[TowerTalk] Big Rak and HDX-555

[Jim Thomson]

Date: Mon, 27 Aug 2018 19:53:07 -0500
From: "Jim" <jimw7ry at gmail.com>
To: <towertalk at contesting.com>
Subject: Re: [TowerTalk] Big Rak and HDX-555

<So you've never owned one?

<Remember, everything you read on the internet is true.  :)

<73
<Jim W7RY

##  I own 2 of em, one is the older AC motor, the 2nd is the newer DC motor. 
The cap went bad in the AC unit, but was fixed.   The oem mast clamp has the advantage that it
will  handle  masts  from  1.750  up to  3.00  inches in diameter.  The drawback to that scheme is
the total clamping force  hinges on using a lot of  tq on the bolts...such that the applied  force is
through the small number of teeth that make contact with the mast.  

##  The K7NV  mast clamp used on my small  K7NV  prop pitch has a huge clamping area.
2 inch ID  =  6 inches of  circumference,   X  6 inches of height =   aprx  36 sq inches of clamping
surface.   Just  pinch the 2 ears   with a pair of vice grips, and the inserted  2.00 inch OD mast will not budge. 
In normal operation with the  6 x bolts  tightened, the flange ears  compress, and the mast can not budge. 

##  The drawback to the  K7NV  scheme is its made for  exactly one specific OD mast only.   Ditto with the 
K7LXC version.   But thats a small   drawback imo, vs the obvious benefits. 

##  The M2  controller  does not have the point and shoot knob feature, like the GH  control box has..which, imo,
really sucks.   But the M2  controller does have loads of pre-sets, et.   At least with the GH box,  you rotate knob to
desired heading, and thats  it.  The rotor ramps  up  through its nine speeds,  cruises  along, till  20 deg before it gets to 
the desired heading, then ramps down.   The  M2 rotor weighs more than the small  PP,  but only has a fraction of the tq. 

##  Another thought here is to tq balance the yagi or yagis, easily done in mech software.  That alone takes a huge load off
any rotor..and  required tq to rotate the array is vastly reduced.  

##  The  OR-2800  rotor, esp when used  with a GH  control box, plus  K7NV mast clamp, is an excellent combo.  The  small
K7NV PP  +  GH control box is even better, loads of tq,  but is not inexpensive.      

Jim   VE7RF