Thank you for visiting RF Cafe!

Your RF Cafe
Progenitor & Webmaster

Click here to read about RF CafeView the YouTube RF Cafe Intro VideoKirt Blattenberger
BSEE
KB3UON
EIEIO

Carpe Diem!
(Seize the Day!)

5th MOB:
My USAF radar shop

Airplanes and Rockets:
My personal hobby website

Equine Kingdom:
My daughter Sally's horse riding website

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
RF & EE Symbols Word
RF Stencils for Visio

Regarding Cable Loss - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues. Please visit the new and improved RF Cafe Forums that were created in September of 2015. Unlike with the old forums where users registered individually, the new forums use a common User Name and Password so anyone can post without needing to create an account. Please find the current User Name and Password on the RF Cafe homepage. Thanks for your participation.

Below are all of the old forum threads, including all the responses to the original posts.

-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews
-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

 Post subject: Regarding Cable Loss
Posted: Thu Jun 16, 2005 11:40 pm 
Hi all,

I had a question regarding measuring cable loss, How to connect the equipments to calculate the cable loss from one end of the cable to another if you have a Signal Generator, Spectrum Analyser and Power meter. How should I connect the cable to and what are the parameters Should I change to know the cable loss.

Thanks in Advance!

Dreamer


 
  
 
 Post subject:
Posted: Fri Jun 24, 2005 11:15 am 
 
Site Admin
User avatar

Joined: Sun Aug 03, 2003 2:02 pm
Posts: 653
Location: Erie, PA
Greetings Dreamer:

If all you need to measure is the loss of the cable, then all you need is the spectrum analyzer (SA)* and, if both ends of the cable cannot reach the SA from the same place, a signal generator (SG).

* If the SA has a generator output built in.

If both ends of the cable can reach the SA and it has a built-in generator, then simply calibrate the SA and place the two cable ends between the In/Out ports and measure directly.

Otherwise, measure the output of the signal generator and either se tthe S/A to give a relative measurement from there, or note the power level to do the math yourself. Then, connect one end of the cable to the SA input and the other to the SG.

A good thing to do is place an attenuator (at least 3 dB, preferably 10 dB) at the output of the SG both when taking a reference reading and when connection the SG to the cable. Doing so helps minimize any error that might be caused due to impedance mismatch between the SG and the cable. When measuring down to tenths of a dB, it can make a noticeable difference in the measurement.

In both cases, be sure that the SG is injecting enough power that the SA can measure easily after passing through the attenuator and cable loss.


- Kirt Blattenberger :smt024




Posted  11/12/2012
Copyright 1996 - 2016
Webmaster:  Kirt Blattenberger, BSEE - KB3UON

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.