[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Fwd: Helix Feed with Cup--Dimensions



>From: K5OE@aol.com
>I received several requests to repeat the dimensional data for this little
whimsical Memorial Day effort.  FWIW, I listened for AO-40 early this
morning, before leaving for work, at around MA=50 and could not hear a
thing--beacon or RUDAK.  Anyone in N.A. have a report to compare at the
same time?  I'll try again tonight when the squint will be more favorable.
>
>The dish is one of K5GNA's smaller dishes (22" x 17"
>x 3-1/2" deep).  It is covered in aluminum screen.
>
>The helix is 3 turns # 10 AWG Cu, 1.6" dia. at 1.125" spacing and
terminates in an N-connector.  The first 180 degrees is covered in 1/4" and
the remainder of the first turn is covered in 1/2" (3/4" for first turn).
The remaining two turns are at 1.125" spacing.  Polarity is LHCP.
>
>The "cup" measures 4" in dia and 2" in height.  
>
>The final spacing was 12" to the back of the coffee can.  
>
>Here are the pix:
>http://members.aol.com/k5oe/helix_cup01.jpg
>http://members.aol.com/k5oe/helix_cup02.jpg
>http://members.aol.com/k5oe/helix_cup03.jpg
>http://members.aol.com/k5oe/helix_cup04.jpg
>73,
>Jerry, K5OE

Jerry,

Nice photos of your dish/cavity-helix feed.  It looks like you are using a
preamp, but I'm confused by the Drake output coax going to the preamp and a
third cable out of the preamp.  Or is this not a preamp?

Good photos giving the view from your tower.  Looks like maybe 40-50 foot
and above tree tops?  I had no idea that there were that many trees in Texas!

I had a good weekend.  I traveled 130 miles over to visit freinds in my old
home town of Hope, attend the Historical Society meeting [more freinds],
and haul a bunch of stuff back from my cabin.  I stopped and visited with
Mike, WL7BQM on my way home to pick up his old [my new] G-5400 rotator and
visit.  Not much done on Sunday.  Monday [our Memorial Day Holiday] I took
down my satellite antennas to install the G-5400 and put the antennas back
up.  I didn't get the 33 inch dish as it was getting late and I didn't want
to start that and not get the new dish installed for the TV system [I'm
stealing my old TV dish for AO-40 and bought a new slightly bigger one for
the TV].

May get to that tonight after work.  Sun stays up til nearly 2300 local
[~18 hours/day sunlight].  

Once I Have the dish up I'll have to play with the feeds.  Maybe make a
cavity-helix to compare with the 5-turn feed.  My timing is not great as it
looks like the bird is being maneuvered for orbit boost. Oh well, I can try
UO-11.  A side benefit is now the 432 antenna is rotatable for working
Leos.  I need a good omni antenna for 2m for that [only have 432, 1268-96,
2400 antennas on the rotator].

Well its time to hit the shower and have breakfast; off to work!  Hope
everyone in US had a nice holiday!

Ed   

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home