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Old Dec 17, 2013, 07:17 PM
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Immersion RC RF Power Meter


Sorry if you guys know about this , but it is about time we have a FPV band friendly RF meter. Cool!

http://immersionrc.com/product-detai...roduct_name=RF Power Meter
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Old Jan 07, 2014, 06:47 PM
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been looking at it myself, only $150
Old Jan 07, 2014, 06:52 PM
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Works great. I found out what channels put out the most power out of each vtx and the DX8.
Old Jan 28, 2014, 03:04 AM
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Any tester of this product ?

Julien
Old Jan 28, 2014, 04:01 AM
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Tons of feedback here: http://fpvlab.com/forums/showthread....RF-Power-Meter
Old Jan 28, 2014, 08:05 AM
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I have one and I like it.

Takes some of the guess work out of FPV..
Old Feb 18, 2014, 03:56 AM
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did anyone test an EzUHF TX yet? what exactly are the outputs displayed? mine jumps up and down. I've selected 30db attenuator, 433mhz
Old Feb 18, 2014, 04:19 AM
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When measuring output from UHF systems, switch it to peak mode, rather than average.
Old Feb 19, 2014, 12:01 PM
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How far do I dare to measure with the 30dB attenuator? 1500mW TXs too much or?
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Old Feb 19, 2014, 01:40 PM
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Quote:
Originally Posted by Stigern View Post
How far do I dare to measure with the 30dB attenuator? 1500mW TXs too much or?
Good question. Some of the TX's are putting out double of what they are rated at depending on what frequency you select. My Boscam 200mw put out 67mw on one frequency and 343MW on another! The Power meter more then paid for it self on that as I noticed way better range and penetration on the 343mw frequency.

If you test a 700 I guess it could really be too much at 1500 or so.
Old Feb 19, 2014, 04:33 PM
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I tested my equipment: https://www.rcgroups.com/forums/show...1#post27559352
Old Feb 19, 2014, 07:32 PM
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Generally speaking, if there's any chance that whatever you're testing puts out more
than 1W peak power, then it exceeds the limits of the meter with the 30dB attenuator.
I wouldn't "push" it at all.
Can add additional attenuators and change the scale in the meter, but you'll often
find that other cheap attenuators are not terribly accurate or consistent across a wide
range of frequencies. For instance, I test one system with 30dB attenuator
and it registers 900mW. I add another 20dB attenuator, set the scale to 50dB
in the meter, test again, and it reads 800mW. That only represents about 1dB
difference, but it means the attenuator is closer to 21dB than 20 at that
specific frequency. Might be off by some other amount at a different frequency.

Obviously should never hook *any* powered transmitter directly into the meter
without the attenuator.

Similarly if testing antennas with no attenuator it's quite easy
to exceed the limits of the meter at short distances by a few dB.
Expect to test antennas at 2m or more, at least initially.
Switch it to dB (instead of mW) scale and try to avoid anything over 0dB.
In this mode you can compare different antennas, and
look at how the signal strength goes up or down as you
reorient both Tx and Rx antennas to get a feel for what the radiation
pattern looks like.
Last edited by Daemon; Feb 19, 2014 at 07:38 PM.
Old Feb 20, 2014, 02:28 AM
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Quote:
Originally Posted by Daemon View Post
Generally speaking, if there's any chance that whatever you're testing puts out more
than 1W peak power, then it exceeds the limits of the meter with the 30dB attenuator.
I wouldn't "push" it at all.
Can add additional attenuators and change the scale in the meter, but you'll often
find that other cheap attenuators are not terribly accurate or consistent across a wide
range of frequencies. For instance, I test one system with 30dB attenuator
and it registers 900mW. I add another 20dB attenuator, set the scale to 50dB
in the meter, test again, and it reads 800mW. That only represents about 1dB
difference, but it means the attenuator is closer to 21dB than 20 at that
specific frequency. Might be off by some other amount at a different frequency.

Obviously should never hook *any* powered transmitter directly into the meter
without the attenuator.

Similarly if testing antennas with no attenuator it's quite easy
to exceed the limits of the meter at short distances by a few dB.
Expect to test antennas at 2m or more, at least initially.
Switch it to dB (instead of mW) scale and try to avoid anything over 0dB.
In this mode you can compare different antennas, and
look at how the signal strength goes up or down as you
reorient both Tx and Rx antennas to get a feel for what the radiation
pattern looks like.
Would this calculator be a pointer into what attenuators to use when measuring different mW?

http://www.rapidtables.com/convert/power/dBm_to_mW.htm
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Old Feb 20, 2014, 06:49 AM
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Quote:
Originally Posted by Daemon View Post
When measuring output from UHF systems, switch it to peak mode, rather than average.

Don't forget you are in UHF and that is well with in the realms of the Ham radio SWR meters meant for UHF. Save the power meter for the microwaves.

73

Chris
Old Apr 15, 2014, 04:50 PM
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Wow got my Power Meter today and found out some interesting things

1) My Boscam 500mw transmitter was putting out 700-740mw of power (nice).
2) The 2.4G receiver antenna that came with my Boscam glasses gave me 0 gain. Yup, same db with or without the antenna. What's scary is I actually flew FPV for about 300-500m like this.
3) I swapped in a Lawmate 2.4G receiver antenna and set to -25db. Then I swapped the stock Boscam 2.4G transmitter antenna for the Lawmate transmitter antenna and WHOA it jumped up to -1db. That's a 24db gain from the one antenna swap. That's pretty incredulous for a stock rubber ducky antenna.

So bottom line is the Boscam 2.4Ghz 500mw is a good transmitter but with terrible antennas. Even swapping it for better rubber duckies will give you pretty good range.


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