[TowerTalk] MFJ 259 accuracy??

Rod Elliott elliottr@hurontel.on.ca
Wed, 28 Oct 1998 01:59:57 +0000


At 15:37 10/26/98 -0800, you wrote:
>
>AA4NC@aol.com wrote:
[snip] It's just this 160 inv. vee >that it can't deal with.
>> 
>> Has anybody had any similar problems with their 259s ??

>I have used one on my 160 inverted "L" and never could get a true
>reading with it.  Swr was never below 3-1 anywhere on 160.  A check with
>the SWR meter in the shack showed the same as yours, everthing was OK. 
>They must not be very accurate down that low in frequency.  73
>Tom W7WHY


For what it's worth, I've had my MFJ259 for 2-3 years and it's never given
me any such problems. I've just checked it (again) on a 50-ohm standard
termination, and it reads absolutely flat 1.00 to 1 VSWR over its entire
operating range of 1.7MHz - 170MHz.

With respect, I believe your problems lie not in the MFJ259, but in the
type of antenna you are trying to measure. With non-symmetrical antennas
like the inv-L you usually have antenna currents flowing on the *outside*
of the coax braid. That will make almost any type of SWR meters read wrong.

Ain't this stuff fun??

73 de Rod VE3IRF




--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm