Output Power vs. S-Units 

Superb video. The 4 guys who thumbs-downed this can't do Maths. 73.

Fantastic video! I listened to a couple guys do that experiment last night. Started at 5-7, on my S meter, and he said he was at 100 watts. Then he progressively went down to 0.3 watts, and he went down to about a 4-4. It’s made me very happy with my brand new G90 (first HF radio). That and making an FT8 contact with Australia, technically Tasmania, which is 8216 miles (13223km) from me, on 10m which was otherwise a dead band. No one else was there.

Well done. great video I love QRP and I had a contact with a Canadian station about 10 Years ago from UK and I was on 5 watts the guy in Canada had a amplifier and I got him to turn his power done to 500mw and I told him I could still hear him. He could not believe it.!

I am happy that you made the point so well. I am on Montserrat in the Caribbean and I did Australia on 100w with a fan dipole on 20 meters. he was suing 400 wats and a beam pointed in my general area. He heard me at 56, and i had him at 55. Antennas are boss

I am new to HF and was just entertaining the thought of adding an amplifier to my shack. I was still in the research mode when I came across this video. With this new information I’m going to hold off and focus more time and attention on my antenna system and grounding. Thank you for the excellent presentation. 73

I was only licenced last year here in EI. I have a "100W" transceiver into a 22m Doublet. Lately, I have really begun to appreciate what you're saying in practice. I have a night time issue where when I use more than 15W output (above 7Mhz) it triggers a neighbours PIR - my receive gets washed out with noise. This has forced me to use low power on those bands after dark. I was really annoyed by this at first but one night I heard a K station calling CQ on phone. I tried him on 5W and made the QSO. I have since made a number of transatlantic phone contacts using

Great explanation of the Rf Power vs S-meter relation. I've only the last couple years started messing with 20 watts or less. It's been fun having relized how well it actually works!

This is a really nice, succinct explanation of the ratio of power to dB. I realized all this empirically one evening listening to my signal via web SDR. I started at 100W and kept dialing down the power. I eventually got down to 0.1W and I could still easily discern the the code. That was when I realized propagation trumps power.

Cliff, that was a perfect no nonsense explanation of transmitted power level against listening level based on decibel level gain. Well done! de WD5L

Finally someone with common sense to teach us the correct understanding of power vs s units. Thank you. Great video making it simple to understand. God Bless

Cliff. EXCELLENT. thank you for putting in the time and effort to make this video. Albert. EI7II.

You handled the math very well, Cliff!---and your picture of the S meter on your rig, graphically demonstrated the point well! Thank you for all the time you put into these informative Vidoe's--- I keep telling myself, I need to get out my old Keathkit QRP rig-- Suppose it would still work? Mack WA2 SJR-- in Western, NY State.

Excellent video. Most people don't know the best way to increase your readability is to put their money into a great antenna. Amps are expensive, add to the complexity of the system, and can cause RFI. Thanks for the great video! Antenna gain makes much more sense.

Thanks Cliff. Enjoy all your videos and this is one of the best. Clear and concise.

Hi Cliff, First so glad to see more videos coming out. I truly enjoy them and learn from you. This latest is wonderful. I was somewhat aware of the power to S level ratios but you made it easy to understand. Hams would be much better off putting their money into an antenna and transmission line system then an amplifier. I honestly can't understand why these amps cost so much. Have a wonderful weekend and keep up the great work. John

That is a great video, Cliff! As a new Ham last summer I heard repeatedly that I should not get a QRP rig for my first HF radio and that left me with the impression that it is much harder to make contacts with QRP. Your video is clear and fact-based. You have me one step closer to trading in my IC-7300 for something more portable, believing that I might just survive with only a QRP rig. (I can’t afford two radios at this time and prefer operating in the field.)

I have known this for many years. But it was really brought home to me when I got a Xiegu G90, an HF radio with 20 watts max output. I am basically able to work (almost) any station that I can hear. There are situations like the receiving station having a high noise level, interference, or one way propagation that make it harder to work some stations. That said, I have worked stations in the U.K., Ireland, and Mexico City with 20 watts in the 3 months or so my antennas have been up at this location (I have been licensed since 1990).

Thank you Cliff for sharing this great video. For a ham like myself who is still learning about how equipment, antennas and all the rest of the gear works, you bring the important issues to the table that might not be so apparent. Thank you again Cliff and I'm glad your back. KO4UWU 73

I am new to ham radio, in fact I only have a President HR2510. Since it is an old unit, I turned down the output power to 4 watts on AM and 12 watts on SSB to prolong the life of the finals because they are now hard to find from what I've learned. Now, I plan to turn the deadkey even lower to 1.5 watts and use it with my RM Italy KL300P amp. But a couple of days ago, since propagation is open on 10 meters, I made my very first contact to Germany 10,000 plus kms barefoot and it sure blew me away. Now, I'm having second thoughts about the amp and just enjoy the challenges of QRP. The joy it brings making long distance contacts in such low power is very rewarding in my opinion.

Well presented. First thought that comes to mind is how many RU-vid videos I've seen saying "Don't go qrp for your first rig. Get 100watts..." Second thought, 'Yeah, I don't think I'm ever going to bother getting a linear for HF."

Awesome video Cliff, my Elmer has been telling me this for years, but your video and examples sure brought it all together! Thank you for sharing!

I always though it would be nice idea to have a digital mode where the DX station sent an embedded reception report that controlled your rigs TX power and vice-versa, with the two rigs just barely, but successfully maintaining contact. Maybe in a semi-duplex fashion.. Cliff, your videos new look is excellent with that narrower field of focus. You really stand out and it looks super-professional.. well done

Love your videos! You really have a laid-back way of presenting things clearly. I've been a ham for over 50 years and still enjoy and learn from your videos. 73 de Dick N4BC

I totally agree with you. I once had a qso with someone transmitting 500 watt. I heard him with around S9+15dB. My TX had 10 watt and he received my signal at S9. He was very surprised until I showed him that the difference between 10 and 500 watts are only 17dB. Taking the tolerances of the meters in count, it was exactly what our S-Meters showed.

Thank you. As an outdoor guy who doesn't want to have to carry heavy radios, I love the idea of qrp. This makes me love it even more. You explained this so clearly and so well. It seems that somewhere in studying for my General test, I was presented with this information but it went over my head. You made it crystal clear. I'm really grateful.

Another eloquent explanation, Cliff. Good job of limiting the subject to something that can be explained in a short time without skimping on details. QRP School is indeed a great name for your channel.

I should have known this. I remember back when I was a CB'er a guy told me that if I thought amplifiers were so great to go park next to a radio station antenna putting out 100,000 watts and see if it blasted my radio. Well, of course, it doesn't. Thanks for the reminder and great explanation.

Thanks so much for this video, I was trying to explain and convince a new ham of these points and your video does it so much better than I could explain.

Great presentation! "Less is more" comes to mind.

This video was the deciding factor in my getting into QRP. I still have my high power station as well, but as I find it quite boring due to the waterfall and 800 watts making the sport too easy, I have a renewed enthusiasm for HAM radio after watching many of your videos. Thanks for giving me my MOJO back. 73's W4LIF

Cliff, you are on fire with all the videos. Keep them coming. I’m a lover of QRP, but like a little power to help get my signal out to more folks. I’m about to start building my Hardrock 50 that just arrived yesterday to help my KX2 out. I’ll take the +1 S-Unit for CW for when I need it.

WOW! What a superb explanation about something that DEFINITELY needs to be explained to those hams, like myself, who have developed preconceived ideas about the subject, out of ignorance .. Thank you very much..and thank you for explaining this in plain language.. 73.. John..G4EIJ

Older post, but thanks for posting, exactly the refresher I needed as I'm researching required battery power for portable ops and how much I can reduce consumption by reducing Tx output and not feel like I'm missing out by not running 100w. My radio's options are 10/50/100w so I'll start with 50 and go down as able, goal is weekend camping with casual radio fun on a 20ah Bioenno on an older (KenwoodTS-50) radio.. thanks again.

Ive been a ham for a long time and an s meter is one of my least used readings. What matters most is what is heard or not heard. My ears make all the measurement i need.

Great explanation Cliff. I strongly believe that resonant antennas, low loss feeder and setting my transmitter up correctly will avoid the need for an amplifier.

Eyeopening for a newcomer like myself. Thank you.

I love it, I love it, I love it! Fantastic video Cliff. You explained this so clearly and with the math it really makes perfect sense. I am not against amps, but like you, I AM a promoter of QRP. I get a FAR bigger thrill from making one QRP contact than I do 10 contacts with 100 watts. Since becoming a HAM in 1992, I have never lived anywhere I could have used a 1500 watt amp. However, if I lived somewhere I could, I'd indeed have an amp to use if needed. But for now, QRP and no ore than 100 watts will keep me content. BTW, I like the soft focus in the background. Vids look very professional!

Thank You for the continued motivation. I finally bought my QRP rig(Elad FDM Duo) and my antenna is a Wolf River Coils vertical and I'm making out to 650 miles in some directions, even though it's too close to my apartment and I'm only using the 3 radials that came with the antenna. Can't wait to get my station out in the open, plus I'm bringing along a Loop antenna and an EFHW antenna too. Thanks again for the motivation 73's

This makes sense for ham radio where Barefoot your probably already running 100 w but for CB 11 meter when you go from 12 watts (ssb) to 150 it's a massive difference lol good video brother

I've done QRP with my Elecraft KX3 running 5W. Taked to a fellow in Virginia who could hardly believe I was only running 5W. He was running 850W and was embarrassed to say I had a good signal. My new station consists of a Yeasy FT-991A, Yeasu FT DX5000, Elecraft KX3, and a home brew vertical. I no longer do POTA due to age but really miss it. I do like working from the beach here in St. Augustine Fl.

This was a great video! Very informative for a Technician about to upgrade to General and sizing up what equipment I"ll need to get me talking on HF. Thank you.

Great video, and details to back up your statements. 73!

Thank you for this very informative video! I also watched your first video on QRP and S-units from a while back and this one is better defined! You can't argue with the math and the visual was great! I laughed at your points on the marketing for the amps. Thanks again for this video, now I don't have that feeling of NEEDING a 100watt rig and I feel better about my QRP Yaesu 817ND.

Thumbs up Cliff for a great video and support our QRP actvities ;-) 73, Paul OM0ET

I like this video I am a adamant QRP operator I also enjoy simpler rigs Much of my gear is rock bound I do strive for efficiency S-Units and decibels do make a difference Of course a little IS all it takes Do not forget A Qrp or Qrpp operator cannot afford to take loss nearly as lightly If a QRP operator does take loss too lightly He will end up buried in the noise Pay attention to loss and make a effort to not give anything away

Cliff thank you very much for your very clear explanation of the power to signal difference I am like a QRP guy like you.

Fantastic video! Thank you this makes me buying a 20 watt QRP radio so much easier when everything I watch says you should get a 100 watt radio to guarantee you make a qso.

Cliff. Thank you. As a new QRP owner (Xiegu G-90) and totally solar/battery, I was all ready to slap down $600 for a Xiegu 100-watt amp. Then I watched your excellent explanation. I've since spent some of that money on other shack necessities. I'm using a TC2M Terminated Coaxial (6-wire) Cage Monopole invented by G8JNJ. It's so broad banded that no tuner is required - less than 2.2:1 from 1-30 MHz. Look it up. Meanwhile, I'll refurbish my TS-520 with new HV caps. I'm no longer a DX Chaser. I could not care less. Into emergency stuff. Makes better use of my time.

GREAT vid. fellow tennessean just a few miles away. thanks for the content

As a new Ham, got my license back in 2016, and yes I still consider myself new. I've learned a few things. Having your SWR's as low as you can get for the frequency your using is preferred. And a good antenna can make even a inexpensive radio sound good. But for HF you want a Antenna up as high as you can comfortably get it, and directional with a rotor so you can point it. I'm pretty much just a 2m/70cm guy, but I do know about antenna's. Good video by the way.

Agree👍.and before you ask if or not but , I am a cb radio hobbyist , 20 watt legal cb radio and the whole world is within reach.

Bravo!!! Thanks for setting the record straight! 73

Great Enlightenment many,, many thanks

Nice and well presented congrats Cliff 73

Great video, well said.

And as always, QRP since 1960, and no complaints from the neighbors or family of interference in the TV, VCR, phone, etc. I can but rarely use 100 watts and if I can hear THEM they usually can hear ME! Thanks for another inspiring video. I think most hams with amplifiers are DX hounds or COUNTY chasers and just don’t want to take the chance that they won’t make the contact. That’s OK too, but for just a regular QSO they could turn the amplifier off. Then there is the few who run the maximum power JUST BECAUSE THEY CAN! Some folks just need bragging rights. This is a hobby and I guess it’s whatever floats your boat. Antennas are more important than power and we sure have been blessed with all the antenna information available out there and also with low cost analyzers. And Cliff, if ham radio improves your odds of “picking up chicks” what don’t wives give us extra credit for being smart enough to pass the ham license test? Thanks again for your excellent videos. I hope to see you at FDIM again this year. Dave K8WPE

Excellent video!

Great video, thanks!

Yes nice =) Glad to see this discussed =) Great content and hope to catch you on the bands Cliff =)

Thanks for another great video, Cliff. I continue to learn from you and recommend your channel all the time. I think I am restating your thesis when I say that more power is useful only when you're trying to get your signal above the contacts noise floor. Therefore, the principal purpose of more power (in the transceiver or as an external amplifier) is to provide an option for those instances when you're trying to make the contact and need more power to get above the contact's noise floor. Thanks again and 73... de AG7TX

That explains quite nicely why I could have a conversation with a couple of different people in New Zealand from Oxnard, CA back in the 1980s with my stock 4 watt Cobra 148 GTL. There's a group of us in the Mohave Amateur Radio Club that are building the QRP Labs kit, The QCX mostly at 20 meters. I'm going to have to break down and learn code. I may have to use my comptuer to send and receive code as I attempted to learn it decades ago and a lot of times I couldn't hear the difference between a dit and a dah.

Very interesting video. I'm going to try to do a few qrp contacts because of this.

Great video Cliff! I am into qrp since I got my license 41 years ago. My first rig was a Kenwood TS-120V, FT-817, IC-703 were on my way, and now I really love my KX2 (even it has flimpsy case which is far from rough as a portable rig should be) 73s od better 72s (hi) de Stephan, DF6PA

Thanks for the video. I know what you're saying is correct. Whether a 2K mile contact can be made (and maintained over a long period of time say 10 minutes) depends to a great extent to the band condittions. I've seen the band change quickly so that stations lost communication for a few minutes while those stations (a net) increased their power to 1 KW trying to maintain QSOs. Only a few minutes later the band changed back and those same hams were able to maintain communications after turning off the big amplifiers. I like qrp and am looking for tips on getting the most signal out. Basically, which feed line and antenna to hook up to my rig. Thanks again.

Tnx Cliff, you inspire me. Gonna go fire up the KX3 and work some SKCC, 73s de KA4NIV

There's definitely a relationship between watts and S-Units and you explained it quite well. There's also a relationship between watts and ego, but I don't know the formula.

Good points to consider, thanks.

Great video Cliff, John VK6NU

I agree with your math, but I have broken pile ups with a little more power when the 100 would not do it. I don't feel the need for a full gallon and a half amp, but 800 to a 1000 does make the difference in my experience. I usually run 20 drive and get 250 out. I do work barefoot alot, and do make qrp contacts too. I don't turn on the amp every time I operate, but on 80 meters at night, when the static crashes take over, you better put some power down, or the receiving station is not going to make their ears bleed any longer then a signal exchange. I love working QRP to stations that run full limit. They say " I'm running full legal limit" and I say, " working 5 watts " LOL!!! So I agree low power can work, but sometimes the added push makes a huge difference. If I was a cw guy ( learning, but find it hard ) low power qrp work would be great. Really love your videos, your production quality is very good. Keep it up, and maybe it will help me get motivated to practice cw.

Lookin' and sounding great.

good information thank you 👍

Great video Cliff... Sometimes the truth hurts... Keep up the good work. Keep those videos coming. Michael VA6XMB

Another great video with great information, really glad I found you. #Subcribed

My understanding of Power issues was a little fuzzy and I can thank Cliff for making things crystal clear. Plus, I can now feel my ulcer starting to heal as I have been worried sick about how I am going to afford a $4000 amplifier sometime before I become a silent key. He didn't mention it but a good antenna can add an honest 2-4 db and that doesn't change the power bill at all.

Great video I really enjoyed it

Great video. When I first started playing with WSPR beacons and FT8 I would experiment with QRP levels as low as 100mW and QRO levels as high as 100W. On good propagation days I could see marginal increase in range but not enough to warrant the added stress on my rig running a digital mode. I learned some good lessons from those experiments and this video made the results a lot more clear. A good antenna is worth an amplifiers weight in gold 73 NE5U Mike

great video. only time i would really like an amp is if my antenna needs encouragement to radiate because it was some sort of compromise design I was forced to use.

This is good to know. Thanks

Nice work!

I had a guy tell me I didn't need a amp to hit the repeater we were on, but I could only hit the repeater with my amp. It was pretty funny.

great video, great information. I’d just like to point out a couple of things. 1. 1 S unit is 6 db only in iaru theoretical recommendations. Very few radios respect that. But it doesn’t matter in the end cause what matters is the real Signal+noise/noise ratio. And is the ear to perceive that. That means if your signal is comparable to the noise even doubling power, 3 db, is a significant difference, as you said. 2. Unfortunately one has to fight strong qrm many times, more than just band noise. And when the receiver has an adjacent guy putting out 1500w is where you’ve got a problem even if you’re strong S9. And so again 3 or 6 db help quite a lot. To work in harmony everybody should lower the power. If I can hear you S9 with 100w why in first place you need an amplifier. So will do the adjacent one and so on. Less qrm, less splatters, less listening fatigue.

May I add sir, now I very well believe that ham old timers say is true. "It is not with the power output you throw that matters, it is in a well made and tuned antenna system that really does the job to be heard and of course if mother nature is on your side, propagation".

Excellent video.im not anti -amplifier, just anti-marketing scams.they've really been around since the dawn of time,audio and rf amps and much more.to me it's deception never could agree with it.thanks for video.

Now i understand why the jump in broadcast radio in watts is so large... most FM stations are broadcasting between 50k -100k watts which is a massive amount more power then us on amateur radio, but to get a really good signal on any old cheap radio inside a house you need to get those s units up very high thus the gigantic jump in wattage that FM broadcast do typically. This really backs up what your saying (I believe) please correct me if im wrong and excellent video, subbed and belled really enjoy your presentation and knowledge.

Thank you!

Hi sir may i ask something does this table you show and value and principles applies also on vhf ? Because i see that you test it in hf all of my rig was vhf ,, thanks 73

Ahhhh i really enjoyed this one

My slogan is always: it's better to invest in a better microphone than in a linear amplifier.

excellent!

Preach it brother

This is all correct . I have the Kenwood ts 480 hx , and have been using it in my work van with a 3 metre outbacker outreach , since the rig first came on the market . My mobile station was about as good as i could do without getting an amp . It is very true the extra 100 watts makes very little difference most times , i have done many tests over the years turning down the power to 100 , 50 10 and 5 watts . I would say that if you have a very good a aerial and low power this is way better than high power with poor aerial . MY Icom ic 703 (10 watts ) in the shack with a 72 metre doublet at 18 metre is every bit as strong as my mobile set up ( many tests over the years ) . Thanks for your video

I was talking to a guy in Florida. I was 100W. He was QRP @5W. I cut my power to 5W and other than a slight increase of noise over signal from me, he had no trouble and we continued the QSO.

Great video and well explained. de N1OMJ... 73

Awesome video. So glad your back. Hoping for more CW stuff. de K0EAP

For weak signals, 6db makes the difference between a contact or no contact. It's all about increasing reliability that's why most commercial stations run power. I agree, most of the time, it's not needed. You can't control conditions, but you can increase readability a little.

The key is antenna..put up a yagi,and you'll be LOUD :D

A great antenna can boost your signal far more than any LEGAL amp!

I guess its not TRUE QRP but I was thrilled to get contacts with New Zealand from Oregon with the same ham on two separate SOTA activations he had me at a "41" RST both times so the amp definitely would have helped bring me up out of the noise a bit better but still perfectly workable even during this time of "Horrible solar conditions"

I respect your comments and agree with the overall theme. I do feel however you undersold the noise floor variable. In my 40 years on the air my experience is that about 1/3 or more contacts are made right around the noise floor, so an amp would be a difference maker for 1/3 of them. While you did caveat with the noise floor I feel you inferred near absolutes without its frequent impact. If an operator wants more success, and in a sharply noticeable percentage, he/she will appreciate the amplifier. Can the operator be highly successful without it? Yes. Will he miss many opportunities over time? Also yes. 73 KM5L

Thanks for that comparison. I've been doing QRP for a while and am surprised at the results. Qrp allows me to run battery power and make contacts on both SSB and, of course, CW. What really makes the most difference is a well tuned and efficient antenna. A beam on a tower is always better than a dipole on the roof. Perhaps you could do a video on antenna performance for QRP operation.