[TowerTalk] Tashjain Towers LM470 Remote tower raising control

[kj6y at aol.com]

The US Tower tower remote, RMC-1000  sells for$4999.95 at HRO.  The relay box consist of 2 motor relays,2 time delay relays, 1 power relay and 20 amp fuse and all the associated terminals and wiring.  All in a large  metal cabinet mounted on the tower.  The control box is simple as it just supplies the voltages to operate the relays.  The US Tower system uses 120 volts to control everything. The old Tri-ex versions were identical but used 26 Volts AC to do the replay controlling.  That's what I have on my LM-470.  The time delays look like a vacuum tube and have a 5 second delay. PN-26NO5.  26 volts, normally open, 5 seconds. The circuits are not complicated,  but the hardware can get expensive.  I just had to replace one of the US Tower time delays for a client and they are over $100,00 
Skip Bolnick, KJ6YCommunications Service Cowww.kj6y.com818-522-5421  In a message dated 7/17/2022 12:06:04 PM Pacific Standard Time, k6mr at outlook.com writes: 
When the LM470 was produced by TriEx, I worked for W6HX who was a TriEx dealer and installer in Los Angeles.  We built the remote systems for the LM470 that TriEx sold.  Basically two big 4 pole relays to switch the motor leads plus the control box to switch up/down and indicate when the tower was fully up or down. The control box used a 4 wire cable (I think) to connect the tower to the inside control box.

The critical part of the control box was two time delay relays to be sure the motor had stopped before reversing directions.  The motor will keep going the same direction if you suddenly try to switch directions because the centrifugal switch on the start windings is open when the motor is running.  The other critical parts were limit switches on the top and bottom of the first section to stop the motor and indicate fully up and down.

Pretty simple device, but you have to think about failure modes.  The motor and winch are strong enough to snap the lifting cable if for some reason it doesn't stop when the tower is fully extended.  I've seen it happen with the manual switch since there is no protection other than the operator on the switch.  It makes a mess of the tower.

Ken K6MR


________________________________
From: TowerTalk <towertalk-bounces at contesting.com> on behalf of Lux, Jim <jim at luxfamily.com>
Sent: Sunday, July 17, 2022 11:44 AM
To: towertalk at contesting.com <towertalk at contesting.com>
Subject: Re: [TowerTalk] Tashjain Towers LM470 Remote tower raising control

On 7/17/22 11:19 AM, Bill Eisinger wrote:
> It shouldn’t be too hard to adapt it such that you could use a smart switch with an Alexa (or equivalent) hub...however you would need wifi or bluetooth access at the tower...

Or, some form of low voltage relays and a hardwire connection.

Or a WiFi connected relay controlled by a dedicated app, but I'd be a
bit nervous about trusting a "safety sensitive" function to Alexa,
without some serious interlocks or a fairly robust physical access
control.  It's kind of like those ideas about automatically lowering
the tower when the wind goes above a certain speed.  It's more complex
than one thinks at first.

I've built a fair number of network controlled devices, some controlling
big heavy things moving around (dish antennas, etc.) - It takes careful
planning and design to make sure it "fails safe".  For this, since
you've already got to have power wires and coax going out there, adding
a few wires to control some relays seems a fairly simple and robust way.





>
> -----Original Message-----
> From: TowerTalk <towertalk-bounces at contesting.com> On Behalf Of Ted Pauck K8NA
> Sent: Sunday, July 17, 2022 11:43 AM
> To: TowerTalk at contesting.com
> Subject: [TowerTalk] Tashjain Towers LM470 Remote tower raising control
>
> I recently purchased the Tashjain Towers LM470 Crank up tower. The tower comes with an electric motor control onboard for raising and lowering the tower, by a switch at the tower. I need to remote control the tower from in my radio room. There will be a camera to watch the tower raising and lowering. Tashjain does not sell a remote control for towers. Has anyone been able to remote control the LM470 or any of the other Tashjain towers?
>
> TU/73  ...  de  Ted  K8NA

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