Topband: BCB Filter (related to Antenna Analyzer question)

[Michael St. Angelo]

Rick,

I've used my LP-100 and FT-817 to measure the antenna impedance at the base 
of my 160 inverted L. I run both from a 12 volt battery.

I've also used my N2PKVNA and Laptop but the LP-100/FT-817 combination is 
less cumbersome.

My antenna is located about 60 feet from the house so I don't get as much 
exercise as you.

Mike N2MS
----- Original Message ----- 
From: "Rick Karlquist" <richard at karlquist.com>
To: "Michael St. Angelo" <mstangelo at comcast.net>
Cc: <richard at karlquist.com>; "Mike & Coreen Smith" <ve9aa at nbnet.nb.ca>; 
<topband at contesting.com>
Sent: Saturday, October 17, 2009 4:03 PM
Subject: Re: Topband: BCB Filter (related to Antenna Analyzer question)


> Michael St. Angelo wrote:
>> Rick,
>>
>> 900 feet? What type of coax are you using?
>
> Open wire line, 4 AWG aluminum, 450 ohms.  A few .1 dB's
> of loss on 160.
>
>>
>> You could probably cancel out the coax by using a VNA like the AIM4170 of
>> N2PKVNA and performing a OSL calibration at the antenna end. You would 
>> get
>> lots of exercise walking back forth to to switch between the open, short,
>> 50ohm and actual load!
>
> Yes, the AIM4170 can calibrate out both the 160 meter BCB filter and
> the open wire line, including baluns at each end and residual coax.
> It is tedious and slow and not perfect, but it does work.  I have
> 350 feet of RG218 going to my MonstIR, and I tried to calibrate that
> out with the AIM4170.  It sort of worked, but there were ripples in
> the response.
>
> And yes, I do get a lot of exercise doing the calibration.  I recently
> acquired a lap top so I can locate the AIM4170 out at the antenna.
> I had quite a bit of trouble getting the USB to serial port adapter
> to work with the AIM4170, but eventually got a special driver file
> that worked on my lap top at least.
>
> Rick N6RK
>