[TowerTalk] Summary of Analyzers DE K0FF

[Norman Hockler]

Thanks for a realistic, concise evaluation.  de Norm N8NH


At 07:45 AM 11/28/00 -0600, you wrote:
>The new 269 allow setting any feedline impedance from 10-600. The next
>nearest thing is the VA-1 Autek analyzer with 10 discreet steps, 25-450
>Ohms.. Problem with the Autec is the digital display and slow refresh times.
>Not what you want for making adjustments. OK for taking a measurement on
>something, but the MFJ's analog meters allow smooth adjustments to be made,
>while dips and peaks are easy to spot.
>
>Either of these instruments also allow you to measure inductance and
>capacitance at the operating frequency. I found this to be especially
>important with toroid inductors. A reading taken with a bench instrument
>that has only a 1 KHz or 100 kHz signal source will inaccurately read the
>true inductance.
>
>Both of these will read R and Z. Only the Autec VA1 will give you the sign
>of X ( as far as I know).
>
>The MFJ can also be used as a frequency counter, and is perfectly adequate
>for a simple test bench, thereby saving a separate piece of gear. As well it
>can be pressed into service as a signal generator, especially is used with
>an external low power attenuator.
>
>The MFJ's frequency coverage starts at 1.8 MHz but with my mod can go below
>500 kHz in two more steps. Top end is 170 and the 269 adds the 415-470 range
>as well, but discontinuous from 170-4115.
>
>Autek's RF-1 has limited features and starts at  1.2 MHz (not modifiable) to
>35.
>The VA-1 has many more features but still only covers .5 - 32 MHz. One handy
>mode will even tell you the offsetting capacitance  (or inductance) needed
>to equalize the X factor.
>
>On my own test bench I have not found a single instrument that will measure
>everything I want to look at. Looking at an actual antenna is the least used
>function here, rather I'm always testing a transformer, filter or other
>device. Therefore I find the MFJ (mine is an older 259a model modified for
>low freq) to be the most useful, backed up by the Autek RF-1, and finally
>the HP 250A RX meter . These have supplanted the various resistive and
>capacitive bridges we used 8ibn the past.
>If starting from scratch now, it would be first the MFJ 269, then the Autek
>VA-1.
>
>
>Happy Building, Geo>KØFF
>http://homepages.dstream.net/K0FF
>
>
>
>--
>FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
>Submissions:              towertalk@contesting.com
>Administrative requests:  towertalk-REQUEST@contesting.com
>Problems:                 owner-towertalk@contesting.com



--
FAQ on WWW:               http://www.contesting.com/FAQ/towertalk
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com