Quick Peek at Decibels (

[@gregmihran8616]

This brought back memories of my college electrical engineering courses - you did a fine job explaining a confusing subject for most HAMmers. Thanks Dave! 73 KJ6ER, Silicon Valley

[@michaeledmonds3027]

Thanks for getting the dB ball rolling.... Now an overview of the S meter function would be much appreciated.

[@HennerZeller]

I used to be confused by dB when there was suddenly a factor 20 instead of 10 involved. Then I learned that is actually when talking about power - doubling the input voltage to some resistive load will increase power proportional to the square of the voltage. Now a square is just a factor of two in logarithms. So 10dB voltage increase will create 20dB power increase.

[@tahlularose9267]

Beautiful, thanks

[@davidsradioroom9678]

Decibels are all based on logarithms. I have to relearn about them all over again.

[@KillerSpud]

I know I've gone over dB several times before, but I've done the actual conversions so rarely that it gets a bit fuzzy. Though the point of using the various dB units is so you don't have to convert, which means it just keeps slipping my mind how it works exactly. Thanks for a great refresher.

[@Fleadog100]

My head just exploded...

[@paulhastings3109]

I must have been absent that day in school I do not remember that at all and I don't recall on my amateur license test

[@phillipleroy1452]

Holy Cow! I think you may have went too deep without holding a smooth line of thought. You confused me and I know what you were trying to get across.

[@BusDriverRFI]

Has anyone ever heard of Alexander Graham Bell? That obscure person is who the bel was named after.

[@James_Bowie]

Does the name Alexander Graham ring a bell?

[@w2aew]

1dB is *not* a factor of 1. 0dB is a factor of 1.

[@davecasler]

You're absolutely correct! Sorry about the error. I'm thinking I may want to redo this video. In order to do a video every day, have to do them pretty quickly. But a subject like this takes more prep including preparing charts in advance and a script. The error you caught me in is pretty basic and I don't want misinformation like that to spread. Thank you for pointing out the error. 73, KE0OG

[@James_Bowie]

@@davecasler I think this video definitely needs to be remade. It's not the clearest explanation I have seen.

[@ahbushnell1]

@@davecasler I would prepare slides in advance of a talk. That will keep you on track. That's what I do. But your doing a great job.

[@Roddy1965]

dBs are used because they are useful, because they make working with extremely small or large quantities a lot more practical. Then if you know a few rules about adding and subtracting logarithms you're really multiplying and dividing numbers that would otherwise be much too cumbersome. The dB is just a ratio expressed in logarithms ('logs'). They only have physical meaning if you know what the ratio was relative to.

[@garrysekelli6776]

I always thought that the Decibel itself was the unit. I'm going to start measuring in Bels. And change the spelling to deciBel.

[@watchcat1898]

I just want to understand how the S/N meter is actually used.

[@ahbushnell1]

Someone will get confused between voltage and db and power and db. i.e. 20 db will reduce voltage by a factor of 10 and power by a 100.

[@ipklondonuk]

Dave did I hear you right? giveaway for October 2019?

[@davecasler]

I must've really been tired when I said that!

[@ipklondonuk]

@@davecasler don't worry Dave, we've all done things like that, I retire in 16 months, I thought I had to work another couple of years lol

[@ahbushnell1]

your equation at 8:34 should be 10*log(a/b)

[@rickn501s]

Nice try, Dave. You are very nice and I know you're trying to help....but please do your homework and make accurate notes before you try to explain something. You're confusing us because you didn't get it right the first time. If 1 db is a factor of one and 10 db is a factor of ten, why is 3 db a factor of 2? I know it is....but you need to explain why!

[@BusDriverRFI]

I think it's pretty evident that it's a mystery to him. He memorizes definitions and apparently has never had to use these processes intimately.

[@stephenw8dbc882]

🤯

[@stevewarner8880]

My hair hurts Dave 73

[@yotubeurk]

Callum M0MCX talk Bananas

[@jimcrance6715]

lost me

[@BusDriverRFI]

It's because you were paying attention.

[@w2tty]

I didn’t follow this one

[@traderlarry]

Rambling, I am sorry to say.