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Difference between ham amps and cb amps
- Thread starter linearone
- Start date
50kw=11 leece nevilles,
15v*320amps=4,800w (assuming you are running them at 15v.)
4800*11=52800 watts
guys routinely have more than 11 on their trucks.
well, maybe not routinely but I know of 5 myself.
15v*320amps=4,800w (assuming you are running them at 15v.)
4800*11=52800 watts
guys routinely have more than 11 on their trucks.
well, maybe not routinely but I know of 5 myself.
Even still at those figures that accounts for only 52,800 watts of DC power INPUT to the amp.Even if you factor in the efficiency at 70% you would still need 75,428 watts INPUT for 50,000 watts OUTPUT.That would be about 16 alternators running 15 volts out and 320 amps each not to mention a whole lotta heat to get rid of. About 25,428 watts of heat actually.What size wire you guys run to deliver almost 6000 amps anyway?
I didnt say that you needed only 11 alts to run 50kw rf out,
I said in my second post you can generate 52.8kw of energy with 11 alts.
something hamsters dont realize is an alternator will provide its full output at a wide range of voltages. you can output 18v at 320 amps etc from a leece neville. A tester will prove this, you can also full field them as well and achieve voltages in excess of 24 volts.
each alt has a fan which cools the internals, when half of them are running in ac with no rectifiers there is almost no heat (much ,much less) generated.
What I am getting at is I am so sick of Ameritron, alpha, etc getting so much credit for a product that has limited run time, lower duty components etc. That wizard has great quality parts and was built to run in excess and not blow up, there is no reason one couldnt drive that amp to legal limit and loaf it along letting it last forever. Even guys with 3cx3000x's their tubes produce 7500 plus and run for a very very very long time. One of my neightbors has a 3cx3000a7 wizard base box that he runs at 7500 avg all day long, had it for 4 years, same tube, same out put, no problems,
I feel like folks should demand high quality, high reliability, high duty cycle in their amps, radios etc. if you called ameritron and told then you held a 2 min key they would void your warranty. I am distrubed by hams who post and say, Oh its ok they all do that. Hamster or Cber, money is hard to come by and we should demand better. there is NO REASON why any "bowl box" couldnt have band switching added for a fee. Does anyone else not see that point?
Also why is it ok for a hamster to employ a grounded grid design (which the above amp isnt) is their projects but when cbers have it they get told they're dumb.
I guess I was poking my finger at most ham products especially ameritron, I was trying to say that not only "ham company" can produce quality. My whole point of bringing up big mobiles was to demonstrate the lack of progression and homebrew spirit in ham radio. Hams struggle with 1kw mobiles. Thats a joke in CB. there have been lots of advancements in the illegal cb worl in the last 10 years and lots more even in the last 2. Thebiggest Ive seen in the ham world is the flex radio which is UBER cool but it took them this long to develop it? guys were controlling their 2510's and yaesus 15 years ago with windows 3.1 pc's.
I guess its just a bitterness I have. This board has taken the turn to wanting to get closer to ham radio yet most of the business transactions on it remain cb radio, even mole who wants to sell stuff is going to sell cb stuff to fund the board, but we only publish front page ham stuff? we put up pictures of fossil ham operators and think thats the furutre and its cool? CB is what primarily drives this board, the post count proves it. the transactions prove it, ....sigh..... im off on a rant here.
all in all, sorry I poked fun at the "ham " amp called ameritron. you do know half theor products are marketed to cber's right?...
time for a lock on my thread I think. Do the honors please?
:headbang
I said in my second post you can generate 52.8kw of energy with 11 alts.
something hamsters dont realize is an alternator will provide its full output at a wide range of voltages. you can output 18v at 320 amps etc from a leece neville. A tester will prove this, you can also full field them as well and achieve voltages in excess of 24 volts.
each alt has a fan which cools the internals, when half of them are running in ac with no rectifiers there is almost no heat (much ,much less) generated.
What I am getting at is I am so sick of Ameritron, alpha, etc getting so much credit for a product that has limited run time, lower duty components etc. That wizard has great quality parts and was built to run in excess and not blow up, there is no reason one couldnt drive that amp to legal limit and loaf it along letting it last forever. Even guys with 3cx3000x's their tubes produce 7500 plus and run for a very very very long time. One of my neightbors has a 3cx3000a7 wizard base box that he runs at 7500 avg all day long, had it for 4 years, same tube, same out put, no problems,
I feel like folks should demand high quality, high reliability, high duty cycle in their amps, radios etc. if you called ameritron and told then you held a 2 min key they would void your warranty. I am distrubed by hams who post and say, Oh its ok they all do that. Hamster or Cber, money is hard to come by and we should demand better. there is NO REASON why any "bowl box" couldnt have band switching added for a fee. Does anyone else not see that point?
Also why is it ok for a hamster to employ a grounded grid design (which the above amp isnt) is their projects but when cbers have it they get told they're dumb.
I guess I was poking my finger at most ham products especially ameritron, I was trying to say that not only "ham company" can produce quality. My whole point of bringing up big mobiles was to demonstrate the lack of progression and homebrew spirit in ham radio. Hams struggle with 1kw mobiles. Thats a joke in CB. there have been lots of advancements in the illegal cb worl in the last 10 years and lots more even in the last 2. Thebiggest Ive seen in the ham world is the flex radio which is UBER cool but it took them this long to develop it? guys were controlling their 2510's and yaesus 15 years ago with windows 3.1 pc's.
I guess its just a bitterness I have. This board has taken the turn to wanting to get closer to ham radio yet most of the business transactions on it remain cb radio, even mole who wants to sell stuff is going to sell cb stuff to fund the board, but we only publish front page ham stuff? we put up pictures of fossil ham operators and think thats the furutre and its cool? CB is what primarily drives this board, the post count proves it. the transactions prove it, ....sigh..... im off on a rant here.
all in all, sorry I poked fun at the "ham " amp called ameritron. you do know half theor products are marketed to cber's right?...
time for a lock on my thread I think. Do the honors please?
:headbang
Where the *uck did that idea come from?? GG amps are easy to build and are stable. They do require a bit more drive levels but I don't know anyone myself that thinks what you claim to be so.
A lot of hams struggle with a lot of things. CBers, too. But there is some truth to what you're saying. I have PERSONALLY talked to long-time hams that have said to my face that it was difficult to get a 500 watt amplifier working mobile and next to impossible to do 1KW. I looked at them like they were retarded and then pointed at my Jeep (only 500 watts; I can't afford the 1KW amp, although my alternator could handle it.)
This is sort-of off topic, but every time I change the front page, I make an attempt to find something interesting in both the Ham and CB sections to put on the front, including the pictures. I've posted threads on the front about old CBs that people have found that were interesting. Most of the threads in the CB section are tech questions about how to repair or tweak a particular radio. Those don't make for interesting front page material. If there were more threads of home-brew CB projects, or other interesting discussions in the CB section, they would be put on the front page. I was going to put Cajun's Merlin antenna thread on the front, but the pictures are too big and the fonts are too large. I also can't put station pics on the front page unless they are in a member's album. I have no problem whatsoever with CB stuff. Hell, I still talk on the CB. However, I can only use what I have to work with for the front page.
OK I see what I missed the first time. I was wondering where you were getting the grounded grid versus grid driven thing. From the way you were presenting it it looked as if your claims were commonplace among the amateur community and THAT is what I disagreed with.GG design is a good design regardless of the service it is used in.It does have it's pros and cons but so does grid driven service with it's more complicated power supply requirements and the fact that they are a little harder to stabilise as well as needing neutralizing.
Grounded grid was used in my example because the Ameritron amp uses it.
Frankly it makes zero sense to use an 8877 grid driven except maybe as a driver for a 10 kw class FM broadcast transmitter.
Makes no difference to my point. An 8877 is a poor choice for a CB amp that is supposed to make 4 kw. Grid driving one will not help the poor little grid which was specifically designed to only dissipate 25 watts. That is to facilitate low IMD numbers in typical grounded grid LINEAR service. Slight mis-tuning of the amplifier output will make the situation worse.
The reason hambones can't make use of all that new science the CB amp builders have is that when you splatter on the ham bands 50 people will get on your case. On chickenband splatter is a status symbol for some.
50,000 watts mobile is a breeze when you don't have to replicate an AM waveform. It isn't as simple as input power = multiplying volts X amps X 1/efficiency factor which is what some of you guys are doing. That equation only works for sinusoidal waveforms. Calculation average input power for a square wave like these guys are transmitting requires integration. The peaks are only there for a short period of time. These "big" radios are really pulse transmitters approaching what is seen in radar.
Look at the FCC hamby definition of an AM signal. A 100% modulated 375 watt carrier is supposed to be 1500 watts P.E.P. even though you use only about 500 watts D.C. to the R.F. amp in a plate modulated rig to make that power. 500 watts DC in = 1500 watts P.E.P out WTF?
Would I buy an Ameritron AL whatever. No way. I build my own stuff out of junk parts!
If I found a Wizardbuilt on my front porch I'd pull out the 8877 and sell the sucker on ebay. Then I'd zener bias the thing, install a trifilar cathode choke, a GS-35B and go work some dog-xray.
Frankly it makes zero sense to use an 8877 grid driven except maybe as a driver for a 10 kw class FM broadcast transmitter.
Makes no difference to my point. An 8877 is a poor choice for a CB amp that is supposed to make 4 kw. Grid driving one will not help the poor little grid which was specifically designed to only dissipate 25 watts. That is to facilitate low IMD numbers in typical grounded grid LINEAR service. Slight mis-tuning of the amplifier output will make the situation worse.
The reason hambones can't make use of all that new science the CB amp builders have is that when you splatter on the ham bands 50 people will get on your case. On chickenband splatter is a status symbol for some.
50,000 watts mobile is a breeze when you don't have to replicate an AM waveform. It isn't as simple as input power = multiplying volts X amps X 1/efficiency factor which is what some of you guys are doing. That equation only works for sinusoidal waveforms. Calculation average input power for a square wave like these guys are transmitting requires integration. The peaks are only there for a short period of time. These "big" radios are really pulse transmitters approaching what is seen in radar.
Look at the FCC hamby definition of an AM signal. A 100% modulated 375 watt carrier is supposed to be 1500 watts P.E.P. even though you use only about 500 watts D.C. to the R.F. amp in a plate modulated rig to make that power. 500 watts DC in = 1500 watts P.E.P out WTF?
Would I buy an Ameritron AL whatever. No way. I build my own stuff out of junk parts!
If I found a Wizardbuilt on my front porch I'd pull out the 8877 and sell the sucker on ebay. Then I'd zener bias the thing, install a trifilar cathode choke, a GS-35B and go work some dog-xray.
You still rock Doc !
Jesus Christ already !! IM truly starting to understand "Freecell's" way of thinking. Its no damned wonder he comes off the way he does when he does with all of this. Must be why he hasn't wasted his time on this thread huh ?
And I was the one who once asked how much was to much ? I guess we can't live forever 295 .
I used to know a whole lot of those guys that ran big 10kw+ mobile specials all the time, and they spent a lot of time on the key. Notice I said used to, honestly a lot of those guys started to develop some serious health problems with they got into their 50's, things like cancer, lukemia, benign tumors. High instances of these disorders when compared to the rest of the population.
That pretty well ended a lot of their association with the radio, being exposed to all that RF is not good for you.
Yes you can make 50kw in a mobile, but it is not the smartest thing that you can do.:headbang
Would surely make this guy wonder all the same. Think I would personally prefer the best tower and beam I could get my hands on rather then all those watts.
Switch Kit,
I might change your mind with this one, sorry.
--------
HiDef,
You posted a few things that you don't agree with in that last post. I'm sorry you don't agree with them, but that just tells me you don't understand what those things are saying, and why.
For instance.
That 375 watt AM carrier and 100% modulation really do equal 1500 watts Pep output. Do the math correctly and you'll see.
4KW from a 3CX1500A7? That must be in them 'Bird' watts, cuz it just won't do that in the real world for very long. At least, not in any typical configuration you will find, CB or Ham bands. Why not? It deal in expected useful life of a tube. Buy lots of life insurance for that tube. Expect to be investigated before ever collecting a cent of it.
(That investigation would include a sanity hearing,I think.)
Splattering is a 'Status Symbol'? Oh, how cute! Nothing like turning a fault into a benefit, right? I'm afraid that I have standards, in some cases more stringent than the FCC's (and in some cases, not so stringent?). I'm afraid that 'splattering' has a negative number rating in my scale of things. I worry about 'status' in relation to how I value stuff, not how anyone else does. So my 'status' in anyone else's estimation just doesn't matter much at all. Hope that doesn't offend you, too bad if it does. I hope I live over it.
I would respectfully suggest that you re-evaluate your standards in relation to "reality" rather than "I wish". I do agree with your evaluation of that 3CX1500 tube, I'm not thrilled with it. There are others that are much more forgiving, and that will do about the same things, with in reason (3CX1200 for instance).
There are 'other' aspects of very high power in a mobile that are just not worth the effort to me. Guess that just depends on your goal, though. If that's what turns you on, then be my guest! Not that it will mean anything, but you have my permission to do so...
- 'Doc
I might change your mind with this one, sorry.
--------
HiDef,
You posted a few things that you don't agree with in that last post. I'm sorry you don't agree with them, but that just tells me you don't understand what those things are saying, and why.
For instance.
That 375 watt AM carrier and 100% modulation really do equal 1500 watts Pep output. Do the math correctly and you'll see.
4KW from a 3CX1500A7? That must be in them 'Bird' watts, cuz it just won't do that in the real world for very long. At least, not in any typical configuration you will find, CB or Ham bands. Why not? It deal in expected useful life of a tube. Buy lots of life insurance for that tube. Expect to be investigated before ever collecting a cent of it
.(That investigation would include a sanity hearing,I think.)
Splattering is a 'Status Symbol'? Oh, how cute! Nothing like turning a fault into a benefit, right? I'm afraid that I have standards, in some cases more stringent than the FCC's (and in some cases, not so stringent?). I'm afraid that 'splattering' has a negative number rating in my scale of things. I worry about 'status' in relation to how I value stuff, not how anyone else does. So my 'status' in anyone else's estimation just doesn't matter much at all. Hope that doesn't offend you, too bad if it does. I hope I live over it.
I would respectfully suggest that you re-evaluate your standards in relation to "reality" rather than "I wish". I do agree with your evaluation of that 3CX1500 tube, I'm not thrilled with it. There are others that are much more forgiving, and that will do about the same things, with in reason (3CX1200 for instance).
There are 'other' aspects of very high power in a mobile that are just not worth the effort to me. Guess that just depends on your goal, though. If that's what turns you on, then be my guest! Not that it will mean anything, but you have my permission to do so...
- 'Doc
Don't worry Doc. I don't get offended by anything on a bulletin board
I have done the math once or twice
The example of 375 watts carrier yielding 1500 watts P.E.P. followed by WTF was offered because anyone who had been doing this on the ham bands for more than 20 years is familiar with the ripoff perpetrated by FCC effective 6/91 IIRC. That is when the AM "grandfather rule" was lifted. I assumed some of the readers might have been there.
This example disproves the equation for input power mentioned earlier in the thread. Rather than making the disproof one large math homework assignment, I choose to cite a well known and accepted set of figures.
Again, 500 watts D.C. input to the final stage, 1500 P.E.P. watts out to the antenna. This is before the bastardization of the waveform done in the CB chain.
Again, D.C. input power cannot be simply calculated by the product of volts amps times 1/efficiency when the waveform isn't a sinewave. That was the point.
Do you dispute my statement that some chickenbanders are so dumb that they think splatter equates with station capability?
I have done the math once or twice
The example of 375 watts carrier yielding 1500 watts P.E.P. followed by WTF was offered because anyone who had been doing this on the ham bands for more than 20 years is familiar with the ripoff perpetrated by FCC effective 6/91 IIRC. That is when the AM "grandfather rule" was lifted. I assumed some of the readers might have been there. This example disproves the equation for input power mentioned earlier in the thread. Rather than making the disproof one large math homework assignment, I choose to cite a well known and accepted set of figures.
Again, 500 watts D.C. input to the final stage, 1500 P.E.P. watts out to the antenna. This is before the bastardization of the waveform done in the CB chain.
Again, D.C. input power cannot be simply calculated by the product of volts amps times 1/efficiency when the waveform isn't a sinewave. That was the point.
Do you dispute my statement that some chickenbanders are so dumb that they think splatter equates with station capability?
It's all good Doc Switch's head is about spinning by now. The math is what it is. I've enjoyed the thread as much as I could possible understand it. There are times I think I might ? Have learned something along the way. The trick there is , if you truly understood what you just learned ? :headbang or if I really needed to know in the first place.
I can surely have that parakeet syndrome going on from time to time which would mean repeating what I heard without understanding it in the first place. If I can't explain why things are the way they are ? but yet make the statement in the first place , it almost doesn't count coming from me.
Switch's head is about spinning by now. The math is what it is. I've enjoyed the thread as much as I could possible understand it. There are times I think I might ? Have learned something along the way. The trick there is , if you truly understood what you just learned ? :headbang or if I really needed to know in the first place. I can surely have that parakeet syndrome going on from time to time which would mean repeating what I heard without understanding it in the first place. If I can't explain why things are the way they are ? but yet make the statement in the first place , it almost doesn't count coming from me.
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