[TowerTalk] Need help estimating cable length of DXE 400 MAX

[Jim Thomson]

Date: Sun, 12 Jan 2020 04:44:01 -0600
From: Phil <pmills7 at comcast.net>
To: towertalk at contesting.com
Subject: [TowerTalk] Need help estimating cable length of DXE 400 MAX

<I am involved in selling items to benefit the estate of a SK.
<One of the items is a unused roll of 400MAX cable that is still
<in the plastic cling wrap it was shipped in.  I know there is
<at least 100 feet of cable there but I think there is possibly
<50 or even 100 feet more.  I don't want to unroll the cable to
<measure it and get it all kinked or dirty.  The roll weighs
<17 pounds.  I've checked the DXE web site but can't find anything
<that gives the weight per foot.  The roll is approximately 8 inches
<inside diameter, 16 inches outside diameter, and contains 55 to 60
<turns.  The packing label on the roll says DXE400MAXDCU200.
<Can anyone help me with a good estimate of the length?

<thanks, 73, Phil   W5BVB


##  I  use  my  B+K   875B   digital  LCR  meter.....Mouser.  Dead  simple.
Measure  the  C  between   braid  and  center  conductor. 

##  Divide total  C   by   known  C  per  foot....  =  total length  in  feet. 

##  Coax  maker  will  publish  the  C  per  foot.   Even  if  they  dont....
just  cut EXACTLY   ONE   foot of  cable  off..... and  measure  the  C.  

##  and  yes,  you  can  zero  out  the  test  lead  stray  C before hand.   

##  The  above simple method  is  dead  on  vs a steel  tape  measure. 

##  The  B+K  875B  will  measure  capacitance    to  as  low  as  .1 pf.....
in  .1 pf  increments.....  and as  high  as  20,000  uf.    It  will  also  measure inductance
to  as  low  as  .1 uh.....  in  .1 uh  increments  and  as high  as  200 Henries. 

##  It  also  measures AC  resistance   down  to   .001  ohms..... in   .001  ohm  increments.

## Im  dead in  the  water  without  it,  as  its my  number  1  piece  of  test  gear,  constantly  in  use.

## The  original   B+K  875  is also an  excellent  unit.  I  bought  one  new  years  ago. 

##  I  used both  of  em,  simultaneously  to  measure, and see if  the pair  of  motorized  coils  In   my  Seco  systems
tornado  drive  track.  They  do. 

Jim  VE7RF