8ft C band dish with CK1S combo LNB not getting KU

[Miketv92]

Hi
I posted on here last month about getting a mesh c band dish, after not having much luck obtaining one locally I ended up ordering tek2000s 8ft prime focus mesh dish. I'd give it 4 stars out of 5 because I had to assemble it with no instructions. It receives c band programming fine with my CK1S C KU combo lnb. Hope this isn't a dumb question but even if I have the dish locked on a c band signal I get nothing on ku from the same satellite when I connect the receiver to the Ku portion. I still haven't ordered the 22mhz switch to recieve both bands without switching the connections. I just want to know if there's something wrong with the ku portion of the lnb or am I doing something wrong? For example I can lock ses3/amc1 on c band and get ION and the feeds but when I try to connect the ku part I get nothing. I've had amc 1 locked on my primestar dish and got all the NBC feeds and COZI programmed into my receiver but can't get anything with the c band pointed at ses 3/amc 1. I get strength but no quality whatsoever on ku on any of the satellites but c band comes in fine. Do I need the 22mhz switch to make the combo work, I've been physically switching between c and ku for the time being. I have the ku set on 10750 which is what it's calls for but I still get nothing. Any help would be appreciated.
Thanks

 

[hank123]

It should work if you are manually switching out the connection on the coax.
Makes me think that there's something else going on. Have you tried switching around the coax moving it from the c side to the Ku side??

Some c band dishes don't do ku well.

What receiver do you have?

 

[Miketv92]

Yea the lnb dosnt have the built in switch so I just disconnect the coax from the C part and connect it to the orange KU portion. Receiver is an X2 HD premium updated with the latest firmware Tek2000 said their 8ft dish has fine enough mesh for KU reception. Just wanted some opinions before looking into a different lnb. I heard some had problems with the ku side being weak on the titanium CK1S combo.

Mike

 

[Miketv92]

And I wonder if the lnb is defective also because the focal length of my 8 is listed as 36 but The scale on the LNB has to be pulled out to 42 on the scale to get certain channels like metv. If I set it at 36 on the lnb I can't get metv on ses 1it only comes in of the lnb is set at 42 and all the other transponders come in stronger when it's at 42. Scratching my head on this one.

 

[Titanium]

While it is possible that the KU section might be defective, I would definitely check why the FD setting must so different on C-band than the calculated position. This incorrect setting would suggest a Focal Length issue with the scalar/feedhorn placement. The FD setting is being modified to place the feedhorn opening at the sweet spot (signal convergence point). KU band reception would be highly compromised with an incorrect FD and/or FL setting. KU band requires a much more precise alignment than with C-band.

Is the Focal Length measurement correct or incorrect when the FD ratio is set to calculated position?

We selected this LNBF design due to the better performance of the KU section. I am unaware of any reviews regarding a weak KU section on the CK1s. As you may already know, all combo C/KU combo LNBF units are a compromise due to the KU frequency signals passing through the C-band frequency tuned cavity and often arriving out of phase at the KU probes. The feedhorn and scalar adjustments are very critical to optimize reception on both bands.

 

[Miketv92]

Titanium
Sorry man didn't mean to make it sound like I was trashing your product. I'm still pretty new at all this and most people who don't know what they're doing will blame the equipment before they admit to user error. The focal length is the measurement from the center of the dish to the bottom of the lnb right? Or do I measure from the center of the dish to the edge of the scaler? Hope I don't sound like too much of a dummy asking that. Like I said I had to assemble the dish with no instructions whatsoever other than a sheet saying to measure the lnb support arms to make sure they didn't send the wrong ones. I contacted tek2000 when I was assembling it and they said I had to bend the rods at the end and to drill small holes in the mesh for Mounting them in the correct holes. So like I said, probably something I'm doing wrong but I find it odd there's no quality whatsoever on Ku when I have the dish pointed and get a excellent c signal with that 42 setting. The ku section coax terminal is sort of crooked looking which makes me wonder if it may have gotten damaged in shipping, the box was pretty banged up when I got it. So if my scaler is mounted wrong can I just adjust the lnb and measure until I get 36 at the bottom of the lnb?

 

[N6BY]

[QUOTE="Miketv92, post: 3995406, member: 199598".. The focal length is the measurement from the center of the dish to the bottom of the lnb right? Or do I measure from the center of the dish to the edge of the scaler? ...[/QUOTE]
That is a good question -- I asked it too back when I was getting started in FTA.

The answer given to me was to measure from the dish center to about 1/4" inside the mouth of the LNB.

In addition, my observations based on trial and error, is that reception is indeed best with the focal point 1/4" inside the LNB mouth.

While I don't have a CK1S, I have attempted to use a similar product (BSC621) and also had very poor KU results. My 90cm offset dish far outperformed the Dual C/KU LNB.

I now use a different approach for my 8.5' dish. I have separate C and KU LNB's mounted side-by-side as close as possible to each other. Also, I use an Invacom LNB for KU because it can handle my 8' dish's 0.40 F/D ratio. (Most KU LNBs are for higher F/D ratios.)

Hope that helps.

 

[Titanium]

Good advice from N6BY! The CK1s install guide may help with the calculations and Scalar/LNBF placement. http://www.titaniumsatellite.com/downloads/Guides/CK1S_LNBF_Install_Guide.pdf

Check the FD ratio and Focal Length calculations against the information provided for the support arm mounting. The support arms need to be bent and drilled at a specific length and uniformly attached to the reflector frame to place the scalar and feedhorn opening at the correct distance from and angle to the reflector surface.

I didn't think that you were trashing the product, but did want to address the performance issues that affect all combo C KU LNBF units.

 

[hank123]

I have a ck1 and love it. I stopped using it because I ran everything into a switch.

I only had a slight loss on the Ku side vs my 90cm.

 

[Miketv92]

Ill measure it once I get home this afternoon. So as long as I get it adjusted to 36 measuring 1/4 inside the lnb it should work. If it does end up being defective is there a way to replace just the ku section without replacing the entire thing. I thought of just getting the C1PLL and just doing c band on the BUD. Since I live down the road from a cell tower makes me wonder if that interferes with reception.

 

[Titanium]

What is the calculated FD ratio setting? What is the calculated FL measurement?

I believe that you're confusing the FL distance with the FD ratio setting. The FD ratio setting is the scale stamped on the side of the feedhorn which the scalar is aligned with. The focal length is the measurement from the center of the reflector to 1/4 inch inside of the feedhorn opening.

If the feed arm support legs are the correct length and installed correctly, the back of the scaler ring will align with the FD ratio scale when the focal length measurement is ALSO the correct measurement. If the Focal Length measurement is not correct when the FD ratio is set with the feedhorn and scalar, the support legs are not the correct length.

 

[Miketv92]

According to tek2000s website the focal length is 35.75 and the f/d ratio is .40.

 

[hank123]

From my reading the have 2 different models and people have had issues.

Are you sure you have the legs set in the correct spot?

Can you share a picture?

 

[Miketv92]

The first 2 were before I got my post in the ground that's the portable base for my primestar dish. Took awhile to get a 3.5 inch post, a guy I know just happened to have some old 3.5 inch metal posts. Made sure it was perfectly level too. Didn't really try it out until I got the post in the ground, just wanted to see it standing up. The legs are where tek2000 specified to install them in the email they sent me about it. They said to measure 5 inches from the rim and there should be a hole to install the bolt and said to punch a hole in the mesh to get to them. Makes me feel a little better to know I'm not the only one who's having issues with their dishes.

 

[Titanium]

I would measure the reflector width and depth and use the CK1s install guide or the FL/FD calculator to verify the settings and measurement. Not a big one on blindly trusting generic factory specs...

First set the scalar to align with the FD ratio stamp using the calculated FD ratio. Then measure the distance from the center of the reflector to 1/4" inside the feedhorn throat. If this FL measurement isn't VERY close to the calculated Focal Length, then the legs are not bent and set to the correct length.

Hard to tell from the photos, but did you use a torpedo level with 90 degree laser layed across the Scalar and again across the feedhorn opening to make sure they are parallel to the reflector and aimed directly at the center of the reflector?

 

[hank123]

http://www.satellite-calculations.com/Satellite/reflector.htm

Like Brian said.
This will take you 15 min and get sure numbers.

From one of your photos the lnbf does not look straight. It looks angled up.

 

[Miketv92]

Yea the first 2 were before I tried to get anything. I may have had the lnb cover just resting on it to see it assembled. I don't have a torpedo laser level yet I just used the inclinometer on my iPhone and it shows the elevation of the scaler to be the same as the reflector same with the lnb. After measuring the lnb, I got 36 inches about 1/4 inside the throat so I guess the arms aren't the right length but the lnb is the correct length from the center of the dish. The cause for not getting any ku reception may be because just now when I tried the ku section the ku coax terminal twisted off. I used needle nosed pliers to hold the terminal and tried to connect the cable but got nothing on strength or quality.

 

[Titanium]

If the connector failed due to a manufacturing or product defect, it is covered under warranty. Contact us via the website or email support@titaniumsatellite.com and we will assist.

A common mistake to over-tighten coax connectors. F-fittings should only be finger tightened then if for a permenent install, an extra 1/8th turn to seat the seal. I also use a cap-full of dielectric silicone grease in any outdoor connector to further weatherproof the rubber o'ring connectors.

 

[MN_Vikings]

Miketv92

I understand you have a different dish than I do but on my 8ft dish the original F to D ratio was 27 3/4 inches with the original one lnb dish mount. (See Photo) If I understand F to D ratio correctly which I measured with a tape measure from the edge of the lnb holder to the center of the dish and for my original lnb holder it was 27 3/4 inches. I glad I measured it before I swapped out my lnb dish mount as when I installed my custom made four port lnb holder it changed the F to D ratio to over 32 inches. I used another member's idea and used 8" bolts with two extra nuts to which I was able to change my the F to D ratio on my four port lnb holder to 27 3/4 inches which was the original distance and allows me to pick up C and KU signals. I noticed from your photos the lnb mounting arms / legs are not mouted to the edge of the dish. I have not seen lnb mouting arms / legs not mounted to the edge of the dish before. If you were to move and remount the lnb mouting arms / legs to the edge of the dish it would shorten your F to D ratio so it would be closer to the dish. What is your F to D ratio currently now in inches? If it is 27 to 29 inches you should be able to pick up C and KU signals. if it is over 30+ inches I would look into remounting your lnb mounting arms / legs out to the edge of the dish to bring in your F to D ratio.

 

[richyrich]

F/D ratio's are exactly that the entire dish as an amplifier of a microwave; focusing a direction inside the cavity; basically a cone from the width of the cavity, to a single point. The distance from the width to the point is the size of interior round cavity; ku is smaller width cavity and needs less of the dish to aim the focused on satellite because it is powered more and slides across the dish and inverts itself (backwards reflection or sliding is called toroidial gain of relective purpose). The VSWR is where the dual bands share the cavity and lose gain in the direction because both cavities are seperate in the distance to the back of the cavity; and if the LNBf is not perfectly aligned with the center of the dish; the angle the ku is seeing is different than the C band lnbf see's; therefore losing focus; or aimed directional gain; which must be perfectly pre-set before arcing the dish for movement. Also, because a ku band dish/lnbf combo must be more perfect at aiming at each satellite on the arc; it must also be within a 1/10" of the perfect focus before it will work at all; and the arc cannot be off more than that. Most branded dishes have a specific f/d ratio; they also have adjustments that provide a very large margin of error, and adjustments are critical for the perfect gain's. Every dish ever made really has sa lightly different f/d; because a dish both in shape and formulated gain in a direction truly is perfect only with "the perfect design"; and this patented pointer/dish; is made for specific frequencies. A flat dish with .40 f/d is better for ku than C; and depth's to .30 are better for C band (less sliding of this lower freq. signal is allowed) so a lower f/d dish design works better per size 8"/10' 6'/6'; and shape of the dish shows in VSWR. How the dish is shaped is a specific formulation for the signals it receives and their powers or freq plan and typical microwave (shape); what any single named dish did (many shapes) was make many many many shapes and sizes available; but they each focus on the same signals that have been there a long time. Shaped dishes that are wider than long; longer than wide; use ku toroidial's; a 8' dish has many of these available at ku band; some of them are very "overpowered" or very high gain's of ku signals (like TVW.); requiring the lnbf's gain to be attenuated; or set lower to accommodate this larger amount of signal it may not be able to handle. The f/d formula does not care for all the formula's a satellite system is based on; it only cares for the microwave which the designed dish perfectly amplifies; but only perfectly without toroidial gain as a factor. Once the lnbf is perfectly set for C Band; normally 1/4" farther away, or more makes it work better; because this removes toroidial reflections ku band has; and the .4 f/d is designed to gain better ku because of it. I would experiment, as many older dishes did need to be changed (i hav found hundreds) at the focal distance to gain (quality and signal) perfect dish reflections at perfect aim.
The way i do it is 1) adjust the focal distance for optimum gain is an experiment; set first to focal distance by formula [square root (squared+squared)]/16d; then if dish f/d is at or over .37 experiment farther distances of focal length; if .37 or under f/d; experiment closer with shorter focal length...A Winegard was the type of dish that printed focal distance of their dish wrong; it is that nobody except I experimented and found perfect focal distances for each of their design's; because i did not get them to work with their printed material on their own dish; and my ecperiments worked instead.