Re: Ham M rotor to DXView

Bill Pence

Unsure if the original poster Steven KN0L is still following...
(If so, can you tell us what direction you are thinking? The hygain dcu3 would be plug and play I suspect but pricy. The diy method is certainly workable...)

I see the ground issue. Dang.

Maybe the async adc readings and averaging in Arduino would mostly overcome this?

I suspect the k3ng should be taking several readings to average the direction readings.

I've not dug into the rotor code. I did not have big issues with the hd73 but the AC on ground would likely have been less, and my rotor cable was a bit sorter as the tower was not high then.

On Wed, Aug 25, 2021, 10:00 AM Joe Subich, W4TV <lists@...> wrote:

 > I'd short 4 to 7 to always have metering.

That was a "standard" modification to the old HAM-M control box.

 > Arduino analog input from pin 3. Cap to ground to help smoothing of
 > reading perhaps.

Cap between terminal 3 (pot high) and 7 (ground/wiper) is not
effective since the AC is modulation on ground (ground shift)
relative to the Arduino reference ground.  One needs to minimize
the AC voltage generated due to the ~7.5A in the resistance of
the wire connecting terminal 1 from the controller to rotator
as that AC is in series with the directional DC.

With the Hy-Gain recommended wire size (#18 up to 125', #16 to 200'
and #14 to 300') the resistance in the terminal 1 connection can be
0.8 Ohms which results in several volts of AC *in series* with the
meter DC.


    ... Joe, W4TV

On 2021-08-25 9:21 AM, Bill Pence wrote:
> I see the logic to just use a cap and transformer and remove the
> controller box entirely.
> You could use the cap and transformer in the existing box.....
> But the rework is not tough.
> I'd short 4 to 7 to always have metering.
> Then brake relay connects 6 to 7
> Then right (ccw?) Relay shorts 1 to 2 and left (cw?) Shorts 2 to 3.
> Voltage divider on 3 to ground to provide 0 to 5 for Arduino input.
> Alternatively, no controller box. 5v on pin 7.
> Arduino analog input from pin 3. Cap to ground to help smoothing of
> reading perhaps.
> Motor Cap connects between pins 4 and 8.
> Transformer "low side" connects to pin 1
> 3 SPST relays needed
> Transformer "high side" connects to normally open on all 3 relays.
> Common on brake relay connects to pin 2
> Direction relays connect to pins 5 and 6.
> Not super hard.
> On Tue, Aug 24, 2021, 11:15 PM Dave Fugleberg <davefugleberg@...
> <mailto:davefugleberg@...>> wrote:
>     The single lever controller would require a little rework but should
>     be do-able.
>     The single lever is just a spring-loaded rotary switch, where there
>     is no contact between any pins when it's at the center (resting)
>     position.
>     Unlike the newer controllers with the three paddle-style buttons,
>     the single lever does not energize the meter circuit unless you move
>     the lever partway right or left. This also energizes (releases) the
>     brake.  Pushing the lever all the way right or left keeps that
>     energized, and also engages the motor CW or CCW. You could easily
>     put the CW and CCW dry contact relays across those two portions of
>     the switch. However, nothing would happen unless you also energize
>     the rest of the controller.
>     There are two transformers in that unit - Power and Instrument.
>     Both have 110 volt primaries. The Power transformer has a 26 volt
>     secondary and powers the motor and brake.  TheInstrument transformer
>     is 23 volts and is physically smaller (lower current capacity) and
>     powers the metering circuit and lights.  The primaries are wired in
>     parallel - moving the lever right OR left connects one side of each
>     primary to one blade of the (nonpolarized) power cord. The other
>     blade of the power cord is permanently connected to the other side
>     both primaries through a fuse.
>     So, if you want to retrofit such a controller, I'd suggest
>     bypassing/replacing the lever switch altogether. Add a toggle switch
>     to energize the primaries of both transformers, a relay to disengage
>     the brake (secondary of power transformer to rotor terminal 2), a
>     relay for clockwise (power transformer secondary to rotor terminal
>     6) and a relay for counterclockwise (power transformer secondary to
>     rotor terminal 5). Those three relays would be driven by the
>     interface of your choice, such as the K3NG Arduino interface. This
>     would also provide a continuous meter indication (rather than only
>     when you move the lever).
>     There are known issues with ripple on the directional pot on the
>     rotor because the center of the pot is common with the motor common
>     terminal. I've seen some blog postings about various ways to deal
>     with that but haven't really looked into it. Shouldn't be too
>     difficult with some filtering.
>     If I can get around to it, I may do just that with one of my old
>     Ham-M controllers so I can use it for the azimuth rotor of the
>     satellite station I'm slowly automating.
>     Note - there were more than one series of that controller, and they
>     are NOT all identical. The above refers to the Series 5 controller,
>     which I believe was the last one of the single lever ones. The
>     numbering in the schematic I have does not make much sense when
>     looking at the actual switch, but it's pretty easy to trace and
>     figure out what is what. I have a picture of the inside of one of
>     mine, and I documented which wire goes where, but your mileage may vary.
>     Good luck whichever way you choose to go !
>     73 de W0ZF
>     On Tue, Aug 24, 2021 at 6:56 PM Bill Pence <pence.bill@...
>     <mailto:pence.bill@...>> wrote:
>         Not sure I'd agree with that.
>         I'd need to find the schematic, but I'd think the switches are
>         configured as:
>         Left a bit, brake engage, left more, rotated
>           slight release, stop rotate, hold bake
>         Center off
>         Right a bit, brake, right a bit more, rotate.
>           slight release, stop rotate, hold bake
>         The k3ng / arduino relay outputs are all dry contacts,
>         So connecting to the switch terminals should be straightfirward.
>         If you want to send my links to schematics
>         I can check and I might need good photos to show where the relay
>         wires connect.
>         Would he happy to help.
>         If course you can always buy a hy-gain dcu3 instead. I still
>         like building stuff.
>         On Tue, Aug 24, 2021, 2:36 PM Joe Subich, W4TV <lists@...
>         <mailto:lists@...>> wrote:
>             That single lever is a two section rotary switch - very
>             difficult
>             to interface with any of the after market boards.  You will
>             probably
>             do best with a replacement controller.  If you choose to
>             build your
>             own from one of the K3NG articles, note that you will need
>             to find
>             a 24V AC @ 5-6A transformer (not particularly common these days)
>             and possibly the appropriate transformer/rectifier for the
>             direction
>             sensing circuit.
>             73,
>                  ... Joe, W4TV
>             On 2021-08-24 12:39 PM, St. Cuda wrote:
>              > [Edited Message Follows]
>              >
>              > Brown with one lever, big meter that is 180-0-180 or S to
>             N to S.
>              >
>              >

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