[Amps] Alpha 87A Power Supply Question
Gary Schafer
garyschafer at largeriver.net
Mon May 3 23:46:37 EDT 2021
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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