How do you choose the best frequency for a given FPV antenna?

Do you just guess, like pinning the tail on a donkey?!

Actually the first meter you mention likely has more utility than the second if its operating frequency goes down from the 2.4ghz you mention to at least 850Mhz.  Although there are people who like build VTX antennas.  Far more are interested in building RX antennas and that most commonly will be in the 2.4ghz-850mhz range.

But with that said, hobby grade analyzers are almost as bad as pinning the tail on the donkey.  Their accuracy is poor enough (some as bad as 20%) they can still cause the builder to miss the mark.  

With our antennas in FPV if you can get someone with a quality, lab grade analyzer to test an antenna, then you can reproduce the same results by using the same materials and the same dimensions.  So the trick is getting someone to do that for you.  

But to pay 200.00-500.00 for an analyzer that provides info that is no more worth it than entertainment value is silly.

I don't think that for someone who is in FPV as a hobby, buying a meter of that kind is necessary.
I would rather spend that money on more and better antennas then on one to use every once in a while.

(20-Aug-2019, 01:14 PM)Krohsis Wrote: Actually the first meter you mention likely has more utility than the second if its operating frequency goes down from the 2.4ghz you mention to at least 850Mhz.  Although there are people who like build VTX antennas.  Far more are interested in building RX antennas and that most commonly will be in the 2.4ghz-850mhz range.

The N1201SA SWR meter frequency range is 137.5 MHz to 2.7 GHz. I have a review of it here : 

But with that said, hobby grade analyzers are almost as bad as pinning the tail on the donkey.  Their accuracy is poor enough (some as bad as 20%) they can still cause the builder to miss the mark.  

How many hobby grade SWR meters do you know of?  Which one was 20% off? The OWLRC Meter is calibrated against a lab grade analyser. This is the same philosophy as Immersionrc's Power Meter, are you equally dismissive of that product?  Although hobby grade I believe it is still useful to compare various antenna combinations. If you match antennas by their curves then it really doesn't matter what the exact frequency is.

With our antennas in FPV if you can get someone with a quality, lab grade analyzer to test an antenna, then you can reproduce the same results by using the same materials and the same dimensions.  So the trick is getting someone to do that for you.  

Where I live you would have to go a loooooong way to find someone with a lab grade analyser. Having something to hand that even just gives you a clue as to the resonant frequency of an antenna has value to me.

But to pay 200.00-500.00 for an analyzer that provides info that is no more worth it than entertainment value is silly.

Agreed. That is why it sells for a little under $100 US.

Maybe I have your N1201SA analyzer all wrong.  Maybe it's a fantastic piece of equipment.  You say it has been tested against a lab analyzer, do you have video of that.  I would like to see it perform against a high quality analyzer.  Frankly, if it performs very well with repeatable results, I likely would be interested in one.  I would like to see it tested against an lab standard through its frequency range.  For $100.00, I would love you to prove me wrong. 

Hobby grade test equipment in general have less accuracy than lab grade equipment, in some cases much less.  There is a reason the hobby grade stuff is priced in the low hundreds of dollar range and the lab grade stuff will run into the thousands and tens of thousands of dollars.  The reason isn't because the manufacturers of hobby grade equipment are philanthropists.  And that lower cost typically means less accuracy which can render the test equipment ineffective and even to the point of being useless if the accuracy is poor enough.  This is particularly true with antenna matching.  Being off even a few percent with have a significant impact on the performance of that antenna.  And for your analyzer to be under 100.00, well it makes me think of the saying, "you get what you pay for"......Yes a poor analyzer would get someone in the ballpark if they are building an antenna.  But so will building from the dimensional standards would get you to the same point, I know as I do it.  But I do that knowing the measurements and materials I'm working with have been verified by a lab standard. 

As far as the Immersion RC power meter, I have seen that tested by JB and it does do OK for what it is.  But a power meter is far easier to build cheaply and get decent results vs an antenna analyzer.  And if the results are off by 5-20%, it isn't a big deal.

Most people who are interested in an antenna analyzer are doing antenna stuff.  I believe a video proving how your analyzer stacks up against a lab standard and if the results are repeatable, you will sell more of them.  Like I said above, if it does perform very well, I would buy one.

Out of fairness to you, I decided to do a little research on the Ham Radio forums.  I figured there had to be reviews of the N1201SA SWR meter, and there was.  For me, if the ham guys say it's a good tool, I will believe them.

Reviews overall were somewhat mixed, but mostly on the positive side.  Most of the hams liked the portability of the unit for field work, with the N1201SA being smaller than say what MFJ makes.  The MFJ model is about $300.00 as well.  The hams that were more concerned with accuracy of the N1201SA compared it to the MFJ, RF Explorer, and Rig Expert.  The N1201SA was not as accurate as those 3, but not horribly worse either.  I haven't found a comparison of the N1201SA to other analyzers on YouTube yet, but I'm still looking.

What I get from those reviews is this.  SWR and its negative effects are less of an issue for voice communications than for FPV.  In FPV if something is less than perfect things fall out of the sky.  With voice comms, you just lose voice connection.  Not to mention, for an RX system, signal to noise ratio is more important than VSWR, but that is a different topic. 

At 100.00 vs 300.00, I can say that the MFJ is NOT 3 times better than the N1201SA....but is the N1201SA good enough for FPV?

Since the Owlrc is not produced anymore are there alternatives?
The N1201SA is only working up to 2.7ghz