US amplifiers.

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ch25
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Re: US amplifiers.

Post by ch25 » 28 Apr 2018, 12:46

Pity, but that pointing out CB B$ made you so picky? C class is not for SSB nor AM. End of story. Anyone say different is ignorant idiot.

BTW C class can be converted to AB, I've done it a few times.
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Re: US amplifiers.

Post by sonoma » 28 Apr 2018, 16:11

here is one of the amps that is rated class C and he calls it a competition amp. this little 2 pill will put out a lot of watts also as a 2 pill. I have one I hook up from time to time and with a high drive mine putts out over 400 watts. the builder calls it a high drive and will take just under 100 watts drive. some guys claim to get close to 600 watts out of it with a high enough input.
I use a galaxy 29hp with mosfets to drive it and it swings good.
if you look at his listing for the amp he states it is for AM. here in the US we do not run FM unless we are just messing around. in the past 45 years I have been on the radio maybe 2 times I have heard some one on FM over here.

http://www.xforceamps.com/item/Straight ... 200HD-M-85

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Re: US amplifiers.

Post by Kaliphan » 30 Apr 2018, 08:52

sureshot wrote:
28 Apr 2018, 10:20
It looks to me that the amps don't create splatter, depends on the radio use and how much distortion its putting out. I rather clever fellow from the US on the tube explained the misconceptions people have on interference that is transmitted. The amplifier just ramps up the splatter from the radio.
I saw that one, he's the idiot who talks crap about having to have traceable calibration certs for everything or you can't possibly do a good job.

He's an obnoxious idiot who doesn't understand the video he was criticising, go back and watch the video he was knocking and pause it when he shows the spectrum analyser screen, do some calculations for yourself for with and without the amp, then work out why Mike is right and Cal boy is wrong.

An amp will do what it is meant to do, amplify the signal you give it, if you feed it a dirty signal it will amplify it but a bad amp and will can create a huge amount of interference all by itself no matter how clean the signal you feed it is.

Think about it, if you have a really crappy audio amp it will sound terrible even if you feed it a signal from the best source money can buy it will still sound crap, same applies to RF amps, if it's badly designed and built then it will 'sound' terrible and distort (RF splatter is distortion in the amplifier and harmonics are greatly increased in power by bad amplifiers too).

All bets are off when you have a crappy redneck amp that's nowhere near linear and overdriven to hell, it will splatter everywhere and create all sorts of interference. How many of those redneck amps have anything even pretending to be a low pass filter on the output?
Last edited by Kaliphan on 30 Apr 2018, 09:08, edited 1 time in total.

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Re: US amplifiers.

Post by Kaliphan » 30 Apr 2018, 08:53

sonoma wrote:
28 Apr 2018, 16:11
here is one of the amps that is rated class C and he calls it a competition amp. this little 2 pill will put out a lot of watts also as a 2 pill. I have one I hook up from time to time and with a high drive mine putts out over 400 watts. the builder calls it a high drive and will take just under 100 watts drive. some guys claim to get close to 600 watts out of it with a high enough input.
I use a galaxy 29hp with mosfets to drive it and it swings good.
if you look at his listing for the amp he states it is for AM. here in the US we do not run FM unless we are just messing around. in the past 45 years I have been on the radio maybe 2 times I have heard some one on FM over here.

http://www.xforceamps.com/item/Straight ... 200HD-M-85
And there we go 'swings good', question is where is all that power that shows on your meter being produced?

I guarantee you there's a large chunk of it being spalttered all over the place.

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Re: US amplifiers.

Post by Buick Mackane » 30 Apr 2018, 10:14

Me personally prefer class A ;)

(Sorry dave) :lol:

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Re: US amplifiers.

Post by sureshot » 30 Apr 2018, 10:42

Buick Mackane wrote:
30 Apr 2018, 10:14
Me personally prefer class A ;)

(Sorry dave) :lol:

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:lol:
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Re: US amplifiers.

Post by sureshot » 30 Apr 2018, 10:47

I'm still going to give it a go putting one together. Them tutorials run a bit fast to glean all the info. A task is finding a good schematic. And another would be finding them toshiba pill transistors. Although it might be possible to modify the board for T0220 devices, which would be cheaper.
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Re: US amplifiers.

Post by ch25 » 30 Apr 2018, 12:29

sureshot wrote:
30 Apr 2018, 10:47
IA task is finding a good schematic.
I would go for BLF188XR. Not that complicated to build, but way better than all that crap you showed us.
5W in, 1kW out.
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Re: US amplifiers.

Post by sureshot » 01 May 2018, 00:19

ch25 wrote:
30 Apr 2018, 12:29
sureshot wrote:
30 Apr 2018, 10:47
IA task is finding a good schematic.
I would go for BLF188XR. Not that complicated to build, but way better than all that crap you showed us.
5W in, 1kW out.
Chris
Thanks for the amplifier model no, I will look it up. To the best of my knowledge I haven't shown any "rubbish" amps, or proposed any so far..
But I will take a close look at your recommendation.
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Re: US amplifiers.

Post by Kaliphan » 01 May 2018, 06:59

BLF188 is a device not an amplifier, bombproof but not cheap, *really* not cheap, once you've got the power supply properly sorted and bought all the bits you might be looking at 400 quid so it's not a beginner or experimenter transistor unless you got six numbers last weekend.

Go and get some circuits for RM amps, then burn them.

Once you've fanned the smoke away, do the same for almost every CB amp circuit you can find.

Then, even though the BLF188 is way out of your league yet, go and have a look at some of the circuits for amps built round it, because it's so expensive people usually design n build proper amps round it.

Go and look up EB104, find out which transistors are used in amps, find datasheets and application notes for them cos almost all the ones for real RF transistors have at least test circuits in them and sometimes full amplifier designs.

DO a lot of reading then build something, run it into a dummy load and work out why it's crap, make the next one better.

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Re: US amplifiers.

Post by sureshot » 01 May 2018, 10:00

Kaliphan wrote:
01 May 2018, 06:59
BLF188 is a device not an amplifier, bombproof but not cheap, *really* not cheap, once you've got the power supply properly sorted and bought all the bits you might be looking at 400 quid so it's not a beginner or experimenter transistor unless you got six numbers last weekend.

Go and get some circuits for RM amps, then burn them.

Once you've fanned the smoke away, do the same for almost every CB amp circuit you can find.

Then, even though the BLF188 is way out of your league yet, go and have a look at some of the circuits for amps built round it, because it's so expensive people usually design n build proper amps round it.

Go and look up EB104, find out which transistors are used in amps, find datasheets and application notes for them cos almost all the ones for real RF transistors have at least test circuits in them and sometimes full amplifier designs.

DO a lot of reading then build something, run it into a dummy load and work out why it's crap, make the next one better.
Yes that price point is out of my league by the sounds of it. I only had a one pill or to pill in mind at most. I'm fairly certain the transistors would have to be T022 devices, as the pill type devices are silly money. Thanks for the advise.
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Re: US amplifiers.

Post by Kaliphan » 01 May 2018, 12:57

Have a look at Earwigger's website then, M0RZF he's done a lot of work with cheap TO220 FETs but the answers aren't what you want to hear.

If you want to do RF with power then you need RF parts.

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Re: US amplifiers.

Post by sureshot » 01 May 2018, 19:28

Kaliphan wrote:
01 May 2018, 12:57
Have a look at Earwigger's website then, M0RZF he's done a lot of work with cheap TO220 FETs but the answers aren't what you want to hear.

If you want to do RF with power then you need RF parts.
Yes thanks I will see if I can find him, it was RF power im interested in. But I realise a lot of the US stuff is AM or geared towards it. If it ran on SSB it would be worth building, but the availability of the Toshiba pills is a bit tough. I'm not paying the stupid prices some UK sellers are asking.
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Re: US amplifiers.

Post by Kaliphan » 02 May 2018, 08:14

sureshot wrote:
01 May 2018, 19:28
Kaliphan wrote:
01 May 2018, 12:57
Have a look at Earwigger's website then, M0RZF he's done a lot of work with cheap TO220 FETs but the answers aren't what you want to hear.

If you want to do RF with power then you need RF parts.
Yes thanks I will see if I can find him, it was RF power im interested in. But I realise a lot of the US stuff is AM or geared towards it. If it ran on SSB it would be worth building, but the availability of the Toshiba pills is a bit tough. I'm not paying the stupid prices some UK sellers are asking.
Start small and work your way up, what you learn building a small amp will make the bigger ones easier.

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Re: US amplifiers.

Post by sureshot » 02 May 2018, 18:47

Yes I'm not going to get over ambitious, start of with something modest for now. Thanks for the help and advise from everyone.
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