I Screwed Up Big Time!!!

[mick d]

I thought I would bite the bullet and break down and get a good lnb because I couldn't understand what was the best lnb to get. I got a dual feed chaparal feed horn and a norsat lnb. I thought the feed horn meant dual feed as in would take the horizontal and vertical simultaneously and feed the lnb. Wroooooong!!!!! I get them both in and see that the feed horn apparently has to be equipped with 2 lnbs. Unbelievable. I can't win for losing. Now I either have to send the feed horn back or get another expensive lnb. What is the advantage of this type of feed horn? Oh yeah I would also have to combine the signal too into one cable.

 

[kirara386]

The main advantage is that you don't need a servo to control the poloarity. This means you can use a multi switch to connect the feedhorn to your FTA receiver.

Basically to get it into one cable you use a multi switch to connect to both LNBs and then use the receiver out to connect to your receiver. It is recommended that you use a power inserter when you do this set up as the vertical LNB will receive 13v instead of the recommended 18v.

Also if you want a voltage controlled LNBF our sponsers have them available. I'm using the Geosat Pro C2 and am very happy with it.

 

[mick d]

I have the Geosat Pro C2 and thought I could get more signal by getting a better lnb, norsat had good reviews, I should have just let it alone, I don't understand why you would buy 2 expensive norsats one for each polarity, and then a voltage regulator and a combiner. I guess less is more.

 

[kirara386]

From what I've read on the forum, if you have a smaller dish it can help having better quality LNBs. I only have a 10' so I can't attest to how expensive LNBs compare to voltage controlled LNBs on smaller dishes.

 

[mick d]

I have a 10' foot dish also, I will just have to stick with my geosat and send the other back. Thanks for your help.

 

[LocutusOfBorg]

I thought I would bite the bullet and break down and get a good lnb because I couldn't understand what was the best lnb to get. I got a dual feed chaparal feed horn and a norsat lnb. I thought the feed horn meant dual feed as in would take the horizontal and vertical simultaneously and feed the lnb. Wroooooong!!!!! I get them both in and see that the feed horn apparently has to be equipped with 2 lnbs. Unbelievable. I can't win for losing. Now I either have to send the feed horn back or get another expensive lnb. What is the advantage of this type of feed horn? Oh yeah I would also have to combine the signal too into one cable.

One type is a dual feed for C and Ku or it could be a dual C feed (needs a C band LNB for vertical and horizontal polarization) or it could be a dual Ku feed. All would require separate coax cables. A dual C/Ku feed will have 2 different size waveguide mounts (the smaller for Ku) while the dual C and dual Ku will have same size waveguide mounts for the horizontal and vertical polarizations - of course, the dual C band would have larger waveguide flanges than the dual Ku feed. The C/Ku feed allows you to receive both satellite bands with one antenna and the receiver selects which band while the C/C and Ku/Ku feeds allow faster switching between polarizations. If you need a feed for just C or Ku, you'll need to return the feed that you purchased and get a single feed for either C or Ku. The vendor might charge a restocking fee for returns and you'll have to pay the shipping charges to return it.

 

[B.J.]

Just to add to the above, back to the original question of WHY, most people who have used the feedhorn you have will say that the quality is superior. I don't use that kind of dual feedhorn, I have a Chaparral Co-rotor, which is one of the C/Ku mentioned above. I got that because I wanted both C and Ku, and I also wanted to be able to adjust the polarity skew. However apparently whenever you block part of the C-band throat with a Ku throat, you lose a bit of signal, so the people who are trying to get every ounce of signal like the dual C-band feeds. Another issue with the Co-rotor is that you need a receiver capable of adjusting the polarotor to the desired polarity.
I know that the LNBs are very expensive, but even the cheapest of the Norsat or Cal-Amp LNBs have better specs than any of those voltage switched LNBFs. Basically, it's just a tradeoff of quality vs convenience. Best quality is the dual-C or dual Ku, most convenient is the voltage switched lnbf, and the Co-rotor style C/Ku is kind of a tradeoff between the two.

 

[Greg Mueller]

I'd keep the dual (H+V) feed horn and buy a second lnb.
I've been thinking I will do that when I get to NM.

 

[truckracer]

You actually bought the best performing feedhorn. If you can spare the cash, get another lnb and use a multiswitch. Those zinwell 2 x 4 or even 4 x 4 (you don't really need a 4x4 but they are cheap on ebay). It will perform like an lnb with less signal loss.

 

[Anole]

If you do keep the dual LNB, C-band only feed, here is a simple mod to power it and do the switching.
If you'll read the thread, the 4x8 multiswitch is quite inexpensive.
I got one to run a quad-LNB orthomode feed, with two LNBs for C, and two LNBs for Ku.

Pendragon mods a 4x8 multiswitch for high voltage on both ports:
http://www.satelliteguys.us/fta-shack/174802-naughty-mods-ii-4x8-switch-all-18v-outputs.html

 

[mick d]

Big help guys, I appreciate it! I am gonna keep the feed horn now and get another norsat. Btw it is a dual c band feed horn. Thanks again everyone!

 

[mick d]

I'd keep the dual (H+V) feed horn and buy a second lnb.
I've been thinking I will do that when I get to NM.

Ricks has them for $65.50 shipping included, was the best price I found.

 

[B.J.]

Ricks has them for $65.50 shipping included, was the best price I found.

One thing about these Norsat and CalAmp LNBs, is that there is quite a spectrum of quality and price. You can get a low cost LNB for around the price you mentioned, or you can pay twice that or 10 times that or even more. People tend to look just at noise temperatures on these things, but there are other important specs, like frequency stability and phase noise.
Back when I was analog only, I had a fairly cheap CalAmp. When the switch to digital (DCII) started, everyone was saying that our current consumer LNBs weren't going to be good enough. I decided to keep my old one and try to get by, and it seemed to work fine, although it later died, so I bought a slightly better LNB, a Norsat with a .75 MHz freq rating instead of the approx 1 Mhz rating of the cheaper LNB, however I didn't notice much difference.
A few years later, however, when DVB-S2 came out, everyone was saying that you needed bigger dishes and higher quality LNBs, so I bought a slightly better Norsat LNB, one that has freq drift ratings down around 0.1 MHz. Again, I found that I didn't notice much difference, and in fact if anything I had a harder time locking the S2 channels, mainly because the stability was apparently a tradeoff for gain. So I actually switched back to my old .75 Norsat, although I've been thinking of giving it another try.
A lot of people recommend getting even higher quality and higher cost PLL LNBs, but I don't think I'm going to invest in one of those unless I see one cheap on ebay.
But anyway, the gist of what I'm trying to say, is that there are many many different models of Norsat (and other brands) LNBs, and one of the advantages of having a feedhorn is that it is easy to switch LNBs if you want to try for higher quality. It's tempting to go for the more expensive ones, however I think even the cheapest Norsat is probably higher quality than any of the LNBFs available, and since there seems to be a tradeoff of gain to get the higher stability, I really think that most people would be just as happy with the cheaper LNBs. I think if you are getting your gain and adjacent sat rejection from the dish, then the high quality LNBs will give you a better signal, but if your dish is marginal size, then I think you're better off getting a bit more gain from the LNB, which is usually going to mean the cheaper one is the better choice.
Ie, I think the $65 Norsat is a good choice. I got my most recent ones from one of the sponsors at the Satforums forum, who is pretty reliable and helpful too, in case you want another source.

 

[1captain]

well B.J. summed all up very well on these LNB's, good job Bill.

an the Kelvin temps have more or less turn out to be a marking technique for todays sellers of satellite equipment.

my self here I have several different models of lnb's on my dishes, an my cheep-est lnbs here are a pair of 8515 Norsats, even have some older lnbs that perform just as good or even better than the 8515 which is the 3535 Norsats 35-kelvin but they are A PLL lnb. but my favorite 1's here that will lock a feed an play whith out drop A drop out, an hold a lock, are Cal Amp Extended Professional lnb's with A 25 kelvin, they seem to perform a bit better than the Norsats. their was a S2 feed last week for the winter X-games,that was very-very week on AMC-3, an the 10-footer with the Cal amps lock it an played it fine, an other people with 10-footers could not even see that signal at all.

now you're less quality lnbs an lnb-f will work for majority of signals out their, till you get a feed that is in the mud or very week, that's when the stability of lnbs an you're dish tuning will pull it it in an get it. now I am not saying go out an by the best lnb, but consider what you plan to do with them an buy with what you aford, their is no need to go broke on just getting a good set of lnbs an a feed for them.

 

[Greg Mueller]

Ricks has them for $65.50 shipping included, was the best price I found.

Thanks for the heads up on that I just bought one

 

[mick d]

You bet Greg, glad ya got one and hope it works well for ya. Hey BJ the $65.50 was the price of the dual feed horn. I did get 2 norsat 8515's for a similar price on ebay. I probably should have stayed with the cheaper geosat because it did do a good job but I was looking to dig those weak signals as you talk about Cap.

 

[mick d]

That is pretty awesome stuff there anole, I am still trying to digest that one. So am I right in thinking that by making this modification to the multiswitch that you are taking the voltage being 18v fed from the receiver from the horizontal side and jumpering it over to also feed the vertical side and by doing this you are not taking the signal over to the vertical side as well?

 

[Anole]

Yea, the idea is not an uncommon one.
Pendragon described the matter pretty well.
There are several ways to accomplish it, but I find his solution quite easy.

Actually, the multiswitch gets its own power, so both LNBs get clean 18 volts, and there is no load on the receiver(s).

 

[mick d]

I will do my best. Thanks.

 

[Greg Mueller]

Thanks for the heads up on that I just bought one

I got my dual lnb feed horn yesterday safe and sound via UPS.
Now the search for a cheap 8115 to match the other one