Topband: cutting coax stubs for 80 meter 4-square

Wes Stewart wes_n7ws at triconet.org
Mon Jun 11 19:15:45 EDT 2018


Rick is correct.  There is room in my AA-55 Zoom for a blocking cap.  However, I 
only connect it to DC grounded antennas.  My 160-meter inverted-L has a 20Kohm, 
10W wirewound resistor connecting the vertical to ground on the antenna side of 
the coax connector as a static bleed.  Without it, I could be the ground path.  
During thunderstorm season, the antenna is folded over and the coax disconnected.

Wes  N7WS


  On 6/11/2018 2:07 PM, Richard (Rick) Karlquist wrote:
>
>
> On 6/11/2018 9:50 AM, Jim Thomson wrote:
>
>> ##  Is there room inside those  rig experts units to install a .01 uf disc 
>> ceramic  cap ??
>> A  50-100  volt  cap would be smaller diameter than a 1 kv cap.   There is  
>> your  DC
>
> On my 160 meter vertical I have been able to pull 1/2 inch long
> arcs to ground on a perfectly clear day.  That would of course
> blow up nearly any capacitor.  Instead, you need an inductor to
> ground.
>
> Similarly, "touching the leads together" before connecting the
> analyzer is poor advice for obvious reasons such as the fact
> that the antenna will charge back up to high voltages in less than
> a second.
>
>> ## On a similar note,  re the MFJ-259B. Can  a HP filter be used, to kill  AM 
>> broadcast
>> junk...or  will the HP filter  screw things up too much ?
>>
>> Jim  VE7RF
>>
>
> An HP filter would royally screw up an network analyzer including
> the 259, unless you calibrate it out, which the 259 is incapable
> of.  Even on a good VNA, it is tricky to accurately calibrate
> out a 9 element elliptic filter.  That is why the answer is
> to get the AA-55 and be done with it.
>
> Rick N6RK
> _________________
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>



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