W5AC Work Meetings

February 1, 2003
April 3, 2004 (#1)
April 10, 2004 (#2)
October 30, 2004

Feb 1, 2003
We had a good number of people show up for our first Saturday Work
Meeting of the year.

The first thing we did was attempt to tune in the NASA channel on the
C-Band dish to keep updated on the Columbia event. However, we were
unable to tune in anything with the dish and the receiver didn't have
any lights on in the front, like it usually does. This is probably yet
another victim of a nearby lightning strike several weeks ago. We
haven't determined yet if the problem is with the LNA, the receiver, or
both. Mike, KZ5M, said he might be able to contact a former club member
who could help us with the satellite receiver.

We next attempted to label every incoming coax cable properly and match
it to a known antenna on the roof, so we have a good inventory of
antennas. There are two antennas on the MSC elevator penthouse that have
mysteriously appeared in the past few years and they aren't ours. One
appears to be a 70cm or thereabouts vertical and the other is of unknown
 frequency and is about 12 inches away from our VHF stack tower. The
coax for these two antennas enters the building through a fan/vent on
top of the penthouse.

The HF antennas were checked out for abnormal SWR and we found that the
mosely beam was awful, as previously reported by Dennis, KD5KQN. Mike,
KZ5M climbed the HF stack tower and cleaned up the connection of the
coax to the mosely and now it tunes to less than 1.5:1 on all bands
except 20 meters, which has a 1.7:1 SWR.

Also on the HF stack is our dual-band 2m/70cm fiberglass vertical which
is in splinters because of the lightning. We discussed replacing it with
something like a Hustler G6-270R dual-band, like we have for the
repeater, because of it's durability and single-piece construction.

Since the OSCAR arrays are taken down for rotor repair (and the 440 FM
Beam thas was also on that mast), we didn't have any way to get on 70cm,
so Gabe, KC5OED, Chris, KD5SYI, and Daniel, KD5UTN removed the discone
and replaced it with the 70cm beam, pointed East. This is a temporary
move until we have the elevation rotor working again, but it allows us
to reach the New Waverly repeater on 442.725 MHz, which is a Saltgrass link.

The poor performance of the 40m and 80m dipoles was investigated and the
connections were cleaned, but they still have intermittent high SWR.
Dick, W5DZ, says they should be replaced, as discussed in our past meeting.

Finally, we measured the SWR on all of our antennas:

Mosely beam: good SWR all bands. Slightly high (1.7:1) on 20m.

R5 vertial:
10m  -  1.2:1
12m  -  1.3:1
15m  -  1.2:1
17m  -  1.5:1
20m  -  1.2:1

6m beam:
50 MHz  -  1.5:1
52 MHz  -  1.7:1
53 MHz  -  2.5:1

2m horizontally polarized beam  -  1.5:1

2m vertically polarized beam  -  1.05:1 (very low)

2m vertical on top of VHF stack  -  1.05:1 (very low)

Also noted was that KANM student radio can be heard on the 6m rig at
50.558 MHz AM. Further investigation should reveal whether this is a
problem with our 6m transceiver or if KANM is not transmitting cleanly.
---------
Addendum:

I wanted to add to the work report list that the 160 Meter Dipole was 
taken down from the tower. The G5RV solution is excellent for 10-80 meters 
but will not address 160 meters. 160 meters is a difficult band to work 
because of the level of static and the length of the antenna that is 
needed. The old 160 dipole apex was tied to the metal tower with a rope 
and the elements were not insulated from the metal tower, so rebuilding 
the 160 dipole as it was is not recommended. We may need to find a 
better solution for 160 at some point.

Mike Mertes - KZ5M



April 3, 2004 - #1 for the semester
Our first spring work meeting turned out to be a good preliminary 
meeting.  Members at the work meeting were KD5NPF, KZ5M, N5TLT, NT5TU, 
and W5DZ.

N5TLT got the KC Tracker working, and it successfully followed a satellite 
as we watched. However, after one satellite, the KCT software complained 
that the rotor was "stalled", and now the satellite array elevation rotor 
(a Kampro KR-500) is frozen in one position.

Taking the el. rotor down for repair (again) requires another future work 
meeting, one that starts early in the morning so that we can take the 
antennas off the array and remove the rotor before it gets hot (and that 
roof gets very hot).  Also for next work meeting, some of our antenna 
coax cable is still unlabelled ('til we follow it down from the tower 
to the shack).

Once the elevation rotor works again, talking to satellites will be as 
easy as running the computer program, flipping on the KCT switch (the box 
with a fuse on the front), turning on the two rotor indicator boxes and 
using the satellite station radio to talk to sats as they fly overhead 
(well, maybe it's not so simple, with Doppler shift and all, but it will 
work!).

W5DZ took down the remains of EGOR and NASA Select rebroadcasting.  The 
two radios used in those operations might have been damaged in the 
infamous lightning strike, and he is checking them out with his service 
equipment.  If they do still work, the club may have a pair of backup 2 
meter radios for future use.  The computer part of EGOR makes noises but 
does not boot.

We now have a more clear workspace where EGOR once stood.  There is room 
for future Echolink, Amateur TV, and other equipment work to take place.

The Kenwood TS-600 6 meter base station rig apparently works except for 
the fact that it is deaf.  The Kenwood 700 base station seems to have been 
dead for a while now.  The other VHF/UHF radios are good.

We did not spend the time today to put back up the 70 cm beam 
antenna, but the 70 cm radio can be connected to the cable on the EGOR 
workbench that has a coax extension on it; that connects it to the 
dual-band vertical antenna on top of one of the towers, though it needs an 
SWR check before transmitting (note: it later checked out just 
fine).  The nearby Saltgrass-linked repeater isn't even on 
Saltgrass at the moment anyway, and that was our primary motivation for 
the beam.  It can still go up at the next work meeting (note: 
Saltgrasas Link is back up as of April 8!).

KZ5M showed us an example of the data radios we'll be converting for packet use.

N5TLT, when observing the satellite freezing rotor problem, noticed that 
the control wires that go to the VHF tower stack rotor have extremely 
ultraviolet-ray-damaged casing.  NT5TU mentioned in an earlier e-mail to 
the listserv that our coax is, in effect, showing its age, and though it 
works for now, we may do better replacing coax to improve reliability 
during emergencies.

Michael Baur - KD5NPF



April 10, 2004 - #2 for the semester
This was a quick workmeeting to take down the satellite array's elevation 
rotor.  Members at the work meeting were Mike KD5NPF, Bo KD5MLR, Mike KZ5M 
and Dennis NT5TU.  As we took down the antennas and rotor, we temporarily 
waterproofed the coax connections and labelled them, and recorded the 
color codes for the wiring that goes to the back of the rotor.

The rotor came down fairly quickly (though putting it back up will take 
longer).  Dennis also completed some more repairs on the G5RV. More of our 
coax was labelled, partly in preparation for putting the rotor back up 
(along with the 70 cm beam antenna) sometime soon.

We found corrosion in the coax of the 70 cm cross-polarized beam antenna 
on the satellite array, as we took the antennas off the array.  The 
antenna was only recently put back up there after earlier rotor problems.  
When the antennas go back up, they need dielectric grease added to 
the coax connections.

Also, the same 70 cm antenna needs a counterbalance, or else it 
will continue to "droop" when the array goes upside down following a 
satellite.  By the way, if you go up the ladder to the VHF tower, watch 
the slightly-loose rung on that ladder right at the level of the main roof.

Some time in the future, we should reinstall the OSCAR preamp for 
better reception while listening to satellites; it was broken a while ago when 
accidentally transmitted into (it is receive-only).  Along with that, we 
need to find a solution that doesn't allow transmitted signal to reach 
that preamp, nor the downconverter on 2.4 GHz (on the barbecue 
grill antenna).

Finally, it'd be nice if we put back up the discone for our 
scanner; it has a place near the HF tower just waiting for it.

Michael Baur - KD5NPF



October 30, 2004 - Disaster Trailer
This work meeting took place Saturday (about 9:30 - 3:00) at Riverside 
Campus.  We did 
some work on the disaster trailer so that we can both install W5DZ's 
portable repeater on it and repaint it for future recruiting opportunities 
(like displaying it at Rudder Fountain).  Members at the work meeting were 
Mike KD5NPF, Kevin KE5CQJ, Mike KZ5M, and Dick W5DZ.

We scraped off many layers of old lettering, decals, and rust.  We removed 
the smaller, existing repeater cabinet from the trailer and drilled holes 
through the concrete "floor".  We didn't have to move the crank-up tower 
over to fit the larger cabinet, though opening the door to the new cabinet 
all the way may interfere with one of the two rear leveling jacks if the jack is down 
(like if the tower is already up).

The group brushed a coat of white Rustoleum paint on the trailer, which 
turned out well.  The wheels weren't painted, though Dick brushed on some 
rust treatment to stop the surface rust (which takes 24 hours to cure).

To finish it, we can paint the wheel rims maroon (if Rustoleum carries 
it) and bolt down the new repeater cabinet.  We should make a stencil of 
the club logo and paint that on, as well.  Dick has requested that we find 
a toolbox that we could mount to the trailer (similar to the kind that 
mounts in the bed of a pickup) to hold trailer gear like coax, power 
cords, a few tools, tape etc.  He also plans to mount a PVC tube to the 
trailer to stow the VHF/UHF dualband antenna when not in use.

(Info from Mike Mertes KZ5M)
Michael Baur - KD5NPF