Jitter

Is there any one wiht any known tricks to get your Jitter down? I’ve tried to hook a customer up that is less than 2 miles form the tower using 900 mhz but cannot get the link cleaned up no matter what I try to do. There is nothing in the air when I do the spectrum analyzer. My signal is there of course but that is it. I get damn near 100% on download test but sucks on the upload form the customer. I get a 76 –dbm with a jitter of 5. I have turned down power I’ve increased power. I have changed out with the M2 14 db yagi to a M2 17 db yagi. Still no luck… I can register but and stays register but the link is so unstable it won’t transmit data but interment. I have tried to mount it low I tried high….Right now it is on the chimney with a M2 17 db yagi. There are several tall trees but not near the house much……I am right at tree top level now……Thanks a head of time for your answers……

1X or 2X? If 2X try 1X.

Typically when the download test is good but the upload is poor it generally means a nearby obstruction such as a tree or in some cases the signal is reflecting off the roof.

Yes it is in 1X…That makes sounds about right. I also noticed that according to google earth they are 489 ft. above sea level. My tower is at 422 ft. above sea level + 100 ft. that makes me 522 ft. Add 25 to the user side as I am on his Chimney so that makes him 514…There fore the trees are killing me and if I get over them, I will be over shooting the tower anyways. I just hate to bail on this customer…Not even 2 miles and not a good enough link…I guess it is what is…I just hate to admit defeat I guess…Thanks Jerry…

Sometimes +25ft on a telescoping TV mast at the customer side will do it.

Alternately you can do a tree install.

Do you have a good source on where to buy these telescoping masts?

Google search for Telescoping Antenna Mast: http://www.acehardwaresuperstore.com/ch … tml?ref=42

Instead of Telescoping masts that are hard to assemble and heavy I favor aluminum poles. I have standardized on the 20ft, 2" OD, .065" wall. This pole is light enough and strong enough that I can attach only the bottom 3-4 feet of it to a chimney or eave and have the rest of it up in the air without guy wires. This is with a 17 M2 yagi and SM on the top. The M2 Yagi Ubolt barely fits a 2" OD pole so this also prevents the yagi from drooping.

mattmann72 wrote:
Instead of Telescoping masts that are hard to assemble and heavy I favor aluminum poles. I have standardized on the 20ft, 2" OD, .065" wall. This pole is light enough and strong enough that I can attach only the bottom 3-4 feet of it to a chimney or eave and have the rest of it up in the air without guy wires. This is with a 17 M2 yagi and SM on the top. The M2 Yagi Ubolt barely fits a 2" OD pole so this also prevents the yagi from drooping.


how much are they for that 20 ft. alum. mast?

Mike

Could you provide a bit more details on the poles?

Do you mount/attach them somehow on the bottom/ground?

Where do you get these at? I am currently using chainlink fences top-rails. they are 10ft, and fit nicely together pretty tight, but they are small diam, and the M2s need some spacers to prevent droop.

Would it be possible to put in a small 5 watt amplifier in this situation?

No amplifiers, ever. Reasons are many but the top reasons are:
1. it’s illegal and expensive if you get caught
2. You will pollute your RF environment
3. They only give you another 3dB if that.

Steps you can take:
1. M2 14dBi Yagi
2. M2 17dBi Yagi
3. M2 17dBi Yagi - x2 stacked (see website)
4. Elevate the above antenna - 10’, 20’ I like the telescoping units as there are already guy wires on it but others mentioned alternatives. Rigid EMT conduit also works well.
5. Tree install - ask Matt - he’s the king
6. Repeater off a nearby customer

Sometimes you can’t get an install and it’s better to give up - really. An unhappy customer is your worst enemy. Winter is coming and ALL of your links are going to change by as much as 10dB when the trees are wet.

Bear in mind your time, and costs against the monthly fee. The idea is to try and get an ROI within 6 mos max. Any more than that and you won’t survive.

Any costs beyond a couple of hours are passed to the customer. I eliminate the risk by telling the customer that they will only pay the additional cost if we are successful. There is risk in this as the customer will expect preferential treatment because they paid extra.

Bottom line, if you think the link is sketchy - don’t install it.

Thanks Jerry…Just thought I would ask is all.

jakkwb wrote:
Could you provide a bit more details on the poles?

Do you mount/attach them somehow on the bottom/ground?

Where do you get these at? I am currently using chainlink fences top-rails. they are 10ft, and fit nicely together pretty tight, but they are small diam, and the M2s need some spacers to prevent droop.


The only fence top rail I use is the 24' ones. I take 1 of the 1-5/8 and put it inside of one of the 1-7/8 to create a simple 50' extending pole that is much more sturdy than the actual extending poles that Jerry suggested. These can be guyed or if you have a tall metal building or oak tree the base of the pole can be put in the ground and the top of the larger pole attached to the eave or a tree branch. From there I have successfully raised the smaller pole a good 14 feet without guy wires with an integrated SM on it. It waves around a bit but an Integrated has a very wide beam width. I am in Northern California where we do not get much wind or snow in this area so I can probably get away with more than others might. Plus by stocking these poles I can always cut them to different sizes easily to fit different situations or for when I just need a shorter single extension for something.

I get the aluminum poles from a local welding shop. I find most metal supply companies can get them. To them its known as round aluminum tubing. They order me 5 at a time for a cost around $70 each. I make the customer pay $50 for half a pole and $100 for a full pole installed.

I use a variety of mounts depending on the situation. Mixing and matching mounts works well for different situations. I find that a 17 yagi with SM on the pole requires about the bottom 3' of the pole attached with 17ft sticking up unsecured. But again I get a max of about 50mph winds a few times a year. However all of these installs did survive our weekend of 80-100mph winds last year.
3" TV mast standoffs that take up to a 2-1/2" pole work great (Tessco # 44156). Gable End mounts on a steep eave work well. The Ronard 4560 Adjustable Universal Eave Mount is my preferred.
I also use the P shaped fence mounting brackets for 1-7/8 fence top rail. They are slightly small but a bit of bending and they fit quite well for attaching these poles to posts or chimneys where a 3" standoff does not work.
The 12", 18", or 24" standoffs work for these poles too as long as you get the ones that take up to a larger pole, like tessco #: 482629. These can be mixed with the 3" standoffs where you have a very shallow pitch roof. Use a 3" on the facia board at the peak and a longer stand off below.
I have also used the foot of a standard canopy dish or integrated mount to use as a base for guying the pole or for attaching it to an eave above on a multi-tiered roof.
I also use 12" standoffs and some length of these poles in the tops of trees for larger antennas or to get out the top of a tree that I do not want to remove the top of.