Mosfet upgrade? Worth doing or waste of money?

[M0GVZ]

Thats what I was thinking but wanted to make sure. Now I know if you did somehow get an actual 40 watts out basically doubling your output, Then the receiving station might notice or help you get over a obstacle but then its, Is it really worth modding it and spending the extra money?

It won't get you over an obstacle. Between me and the next town 12 miles away is a small hill. 100W won't get me there. Yet I drive a mile down the road so I clear the hill and 4W makes the journey with a S9 report.

Going from 20W to 40W sounds a lot but on a calibrated S meter its half a S point. 1000W to 2000W sounds a lot too but you'll only see the same half S point increase.

 

[2RT307]

And that's exactly why I run a used AL-80B at 800 watts instead of spending a fortune for legal limit amp.

73,
Brett

 

[binrat]

I did an upgrade (repair) to a friends Cobra years ago after he blew the final. I saw a conservative 30 watts after.

 

[Cruiseomatic]

Interesting the amount of power to strength gain. My next question is, To see any noticeable increase in signal strength off 12-ish watts PEP input, What size (amount) of "enhancer" would I need to run? 100? 200? 3? There is a ton of noise in my area no matter where you are and sometimes, radio alone will not get you heard even 1/3 a mile down the road.
Not that talking is critical and listening is, But sometimes its dead air until someone says or asks a question. I ask for a radio check just to break the dead air up and start a conversation and see how far I can get or see whats going on locally sometimes.
Simply asking if anyone has their radio on doesn't do it anymore unfortunately.
Thank you to all who have contributed to this. Nice to learn the truth about things and not from "truck stop schools", Lol.

 

[Captain Kilowatt]

Each doubling of power results in about one half S-unit increase so therefore to increase a full S-unit you need four times the power. 50 watts is one S-unit stronger than 12 watts. 200 watts is one S-unit stronger than 50 watts and 800 watts is one S-unit stronger than 200 watts so in reality 800 watts is only about three S-units stronger than 12 watts. Hard to believe when you look at reality isn't it?

 

[Cruiseomatic]

It is. So is the math on doubling. I thought 12 doubled up was 24 and so on.

 

[2RT307]

Each doubling of power results in about one half S-unit increase so therefore to increase a full S-unit you need four times the power. 50 watts is one S-unit stronger than 12 watts. 200 watts is one S-unit stronger than 50 watts and 800 watts is one S-unit stronger than 200 watts so in reality 800 watts is only about three S-units stronger than 12 watts. Hard to believe when you look at reality isn't it?

Don't cloud the issue with facts! Lol

 

[Captain Kilowatt]

It is. So is the math on doubling. I thought 12 doubled up was 24 and so on.

I rounded to 12.5 to make it easier to make 50, 200 , 800 etc. OK so it was really 12 watts doubled to 24 and then to 48 watts for one S-unit. Then it would take 196 watts to make another S-unit gain and then 784 watts to make another. Sue me.....your meter is less accurate than my rounding. 50 watts is actually 6.197888 dB gain over 12 watts rather than 6.000000dB or about 0.0001 of an S-unit difference.

 

[binrat]

I rounded to 12.5 to make it easier to make 50, 200 , 800 etc. OK so it was really 12 watts doubled to 24 and then to 48 watts for one S-unit. Then it would take 196 watts to make another S-unit gain and then 784 watts to make another. Sue me.....your meter is less accurate than my rounding. 50 watts is actually 6.197888 dB gain over 12 watts rather than 6.000000dB or about 0.0001 of an S-unit difference.

Ohh, my head hurts...

 

[Captain Kilowatt]

Ohh, my head hurts...

My whole body hertz. I think the kidney stone factory has started production back up again.

 

[ExitThirteen]

Does it "Mega hertz"?






~Cheers~

 

[Cruiseomatic]

I rounded to 12.5 to make it easier to make 50, 200 , 800 etc. OK so it was really 12 watts doubled to 24 and then to 48 watts for one S-unit. Then it would take 196 watts to make another S-unit gain and then 784 watts to make another. Sue me.....your meter is less accurate than my rounding. 50 watts is actually 6.197888 dB gain over 12 watts rather than 6.000000dB or about 0.0001 of an S-unit difference.

Now my head megahertz..... It takes that large of a jump to make a difference? So basically, Get a 200 and call it good? Now to figure out the 4:1 ratio on the radios to achieve great audio and decent tx power..... Rf is so fun on the mathematical side and calculating what is to what and..... Lol.

 

[Captain Kilowatt]

Rf is so fun on the mathematical side and calculating what is to what and..... Lol.

BWAAAAAAAHAAAAAHAAAAAHAAAAAA! You are funny! That's the simple stuff. Try figuring out the values of capacitance and inductance to make an antenna matching network or phase relationships between multiple antennas. That will make your head swim. That's what's wrong with me. I spent 22 years in commercial broadcasting and never recovered.

 

[Cruiseomatic]

I was being very sarcastic, Lol. I'd love to do commerical RF as a career but I'm into analog more than anything as it seems to be a little more "reliable" than digital. And there is way more math that I've ever really learned period involved.

 

[Cruiseomatic]

I say analog is more reliable from my experiences in both personal use and at work now. When you had low signal strength, With analog, The message could still be communicated. Digital, If you don't meet a certain threshold of data content, forget it. Seen it last night actually.
I work with local PD and use the same radio they do. A unit keyed up right beside me, got the 3 chirps, asked for case number. I never heard any of it on mine. Neither did dispatch. He had to keep trying over and over before it went.... And these are public safety radios that peoples lives depend on and have to work no matter what instantly....? Yep. Ever tried to watch digital TV now days and its raining outside? Bunches of fun. Wait until the wind blows, Even better.... Yep, Digital is so much better alright... Rant over, Lol.
What is the formula for calculating db gain in so many increments? And where can I find radiation takeoff angle diagrams for say 1/2 wave, 5/8, etc...?