[TowerTalk] Rotator Choice for Larger Yagi

[Jim Thomson]

Date: Tue, 3 May 2016 21:12:06 -0500
From: Patrick Greenlee <patrick_g at windstream.net>
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Rotator Choice for Larger Yagi

Oh, by the way... There is a Green Heron controller especially for the 
K7NV prop Pitch conversions.

##  yes,  my small K7NV  PP  also came with the mating GH controller.
It looks just like a regular RT-21  GH box.  The difference is... the custom
GH box for the PP  only puts out one vdc.   It uses an internal hammond xfmr. 
It only uses 5 wires for control. 3 for the dc motor inside the PP, and the other
2 are for the digital pulsed output of the PP.    K7NV modifys the end of the 
shaft of the PP internal motor, with the addition of the rotating magnets... plus
its all balanced too.  They silkscreened K7NV on the front of the modified boxes. 

##  If  I remember correctly, the regular RT-21  GH box  provides for several different
AC voltages..and also several DC voltages. IE: the rectifier assy can be jumpered in or out
depending on whether a DC or AC motor is used.  Between all of that,  the GH box will
control any rotor.

##The Modified, one off GH box made for the K7NV pps is superb,  with its  point and 
shoot capability..with a single calibrated  knob,  and digital readout down to .1 deg. Plus the 
9 speed  ramp up /down feature makes for transparent use.  Or  pc control the mess. 
Point the knob at say  JA.... and it starts up slow. ramps up to max speed, then cruises along
to JA... then the ramp down engages..till it comes to a full stop.   No slamming tq on and off.
Which is good, esp on ramp down, with a heavy array. 

##  The small PP takes  1 min + 50 secs to turn once.   So max speed is just a bit over 1/2 rpm. 
So no speed demon, but loads more TQ.   I checked my old notes, and the small PP  I owned
back in the mid 70s  was also 1 min + 50 secs to turn exactly 360 deg. 

##  Sure, the K7NV pp is  expensive, but they are trbl free, work good,  don’t crap out, loads of tq,
and hold a big array.  His mast clamp assy is superb..which is also available for the OR-2800.  

Jim  VE7RF