EME dish

[W5DTW]

Greetings to all from Texas,
I have the opportunity to acquire a Vertex model 6.1M-KPK dish and was wondering any of you thought this would be suitable for adapting for use on 23cm EME?
I have not been able to get much technical information on it; I will try to post are a couple of pictures of the same model dish.
I am talking about the dish only I will not receive the pedestal, elevation or azimuth controls.
73
Craig A Tull
W5DTW

Living Life In The Rural Lane

[W9GB]

I have the opportunity to acquire a Vertex model 6.1M-KPK dish and was wondering any of you thought this would be suitable for adapting for use on 23cm EME?
I have not been able to get much technical information on it; I will try to post are a couple of pictures of the same model dish.
I am talking about the dish only I will not receive the pedestal, elevation or azimuth controls.

Craig -

The pedestal and AZ-EL controls would have been nice bonus.
Paul Wade, W1GHZ is a very good reference for EME usage of large dishes.
http://www.qsl.net/n1bwt/

It looks to be a Cassegrain feed --- Ku-Band Earth Station.
http://www.sky-brokers.com/home/prod...motorized-used

Vertex Earth Station Antenna 6.1m
Compact Cassegrain Ku-band, Rx/Tx, 2-port Linear Feed, 2-Axis Motorizable Mount with AZ/EL jackscrews, Kingpost Pedestal Mount, #original motors and Vertex 7133 Indoor & Outdoor Controller (there is no tracking capability with this controller and must be upgraded to the 7134 for tracking), Hub enclosure 152cm (60inch), 91cm (36inch) depth, 20-piece precision-formed aluminum panels with heat-diffusing white paint. Lightning Protection Kit.

Vertex has dis-continued this model. The 6.3m is its replacement.

This dish appears to be a deep dish with an F/D = 0.28 .. 0.4
* low noise because of low spill-over
* easier feed construction (symmetry of H and E plane is a problem,# but not a big one)
* a wide angle feed gives a small feed. this reduces size and# obstruction
* a high f/d needs a high gain feed for the narrow beam width. this# results in possible sidelobes by the feed.

Good discussion on topic.
http://www.vhfdx.info/discuss/dishes.html

[W9GB]

Craig -

I believe that radio amateurs should have open discussions (learning does not occur without that process).
Private e-mails accomplish nothing -- but confusion and more questions on your part.

FIRST, I provided an ID for you of this Earth Station Dish.
SECOND, this dish is offered FOR SALE by numerous surplus dealers at substantial prices (I found 3 of this model posted over past year).
THIRD, as I noted earlier, this is a "Deep" Dish (F/D ratio) .... which has advantages and DIS-advantages for Moon (EME) or satellite usage. (f/D of 0.25 is DEEP and ~ 0.5 would be SHALLOW)

PAGE 56 of the July 2012 issue of QST covers Parabolic Dish Focusing !! -- Paul Wade, W1GHZ author.

I believe you said that a 2,000 mile trek is required to "pick it up" --- I would not bother with that shipping. You would be better off find an old 10 to 12 foot TVRO dish.

When Ken, KA0Y first assembled his 40 foot (later expanded to 50 foot) EME dish in late 1970s ... he used a surplus Navy Gun Mount (Univ of Iowa surplus in 1970s).
NOTE the F/D of this EME dish.
http://www.ka0y.com/dishpic5.htm

Dr. Robert Suding, W0LMD (Confier, Colorado) did have a web page -- with photos for TVRO conversions for AMSAT satellite usage, EME and microwave experimentation. Robert usually attends the Central States VHF conferences. That web page has been DEAD for past few years.
http://forums.qrz.com/archive/index.php/t-136936.html

Lastly, Central States VHF Conference is in Cedar Rapids, IA at the end of July (this month)
http://www.csvhfs.org/2012conference/index.html

w9gb

[W5DTW]

What did I do to deserve this?

Craig -

I believe that radio amateurs should have open discussions (learning does not occur without that process).
Private e-mails accomplish nothing -- but confusion and more questions on your part.
Nice flame job guy! a great tribute to the extra class stereotype!!!!

FIRST, I provided an ID for you of this Earth Station Dish.
You ent me a link to the same page that had the pictures I posted!
SECOND, this dish is offered FOR SALE by numerous surplus dealers at substantial prices (I found 3 of this model posted over past year).
Not sure what you mean by this, I have had a multi decade relationship with the company that is disposing of this dish and I assure you I can get it for far less than scrap value.
THIRD, as I noted earlier, this is a "Deep" Dish (F/D ratio) .... which has advantages and DIS-advantages for Moon (EME) or satellite usage. (f/D of 0.25 is DEEP and ~ 0.5 would be SHALLOW)

PAGE 56 of the July 2012 issue of QST covers Parabolic Dish Focusing !! -- Paul Wade, W1GHZ author.

I believe you said that a 2,000 mile trek is required to "pick it up" --- I would not bother with that shipping. You would be better off find an old 10 to 12 foot TVRO dish.
Again not sure what the "pick it up" quotes are about as I would go and pick it up myself...
When Ken, KA0Y first assembled his 40 foot (later expanded to 50 foot) EME dish in late 1970s ... he used a surplus Navy Gun Mount (Univ of Iowa surplus in 1970s).
NOTE the F/D of this EME dish.
http://www.ka0y.com/dishpic5.htm

Dr. Robert Suding, W0LMD (Confier, Colorado) did have a web page -- with photos for TVRO conversions for AMSAT satellite usage, EME and microwave experimentation. Robert usually attends the Central States VHF conferences. That web page has been DEAD for past few years.
http://forums.qrz.com/archive/index.php/t-136936.html

Lastly, Central States VHF Conference is in Cedar Rapids, IA at the end of July (this month)
http://www.csvhfs.org/2012conference/index.html

w9gb

[W9GB]

What did I do to deserve this?

Craig -
The follow-on was not specifically directed to your query.
I can see how that may have been interpreted that way. My apologies, as that was not intention.

Some QRZ readers believe that they should send me private e-mails, follow-up questions, and comments -- rather than posting here in the Technical forum. That occurred in this instance about our question.

THAT cowardly behavior is not the intention of this technical forum (education),
or my volunteered time here on QRZ.

w9gb

[W5DTW]

Ok how about this one, I spotted this not too far from the house and it looks like it is not in service, maybe 16 foot or so.

[W9GB]

Tape measure and some time, you can calculate the F/D. It appears to be shallow, 0.5 would be a guess (without measurements or mfg. specs).

[W5DTW]

Well it looks like this may be the one, I remember seeing this from the highway years ago but the vegetation had grown up and I had not been able to see it for several years now, it is a 16' fiberglass, looks pretty shallow but I have not had the chance to measure it, I have talked to the owners, the wife said I could have it but the husband wants to negotiate, hopefully the wife will win but in any case it should still be cheap and without the problems associated with the obsolete corporate units like the one above, I know fiberglass dishes are heavy but in some ways look easier to work with.
Craig

[W0AAT]

I did the 10 footer on 1296, frustrating at times because it was marginal size wise. This was cw/ssb only, new digital modes would likely work okay.

[W4OP]

A shallow dish ( F/D>0.5) is fine for 1296MHz. The W2IMU horn will illuminate it nicely. I can't tell from the photo if the dish is fiberglass or aluminum. If fiberglass the FIRST thing to do is runs strings at right angles across the face. They should just touch each other. The problem with glass dishes that have been left pointed for extended periods is that they warp. Not only does this degrade the gain, but sidelobes develop, focusing becomes fuzzy and it's just a mess.

Dale W4OP