My Ham Shack - Your Shack. Pictures. Blogs. Projects.

Tom Tom
Extra Class
K8TQ Ham Since 1972
United States

View Profile
Viewed 2599 times

My Web SiteOpens in a new window


View All 1 Pictures


View All 0 Connections

Request Connection


Other Callsigns
Seems like I have to do something to change my call letters on this site. My call is no longer k8tq. It is w8qlf and it has been for quite a while. I'll see what I have to do to get my call letters changed here.

My Ham Radio Interests


Other Interests


The Power of Amateur Radio (in watts)

From K8TQ

3/11/2019 2:33:39 PM (1 comments) Add a commentAdd Comment

The POWER of Amateur Radio (in watts)

There's one topic or point of discussion that Amateurs just love to discuss on the air and that's POWER (echo echo echo ). They talk about their amplifiers and talk about building amplifiers. They talk about their transistors, high voltage, low voltage, current and they even talk about high mu vacuum tubes (valves) which are always another great topic.

Some Hams talk about amplifiers they've built while others talk about building an amplifier but never actually build one. That's part of the hobby too. There's always something Ham's want to do to improve their radio stations or do something experimental just for the shear enjoyment of it. Amateur Radio is what YOU make it for yourself.

Personally I don't spend that much time on the air. I do listen to the CW band quiet a bit and I generally put it on a cw frequency and whomever happens on to that frequency is who I listen to. Usually I am working on a project and I do hear a lot of white noise but someone does happen along and I do get to listen in.
You don't find rag chewing in CW band as often as you used to. Normally I hear signal reports, names and their QTH, however there is a good rag chewing QSO every once in a while which is great.

I spend some of my Ham Radio time reading about other Ham's experiments and achievements and my remaining time I design my own flavor of equipment and experimenting and trying it out. That's a bunch of fun too.
You can have a lot of fun with Ham Radio without a lot of power. I know that is hard to believe with all the QRM in the phone bands but it is true. I am not a POWER JUNKIE but in the same breath I am worried that I might be and I don't know it.

I do have an amplifier that will exceed 1 KW but will not exceed legal limit. I'll turn it on once in a while when the bands are terrible and it helps out.

Just like the Ham's in my opening paragraph, I do like to talk about amplifiers and I like to build them as well as talk about building them. With all that being said I may be a power junkie about 50 % of the time but I'm still not sure if I am. When push comes to shove I really don't need an amplifier but I want one and I'm not giving mine up.

Since I will not spend a bizillion dollars building my own transceiver up to snuff with Yaesu and Kenwood, not that I know much about that technology but I guess I'll build what I know and build what I can afford to build. It can get pretty expensive building older technology equipment that is just as popular today as it was 30 years ago.

I know one Ham that has an amplifier that will do almost 10KW output key-down. He swears he never runs more than 1500 watts PEP output. I know several other Hams that have amplifiers that will do between 4 kW and 5 kW output. They say they run their amplifiers balls to the wall all the time. You know, I believe them too because you visibly see the side effects of all that RF. One Ham doesn't have any hair the other Ham's teeth are falling out and another one has a stomach so large that it makes him look like he's pregnant. He said it was a beer tumor LOL. I'm only kidding about the side effects and the Hams. The devil made me say that. I really don't know anyone that runs more than 1500 watts. :)

In two other topics a little farther down this page I talk about QRP communications which I use more frequently than modes that require copious amounts of wattage, even though we all know that there's something about watching that needle swing all the way over to the other side of the meter when you're talking.

I am talking about power output and amplifiers here because most all Hams have an affinity or need to have the loudest signal that they can have. Everyone wants to be heard and why not?

All joking aside, let me give one giant compliment to Ham radio operators which are generally not understood by outsiders or non Amateurs. Ham radio encompasses every natural science known to man in an in depth manner. Lets face it, if you want to talk around the world you can use your cell phone. Talking around the world using a radio has a mystique or some unknown attraction to some people that they just have to do it. And once you get involved with it, chances are you are going to be pulled deeper and deeper into the technology of radio communications. It's hard to explain just why people fall in love with radio but they do.

Ham's enthusiasm vary as to interest and depth of interest depending on the individual. I have often wondered how many engineers, technicians, chemists, physicists, mathematicians, astronomers, meteorologists, computer programmers, IT gurus and the list only grows, which as an end result Amateur Radio has spawned? That number has to be large but will always be an unknown. I think that's pretty cool.

If you have listened to the Ham Bands for any length of time you already know that Hams continuously compare signal strength day after day and night after night while trying to improve their signal strength in between reports. We all know that improving our antenna systems is the cheapest way to improve on our signal strength most of the time but we also know that a Linear Amplifier or RF Power Amplifier also know by many other names will increase our signal strength by increasing our power output to the antenna.

Unfortunately Plutonium has not been legalized for use by Amateur Radio Operators. So Ham's are not powering their Mr. Fusion nuclear reactor which in turn powers their Flux Capacitor to provide the needed 1.21 Gigawatts of Electrical Power to drive a 3-5million/ZG Stromtanium tube made by TittriMac. So for now we just have to do with what we have.

There is so much misinformation and wives tales out there about power and signal strength that I thought I would shine one LED worth of light on the subject and bring to you the simple truth about wattage and signal strength in this vast cosmic arena of endless chatter called rag-chewing.

Of course my sarcastic sense of humor may confuse some readers while other may just chuckle and finish reading what I have written. Whatever the case may be I continue to press the keys on my seven dollar keyboard.
Part 97 of the rules and regulations allows Amateur Radio Operators AKA Ham Radio Operators to use an upper limit of One Thousand Five Hundred watts (1500 W) of RF power output. Many Hams will tell you that half way to legal limit is 750 watts. That may be true in some respect but when it comes to comparing signal strength, Amateur Radio Operators who are in the know are talking about another half way point that is measured in terms of gain.
So I'll compromise with you. I will agree that 750 watts is half way to legal limit and I would rather have this half way than the other half way measured in dB or decibels gain. Which is a more down to earth apples to apples and dust to dust kind of measurement.

Don't you just hate it when there's more than one way to measure the same thing in a different way that sometimes just does not make sense and gives an answer that even is more confusing and makes even less sense than the the new math that everyone talked about 30 years ago and no one still understands that.

Sheeeeeeeeeeeeeeesish !

If the above sentence is not the epitome of a run-on sentence I just don't know what is. But sometimes you have to break the rules to make yourself feel better only because the explanation is actually harder than what the actual problem is.

Anyway here is the facts. 750 watts is half way to the legal limit of 1500 watts. With that being written 387.2983 watts is half way to legal limit of 1500 watts.

The first answer of 750 watts is on a linear scale or an evenly weighted scale between 1 and 1500. The second answer is on a algorithmic scale which better describes an unevenly distributed scale where the first 387.2983 watts is just as powerful as the remaining 1112.7017 watts. I hope that makes sense to you but in terms of gain it's factual.

I've always seen some ball park figures in magazine articles or some GURU EXPERT on the air professing some number on or about 375 watts to be the half way or mid point for gain half way to legal limit. Half way is certainly a hallmark or milestone improvement over what seems to be a standard rig output of 100 watts.
Anyway, I must have been really bored last night when I decided to run the numbers to find that midway point in terms of gain. This task took all of a minute and a half if that long and I did not even have to sharpen my pencil.

We've all seen the formula 10Log(P1/P2) which is a comparative power formula. It's so simple even a caveman can do it. Also from that formula we can derive if Y=Log10(X) then we can prove X=10^Y. Grab a calculator if you don't have a pencil and do it for yourself.
Since last night, when I finally took the time to calculate just where that midway GAIN point really is, life is now complete for me and I can live out my life in contentment.

There is no doubt that the pinnacle of life has been found in Amateur Radio and I am totally complete knowing that 387.2983 watts of RF energy is that midway point between 100 and 1500 watts in terms of gain.
Just when we all thought that the answer to life, the universe and everything was 42, we actually find that 387.2983 is the correct answer. The trick is just knowing what the question is.

Related topics to that half way point
To compare 387.2983 watts to the 100 watts that your rig will probably output is almost 1 S Unit or almost 6 dB above or stronger compared to your barefoot 100 watt rig. With that being said 1500 watts is almost 2 S Units over your 100 watt radio.

To buy that first S unit will cost you in the neighborhood of four to five hundred bucks if you are buying a used amplifier. To buy that second S unit to get to full legal output of 1500 watts, may cost you five thousands dollars more if you are buying a new amplifier. However that depends on the brand name of the amplifier and the bells and whistles it has. If you buy an older pre-owned amplifier you may only pay another $500 above what you paid for your half way 387.2983 watt amplifier.

Your S Meter and what it really means
It's extremely hard to tell the difference between 1000 watts and 1,500 watts when you are on the receiving end of a radio signal and I'll explain that.
If you look at your S meter on your radio and the scale starts from left to right 1 thru 9 and then many S meters are graduated differently after that. After the 9 on your S meter your graduations are in dB or decibels. Many scales are a bit different but still after the number 9 the graduations can be different but still counted in dB. I'll just use the 1 ~ 9 to explain the difference between 1000 watts and 1500 watts when receiving a radio signal.
Lets take the division between the number 8 and the number 9 on your S meter. Some meter manufacturers will not print every number between 1 and 9. Often you will find every other number such as 1, 3, 5, 7, 9 and a mark in between those numbers to represent the unprinted numbers. That's not always the case but you just have to use a little common sense and you'll probably figure it out.

When you are receiving and your meter is in the signal strength mode, S units make up about the first half of your meter and decibels or dB's make up the rest of your meter's scale. Most S meters are first graduated in S units which each S unit is equal to 6 decibels or dB's.
The distance between the 8 and the 9 is really small. There may be an eighth of an inch (.125") between the mark that indicates where the 8 should be and the number 9 is printed.

If we divide the distance between the 8 and 9 six equal times, that does not leave much space between those six divisions. So we are going to say each of those 6 divisions that you made between the number 8 and 9 are 1 decibel each. That's saying there are 6 decibels per S unit. However in reality those six divisions are not equally spaced or linear. But for the sake of argument we'll say they are in this example.

That makes each division between the 8 and 9 on your S Unit scale about .021". That's about the thickness of four or five human hairs. I would have used the RCH scale but I could not find an international conversion for a RCH. And for those of you that like the metric system like I do, that's .53 mm for each of those 6 divisions when splitting the distance between the 8 and 9 on your S Meter's equally six times.

For HF & VHF bands one definition of S9 is a receiver input power of -93 dBm. This is the equivalent of 5 microvolts in 50 ohms. One S-unit corresponds to a difference of 6 decibels (dB), equivalent to a voltage ratio of two, or power ratio of four.

The Real Comparison for Wattage

Okay! Now here's the comparison between 1000 and 1500 watts. Let's say you're talking on SSB to your buddy in Tasmania and his signal strength is an S8 and he's running 1000 watts. You can hear him okay most of the time and for the frequency and time of day you feel that's a pretty good signal. We'll all agree with that. That's not bad. There are some static crashes and you ask him if he can QRO to 1500 watts. Numerically on a linear scale that's another 33% when compared to 1000 watts. However that will not increase his signal by another 33% or another 1/3rd in signal strength.

Increasing his power by 500 watts only increases his received signal strength by two of those 6 imaginary divisions we made between the number 8 and 9 on your S meter. In fact it will only increases 1.8 of those 6 marks we made between the 8 and 9. That's a little bit of an increase and the human ear can hear the difference but it is not what you would call a tremendous difference. To understand this all we have to do is refer to the basic natural log math which we calculated above to calculate dBratios of P1 divided by P2.

So here's my point. We can buy or build an amplifier with an output of 1000 watts comparatively inexpensive to building an amplifier of 1500 watts. If you jump up to buying or building an amplifier of full legal limit or more you will be spending a ship load more for 1500 watts and only gain 1.8 dB over the 1000 watts which may not be detected by anyone listening.

A surplus $50 tube to generate 1 KW (one thousand watts) is extremely desirable. You can buy a few of these tubes and they could last a lifetime. Or you can buy one tube that puts out 1000 watts for $230 and replace that tube many times over a lifetime if you drive it to hard or even inadvertently tune your amplifier wrong.

The Cost Of Running Power

After giving this next statement a lot of thought I believe there are three distinct categories of amplifiers when it comes to QRO. I know we have those gray areas in between but please forgive me when I am limiting this to three categories.

The first category and price range is an amplifier of 300 watts up to about 500 watts output. You are going to be able to find a wide range of amplifiers for HF both in power and price in the entry level category. That entry level is significant and just may be the one and only amplifier you will ever buy. That may be enough for you. Actually I have heard stations running 100 watts who seem to be a little weak for the conditions and then turn on a 400 watt amplifier and it made all the difference in the world. I spent a lot of time talking about that midway point in gain for a reason and that's because it is truly significant.

The second category of amplifier is above 500 watts and up to about 800 watts. 600 watt amplifiers are common and do a really good job when you need to help your weak signal in poor conditions. If you purchased an amplifier that outputs 800 watts that is really significant because 800 watts is only 2.73 dB below 1500 watts output. The human ear can perceive 2.73 dB so it still makes some sense stepping up to 1500 watts output if you ever wanted to. But that last 2.73 dB can cost you as much or even more than what you paid for everything below 800 watts.

The cost of an amplifier in the 600 to 800 watt range can be expensive but if you are lucky you can find one that may fit your budget.

The last category of amplifier is 800 watts and above. Generally you will find commercially made amplifiers that range from 800 to a thousand watts to full legal limit output of 1500 watts and above. When I say above, there are many commercially available amplifiers that will run almost 4kw output. Some even more

Many Hams like these 4KW amplifiers because they will run at full legal limit and run cooler without straining the components to their maximum capacity. Then again, there are the RF Bullies out there that run their equipment for all they are worth all of the time.

BTW, The term RF Bullies is a term I've borrowed from an Amateur that has more time on the air than I can even think about having. His call is W8OO and his name is Steve. Great Amateur and wonderful person. Steve also says an amplifier is for your friends and he's absolutely right.

You will have a variety of price ranges to choose from if you decide to go with 1500 watts and above. At today's prices you can buy a nice tube amplifier that will run full legal limit PEP output for about $1500. If you look around you can find a used one for $900. On the upper end of the scale you can spend above $5000.

The bottom line is what you want and what you are willing to settle for. I am going to list below several reasonable steps in gain and wattage that will help you compare your selection of power output in comparison to wattage over your standard 100 watt transmitter / transceiver. I have my favorite ranges for the money spent and decibels gained and I'll probably tell you that too.

Over the years there have been many Amplifier companies that have gone out of business for one reason or another. The longer you are in business it stands to reason you will probably sell more amplifiers.

I like many older amplifiers for various reasons and of course I like the newer amplifiers for the same and different reasons as the older one's because technology has advanced.

It seems the most popular amplifiers on the market today are made by Ameritron. I have heard varying reports of good and bad quality but they have sold more amplifiers than any other amplifier company out there. Personally I have had several. In fact when I count them I have had six of them. They are okay and I have had problems from time to time with them. They have so many amplifiers in different power levels that you actually have a choice of how much gain you want to buy at different price levels for the same wattage.

I am not pushing or endorsing Ameritron products but I am using them as an example because they do have so many amplifiers of different power levels.

Here's what makes sense to me, if you do not have an amplifier already. These amplifiers are available used as well as new on a regular basis. What ever you do make sure you shop around for an amplifier that meets your requirements.

600 watts, AL-811
800 watts, AL-811H
1000 watts, AL-80B

Above 1000 watts search Ameritron web site.
If I were to choose the best amplifier for the money when buying new, I would have to go with the AL-811H. However I definitely think the AL-80B is a good amplifier too. Prior to the recent price hike by Ameritron over the past year I would have said the AL-80B if you were buying new. Either way if you can get an 811H or an 80B used they probably are the best buy for the dollar to dB ratio. To me, if you can acheive near the 1 kw output you are at a confortable power level.

I say that because the components in your antenna system do not have to be super heavy duty to handle the higher RF voltages and you are still within the rules that you can use common duty components.
Fun Question Comparing Power
Let me leave you with this question. I am only asking this because I heard of a CBer running 25,000 watts on 27 MHz (Citizens Band). Can you imagine that, TWENTY-FIVE THOUSAND WATTS! OMG! I find that hard to believe but for the sake of laughter we'll say it is factual.

Here's the question:

If I am running full legal limit of 1500 watts in the Amateur Band and you are receiving my signal at S7 how many watts do I need to increase my power to get to a S9 signal report? That's assuming everything remains the same and the only thing that changes is an increase in my power output.

The answer is at the end of my QRZ page. The number is surprising.

Read the 1 comment after the break below.


by WB4IUY 11/14/2019 8:16:52 PM

Would that be around 24kw for S9?? Great blog!

   Login to Add a Comment