520Mhz Antenna Analyser

[VK3DXE]

I wonder if anybody's seen this one and/or had any experience with it?

http://www.409shop.com/409shop_product.php?id=122270

COLOR GRAPHIC VNA ANTENNA ANALYZER, VHF/UHF 133-177Mhz, 195-280Mhz 395-520Mhz

Pocket-Size, Incredible Performance! Truly accurate SWR, R, X and Z!

This pocket-sized wonder breaks the mold for analyzer design with user-friendly convenience, top notch accuracy, and a vivid TFT multi-color display. Don`t let the size fool you, KVE-520 is packed with all the VNAfeatures and performance you need!

For example, get data for SWR, resistance (R), reactance (X), and impedance magnitude (Z) delivered on a color-coded high-resolution bar-graph display or sharply defined swept-frequency plots.

Get continuous DDS frequency coverage with 100-Hz resolution and a full selection of tuning steps and sweeps.

There`s a movable marker that calls up alpha-numeric data for any point on any plot -- and a memory to capture current data when you turn the analyzer off.

Get other useful features too, like a built in help menu and a field-strength indicator warns when powerful interference is present.

Best of all, juggling batteries is a thing of the past -- a long-running lithium-polymer power source is built right in. Recharge via any USB port.

Checkout these specifications:
• Single-frequency and swept frequency operating modes
• Truly accurate SWR, R, X, and Z measurements
• Seamless DDS coverage with 100-Hz resolution from 133-177 195-280 395-520Mhz
• Smooth "skip-free" encoder tunes fast or slow without missing a step
• Powerful +5-dBm stimulus generator overrides local interference
• Field-strength meter measures local signals, detects potential interference
• DDS generator precision signal source
• Vivid 1600-pixel/inch color graphics on a 2x2 inch non-glare TFTscreen
• High-lumen output, easy to read in direct sunlight
• Easy setup, only four control switches with convenient on-screen soft menus
• Personalized ID function programs your call or name onto the display
• Built-in 3.7-V 1800- mAH lithium-polymer battery charges with Battery Status Indicator and Auto Shut-off.
.

• Charge % always displayed, multi-color LED monitors charge status
• Built-in clock shows elapsed time when unit is turned on
• Breakthrough miniaturization 2 3/4W x 3 1/2H x 1 3/8D" high-impact case, 5.1 oz.

• Has BNC connector.

[VK2FABS]

Whilst "hacking" through Youtube over the last few weeks to months in trying to decide on my equipments, I came across a clip on it. Just did a search and there's now one more, but all in mandarin Chinese.

https://www.youtube.com/watch?v=3fE7eHGQoBg
https://www.youtube.com/watch?v=sT5tSXtm-k4

Clearly a new product that's just filtering out. But I understand they also had a HF bands analyzer (KVE60C/MFJ223) and that had pretty decent reviews. Guess the company is expanding its product range. Have not found any in-depth reviews but guess it's too new. Maybe you can get one and do a review. Might put you on Youtube's most watched list. Maybe not. This is only AR.

[ZL2ADU]

Great device.. I purchased one about 2 months ago.. I used it to get my 4 X 2m yagi all on the same freq. made a difference to the SWR. Also works just as well on 432 as it does on 144.

[VK2XSO]

Time to upgrade the Sark-110.
I did say that if those guys didn't get their act together with a 500MHz version, the chinese will eat them alive.
It won't be long before we see 1500MHz or 2500MHz.

[VK1JA]

Can you use these little devices to measure the electrical length of coax?

[ZL1RS]

Yes. Someone might have a better way, but this is what I do with my SARK-110 ...

Place a BNC Tee on the Sark output cable
Do an OSL calibration to account for the Tee
Leave the 50 ohm termination on one port of the Tee and connect the cable under test to the other port.
Sweep (and narrow down) to find the SWR dips which occur at frequencies where the cable is a multiple of a halfwave length
If required, use a little bit of maths to work out the VF or electrical length at your frequency of interest
(note: take into account any connectors used)

This method is used frequently here to produce equal electrical lengths of phasing lines to feed stacked Yagis arrays; or to make 1/4 WL transmission line transformers to match different antenna feed point impedances e.g. a 1/4 WL of 75 ohm coax to match the approximate 100 - 120 ohm impedance of full wave loop at HF to a 50 ohm feed line; or a pair of 1/4 WL 75 ohm coaxes in parallel to produce a 37 ohm transformer to match a 28 ohm dipole in a VHF Yagi to a 50 ohm feed line (aka "DK7ZB match"); or to make 1/2 WL 2 and 4 port power dividers from 75 and 50 ohm coax to combine 2 or 4 Yagis in an array, etc, etc.

Some cables are 'quite good' in that the same physical lengths cut from the same drum end up very close to the same electrical length, others are not so good and raise questions about their quality. Quite often the quoted (or expected) velocity factor of a particular cable is proved to be quite inaccurate (particularly with foam dielectric cables).

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