Abort, Retry, Fail?

My 16-element Yagi for 2.4GHz, 25dBi gain.

The answer is: Fail. We won’t abort though, but retry. When we were setting up our long range WiFi network, we ran into some problems. At PA2AYX’s side, everything is fine. At my end it’s not. The 16-element Yagi, bought on eBay for less than $15, is fine. My access point (TP-Link TL-WA5110G) is fine. Power output is fine. The coax cable between the AP and the Yagi is not. Far from it, to be exact.

Scam, scam, scam
When I ordered the 10 meter long cable, it was advertised as “low loss cable for 2.4 GHz’. When the cable arrived, I quickly realized that I got scammed. The cable proved to be ordinary RG-58, a cable I would only use for HF, nothing else. So here we are, most of the Yagi’s gain is eaten up by a poor cable. 10 meters of RG-58 @ 2.4GHz equals a loss of at least 10 dB, probably more. 10dB is a lot – both RX sensitivity as well as TX power are divided by a factor of 10. LMR-400, the cable I expected to get, loses only 0.22 dB per meter. This means 2.2dB cable loss, which is more or less acceptable. Better numbers, sure, but dangerously close to 3dB, a factor of 2. Here is a list of cable losses, at 2.4GHz:

  • RG 58: 1 dB per meter.
  • RG 213:  0.6 dB per meter.
  • RG 174: 2 dB per meter.
  • Aircom: 0.21 dB per meter.
  • Aircell 7: 0.38 dB per meter.
  • LMR-400: 0.22 dB per meter.

Learning curve
In spite of the crappy setup at my side, my signal came through. The distance between our two stations is a little bit more than 1 Km, and we don’t have a completely free line of sight. There are some trees in the way, plus a sporting complex. All in all not bad, but not good enough. My setup will be changed completely. I don’t want to calculate cable losses at all, so I ordered an access point which can be mounted directly under my Yagi. These nifty devices are made by EnGenius and other companies. The power output varies from brand to brand, but the options are more or less the same across the board: AP, repeater, and bridge. Power is supplied by POE (Power over Ethernet), the only cable going down into my shack is an ordinary Ethernet cable.

The EnGenius EOC-2611P.

Long range WiFi networks: what not to do
If you own a low power access point, don’t buy so-called ‘boosters’. Apart from the fact that they’re often very unreliable, these things won’t solve your problem. Invest in a hi gain outdoor antenna and low loss cable instead. If possible, replace your ordinary AP by something like the EnGenius EOC-2611P, and put it high up in the air.

Within a week or 2 we will be able to report failure or success. I expect the latter.


3 comments on “Abort, Retry, Fail?

    • That would be nice to know. It’s a quite cheap antenna, and the elements aren’t always properly aligned when they arrive. Just a matter of poor quality control I guess. Easy to fix though.

      There are three of these in service at the locations of three different Ham operators. They seem to do the job just fine, but history learns that manufacturers like to exaggerate a lot when it comes to gain.


  1. I would recommend to use anything made by Ubiquiti for any long range WiFi endeavors. They are just doing it better. I’m using them for years, a quite happy with results.

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