8ta and external directional antenna

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Methias

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Has anyone been able to get the E1820 8ta modem working with an external directional antenna with a universal coupling working?

I've just myself the bundle from Uniterm and it I am getting absolutely no benefit from the antenna.

My problem must be one of the following:
a) Uniterm sold me a dud antenna or coupler
b) I'm using the coupler incorrectly
c) The 8ta network is just completely pathetic

I attached the antenna to a +- 2m metal pole on the roof and sat on the roof using my laptop and MDMA to get the dbi of the signal and rotated the antenna bit by bit to check the signal strength. It didn't budge.

I screwed the antenna into the coupler and placed the coupler against the modem (held on now with a rubber band). Is this the correct way to attach the coupler to the modem?

Anyone got any advice as to what I have done wrong?
 
I don't have all the answers but you should try the coupler on both sides of the modem as well. In my experience these couplers lose a lot of the signal and you'd be much better off using a direct connection. The E1820 has a socket on the side for a CRC9 plug. You would need a Pigtail, a short cable, with a matching SMA connector on the one end and a CRC9 on the other. Then if plugged into the E1820 you could expect about a 6db gain, which is very good as 3db is doubling the signal, assuming both are in the same place. The antenna is usually advertised as 11 or higher DB gain but most is lost in the 6 metre cable at the high 2100 ghz frequencies. The main advantage of an antenna is that you can position it in the right place pointing it at the tower without obstruction in a place where you could not with the modem itself, such as outside. One word of caution, these Pigtail adaptor cables usually sell for about R40 (on BidorBuy) but for some reason the big boys ask more than R300 for it, no idea why? Nothing to do with quality. Lastly if you could convince your ISP to tell you where their towers are, you would save a lot of time and frustration.
 
The problem with a pigtail on my E1820 modem is that it connects to the axillary antenna, and from what I understand this will now show up in MDMA, so I'll have no way of knowing the antenna is correctly positioned.

Inside the house I measure between 89 and 83db strength. In the roof I was getting 81 - 73db, at one point in the garden I was able to get 65db. Now that should be an excellent signal and yet I try connecting to the 8ta network and my speeds are pretty much what they are inside. Does this make any sense?

I don't know if it makes any difference but I am trying to use the LPDA11A antenna from Uniterm.
 
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Methias said:
The coupler is similar to this one:

http://www.dbg.co.za/product_info.php?cPath=32_36&products_id=174
Click to expand...

I got one of those from them too but find it very ineffective negating the antenna gain. I'm not the fundy on Modems but am very surprised that plugging an external antenna would not be the correct way to go. No idea how it could affect the MDMA results negatively. I don't believe that signal strength translates directly or linearly to transmission speed. Once over a certain strength, say better than -90 it shouldn't be a throttling factor. Your speed issues are probably related to other causes. Does the speed change with the time of day? Number of subscribers on the tower? Do you use a router? etc.
BTW I use the 8.TA software on my Mac and can clearly read the signal strength in dBm and see the difference immediately (nearly) in changes I make with the antenna or position or without the antenna plugged in.
 
Rick@Harties said:
I'm not the fundy on Modems but am very surprised that plugging an external antenna would not be the correct way to go.
Click to expand...
I think everyone was surprised when we figured this out, read all about it here:
http://mybroadband.co.za/vb/showthread.php/276198-Cell-C-E1820-External-Antenna-Connector
Rick@Harties said:
No idea how it could affect the MDMA results negatively.
Click to expand...
It doesn't affect the results negatively, there is just no effect, i.e. connecting an antenna on the external antenna connector results in no change in the signal strength reported by the modem, connecting an antenna using an inductive coupler results in an increase in the signal strength reported by the modem.
 
ginggs said:
Notice the description in the title of that web page: "Universal Cellphone Coupler". You are wasting your time not using the sleeve type inductive coupler.
Click to expand...

It has been reported that the E372, E367 (E353) work with the external antenna and the inductive coupler is optional.

Note: the branded rotating 8.ta modem is an E367.

Edit: I am installing today and will confirm.

Current stats:

RSSI: -95dBm
Signal Strength: 58%
RAT: HSPA+
Down: 4.00 Mbps
Up: 2.50 Mbps

Initial test:

RSSI: -87dBm
 
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I have an 8ta branded E1820 modem. Maybe I should go in and purchase a E367 modem then. And return the coupler to Uniterm and get a connector (CR9 I think) to plug directly into the modem.
 
phaktza said:
It has been reported that the E372, E367 (E353) work with the external antenna and the inductive coupler is optional.
Click to expand...
OP was using an E1820. My comment about wasting your time not using the sleeve type inductive coupler only applies to the E1820.
 
Methias said:
I have an 8ta branded E1820 modem. Maybe I should go in and purchase a E367 modem then. And return the coupler to Uniterm and get a connector (CR9 I think) to plug directly into the modem.
Click to expand...
I think the Uniterm pigtail sells for about R250, I bought one on bidorbuy for R42 works perfectly with my E367 and Uniterm LPDA Antenna, get +-8dbm gain.
 
Strange thing about that E1820. Can say for sure that my external Yagi plugged into my E353 works well. I will try a new E367 this weekend too. Another point of interest about polarity. When turning my laptop upright, i.e. 90 degrees, with the E353 plugged into the USB, no antenna, the signal increased about 6dBm. Not easy to use it that way. The new E367 has an hinge and will allow the modem to be upright, will try that later.
PS I also use a R42 Pigtail.
 
Polarity matters and distance from the desk increases as well (which affects receiver antenna). V short extention cable can be used with E353 for this purpose. No need for E367.
 
Methias said:
I have an 8ta branded E1820 modem. Maybe I should go in and purchase a E367 modem then. And return the coupler to Uniterm and get a connector (CR9 I think) to plug directly into the modem.
Click to expand...

I actually switched out the CRC9 connector for a TW9 connector as it fitted slightly better, but both work (with a little force).

Sent from my HTC Desire HD using Tapatalk
 
ginggs said:
OP was using an E1820. My comment about wasting your time not using the sleeve type inductive coupler only applies to the E1820.
Click to expand...

I know, I just want to make it clear this isn't a general comment and certain 8.ta modems don't require the more expensive inductive coupler.

Sent from my HTC Desire HD using Tapatalk
 
sajunky said:
Polarity matters and distance from the desk increases as well (which affects receiver antenna). V short extention cable can be used with E353 for this purpose. No need for E367.
Click to expand...

Sure but it's a lot easier to use in a laptop as a stand alone. Also less chance of breaking it.
 
Rick@Harties said:
Sure but it's a lot easier to use in a laptop as a stand alone. Also less chance of breaking it.
Click to expand...
Of course, but there are two things:
- cost of a new modem vs. short piece of cable
- rotating head is not as good as it looks. I found it doesn't give a good connection. When you rotate head it happens to reset and reload drivers.
 
sajunky said:
Of course, but there are two things:
- cost of a new modem vs. short piece of cable
- rotating head is not as good as it looks. I found it doesn't give a good connection. When you rotate head it happens to reset and reload drivers.
Click to expand...

Definitely not on the e367.
 
No wouldn't recommend buying another modem just for the hinge, a short cable is fine but you'll have to hold it up and away from metal.

Hope nobody tried replacing the capacitors in it.
 
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