Ham Radio Basics: Why You Need a SWR Meter
Вставка
- Опубліковано 2 лип 2024
- An SWR meter is one of the best investments you can make if you’re a ham radio operator. It’s something you invest in and use for decades as you buy new antennas over the years. Don’t cheap out on what you get, it’s worth it to buy a quality meter. It will serve you well for many years.
In this video, I talk about what SWR is and what is considered a good SWR for your ham radio. Then, I dive in and show you a current SWR issue I’m having with my Diamond X300 I recently put in the air.
Buy the OPEK DL-60 Dummy Load: amzn.to/31g3qVZ
0:40 - Overview of SWR Meter
1:42 - Overview of a dummy load
2:37 - What is SWR?
3:40 - Why you should care about SWR readings
4:08 - What is the perfect SWR reading?
4:57 - What causes a high SWR reading?
6:03 - Testing my Diamond X300 antenna
Follow me on Instagram: / k0lwc
Follow me on Twitter: / k0lwc
Read my blog: www.k0lwc.com - Наука та технологія
Thanks for all your great videos Matt
Very clear explanation! Thanks!
I'm getting ready to take the test and this really cleared some things up for me. Thanks !
This was extremely helpful
Nice video. I sure wish UA-cam was around when I first started in the ham world.
Then again , that was before PCs even existed.
When I recently heard the expression “dummy load”, I immediately thought of the Sniffer in Chief’s Dementia Diaper.
🤣
Thanks again.
A very clear and concise presentation. Great job.
Thanks!!
SWR is important though it shouldn't be an obsession. Anything less than the start of auto power fold back should work well. Even if you are at VHF, good quality low loss coax will not have that much increase in loss. Kind of a rule of thum, less than 1.5 is fine. On HF I might even let things go as high as 2.0 before I would worry. The reflected power is reflected back added to the radio output. The biggest problem I find with antenna to coax mismatch is that it makes the impedance that appears at the radio vary with distance from the load.
Thanks! I was hoping you would have explained the FWD and not only REF. My REF = 1,1. But FWD=0.
For those who dont know, a dummy load is basically a resistor that has an ohm rating matching an antenna. Thats how its able to virtually be an antenna
Thank you for this excellent explanation of the practical application of SWR!
That was an excellent explanation thank you for taking the time to make this video
Well done!!! Thanks.
Good stuff! Thanks for the information
Maybe talk about the dirt cheap alternatives you can use besides expensive SWR meters. Like a bridge circuit or other power meters.
What do you use?
@@K0LWC - the cheap eBay low power ones shipped from China are $20. If you are careful that can do the job. I tend to borrow expensive $200 meters from clubs or club friends.
Shouldn't one recalibrate the meter when changing the frequency to analyze?
Yes, the meter must be recalibrated when changing frequency and most especially when changing power levels. Setting the calibration level (essentially a relative forward power reading) at high power and then keeping that same level when switching to a lower power output will result in an inaccurate (artificially low) SWR reading. Remember that SWR is a function of pure resistance along with inductive and capacitive reactance. Those values change with frequency but not with power level. Therefore the SWR of an antenna system will remain the same at a given frequency regardless of power output and thus one should expect to see the same SWR value on the meter no matter what power level is used.
@@BrianEsche The difference in in SWR when recalibrating between 148 and 144 is pretty nominal. I could see if you needed a precise reading, but when judging resonance and seeing how out of whack it is, it works fine. I did remove the section on power levels though, given your feedback, Brian. Thanks for posting!
Cos my field is in computers and being a semi-pro, i have some idea, , your wondering, what the hell is an SWR, SWR stands for "Standing Wave Ratio", the transmitting signal travels along the antenna (FORWARD) and refects at the end, returning down the antenna (REFECTED), the forward signal interferes with the reflected signal causing constructive or deconstructive interference, differant lengths create differant phases along the antenna, when a peek meets a peek there is max emission, and when a peek meets a trough there is zero emission, an SWR ratio of 1:1 is perfect constructive interference, where the cycle appears STATIONARY on the antenna, creating a perfect waxing and waning electo-magnetic field, as the electric field collapses, the magnetic field increases and vice versa, , ,Without that load absorbing energy, the energy instead appears as a high voltage or high current somewhere which may not be equipped to handle it, ,
So basically, an ideal 1:1 SWR will produce a low 50ohm resistance match where the antenna does work, the SWR is relatively constant along the feedline, the impedance will vary along the line unless it is perfectly terminated (that is, the SWR is 1.0 : 1). This is an important concept for impedance matching, because with a high SWR, the impedance at the final output transistor load inductor could be lower than 50 ohms, and produce a high current that damages the finals, , ,
PS - a 1:1.5 SWR = just a 4% loss \ a 1:2 = 11% loss \ and a 1:3 = 25% loss
Thank you. Great info for us new guys. So if you are just about ready to hoist the antenna up onto the roof, can you test the SWR and resonance with a HT before tightening things up, or is it best to use the radio you plan on using for said antenna?
HT could complicate things. I would use the radio you’ll use everyday on the antenna. Either set it up temporarily in open space (PVC pipe is one idea) - or just know what once it’s up to test before tearing down your ladder etc. where you place it permanently could impact the SWR - so just be sure to test once it’s mounted, but be prepared to head right back up if needed.
Very informative
The SWR meter is also very important, when choosing a antenna for your HT. I have the Abbree 18.8 inch version, and on my TYT UV8000E, with the frequency set to 146.000, I have a SWR of 1.0, and all 10 watts of power from the radio. So yes if your SWR's are bad, it can damage your radio, be it a base station, mobile rig, or a HT. Stay Safe and 73's, KI7BSL, I'm out.
Can I just leave this hooked up to read the incoming and outgoing readings at all times?
So if you're antenna tuner is situated at the rig end, rather than at the antenna end of the system, then although your xmitter thinks it is working into a resonant antenna, it may not be, in which case a lot of power will be lost because of standing waves on the coax cable. So I guess that this is why it is better to install the tuner at the antenna end of the system? I guess that the whole idea is to maximize standing waves on the antenna, and nowhere else?
Nice.........
Shouldn't it be that it should be at the FORWARD mode when you calibrate and when reading your SWR then switch it to REFLECT to read how much reflected power in WATTS is going back to your radio?
In my opinion a SWR meter is important on the 11 meter band too....
Well it goes without saying.
I have 40w coming out to antenna! Swr 1.10 and power 37. 1 and reflected power .113
Is this good?what is more important Swr or reflected power?
* ** YOU GUESSED IT MY FRIEND IM NEW!
WILL WAIT FOR YOUR REPLY!THANKS EVER SO MUCH!!!
i have a cb radio swr meter, can i use it for 2m/70 radios too? or is there a difference because of the higher frequency?
You’ll likely need another meter.
@@K0LWC okay, thank you.
Not very accurate. As an example often an antenna with more then one element exhibits maximum directivity and gain at a higher swr point.
New ham radio operators are likely running a simple vertical.
@@K0LWC if you're teaching better to be accurate. VE2AED
This comment is way outside the scope of this video, and rather vague anyway.
@@paulm0hpd319 try spelling. I say it's vague for one reason, the old then instead of than. And it's still outside the scope. I'm a CBer and know more than most hams anyway.
Go to another video platform. UA-cam SUCKS.
Why does UA-cam suck?