SWR meter - A DIY project - RC Groups
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Dec 13, 2011, 09:25 AM
Engineer for Christ
IBCrazy's Avatar
Mini-HowTo

SWR meter - A DIY project


It's been a while since I made a tutorial so I figured it's time for another one. This is my DIY SWR meter. The complete build and operation instructions can be found here: http://fpvlab.com/forums/showthread....urself-project

It is made of 5 parts:

Directional coupler
Microwave detector diode
Resistor
Capacitor
Short RG316 jumper

You must be a master at soldering to build this, but it's cheap and works all the way up through 5.8GHz. That's right, a 5.8GHz SWR meter. Finally!

SWR is calculated as follows:

p = Vr/Vf

SWR = 1+p/1-p

Videos of how to use it:

Forward power
IBCrazy's DIY SWR meter - Forward power (1 min 0 sec)


Reverse power
IBCrazy's DIY SWR meter - Reflected power (1 min 23 sec)


Good luck and have fun with this one.

-Alex
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Dec 13, 2011, 09:56 AM
never mind the boll⁣⁣⁣ocks
brosius85's Avatar
ooooh

im off to google what SWR is lol
Dec 13, 2011, 10:03 AM
Registered User
Quote:
Originally Posted by brosius85
ooooh

im off to google what SWR is lol
SWR: Standing Wave Ratio. It's a means of determining how closely matched the antenna system impedance is to the transmitter. "Perfect" SWR is 1:1. "Typical" for amateur radio is between 1.2:1 and 1.5:1.

Ask a silly person, get a silly answer...
Dec 13, 2011, 10:32 AM
Registered User
noxnflame's Avatar
woo thanks man! This looks like a col project to finally test my antennas that don't really look "right"
Dec 13, 2011, 11:25 AM
Registered User
Does it work with 5.8GHz item ?


thanks
Dec 13, 2011, 01:30 PM
Registered User
Is this diode OK for swr-meter ?

http://www.rs-components.co.id/diode..._from_store=id


Thanks
Dec 13, 2011, 03:21 PM
Engineer for Christ
IBCrazy's Avatar
^That should work fine. I used an Agligent HSMS-286K. This stuff is very hard to spec out, sadly...

-Alex
Dec 13, 2011, 04:26 PM
Registered User
Quote:
Originally Posted by brosius85
ooooh

im off to google what SWR is lol
More accurately it's a VSWR bridge/meter.

Also, careful using RG316 at 5.8GHz, it's not rated to that frequency.
For 5.8GHz, you need CLF200 or similar/better.

Well done again Alex.

Nigel.
Dec 13, 2011, 05:17 PM
Registered User
Is it good CERAMIC capacitor 0,01uf (or 0,1uF ) 100V ?


thanks
Dec 13, 2011, 10:41 PM
Registered User
Awesome! I've been waiting for this. Thanks IB!!!
Dec 14, 2011, 01:26 AM
Ikaruswannab
Hi Alex,

Can you suggest a parts list for this project??
Thank you for sharing.
Teo
Dec 14, 2011, 01:29 AM
Navigator
volto's Avatar
parts list is over on the 'lab
Dec 14, 2011, 03:05 AM
Registered User
Quote:
Originally Posted by volto
parts list is over on the 'lab
site seems to be down cant access it ...
Dec 14, 2011, 03:26 AM
Registered User
Toysrme's Avatar
awesome. now upsize the parts so you can knock out about 150 for the website. too lazy to solder!
Dec 14, 2011, 04:07 AM
It just keeps getting better!
Blue Sky's Avatar
Outstanding!
Just what I've been waiting for.


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