[Fourlanders] Report from last weekend

[Jim Worsham]

I am not surprised that we are finding problems with those cables.  Some of
those cables date back to before I started with the group back in the 90s.
We should probably just replace all of the cables on all of the antennas
with the possible exception of 6 since those cables are relatively new.  I
would be careful though about changing the feeds to the hairpin type matches
we are using on 6.  First I am not sure that match would scale up frequency
wise very well and second I am convinced that match is why we have rain
static build problems on 6.  The driven element floats and the only way the
static charge can discharge is down the feedline.  I would like to see if
there is a way to DC ground the driven element to the mast but I haven't had
the chance to research that yet.  Anyway, Dick K5AND has a lot of practical
experience with such things so maybe he has some good input and suggestions.
The baluns on the 2 meter EME antennas being upside down and filling with
water reminds me of the upside down rain filled rotator incident a couple of
years ago.  I guess we need to start painting red arrows with "This Side
Down" on everything.  I have a laptop (possibly two) available to use with
the analyzer.  They are hand-me-downs from my son David which means they are
probably better than anything any of us own!  Anyway, just remind me Bob
before I come up next time and I will bring one to try out.  I never did
hear how we did in the contest other than it wasn't very good.  How bad is
not very good?

73
Jim, W4KXY

-----Original Message-----
From: fourlanders-bounces at contesting.com
[mailto:fourlanders-bounces at contesting.com] On Behalf Of Bob Lear
Sent: Saturday, October 01, 2011 1:50 PM
To: fourlanders at contesting.com
Subject: [Fourlanders] Report from last weekend

Ron and Scott came up to take down their 432 and 2m stations on Sunday. 
  That part was uneventful.  I was going to leave the 2m antennas up for 
a while longer even though I had already done the 2m sprint with them 
(12 Q's, 7 grids, from FM06 to EM80).  We started testing the antennas 
with the Array Solutions AIM UHF Analyzer and started seeing some weird 
things, worse than I saw when I ran the plots a couple of weeks ago 
after the contest.  So we decided to investigate.  BTW, we were also 
taking down the 2m EME antennas and wanted to check them as we found 
some issues after taking them down.

We cranked the 2m mast down and when we disconnected the hardline the 
guts came out of a UHF-N adapter!  (And it wasn't one from my 
collection!)  So that was a problem, but we tested the hardline and it 
looked good on the TDR, but on up to the antennas still didn't look 
good.  (I will send some plots later).  Well we got the rotor loop off 
and it really didn't look good as a cable.  Had some funky non-periodic 
+/- 5 ohm oscillation in it.  The PD checked OK.  The phasing lines 
(which date back to the 2m5wl's) also didn't look very good, so we 
decided to chuck all three of those cables and make new ones for 2m. 
Well we also tested the antennas with a known good cable and they don't 
look very good either.  We think the M2 feeds have aged along with the 
75 ohm TV coax balun/hairpin section.  We are going to investigate our 
options  with those 2M11SSB antennas.  Does anyone in our group know of 
a feed update for those antennas?  It sure would be nice to feed them 
like the K1FO style or the direct feed like on the 6m antennas.

We found the problem with the 2m EME antennas were that the plastic 
boxes (balun/hairpin) on the 13b2's were full of water.  We think that 
happened after the contest as I don't think there was any rain that week 
after we put the antennas up before the contest.  Anyway, they looked 
like crap too and again, it would probably be a very good thing to 
replace the CC feed with something more up to date and hardier.  Any one 
with info there, please let us know.  We are going to see if they will 
dry out, but we think the coax balun got saturated and will at the least 
have to be replaced.  An updated feed would make those CC's much better 
antennas, even with their equal spacing, although it would not be hard 
at all to move those elements with a complete redesign.  Any of you with 
13b2's remember to have the weep holes in the box down.  We had left 
them upside down on the Az-El array after the contest (now known to be a 
mistake) as we had tracked that far and they had turned over.

The 222 antennas performed great for the 222 sprint (11 Q's, 9 grids) 
which may have rivaled our September contest results, but I was still 
disappointed that a lot of folks that I would have expected were not on. 
  Anyway, since the sprint, I have taken down the 222 antennas also and 
they looked ok on the TDR.  I did find that the rotor loop was bent 
pretty hard at one end and should probably be repaired, but it is long 
enough to just cut a little off and reinstall a connector.  I will test 
it again and take care of that.

The consensus from the work session last Sunday was that we just can't 
live without the AIM UHF Analyzer.  We can't thank Kim enough for 
obtaining this most useful instrument for the Fourlanders!  Pretty much 
everything we could test we did.  We even took a PC on a cart outside as 
I don't have a laptop to operate it with, but it sure would be even more 
useful if we have a way to make it more portable.  It will be excellent 
to test our antennas on the mountaintop as we set up and make sure we 
don't have any problems.  Also I plan to TDR all the feedlines before 
the contests too.

So special thanks to Kim for the Analyzer!!!

Final thing to report was that Tom and I went to the Ten-Tec hamfest. It 
was sort of like one of our contests as the highlights all involved good 
food and drink.  The hamfest was OK, larger than we've seen before, but 
very little to tempt us this time.  The Catfish House for lunch on 
Friday, the microBrewery/Steakhouse for dinner, and FatBuddies BBQ in 
Franklin on the way home Saturday made for a proper Fourlanders type 
outing.  We really need to put FatBuddies on our contest trip itinerary 
again as it was most excellent.

73, Bob

Don't forget the 432 sprint Wednesday night 7 to 11 PM local
The East Coast 70cm net comes on .090 at 9PM and they will facilitate 
everyone on getting to work all the grids available on the net.


_______________________________________________
Fourlanders mailing list
Fourlanders at contesting.com
http://lists.contesting.com/mailman/listinfo/fourlanders