#42 Tutorial HAM / CB Radio Electronics: What is PEP Power and how to measure?

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#42 Tutorial HAM / CB Radio Electronics: What is PEP Power and how to measure?

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TRX Lab

9 жыл бұрын

Step by step explanation and experiments around PEP and AVG power on a SSB transmission

Пікірлер: 58

@AntoNio-nw7kx 3 жыл бұрын

Really usefull explanation! you are great in make easy complex things. I apreciate it so much. Thank you for the precious time that you give us in those wonderfull explanations.

@ElectronicsNotes 7 жыл бұрын

Useful video - there is a lot of misunderstanding about PEP, average power, etc. Well done.

@TRXLab 7 жыл бұрын

Yeah that is true... Thanks for watching Cheers

@karlfell3768 9 жыл бұрын

Really good demonstration between the maths and real world readings. Much easier to make a calculation of expected tx output using simple mathematical formula. Karl

@TRXLab 9 жыл бұрын

Karl Fell Yea, with this method we can check our SWR/Power meter... Thanks for feed back Karl!

@technos123 9 жыл бұрын

Very interesting and educational video as usual. Very well explained.

@TRXLab 9 жыл бұрын

technos123 Thanks for your feed-back. It is always good to hear that the videos meets the expectation :-)

@budleyca1 9 жыл бұрын

Very informative and good explanation...tnx for sharing... Bud...

@TRXLab 9 жыл бұрын

budleyca1 Hi Bud, thanks for feed back!

@Lycantroph71 8 жыл бұрын

Great explanation, thank you very much. Your homemade coupler is very interesting. What are the values of the two resistors you used?

@IZ0MTW 2 жыл бұрын

Nice and interesting as you always are. Aside, I believe that your Siglent awg is capable of giving you two tones from one port. I’m sure it has a combiner itself inside, so you don’t need the external one you made. You might wanna check in the manual. Tschüss

@TRXLab 2 жыл бұрын

yes my new X Version is able to do it..

@xjohn1970 Жыл бұрын

@TRX Lab The Palstar PM2000A has a true PEP reading circuit in it. The PM200A will Read AVG Watts Or true PEP Watts. Palstar PM2000A. Check it out.

@baghdadiabdellatif1581 2 жыл бұрын

Thank you peter

@tangoseal1 8 жыл бұрын

Your videos are great! Thank you!!!

@TRXLab 8 жыл бұрын

+Eric Owens Thank you Eric! 73

@user-su5sq5ib3i Жыл бұрын

Can you do a video on showing how to setup for a trapazoid pattern on AM? Thank you and 73

@plentygood422 Жыл бұрын

Can you explain how you get the 2 tone looking like that and so stable on your rigol..struggling with mine

@bjorlfale1872 6 жыл бұрын

I note that to calculate the average power with two tones, that's exactly the (fallacious) RMS power divided per 2 : (Vpp/2/sqrt(2))^2 /50 /2 (recalling that the signal is between the peaks and 0 half the time, that sounds to make sense)

@TRXLab 6 жыл бұрын

Thanks for watching 73

@iw0hex 9 жыл бұрын

Thanks for this video, P. Best 73s Pasquale.

@TRXLab 9 жыл бұрын

Pasquale IW0HEX Thanks Pasquale! 73

@josemiguez2375 7 жыл бұрын

instead of using a 40db attenuator,it would be possible to use a 1:100 oscilloscope probe connected to the amplifier output and make a direct reading in the oscillocope screen?

@TheFunkman 8 жыл бұрын

Ok thanks. I will.

@REKlaus 3 жыл бұрын

I don't know where the "16" in his "Pavg" formula comes from. 40+ years ago I was taught "Pavg = (Vpeak x .5)squared / Rload", which still works when using his voltages. Vpeak x .5 = Vavg.

@dinosworkshop6870 9 жыл бұрын

Well, that's a wrap ! I'll make it simple and easy on myself. I'l just throw away my TI-92 calculator and buy a LP100a. No use to use a formula when using the LP-100 becausev it is all already there. Terrific explanation and demonstratiion!! Thumbs up and thanks for the video. kc5okn

@TRXLab 9 жыл бұрын

Satellite_Guy HaHa yeah you are right to buy a LP100A is the best you can do:-) !!

@dinosworkshop6870 9 жыл бұрын

Next a explanation of the relationship of db to power would be useful. tnx

@TRXLab 9 жыл бұрын

Satellite_Guy okay will do it on the list....

@repairfreak 9 жыл бұрын

I'm confused, so is the Average Power output in watts calculated greater when feeding a dual tone input verses feeding with a same amplitude single tone? Or is only the PEP higher with a dual tone, but calculates to a lower Average Power output in watts when compared to to Average Power output when using a single tone of same amplitude. I was under the previous assumption that PEP power output in watts is the same as Average Power power output in watts regardless of if it is produced by a single audio input frequency or a dual.

@TRXLab 9 жыл бұрын

Mike K Hi Mike, yeah you second assumption is right. Dual tone means higher PEP power while the Avg. power drops at the same time. You can see it very clearly when you carefully watch my AF experiments. You find the both AF signals adding up. What you see in the AF experiment also happens on RF. Single ton means PEP= AVG while PEP with single tone is lower than on dual tone. This issue still confuses may OM's as it is really tricky. Hope this helps a bit 73

@andreasviehmann5805 8 жыл бұрын

Was ich aber komplett vergessen habe , ganz zum Schluss rechnest Du mit 120V wo bei dein Scope nur 1,21V anzeigt und rechts im Bild der Teiler bei x1 steht, ist dort also ein 100:1 Teiler an der Meßspitze geschalten, das geht hier so nicht hervor auch nicht wo das TX Signal dabei abgegriffen wird weil durch den Tastkopf am Antennenausgang wird durch die Kapazität der Messvorgang zum Power Meter doch komplett verfälscht. Ich hoffe dass Du hier zu den Messungen eine kurze Erklärung parat hast für all diejenigen welche das nachmessen möchten aber nicht die Ausstattung haben wie in deinem Lab und ev. mit einem ganz normalen Wattmeter ohne AVG messen werden.

@TRXLab 8 жыл бұрын

Das ist im Video erklärt Andreas. Hinter dem Sender ist ein 40db leistungs dämpfungsglieder. 40db im spannungsbereich bedeutet Faktor 100. hoffe das hilft. 73

@TheFunkman 8 жыл бұрын

The LP100A is obviously a great meter. But, at $450US that's out of my budget and I assume most small shops and hams. It would be nice if they offered a kit.

@TRXLab 8 жыл бұрын

+Rudy Rutenber Hi Rudy, yea you are right it is not the cheapest one but you should visit Larry's web site and leave him a message telling about the idea of a kit. He will most likely answer you.

@gixerags750 5 ай бұрын

You probabaly are better off with the more budget LP600.

@gixerags750 5 ай бұрын

Couldnt be bothered mentioning the 2 resistor values even after a few requests in the comments...now how hard would it be mentioning the 2 resistor values ???

@225rc 9 жыл бұрын

Can you do more cb stuff??just starting out and trying to learn.

@TRXLab 9 жыл бұрын

225rc Well certainly yes but there are already a lot online..73

@glasspaul101 Жыл бұрын

They never show or explain how to connect the radio to the scope. Sampler or a intenuator ? correct?

@TRXLab Жыл бұрын

watch video #159

@TheFunkman 8 жыл бұрын

By the way, how many years did it take you to accumulate all that gear?

@TRXLab 8 жыл бұрын

+Rudy Rutenber Well, the gear changed over the years again and again. So I can't really tell you how long it took to set it up that way. Actually I'm again adapting to new needs.

@BWWGL9 8 жыл бұрын

TRX, DO YOU MODIFY CB RADIOS? I HAVE A GALAXY 959 I WANT TO HAVE SOME MOD MADE. Please let us know, THANKS in advance. Bill

@TRXLab 8 жыл бұрын

+BWWGL9 Sorry Bill, I don't 73

@tangoseal1 8 жыл бұрын

+BWWGL9 Contact BBi in Idaho or Bell's CB Shop in Florida. I do not do CB, I do HAM, but these two are really good at the business of CBs.

@bigfoottoo2841 6 жыл бұрын

PEP power is simply the average power of the peak

@TRXLab 6 жыл бұрын

Well I would carefully rethink your statement. 73

@manfredcaranci6234 2 жыл бұрын

I think your statement is closer to the truth. PEP is the AVERAGE POWER over one cycle taken at the PEAK of the modulation ENVELOPE. This is true whether you use one tone or two for SSB. The issue with one tone is that the output is a constant envelope, single-frequency sinusoid at either the upper or the lower side frequency. SSB transmitters normally don't run at this power on a continuous basis. But if you use two tones, then the amplitude of the two tones must be equal when added together to the amplitude of the single tone. The PEP will be the same, but a power meter designed to measure the AVERAGE power will indicate only HALF of what it was with one tone, since the envelope is no longer constant. To get the PEP, simply multiply that average by 2. The advantage with two tones is the TX does not operate at maximum power on a continuous basis, as it would for a single tone.

@r.f.lab-renefilho1453 6 жыл бұрын

Hi Friend ! Please. I liked to Know the valor of resistors in this case. Can you report ?

@TRXLab 6 жыл бұрын

What resistor do you mean? The load is always 50 Ohm

@r.f.lab-renefilho1453 6 жыл бұрын

Thank you very much for information ! Need to be compatible with the generator output, Understood !!!

@andreasviehmann5805 8 жыл бұрын

Deine Videos sind super, das muss man deutlich mal sagen, jedoch warum nicht in deutsch ? Sehr schwer dir zu zu hören in englisch das würde in deutsch viel besser kommen oder wie wäre es in 2 Ton :-)

@TRXLab 8 жыл бұрын

Hallo Andreas, vielen Dank freut mich das dir meine Videos gefallen. Leider ist die Videoproduktion eine einmannshow und ich habe keine zusätzliche Kapazität um die Videos nachzuvertonen. Auf der anderen Seite ist ca. 85% meiner Zuschauer englischsprachig. Somit stecke ich ein wenig in der Klemme😀😀 Danke für deinen Kommentar. 73