Noob seeking advice to eliminate setup issues w/Surecom SW-102 meter

[jackstraw77]

(preamble and noob context, not offended if you just skip to QUESTION below), New to the hobby, but long time interest. Brought in (for starters) by the need to HT's for road trip season in remote areas. Getting ham gear for versatility and getting licensed with my nephew who's excited for me to teach him the engineering stuff (and he's jazzed about getting a callsign). Next year if he still has interest I have no problem spending real money, but starting with entry level budget 5W radios this first time out which will fit our needs for now. Still want to make sure I'm getting the most bang for buck though, and spend a few bucks more for quality antennas. After watching gobs of reviews and demos, i've narrowed it down to a radio couple options. I'm well familiar with inconsistent chinese manufacturing, especially for stuff at this price, so I bought a Surecom SW-102 budget meter to see if the units I got behave like the YT demos. I do realize I'm jumping the gun a bit SWR testing on ham band, our test is in a couple weeks, and and it's a couple short bursts late at night at the bottom of a building so thick not even the strongest local FM stations can penetrate.

QUESTION:
Anyway, I could use advice on whether I'm setting up the Surecom SW-102 right (seemed straightforward) to know if I should trust the readings I'm getting. I'm seeing readings that are higher than a lot of YT testers using basically the same setup. Trying to compare a Nagoya 771 (purchased from highest volume seller on Amazon, BTech, for what that's worth), and equivalent 15" dual band ABBREE and TidRadio versions that came with the two radios (I checked to confirm they are all exactly the same length). I know this setup isn't going to be 100% accurate, I am mainly interested in how the antennas perform relative to each other with the same test setup and conditions. I needed SMA adapters and I bought a cheap $13 set so let me know if that could create inconsistency from one antenna to the next. Nothing else in the setup, just the radio and antenna with adapters to the meter, everything secure. I know ideally you want a ground plate between the antenna and meter, I thought my SW-102 was going to include it but it didn't. I can make a plate myself if it's critical, but again the goal was just to compare them not necessarily get a dead on balls accurate number for each. If lack of ground plate could affect different brands of the same size antenna differently that'd be good to know. Anyway the ABBREE reads about 1.5 on both bands both power levels. The Nagoya ranges from 3.5 to 7 depending on the power and band. The TIDRadio one reads about 2.5 on 2m and crazy 19.99 (not sure if that's as high as it will read) on 70cm. I checked to make sure everything was still connnected securely. Readings were pretty consistent for the antennas on both radios. That seems crazy to me that TIDRadio would ship a dual band antenna that's so out of whack for one of the bands it claims but could that just be defective? I expected the Nagoya to perform the best (assuming it was genuine from the highest rated seller) but it was also pretty poor and way higher than YT testers with similar radios. I'll pay a bit more if anyone knows a guaranteed seller of legit Nagoyas (if it matters). Or take recommendations for another brand. What are things I can check to eliminate inconsistencies?

 

[K7MEM]

I would say that the SW-102 will work fine for your purposes. However, don't get too hung up on the numbers. While the unit might present the frequency very accurately, the power and SWR might be only about 10% accurate.

One piece that you seem to be missing is a Dummy Load. You shouldn't be doing any on the air testing until you are licensed.

Antenna manufacturers say a lot of things about their antennas. Some of it is true, some, not so true. But to prove everything about a antenna you might need a lot of test equipment. For the most part, you just need to buy it and try it. Of course, you could build your own antennas. They are not that difficult to construct.

If you want to evaluate an antenna, you might start with a NanoVNA. They are relatively cheap. I have a NanoVNA H4 that will allow me to scan a antenna from 10 KHz to 1.5 GHz. The screen is a little small, but mine connects to my W10 computer. I can control/view everything from the computer, on a much bigger screen.

When I first started in Amateur Radio (1965), I never heard of a SWR bridge. I couldn't afford one, even if I did. My initial 2-Meter setup was just a Heathkit Twoer (AM). As an antenna I made a folded dipole out of some scraps of 300 Twin Lead and RG-58 coax. I only had about 10 feet of coax so I had to tape the antenna to the wall behind my radio. Over time, I improved my setup, but initially that worked fine. To check my output, I used a light bulb. The Twoer came with a #47 Pilot Lamp (pretty pricy huh?) that plugged into the antenna jack. At the time, we delt with "Input Power" rather than "Output Power". There was a jack on the rear of the Twoer that allowed you to measure plate current and voltage, to calculate "Input Power". Repeaters didn't exist then and FM was in it's infancy, but there was no scarcity of contacts.

Today, I have a couple of 2-Meter radios for working FM and Repeaters, but I don't use them very much. I set them on scan, but it only comes up with activity about once a week. And that is with 20 Watts and a 3-element Yagi at 20 ft. At least in my area, I am less than impressed. I don't own a HT, so you may have better luck that I do.

If you are going for your tests soon, make sure you also take a try at the General class test. Practice exams can be has on QRZ.com. There are a lot of new hams that take all three tests in a single session and come out a Extra. A General or Extra will give you good access privileges in the HF region (1.8 - 30 MHz). Good luck on your tests.

 

[dlwtrunked]

Just a general comment on what you are planning. Measuring SWR and power and the like to compare antennas like this is not a complete comparison and lacks a key component. That will not take into account the radiation pattern of the emitted signal. And nearby object can effect the results. I actually did an antenna comparison that looked at the signal levels by using a receiver at home and going to a fixed location about 3/4 miles away and putting the transmitting HT in exactly one location n the clear being held as close as possible identically at the same position. This was with a UV-18 Pro GPS. ***Please do not start an anti-Baufeng thread as there were reasons that this was the radio used for this particular test (yes, I have better radios)*** And testing an HT is with different antennas is tricky as how you hold it will effect the results. Some will say you should do it with a cat tail but who actually uses a cat-tail in the field? Anway, I have attached a copy of the results. Note: Listening by ear to the signals (recorded) seemed to indicate the results were more or less valid. In the plot, farther right is better VHF and farther up is better UHF---you might want to similarly plot your results. Due to the complexities, even I consider my tests less than perfect and perfect is likely not possible.

 

[mmckenna]

I know ideally you want a ground plate between the antenna and meter, I thought my SW-102 was going to include it but it didn't.

Not "ideally". You actually DO want something to replicate the couterpoise that the radio provides. Even if you are just sticking the meter directly on top of the radio, it's not going to be accurate.

I can make a plate myself if it's critical,

It is.

but again the goal was just to compare them not necessarily get a dead on balls accurate number for each. If lack of ground plate could affect different brands of the same size antenna differently that'd be good to know.

It will.

Anyway the ABBREE reads about 1.5 on both bands both power levels. The Nagoya ranges from 3.5 to 7 depending on the power and band.

You are talking SWR, right?
The fact that the power level changes the SWR means that the lack of ground plane/counterpoise is resulting in a lot of stray RF getting into things. It is NOT going to be accurate.

The TIDRadio one reads about 2.5 on 2m and crazy 19.99 (not sure if that's as high as it will read) on 70cm. I checked to make sure everything was still connnected securely. Readings were pretty consistent for the antennas on both radios. That seems crazy to me that TIDRadio would ship a dual band antenna that's so out of whack for one of the bands it claims but could that just be defective?

1. It could be defective.
2. The lack of ground plane/counterpoise is effecting things.
3. It's a cheap Chinese antenna mass produced and sold with mass produced cheap Chinese radios. There is usually little to no quality control, and they really don't care. It may be faulty, it may not. You never know with the low buck Chinese stuff.
4. SWR will be impacted by things around the antenna, you, walls, computers, wiring, etc. Don't assume you have an accurate testing platform there. Your SWR readings are pretty much meaningless.

I expected the Nagoya to perform the best (assuming it was genuine from the highest rated seller) but it was also pretty poor and way higher than YT testers with similar radios.

Beware of YouTube radio experts. There is no proof that these guys know what they are doing, they are just some random dude with a youtube channel. Just like this website is a bunch of random dudes with radioreference accounts.

I'll pay a bit more if anyone knows a guaranteed seller of legit Nagoyas (if it matters). Or take recommendations for another brand. What are things I can check to eliminate inconsistencies?

You need to create a proper test environment. The antenna needs to be in the clear and properly mounted on a ground plane that is at least 38" across. As stated above, you need a proper 50Ω dummy load to calibrate things.

And even then, this is a cheap Chinese radio with cheap Chinese antennas with cheap Chinese adapters and a non-calibrated power meter done in an uncontrolled environment. Might be fun to compare antennas with that setup, but comparing the results to anyone else is an exercise in futility.

The flexible antennas that come with hand held radios are not perfect, even if you are buying high end commercial/public safety stuff. They are designed to work in specific environments with a lot of variables and even then, work "good enough".

I have calibrated test equipment and done this in a proper environment with Motorola and Kenwood antennas, and you'll still see high SWR and some inconsistencies.

It's a hobby, and what you are doing is a fun experiment, but I'd not get too hung up on the results, and I would absolutely not compare them to others. You and your nephew should focus on getting your licenses and trying out the radios and see if they do what you want with the antennas you have.
If this is for a road trip, you'll get much, much better results with external antennas outside the vehicle. Hand held radios in the car are likely going to be disappointing without it.

 

[mmckenna]

So, someone pointed out that what I wrote my be problematic.

Let me clarify:
Many antennas are designed to work with either a ground plane or a counterpoise.
On a mobile antenna, the ground plane might be the metal body panel under the antenna.
On a portable radio, the counterpoise would be the radio chassis and the capacitive coupling of the users hand holding the radio.

Unless you can mimic those with your setup, your test is not going to be accurate. If this is the way the YouTube folks are testing it, then it's not accurate either.

To specifically test portable radio antennas, I took an old radio and gutted out the interior and soldered coax directly to the antenna jack. I could screw on an antenna and test using an analyzer while holding the radio in my hand, thus mimicking the the counterpoise provided by the radio chassis and the capacitive coupling to my hand. That gave consistently repeatable results that lined up correctly with legit Motorola or Kenwood portable antennas.

Mounting a portable radio antenna on a flat ground plane would not mimic real world scenarios, but would likely remove some of the variables from your setup. It likely would not prove accurate readings with a known good antenna, but it would be an easy test and give you some level of consistency so you could try various antennas and compare.

If you are simply screwing the portable radio antenna onto the back of the SWR meter, then that's not going to provide a ground plane or a counterpoise as the manufacturer may have intended.

But I wouldn't get too hung up on this. High SWR isn't going to damage the radio. It's not going to work as efficiently as it should, though. If it did, designing portable radios would need to take into account if the user was holding the radio in their hand, having it clipped on their belt, or sitting in a cup holder of a car.

There are a lot of variables that come into play here, so trying to do a 100% accurate/real world test is going to be difficult to do consistently with consumer/hobby grade equipment in your basement.

You asked a pretty straightforward question that involved a lot of details in the answer. I was trying to keep the reply simple. Hopefully one of these replies makes sense.

 

[merlin]

You are looking for generalized results, about any SWR meter will fill your bill as long as it is good for the bands you want.
I'm a lot more pickey so Byrd or equal is what I have.
Looking to analyze or compare antennas, you are better of with a Nano VNA. Cheaper than rig expert.

 

[AK9R]

I'll condense the previous informative responses to your questions down to just this: "Testing handheld radio antennas with simple test equipment is generally a waste of time."

And, this: "A 50 ohm dummy load will have an SWR of 1:1. So, don't get hung up on SWR readings."