How to improve your wireless experience

Voldemort

Death eater
Joined
Apr 8, 2006
Messages
6,782
Reaction score
192
Location
The river Styx...
Hi guys

Over the years ive had plenty of forumites complaining of signing with the various companies only to be disappointed with regards to things like signal level, throughput, latency, even though when they sign these contracts the coverage maps show full coverage. Its important to note that there are a couple of factors that these maps do not take into account:

1- trees: Trees affect radio frequency on a big scale. If you are in a heavily wooded area the RF will be diminished and the problems will be complimented by the structure you stay in.

2- Zinc roofs: Even though your roof might be tiled your zinc roofed garage, for instance, would be getting in the way like a lead plate to radiation- Ive solved thousands of complaints like this with either a yagi antenna installation or a WCDMA flat panel antenna. Bear in mind with this that if you are in a complex your landlord would need to approve the yagi install, and in complexes like Lonehill, fourways or Sandton this would be difficult.

3- Stone: Aside from lacking line of site- stone is pretty much the worst. I have sites on properties whereby the owners arent even getting proper signal from it thanks to their stone fireplaces, or the stone additions their neighbours have added to their houses. To fix this we try and add cell extenders pointing either away from the stone or over it, in most cases this remedies the situation.

4- Resistence from homeowners: The majority of the complaints that i get in the Gauteng area are from residents not wanting us to construct a site in their area. Anybody who has ever done research into this field knows and understands the risks of electromagnetic frequency and understands the levels at which they are being produced- one has a greater chance of developing cancer from using their microwave oven than they have of being irradiated by a tower- this matter has been proven, yet every time Carte blanche releases a broadcast about how some sheep farmer in New zealand got a brain tumor then everybody is up in arms. I have personally been at arms length with hundreds of cell phone towers replacing equipment for 6 years and can happily say that im not only fit as a fiddle, but im running the 2 oceans marathon next year for the 3rd time.

5: Office complexes and double storey houses: The concrete slab is a factor, dont fool yourself- the concrete is about as blocking to us as superman is to kryptonite- check the 2nd floor of your house and you will feel our pain.
I was in Korea a year ago and they had cell extenders installed to catch a site 400m away- if they are struggling with signal? Then God help us all...

The reason i compile this is not just because of signal issues- its to look out for you in the first place- if you have a tower in your area thats sporting 400kbps download and 1.2mbps upload? Its a congested tower and needs to be reported- extra transmission is needed on the site! What would be even better is if a new tower could be constructed!
My recommendation to you is that when you want to choose a service provider on contract, rather take them on prepaid and try them for a Gig or 2, then make your descision- it will save both of us a lot of trouble.
 
i concur....great post.

just for clarification, if the neighbors have stone in their house, it will only affect me if they are in my direct LOS? would be crazy if they just had to be in the general area.
 
My roof is made of slate, which contains iron. The previous owner had put his VHF and UHF TV aerials inside and told me how rubbishy they were. I put them on a mast on the chimney and hey-presto, they worked 100%.

Also a factor is rain on trees. I use a 14db outdoor antenna for my 3G modem and when it rains the signal drops off. It is pointing into some trees about 20 metres away. The same applies to DSTV signals. The satellite is only 24 deg off the horizon and it is easy fot trees to be in the way.

The metal / reinforced concrete / trees need to be between your receiver and the transmitter. If it is more than 20 deg away, then it will not have any effect
 
Few points:

1. Any external antenna mounted in good reception area ia better than no antenna. 7dBi window mounted antenna is a good compromise comparing to the large outdoor antenna.

2 Directional antenna is better than omni-directional due to elimination of multiple signal path.

3.Power delivery problems are typical for USB modems. It shows every time when new technology comes and early devices are not power optimised. Example: early 7.2Mbps and 21Mbps modems. Power requirements will increase in poor reception areas. If experiencing frequent disconnects, modem hanging, etc., try different USB port, self-powered USB 2.0 hub or switch to battery operated modems or use phone as a modem.

4. Cable extension allow to move modem to the better reception space (see above), but create power problems, so cable must be short (30cm maximum)). Self-powered USB 2.0 hub allows to extend lenght of the cable 5m or more. Other solution is custom in-cable filter.
 
Last edited:
Excellent points! Yes rain does affect RF, but funny enough RF carries a bit further over still water ie lakes.
@Sajunky, just to clairy for the people that is the USB cable and not the external coax. with the coax the signal loss is measured at a general median of 0.1db per meter, although i reckon that figure from experience to be incorrect somehow?
 
with the coax the signal loss is measured at a general median of 0.1db per meter, although i reckon that figure from experience to be incorrect somehow?
It depends on your type of cable and the frequency, but 0.1dB/m sounds too low.

RG-58/U cable loses approximately 1.0dB/m @ 2400MHz.
Low-loss LMR-195 cable loses approximately 0.6dB/m @ 2400MHz.
 
2 Directional antenna is better than omni-directional due to elimination of multiple signal path.
A directional antenna also allows you to aim at less congested base station, possibly further away.
 
@Sajunky, just to clairy for the people that is the USB cable and not the external coax. with the coax the signal loss is measured at a general median of 0.1db per meter, although i reckon that figure from experience to be incorrect somehow?
Of course, RF cable is not USB cable. For others note that modem transmit and receive radio frequency signal and RF cable extends place of the radiating/receiving point (from internal modem antenna to the external antenna).
If your experience is at 35MHz, it could be 0.1dB, but if you work on 2GHz+, then ginggs figures are correct. 20m cable would consume all antenna gain, even with low-loss LMR-195 cable. It is why other solutions are in place for moving transmitting device (modem) closer to the antenna. Wired or wireless 3G router like Huawei B683 will do a job. USB extension will work in study or bedroom.

Coming back to RF cables, professional antenna installators use thicker cables which give lower loss and capacity per meter and better shielding (lower noise levels for receiver). Very popular is LMR-240 and CA-400, but in home enviroment router is more convenient.

Coming back to my first post, how many people use window mounted antenna?
 
Last edited:
You make a good point, when this was explained to me it was by an installer whilst installing a cell extender so yes they work with thicker cables, nice one :)
In answer to your question, i give many clients window mounted antennas, more so in the urban areas of course, generally works a charms unless your neighbour has built his new monstrosity to high, thereby blocking ground coverage- as is the case in places like Midstream estates. We are building 5 new sites in the area, sorely needed.
 
The cheapest quality modem with external antenna connector is from MTN: Huawei E352 14.4Mbps.
Pigtail SMA (most popular antenna connector) to CRC9 (modem connector) around R70 from Otto Marketting.
 
One thing not mentioned is the effect of thatch. Living in a rural area I have a dedicated Poynting data antenna up in the roof of my thatched home, pointing directly with line-of-sight to the tower -- but through a fairly thick thatched roof built on wooden poles. What influence if any does the thatch have on signal?
 
Bought one of these a while back for my E367

attachment.php


Just a word of warning, be very gentle plugging and unplugging this connector.
I broke off the barrel part of the socket inside the modem, which came out stuck in the end of the CRC9 plug.

Was quite a job to dismantle the modem and solder the tiny barrel back on again!

Now it is plugged in permanently and held in place with a cable tie to reduce strain on the connector.

attachment.php
 
Thank you Base122 for sharing your experience. I managed to release side latches so far, but is not enough. Which other latches should be released first: from rotating head or opposite side?
 
Last edited:
Thank you Base122 for sharing your experience. I managed to release side latches so far, but is not enough. Which other latches should be released first: from rotating head or opposite side?

Sorry haven't been following this thread for a while.

Take a look at the pictures on this site:
http://www.mobilabredband.se/galleri/?album=1&gallery=21

You have to first remove the small screw near the SIM socket. It may be covered with some white or black seal of sorts.

Then start from that end (opposite rotating head) and very carefully and gently with a small screwdriver, prise open the casing. When you get to the rotating head side of the casing, it is more difficult, but will come apart eventually.

Soldering the antenna barrel back on is a very tricky procedure. Make sure you DO NOT use a soldering iron that is too hot, or you may melt the plastic part of the connector. Try not to use too much solder, as it may flow onto the barrel and make the diameter larger, preventing the crc9 plug from fitting over the barrel. I had to modify the crc9 plug a bit to get it to fit properly.

Of course, this procedure completely voids your warranty :D

attachment.php
 
Last edited:
You have to first remove the small screw near the SIM socket. It may be covered with some white or black seal of sorts.
Many thanks, this screw I missed! I was fooled by white sticker which looked like water damage indicator. It looked to me impossible job, so I decided to put is aside and wait...

Now I can continue. :) :) :) :) :)

Edit: Done. Now this tube is soldered on top only, so any rotating force would break it again. But it seems it was always like that... I adjusted tension of the plug. If I did before it would probably never break off, always learning... Now it has to be permanently fixed like on your photo.
 
Last edited:
I would get myself one of these in a flash, if it covered Cell-C frequency as well, but it does not, alas.

I live in a Sectional Title complex, and this would be ideal ...
 
Unfortunately no 900MHz. They say "Wind operation 120km/h". With sucking mounting! It is probably copy-pasted from some other device :)

I have similiar one with wall mounting. It is AlanDick INP-C0825-10A. It covers all needed freqencies: 824-960, 1710-2200 and 2400-2500. Inside I see very clever design. Just received Type N connectors, going to test it soon. :)
 
Top
Sign up to the MyBroadband newsletter
X