antenna analyzer?

SpaceForceCmdr

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Looking for some recommendations for a reasonably-priced antenna analyzer. I have a multiband, trap dipole in my attic, and it works on 30/20/15/10, but not 40m. I'm guessing I need to make some tweaks to it, but need the proper tool. Not even sure I can get it to work on 40m, but figure it's worth a try. Thanks!
 

tweiss3

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littona

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The NanoVNA does have a steep learning curve, but if you take it slow, it's a great little device and much cheaper than the other options. You will need to pick up some adapters, but those are cheap on Amazon and other places.
 

k6cpo

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The NanoVNA does have a steep learning curve, but if you take it slow, it's a great little device and much cheaper than the other options. You will need to pick up some adapters, but those are cheap on Amazon and other places.
I agree on the steep learning curve. I've been at this for almost 12 years and I still can't get the hang of the NANO VNA. If you're just starting out in ham radio, I'd recommend one of the MFJ analyzers. They are much easier to use and have a lot of other uses beyond measuring antenna SWR. The Rig Experts are great analyzers, if you can get one. There are made in Ukraine and have been somewhat difficult to obtain lately. They are also much more expensive than the MFJs which are made in the USA.
 

W0JOG

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What is the total length of your dipole? That will tell you whether or not it is ready for 40 or below. No antenna analyser needed for that, just some reading of the handbook.
 

popnokick

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The AnySecu PS100 Analyzer (linked on Amazon by vagrant) is a fine analyzer. In fact I have had one for years and like it a lot. HOWEVER, it's lowest frequency is 140 mHz and it will NOT work for the HF bands for which SpaceForceCmdr wants to use it. I also have a NanoVNA and it is not especially difficult to use IF you connect it to a laptop computer with appropriate software. I also have the prior version of one of these -
MFJ MFJ-223
... and it is my "go to" portable analyzer for use in the field (or crawling in the attic). Yah, yah... I know... MFJ. But it is very easy to read and use, rugged, and portable. I've had / used the other needle-type MFJ meters and the digital meter is much more durable. And you WILL drop your analyzer at one time or another.
 

jwt873

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I've got a Rig Expert AA-600.. Expensive, but works well. I just used it today checking out a problem I was having with my 432 MHz Yagi antenna.

I recently picked up a NanoVNA-F V2. (I needed it for my 1.2 Ghz antennas). The AA-600 only goes to 600 MHZ. The VNA isn't that difficult to use for simple SWR readings.. But it requires that you do a calibration process, screwing on open and then shorted loads for each freq band in order to get accurate readings.
 

SpaceForceCmdr

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Thanks for the tips, everyone! I will check those out. The Nano sounds like it might be a bit complicated for me at the moment, since I'm still very new.

What is the total length of your dipole? That will tell you whether or not it is ready for 40 or below. No antenna analyser needed for that, just some reading of the handbook.
It's the Kelemen trap dipole, 34.8 ft.
 

W0JOG

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34.8 feet. So add enough wire to make it a 40 meter length total. It will actually come out less than a plain 40 meter dipole, but experimenting with the right length by putting on a bit more wire and shorting the ends until you reach resonance and you'll know a lot more about antennas without some gadget. You'll be able to know resonance with your rig. Put a little power into the antenna and swing the VFO for a best reading in output. That's resonance done the old fashioned way..
 

popnokick

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Indeed, he has the Kelemen Trap Dipole. And he is looking for an antenna analyzer to help him follow the tuning and resonant frequency adjustment instructions in the Kelemen manual, which are -
Tuning
Your Kelemen-Antenna was factory-tuned to the low end of the specified band(s). As all antennas are influenced by their environment you may have to fine tune your antenna accordingly.
The following steps are recommended:
- To shift the resonance to a higher frequency on all bands increase the size of the loops to the strain relief on both sides. A few centimetres may well make some difference. Shortening the leads will rarely be necessary. To lower the resonant frequency on all bands make these loops smaller.
- To increase the resonant frequency on the lowest band fold back some wire at the egg insulator and secure it with tie wraps. Shortening of the wire will rarely be required. To decrease the resonant frequency do the opposite, there will be sufficient extra length of wire.
- By changing the shape of the traps you can adjust the resonance on single bands. This is particularly interesting for multi-band antennas for 3 or more bands.
- Slight squeezing of the traps (slightly oval) will increase the resonant frequency on the corresponding band and - to a decreasing degree - on the subsequent lower bands.
By careful combination of these three methods you can tune your antenna in its actual place to your favourite frequencies on each band.
 

dwhit29689

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I read-up on the NANO.
I'm old, frail, crippled, can't see well and I had the funds.
I'm happy with my two month old AA-230 ZOOM.
Easy to use, easy to read and calibration doesn't need to be performed often...but that's easy too.
I've seen used units available on RR and QTH.
 

Thorndike113

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I own a Nano VNA SAA-2N. It uses N connectors (common with UHF installations) off of the bottom of it but comes with a case, stylus, the calibrating connectors and is pretty robust. The disadvantage to it compared with the smaller VNA's is that it cannot be connected to computer software as there is none. It does cost around $170 so if you are serious about antennas and antenna building, this one is for you. If you just need a VNA for occasional use just to check SWR's and don't want to spend a lot of money, they have the smaller cheaper ones that use SMA connectors for less than $100.
 

SpaceForceCmdr

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Thanks for the tips, all! I think I posted in another thread, but I got my antenna working an all bands :) I ended up getting a Rig Experts analyzer, and was able to tune up the 40m band, and improve others. My SWR at 40m was around 11-12. Resonance was around 6600 khz. It was a pain because I had to make a few trips up into the attic crawling around, but shortening each end of the antenna by about a foot did the trick. I squeezed the circular traps for 20m into an oval shape, and that improved the SWR there (even though it already worked with my radio's tuner). All is well for now!
 
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