PigTail - the adaptoid cable, usually 6"+ in length that is used to convert from the FCC-mandated proprietary antenna connection to (usually) a standard N connection (Male or Female, I can never figure out which... the end with the spinny thing on it).  It's generally made out of a thin, and fairly flexible cable.

One problem that comes up with Pigtails is that they are lossy - due to the use of LMR-100 or thinner cable.  LMR-400 loses about 3 dB (half) every 40 feet, so a really thin cable should be spewing loss every inch, right?  Well, as a test, me and the WirelessSupplyGuy did a test tonight to see.

 Does anyone have any numbers on how their signal drops using a longer length of coax?  If no one else has already, I can do a test with a 50 and 100 foot cable of LMR-400 on a LinksysWap11 at awip node 1  --ForrestEnglish


I hooked a 12", 19", and 1.5 meter (many many inches) cable into my Airport Base Station, one at a time, of course.  From there, a took a Stylistic 1200 running Orinoco's Wireless Client software (with the send and receive SNR bar graphs) and measured the average Signal-to-Noise Ratio (SNR) in 3 locations outside my house:
 1. Under the antenna - usually a Dead Spot (Porch)
 2. Across the street, in line with a pair of huge fir trees (Trees)
 3. At the corner - with decent line of sight to the antenna (LOS)

The Amplifier was a Teletronics 1-Watt outdoor amplifier, an indoor HyperLinkTech 1-Watt amplifier produced similar results.

 ||PigTail Length||Porch||Trees||LOS||
 ||12"||26/12||32/20||33/24||
 ||19"||25/11*||30/21||34/22||
 ||1.5 Meter||26/12||33/23||36/23||
Signal strength measured in dB (m?)

The 19" cable had an initial Dead Zone (Porch) measurement of 31/18 (!!), but since that's a Dead Zone, the meters had a tendency to vary widely, so it was thrown out.
The results are pretty interesting, however.  All measurements are within 1 or 2 dB of each other, suggesting that the PigTail length has very little to do with signal strength output OR input.  Be aware that this isn't 100% proof positive, but I was expecting a 10-20% signal loss with the 1.5 meter cable (it's HUGE!)

-DanRichardson
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