Output Power vs. S-Units

This is one of the most important concepts in ham radio... the relationship between transmitted power and received signal strength. Sadly, many hams aren't familiar with this topic and falsely believe that buying a 1,500 amplifier will make their signal LOUD.

[timgtm]

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

[odhinnsrunes]

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.

[ado]

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 <15W.
For any newbies out there - don't sweat the big guns with big power, just wait for them to move off the field and you'll get your DX. Focus on your antennae. 73 EI9HAB

I tweeted this video - it's that good :)

[Stingmni]

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

[johnkershaw]

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

[ksb]

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.

[johnc]

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

[radiotec]

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

de WD5L

[stuarthall]

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.)

[franciscolopez]

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.

[Hidden_Destinations]

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.

[loctitems]

Well presented. First thought that comes to mind is how many YouTube 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."

[terrybush]

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

[janiceemery]

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

[richardmacleery]

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

[maxmeranda]

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

[AzPauly]

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.

[gsansoucie]

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.

[joewoodchuck]

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.

[kellyw]

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.