[Fourlanders] 6m antenna problem

Fri Jan 8 02:07:08 EST 2016

I would second that notion Ron. I started getting weird readings on my MFJ-269 a few months ago. Finally put a 50 ohm load right on the MFJ and it didn't give a good reading. So something has gone south in it's circuitry after many years of use. At first I thought battery corrosion. But didn't see any of that when I pulled it apart. I have so many projects, I just buttoned it back up and added it to the "round-to-it" pile. 

Back to the cross needle Daiwas I have hooked up anyway. It is hard to beat the antenna analyzers for portable convenience though. So I sure hope I can get the MFJ going again.

73,
Charles
K4CSO 
  ----- Original Message ----- 
  From: ww8rr 
  To: Jim Worsham ; Scott Spencer 
  Cc: fourlanders at contesting.com 
  Sent: Thursday, January 07, 2016 7:52 AM
  Subject: Re: [Fourlanders] 6m antenna problem

  As i said to Bob in another email, put all the fancy equipment aside for a moment and grab an old fashion analog Bird to confirm these inordinate SWR readings before getting too concerned

  Ron

  From my Samsung Galaxy S4

  -------- Original message --------
  From: Jim Worsham <w4kxy at bellsouth.net> 
  Date: 01/07/2016 3:19 AM (GMT-05:00) 
  To: Scott Spencer <scott at nn4w.com> 
  Cc: fourlanders at contesting.com 
  Subject: Re: [Fourlanders] 6m antenna problem 

  I agree with Scott.  It sounds like test equipment or some other cold related error.  All of those antennas didn't go bad at the same time.  Wait until we get a warm day and check it again.  If you hadn't checked each antenna individually I would suspect the stack match box.  Another possibility would be that hardline I gave you.  You know that hardline was on my tower for nearly 20 years.  No guarantee on how good that is.

  73
  Jim, W4KXY

  Sent from my iPad

  On Jan 6, 2016, at 9:27 PM, Scott Spencer <scott at nn4w.com> wrote:

    Bob,

    The one thing that sticks out to me is that you’re seeing the same results with both the Omni’s as well as the beams.  I do a lot of testing in my job, and if you have a known good value from a previous test, but a bad value from a later test, you have to suspect the test scenario or the test equipment setup.

    Using the AIM, have you run a calibration? Also, what do you see when running the test against a dummy load?

    Scott
    NN4W

      On Jan 6, 2016, at 7:05 PM, johnnykludt at earthlink.net wrote:

      Bob,

      The thing I find odd is I  was using those antennas with the FT897 and I was having no trouble with swr.  Strange

      Johnny

      Sent from my Verizon 4G LTE Smartphone

      ------ Original message------
      From: Bob Lear
      Date: Wed, Jan 6, 2016 16:25
      To: FourLanders Contest Team;
      Subject:[Fourlanders] 6m antenna problem

Need some advice about the 6m antennas.We put them up last Saturday, connected a radio and heard stations in Texas on both the omni's and beams along with the usual local beacons.  Nothing else was done then and we didn't pull the hard line into the shack until Monday this week.  I ran Kim's AIM UHF analyzer on them and things didn't look good.  First I thought it was a jumper or the PD, but after eliminating some stuff, it looked more like the problem was in the stackmatch relay box.  Today I took the analyzer out to the tower base and started checking the antennas themselves.Still not looking very good, at least nothing like we've been used to in the past.The omni's have a 4:1 + swr around the normal operating frequencies.  They seem to be most resonant at 155 MHz where they show 1:1The beams look just alike when scanned separately and also show about 4:1.  The lowest swr on them is about 2:1 at 150 MHzboth above observances on the AIM and my MFJ 259 are consistent so it's not the devices.The computer crashed outside apparently due to the cold and I"ve brought it back in and it's working OK.  I've scanned from here, with antennas separated (no stackmatch) and through the stackmatch. They just don't look good at all.  SWR staying much too high like 4:1 at operating frequencies and higher elsewhere.  The stacked pair showed 1:15 swr at 135 MHzCould this be because of the cold weather.  It's probably only about 35 outside here right now.   I don't think I've ever used these instruments in such cold weather before.BTW:  all the feedlines look good when TDR'dAny ideas from the peanut gallery?Thanks and if we get any warm weather I'll do this all over.Bob_______________________________________________Fourlanders mailing listFourlanders at contesting.comhttp://lists.contesting.com/mailman/listinfo/fourlanders_______________________________________________
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