Found a C band dish.Now what?

[ILoveSats]

Several ways. By knowing just exactly where your local cell towers are, then placing your dish behind a building, wall, or RF fence that can block that signal from getting into the dish, yet that doesn't interfere with aiming at satellites.

Or, knowing where your local cell towers are, then using a spectrum analyzer to look for intruding signals, confirm they exist, and putting the dish behind a building or wall that blocks that specific direction.

Things of that sort. Just be aware that in some areas, 5g microcells are actually being mounted on telephone poles right IN peoples neighborhoods. IF you have to aim through one, that's not easy to block. Though once again, IF you know where it's located, you MAY be able to install the dish pole where it'll be shielded by a wall to block that signal.

I thought I'd share some image to show what my terrain looks like and the limited amount of Sky I have access to.

Picture #3 is what it looks like standing right behind my 90cm Ku dish. The house is 60 feet in front of me. Image #4 presents the limited view of open sky I have access to. I currently can see satellites between 77W to 103W. Photo # 2 is a frontal fiew looking directly into the dish. Behind you will notice another house. Image # 5 shows another house to the west on a hill. Picture#6 is looking east and a high hill side can be seen in the distance. Finally, image #7 shows the cul de sac I live on. I don't expect to see any 5G antennas on this street given how many trees fall on the lines and the utilities failure to trim limbs to prevent outages.

If I put up the dish I found I expect it to be placed to the right of the Ku dish from a frontal perspective.

Is there a risk of signal interference coming from behind the dish and ricocheting off the house into the dish? On the amateur 2 meter band this is possible and it actually helps receiving a repeater some 15 miles away. But in this scenario I'm using a whip antenna/ rubber ducky.

 

[Titanium]

At C-band frequencies (4GHz), signals are highly attenuated by non-reflective objects or surfaces. As long as you have a window through the trees to view the target satellite(s), the vegetation and buildings will usually work to your advantage, attenuating undesired off axis signals.

Metallic surfaces would act as a reflector, but your home appears to be clad with wood siding. I would not be concerned with signal reflections as the wood would absorb and not reflect these frequencies. Terrestrial signals will most likely enter the feedhorn from in front or from the sides of the reflector. The reflector will also act as a shield to prevent signals from behind the dish from "seeing" and entering the feedhorn.

 

[ILoveSats]

At C-band frequencies (4GHz), signals are highly attenuated by non-reflective objects or surfaces. As long as you have a window through the trees to view the target satellite(s), the vegetation and buildings will usually work to your advantage, attenuating undesired off axis signals.

Metallic surfaces would act as a reflector, but your home appears to be clad with wood siding. I would not be concerned with signal reflections as the wood would absorb and not reflect these frequencies. Terrestrial signals will most likely enter the feedhorn from in front or from the sides of the reflector. The reflector will also act as a shield to prevent signals from behind the dish from "seeing" and entering the feedhorn.

Actually, I have aluminum siding. How does this change things?

 

[primestar31]

Actually, I have aluminum siding. How does this change things?

Your dish won't be pointed at your house, so likely changes nothing. As Brian said, 5g signal intrusion is basically line of sight bearings. Now, an 8 foot dish has a wider degree of "view" than a 10 foot or larger dish, so might be more susceptible to signal intrusion, depending on where your 5g sources are, and where your dish is aimed at the moment.

You can't eliminate ALL possible issues you may have before putting up your dish. So, don't analyze this to death. Put it wherever your site check tells you might be the best place, and think happy thoughts.

Do a site check here, on the EXACT coordinates of where you propose to install the dish, and to possible receivable satellites: DishPointer - Align your satellite dish

 

[ILoveSats]

Well my wallet tells me different. It doesn't make sense to spend time and money in vain when you can overthink things first to ensure you have alleviated as much of the downside beofre arriving to a final decision. I believe it pays to be prudent and understand why you made the decision you did and the facts its based upon. Sometimes it can be easy to spend someone else's money. That's why my decision making process must be based on the science and educational input offered by others. I believe that's really important! At the end of the day if things don't work out it will be my fault right?

 

[ILoveSats]

Your dish won't be pointed at your house, so likely changes nothing. As Brian said, 5g signal intrusion is basically line of sight bearings. Now, an 8 foot dish has a wider degree of "view" than a 10 foot or larger dish, so might be more susceptible to signal intrusion, depending on where your 5g sources are, and where your dish is aimed at the moment.

You can't eliminate ALL possible issues you may have before putting up your dish. So, don't analyze this to death. Put it wherever your site check tells you might be the best place, and think happy thoughts.

Do a site check here, on the EXACT coordinates of where you propose to install the dish, and to possible receivable satellites: DishPointer - Align your satellite dish

If I put up the dish I found I expect it to be placed to the right of the Ku dish from a frontal perspective.

 

[ssj925]

The main reason for a larger 10-12 ft dish is due to the increase in frequency/polarity overlap on adjacent satellites. No doubt that a larger dish will provide a benefit by increasing the signal to noise ratio for a target satellite signal and negating terrestrial interference (including 5G), this is not the primary reason for installing a larger dish.

As the North American C-band satellite downlink bandwidth narrows from 3700 - 4200MHz, then 3800 - 4200MHz and in a year to 4000 - 4200MHz, this remaining frequency range is being utilized for simultaneous transmissions on both polarities. In days gone by, overlapping frequency ranges would alternate polarities on a satellite and between adjacent satellites, decreasing the potential for cross polarity and adjacent satellite signal interference. As uplinkers optimize their bandwidth usage, higher FECs ratios are being implemented and the resulting higher SNR requirement. Now a larger satellite dish is often needed to provide higher signal gain and most important, to shape a tighter beam width to reject signals from adjacent satellites.

While it is a great idea to install a 10 or larger reflector, in the real world, I would not reject or discard an 8 foot dish. It is a great starter dish and will be useful for receiving most services. If you enjoy the hobby, keep on the lookout for a larger dish and upgrade if and when it is possible!

Filters may not be necessary. If an offending interfering signal is identified and the intensity measured, a filter would be selected to attenuate to a provide a manageable SNR in the the frequency range.

I thought the newer satellites don't require as large dish? Maybe I heard wrong.

Actually looking more closely most of the sats from 89w to 139w are between 80cm to 170cm (avg being 132cm), so maybe my location is just decent for c-band. 87w downward require 130-230cm. Unless all this will change too.

 

[Titanium]

I thought the newer satellites don't require as large dish? Maybe I heard wrong.

Newer satellites usually have higher output power. This higher power can be good or bad... The Good: A smaller dish will receive a stronger signal.
The Bad: Stronger satellite signals will also provide a greater chance for stronger interfering signals from adjacent satellites to decrease the Signal To Noise ratio and prevent reception of the target transponder.

A smaller dish "sees" a wider beamwidth, I.E. more area of the sky and potentially more satellites. A larger dish has a narrower beamwidth ( "sees" less of the sky), focuses the gain of the narrower main lobe on the target satellite and attenuates the "noise" of the undesired satellite signals from the off axis adjacent satellites.

The gain on a smaller dish might be adequate to receive a strong enough signal from the newer and higher power satellites, but the resulting wider beam cannot reject the unwanted signals from adjacent satellites.

 

[armadillo_115]

I thought the newer satellites don't require as large dish? Maybe I heard wrong.

Actually looking more closely most of the sats from 89w to 139w are between 80cm to 170cm (avg being 132cm), so maybe my location is just decent for c-band. 87w downward require 130-230cm. Unless all this will change too.

Those cm sizes are for ku band, NOT for C Band. C band sizes are listed in meters. (m) For instance: 3m, which would be approx a 10 foot dish

edit typo

 

[ssj925]

Newer satellites usually have higher output power. This higher power can be good or bad... The Good: A smaller dish will receive a stronger signal.
The Bad: Stronger satellite signals will also provide a greater chance for stronger interfering signals from adjacent satellites to decrease the Signal To Noise ratio and prevent reception of the target transponder.

A smaller dish "sees" a wider beamwidth, I.E. more area of the sky and potentially more satellites. A larger dish has a narrower beamwidth ( "sees" less of the sky), focuses the gain of the narrower main lobe on the target satellite and attenuates the "noise" of the undesired satellite signals from the off axis adjacent satellites.

The gain on a smaller dish might be adequate to receive a strong enough signal from the newer and higher power satellites, but the resulting wider beam cannot reject the unwanted signals from adjacent satellites.

Thanks this clears things up

Those cm sizes are for ku band, NOT for C Band. C band sizes are listed in meters. (m) For instance: 3m, which would be approx a 10 foot dish

edit typo

They're for C-band. I have Ku sizes listed as well in my post: Trying to get into C-Band, may have found a dish?

A 170cm dish would be ~5.5ft to roughly 6 ft dish. I myself was kinda surprised to see lots of the size recommendations from my area. But as mentioned above I definitely see why larger is still preferred.

 

[armadillo_115]

Okay, I was wrong. I'm glad you got it all figured out. You win!

I'm done.

 

[N6BY]

ILoveSats,

For what it’s worth, I have a solid 8 foot dish and I receive MOST satellite services up there. I bought one of Titanium’s 5g filtering lnbf (s) and that took care of my 5g issues. I also have a kU side car set up on that dish and it works well also.
Yes a 10 footer would do more, but I’m very satisfied with my dish set up.

John

Same here. I have a solid 8' and a 10' mesh dish. I also have heavy 5G which Titanium's 5G filter LNBF works well to eliminate.

So I wouldn't worry about 5G or dish size. Also, you don't need an actuator to try it out. If you get good signals you can always get an actuator later. Just get a receiver and a Titanium filter and enjoy the hobby.

 

[ILoveSats]

Newer satellites usually have higher output power. This higher power can be good or bad... The Good: A smaller dish will receive a stronger signal.
The Bad: Stronger satellite signals will also provide a greater chance for stronger interfering signals from adjacent satellites to decrease the Signal To Noise ratio and prevent reception of the target transponder.

A smaller dish "sees" a wider beamwidth, I.E. more area of the sky and potentially more satellites. A larger dish has a narrower beamwidth ( "sees" less of the sky), focuses the gain of the narrower main lobe on the target satellite and attenuates the "noise" of the undesired satellite signals from the off axis adjacent satellites.

The gain on a smaller dish might be adequate to receive a strong enough signal from the newer and higher power satellites, but the resulting wider beam cannot reject the unwanted signals from adjacent satellites.

Brian,

You stated "As long as you have a window through the trees to view the target satellite(s), the vegetation and buildings will usually work to your advantage, attenuating undesired off axis signals." I understand this as it applies to amateur radio as well.

However, Primestar31 stated "As Brian said, 5g signal intrusion is basically line of sight bearings." Is Primestar31's comment in line with your statement that I just quoted above? I think he is referencing this comment?

When we speak of interfering signal attenuation do we mean at the location where 4GHz signals enter into the LNBf? OR even anywhere in the atmosphere between the satellite and the reflector?I believe we mean where signal enters into the LNBf but then why doesn't 5Gsignal effect whats coming through the atmosphere?

Below, you also stated "A smaller dish "sees" a wider beamwidth, I.E. more area of the sky and potentially more satellites". Would an example of this be the Sirius XM signals we can receive in our cars without interruption?

73

K9JPT

 

[N6BY]

K9JPT,

Based on your call sign location, the 5G coverage map shows that your area has 5G and you would likely need a 5G filtering LNBF.

Brett

 

[ILoveSats]

K9JPT,

Based on your call sign location, the 5G coverage map shows that your area has 5G and you would likely need a 5G filtering LNBF.

Brett

I would not rely on a call sign. I'm in upstate New York. Nonetheless, how much 5G is too much 5G? Filters, I would imagine, can be added later if it's determined an issue exists. And based on what I have learned so far in this post there is a chance that the terrain, vegetation and even houses may absorb 5G interference. Attached is a 5G map of my area.

 

[Titanium]

Brian,

You stated "As long as you have a window through the trees to view the target satellite(s), the vegetation and buildings will usually work to your advantage, attenuating undesired off axis signals." I understand this as it applies to amateur radio as well.

However, Primestar31 stated "As Brian said, 5g signal intrusion is basically line of sight bearings." Is Primestar31's comment in line with your statement that I just quoted above? I think he is referencing this comment?

The vegetation and buildings will attenuate the terrestrial signals from having an unobstructed line of sight path from their transmitter to your feedhorn.

When we speak of interfering signal attenuation do we mean at the location where 4GHz signals enter into the LNBf? OR even anywhere in the atmosphere between the satellite and the reflector? I believe we mean where signal enters into the LNBf but then why doesn't 5Gsignal effect whats coming through the atmosphere?

We are talking about preventing unwanted signals (noise) from entering the feedhorn via line of sight or reflection. RF signals are directional and not mixing or significantly redirected in the atmosphere. There is minimal depolarization of the satellite signal. The terrestrial signals are beam shaped to focus where the operator wants the signal. Remember that the terrestrial signals are part of a managed cellular network and managed to have optimized overlap. Directing these signals into the atmosphere would be a waste of RF. LOL

Below, you also stated "A smaller dish "sees" a wider beamwidth, I.E. more area of the sky and potentially more satellites". Would an example of this be the Sirius XM signals we can receive in our cars without interruption?

A different beast... Sirius XM uses low orbit satellites and local FM stations provide fill data in cities where the satellites may not be visible between buildings or in parking structures. These antennas are omni directional to allow them to "see" multiple satellites simultaneously and the hardware selects the best signal and seamlessly switches with these synced sources.

 

[Titanium]

I would not rely on a call sign. I'm in upstate New York. Nonetheless, how much 5G is too much 5G? Filters, I would imagine, can be added later if it's determined an issue exists. And based on what I have learned so far in this post there is a chance that the terrain, vegetation and even houses may absorb 5G interference. Attached is a 5G map of my area.

5G is a celluar network standard and not a band or frequency. 5G maps are only as good as knowing what bands are being used at these sites.

 

[mr3p]

I wouldn't view 5g as an obstacle as that can be overcome with a new LNBF if needed. IMHO, your biggest limitation is your LOS and 8ft dish size. Mesh can be replaced and rust can be removed on your mount but you're going to have to spend time and money and you're going to need a friend to assist. My dish was probably in similar condition when I pulled the trigger on refurb, before and after pictures here.

 

[primestar31]

Here's my latest dish install from late 2018, it's a SAMI 8ft dish, and near step by step what I did. This was my 6th C-band dish install, first was in 1984 at another house. Very much, if not the same dish as the one in your photos. Lichen growing on it and everything. IF you want to see what it can take to install one with a tight satellite arc:

I'll take "Name that satellite" for $500 please! HELP!

SCORE!!! I went over to another neighborhood 5 miles away where I remembered there was a c-band dish on a 20ft pole above their garage. That dish was gone. So, I decided to just drive around a little, and go down some roads I almost never go down. On the SECOND subdivision road, which is a...

www.satelliteguys.us

 

[N6BY]

I would not rely on a call sign. I'm in upstate New York. Nonetheless, how much 5G is too much 5G? Filters, I would imagine, can be added later if it's determined an issue exists. And based on what I have learned so far in this post there is a chance that the terrain, vegetation and even houses may absorb 5G interference. Attached is a 5G map of my area.

As Brian stated earlier, the 5G map doesn't tell the whole story. In our case the problem is the usage of a particular part of 5G (Band N77 from 3700 to 3800). There are numerous other bands that 5G can use besides N77 that won't interfere with satellite reception.

However, the only real test is to try an unfiltered LNBF and see if it works. If it doesn't you will have to buy another LNBF (a filtered one). If it was me, I would just buy a filtered LNBF and get it over with.