sent: Monday, May 3, 2021 8:26 PM
> > To: Amps at contesting.com
> > Subject: Re: [Amps] Alpha 87A Power Supply Question
> >
> > All,
> >
> > First Thank You to all who replied!!! I received a lot of
> replies off
> > list, too many to answer individually. So I will attempt to answer
> > all the questions in this one response as best as I can. It does
> > appear that I need to add a little more detail surrounding
> my setup as
> > a lot of the questions were centered around that, and then
> some about
> > how the Amp was wired itself...etc. So here goes.
> >
> > It is a 3/6 cable with a ground wire that runs from the Main
> > Electrical House Panel to a 4 Pole 50amp Dryer Receptacle in the
> > bedroom. From there the sub-panel is plugged into the dryer
> > receptable using a 4 Pole Dryer Plug
> > (L1,L2,N,G) . 2ea 120Vac and 2ea 220Vac Circuits come out of the
> > sub-panel, each with their own CB. One set of 120Vac
> receptacles are
> > wired into L1, Neutral and Ground. The other is wired into L2,
> > Neutral and Ground. The 3 Pole 220Vac Receptacles are
> wired to L1, L2
> > and Neutral, more on that later.
> > One gentleman asked me why 2 independent 120Vac Circuits,
> why not use
> > just one 15amp Circuit for all the 120Vac needs? I split
> out 2ea so
> > that I could balance the load across L1 and L2.
> >
> > Another Gentleman discussed a 4 Pole Dryer Receptacle
> versus the older
> > 3 Pole Receptacle, and that was much appreciated as it jogged my
> > memory of how I had this setup at my father's house when I
> was having
> > to take care of him in Mississippi.
> > I did not run a dedicated 220Vac to the bedroom where I had a
> > temporary station setup, yet just borowed from his Dryer Receptacle
> > that was in the laundry room across the hallway when the
> dryer was not
> > in use, which was not too often. And his Dryer Receptable was the
> > older 3 Pole type, L1, L2 and N.
> > And that answers why I wired the 220Vac Receptacle off the
> Sub-Panel
> > that was feeding the Alpha at that time the way I did.
> >
> > The 220Vac line coming out of the Alpha is wired into a 3
> prong plug,
> > L1, L2 and a "Green Wire". After re-reading the 87A manual this
> > morning, it does say that the Green Wire can either be wired to
> > Neutral or Ground, stated in that order.
> > So, when I wired up the 220Vac Receptable all those years
> ago for use
> > in my Dad's house, I wired the 3rd prong to Neutral such that the
> > Alpha's Green Wire will be connected to such.
> > The manual indicates it can be wired either way, to N or G.
> > While under use at my fathers house, there was no low level
> 60Hz hum
> > in the speakers, but then it was not a true 4 pole service
> like it is
> > here now.
> >
> > After coming back from Mississippi permanently, I just recently
> > started getting this station back together. Keeping in
> mind that the
> > Dryer Plug for the Sub-Panel was setup for 3 Pole and that
> it can plug
> > into a 4 Pole Receptacle, I did use that arrangement to temporarily
> > get power to test out the Alpha after the big move. During that
> > recent testing, prior to having a dedicated 4 pole 220Vac Line
> > installed into this bedroom, I did not experience any low
> level 60Hz
> > hum with the Alpha plugged into the Sub-Panel.
> > Keep in mind that all of the 120Vac equipment was being
> powered by the
> > "Bedroom" Circuit at that time, not this new 4 Pole 220Vac
> Circuit.
> > So this is prompting me to rewire the 220Vac Plug and taking the
> > Alpha's "Green Wire" to Ground as opposed to the Neutral
> and see what
> > happens.
> >
> > And lastly, a Gentleman asked me about Station Grounding,
> is all the
> > equipment bonded together and is there a Station Ground.
> There is no
> > Station Ground at this time, it is floating, or using the
> Ground that
> > comes in from the 4 Pole 220Vac Circuit. I plan on installing such
> > this weekend.
> > Not just a "Ground", but an RF Ground that extends from
> ground rod to
> > ground rod that are appropriately spaced from each other
> and that are
> > bonded by copper shielding. As for the bonding of the equipment to
> > each other, that is actually being accomplished by the Coax cabling
> > that interconnects the equipment. The SO239 connecters are
> bonded to
> > the equipment chassis, so when you connect up a Coax from
> one piece of
> > equipment to another, you are affectively bonding those chassis
> > together using the ground shielding of the Coax.
> >
> > So I think my first step is to re-wire the 220Vac
> Receptacle that is
> > feeding the Alpha and see if that helps. If that does not
> eliminate
> > the hum, the next is to replace the Caps in the Transformer Line in
> > the Alpha, one may be leaky as one Gentleman said.
> >
> > Again, Thank You all for your replies, advice and guidance.
> > I certainly have some more ideas now and a path to move
> forward with.
> >
> > Thank you,
> >
> > Mike
> > W5CUL
> >
> >
> > -----Original Message-----
> > From: Amps <amps-bounces at contesting.com> On Behalf Of
> > w5cul at sbcglobal.net
> > Sent: Monday, May 3, 2021 12:26 PM
> > To: Amps at contesting.com
> > Subject: [Amps] Alpha 87A Power Supply Question
> >
> > Good Afternoon Gentlemen,
> >
> >
> >
> > I have a rather quirky situation and a question about it.
> I have been
> > chasing down a low level 60Hz hum I get across my speakers
> when I plug
> > my Alpha 87A into a shared A/C Service for the shack. I say shared
> > because I am referring to a dedicated 6AWG 220Vac line that
> runs from
> > the Main Electrical Panel for the house to the shack
> (bedroom). From
> > there it is connected to a Sub-Panel that splits out 2ea
> 220Vac Lines
> > and 2ea 120Vac Lines all with appropriate CBs. All the 120Vac
> > equipment to include Transceivers, computers, speakers etc...are
> > powered by the two 120Vac lines.
> > The Alpha is powered by one of the 220Vac Lines. So as the issue
> > goes, with all the 120Vac plugged in and powered up, transceiver
> > turned on, white noise emanating from the speakers, the
> moment I plug
> > the Alpha 87A into one of the 220Vac sockets, CB turned off, I
> > immediately get a low level 60Hz hum coming out of the speakers.
> > Since this sounds like a neutral or ground feedback loop,
> it prompted
> > me to check the wiring on the Alpha. So I unplug the Alpha and
> > perform a continuity check from Leg 1 of the plug to the chassis of
> > the Alpha, Leg 2 to the Chassis and Neutral to the Chassis. As for
> > the 120Vac Legs, there is no continuity to the Alpha Chassis. But
> > there is direct continuity from the Neutral of the 220Vac
> Alpha plug
> > to the Chassis of the Alpha. So the question I have is should the
> > Neutral on the Alpha plug have such continuity to Chassis
> Ground, or
> > do I have a bad Capacitor somewhere in the Alpha? I will
> say that the
> > Alpha 87A does operate as it should and does put out full power.
> >
> >
> >
> > Thank you in advance,
> >
> >
> >
> > Mike
> >
> > W5CUL
> >
> >
> >
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