From:	Preston -(PDCD)	TO:	ALL

Date Posted:	201999-1-4 2:20:00
Message: Body:	Before reading this I Do NOT claim to be an engineer. This letter may prove that to you. However if you feel I've made an error please be kind an bring it to my attention. The lower the noise number the better the unit. C-band LNBs are rated in Kelvin and range from 40 K to 15 K or less. Ku-band LNBs are rated in dB and range from 1.0 dB to .5 dB. The lower the L.O. stability number the better the unit. For example: The standard Norsat Commercial DRO LNB has an L.O. stability of approximately + 900 kHz, with options available down to + 150 kHz or better. DRO is the common line of lnb's on the market. A PLL LNB is normally used in commercial applications and are available with options of + 300 kHz down to + 5 kHz or better. The L.O. stability will not give you a better picture, but more so stay one continous level of quality. This is a area that makes more difference in digital than in analog. Simply because anaolg is a sloppy signal in that if your close to it it'll begin to come in. Digital however requires a minimum level then locks. We in this forum have seen Mr.4DTV answer the question: Why does my Quality read higher than my signal. This is not a quote so forgive me if I get it wrong Mr.4DTV but his reply was that it is based on your noise level. Well generally speaking your noise (unwanted signal) level is going to be a factor of your temp. rating IE. 17 degree lnb. Your rating of an LNB is how much noise (unwanted siginal) it's sending to the receiver. Please keep in mind that your LNB collects the signal from the dish, amplifies it approx. 100,000 times and sends it to your tuner. If you have a higher temp lnb, that means you are sending a higher ratio of noise to the tuner. This in turn is more work your tuner/receiver has to do to clean up the signal to produce a clean picture. Typical Gain is the rating of how much the signal actually got boosted during this amp. process. This is a very important factor in getting a clean picture. Gain is how strong the signal is. This rating is measured in db. The common LNB on the market today is 65 db. I have also done a test at our store. It was with a 5' spun aluminum dish (patio ring mount). With a 4DTV receiver. The reason I choose this dish was because it would provide a lesser level of signal thus anything would cause a bigger change. A 17 vs 30 degree lnb Eagle aspen made by macom had little difference (3) in quality strength none in signal. Picture looked the same. 20 vs 30 Cal Amp 2 lower than the Aspen in quality 5 lower in signal. Picture looked like it had a few more sparklies. Testing norsat today. (+_+) Preston

Date Posted:

201999-1-4 2:20:00

Message:
Body:

Before reading this I Do NOT claim to be an engineer. This letter may prove that to you. However if you feel I've made an error please be kind an bring it to my attention.

The lower the noise number the better the unit. C-band LNBs are rated in Kelvin and range from 40 K to 15 K or less. Ku-band LNBs are rated in dB and range from 1.0 dB to .5 dB.

The lower the L.O. stability number the better the unit. For example: The standard Norsat Commercial DRO LNB has an L.O. stability of approximately + 900 kHz, with options available down to + 150 kHz or better. DRO is the common line of lnb's on the market. A PLL LNB is normally used in commercial applications and are available with options of + 300 kHz down to + 5 kHz or better. The L.O. stability will not give you a better picture, but more so stay one continous level of quality. This is a area that makes more difference in digital than in analog. Simply because anaolg is a sloppy signal in that if your close to it it'll begin to come in. Digital however requires a minimum level then locks.

We in this forum have seen Mr.4DTV answer the question: Why does my Quality read higher than my signal. This is not a quote so forgive me if I get it wrong Mr.4DTV but his reply was that it is based on your noise level. Well generally speaking your noise (unwanted signal) level is going to be a factor of your temp. rating IE. 17 degree lnb. Your rating of an LNB is how much noise (unwanted siginal) it's sending to the receiver. Please keep in mind that your LNB collects the signal from the dish, amplifies it approx. 100,000 times and sends it to your tuner. If you have a higher temp lnb, that means you are sending a higher ratio of noise to the tuner. This in turn is more work your tuner/receiver has to do to clean up the signal to produce a clean picture.

Typical Gain is the rating of how much the signal actually got boosted during this amp. process. This is a very important factor in getting a clean picture. Gain is how strong the signal is. This rating is measured in db. The common LNB on the market today is 65 db.

I have also done a test at our store. It was with a 5' spun aluminum dish (patio ring mount). With a 4DTV receiver. The reason I choose this dish was because it would provide a lesser level of signal thus anything would cause a bigger change. A 17 vs 30 degree lnb Eagle aspen made by macom had little difference (3) in quality strength none in signal. Picture looked the same.
20 vs 30 Cal Amp 2 lower than the Aspen in quality 5 lower in signal. Picture looked like it had a few more sparklies.

Testing norsat today.
(+_+)
Preston