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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
"Telstar Electronics" wrote in message
ups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk |
SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
"Dr.Death" wrote:
"Telstar Electronics" wrote in message ups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk He's trying to squeeze every dime out of his free google advertising dollar. Chapter 11 next. |
SkyWave 2879AB Amplifier
jim wrote:
Steveo wrote: "Telspam Electronics" wrote: http://cg/spam Things must be slow. didn't he get booted off a provider for spamming? Rumor has it. |
SkyWave 2879AB Amplifier
Steveo wrote:
"Telspam Electronics" wrote: http://cg/spam Things must be slow. didn't he get booted off a provider for spamming? |
SkyWave 2879AB Amplifier
On Thu, 18 May 2006 15:36:25 -0500, "Dr.Death"
wrote: "Telstar Electronics" wrote in message oups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk Well if he is going to spam a group with this he should have at least picked the proper group. alt.homebrew.doorstop |
SkyWave 2879AB Amplifier
"Steveo" wrote in message
... "Dr.Death" wrote: "Telstar Electronics" wrote in message ups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk He's trying to squeeze every dime out of his free google advertising dollar. Chapter 11 next. ROFLMAO I'm surprised dogie hasn't ratted him out, there is no disclaimer about using it on 11 meters. Have a good weekend, I'm off to the lake. |
SkyWave 2879AB Amplifier
wrote in message
... On Thu, 18 May 2006 15:36:25 -0500, "Dr.Death" wrote: "Telstar Electronics" wrote in message roups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk Well if he is going to spam a group with this he should have at least picked the proper group. alt.homebrew.doorstop Or alt.overpriced.boatanchor Have you seen how much he wants for his no frills two pill splatterbox? |
SkyWave 2879AB Amplifier
Thanks for the constructive inputs... I always have time for my
engineering colleagues. www.telstar-electronics.com |
SkyWave 2879AB Amplifier
"Dr.Death" wrote:
"Steveo" wrote in message ... "Dr.Death" wrote: "Telstar Electronics" wrote in message ups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk He's trying to squeeze every dime out of his free google advertising dollar. Chapter 11 next. ROFLMAO I'm surprised dogie hasn't ratted him out, there is no disclaimer about using it on 11 meters. Dogie still uses his bootleg realistic. (he has the secret conversion for the freeband). Have a good weekend, I'm off to the lake. OH you dawg! Have fun and Go Cavs tonight! |
SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
"Steveo" wrote in message ... jim wrote: Steveo wrote: "Telspam Electronics" wrote: http://cg/spam Things must be slow. didn't he get booted off a provider for spamming? Rumor has it. Very good layout PC board, that takes allot of work. Hope he sells them all day to CBers, I don't care where they go. Some of the so called BIG amps( Dave Mades, ect ) look crappy inside because the designers are not very bright.Some look like they were built in a cow barn. |
SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
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SkyWave 2879AB Amplifier
"I AmnotGeorgeBush" wrote in message
... From: (Dr.Death) "Telstar Electronics" wrote in message ups.com... I'm surprised dogie hasn't ratted him out, Are you really? Dogie and Griffy are buds! That makes sense. |
SkyWave 2879AB Amplifier
"I AmnotGeorgeBush" wrote in message
... From: (Dr.Death) "Telstar Electronics" wrote in message ups.com... I would think that a regular in the group would have better sense then to spam the group with his product. You can now join Lou Franklin and AAA Rf Products.plonk Lou has good stuff. I agree, but am tired of the monthly spamming of the group. If he wants to post and have it as his sig file, that would be cool. |
SkyWave 2879AB Amplifier
JSF... you're right about those "big amps". They are nothing but
hay-wired prototypes, mostly designed and constructed by persons having no electronic background. I have looked at many of them over the years and have found that they have major flaws such as inadequate cooling, improper tuning, and instabilities/oscillations caused by improper layout and long wires running around all over inside. Because of these issues, their owners must keep a steady stream of expensive output transistors flowing through them... if you know what I mean... LOL www.telstar-electronics.com |
SkyWave 2879AB Amplifier
On a sunny day (22 May 2006 04:45:06 -0700) it happened "Telstar Electronics"
wrote in .com: JSF... you're right about those "big amps". They are nothing but hay-wired prototypes, mostly designed and constructed by persons having no electronic background. I have looked at many of them over the years and have found that they have major flaws such as inadequate cooling, improper tuning, and instabilities/oscillations caused by improper layout and long wires running around all over inside. Because of these issues, their owners must keep a steady stream of expensive output transistors flowing through them... if you know what I mean... LOL www.telstar-electronics.com Hi, I am reading on your website http://www.telstar-electronics.com/S...Amplifiers.htm about efficiency and conductingangle. My question, has anyone ever attemped a class D (pulse width) modulated amp with MOSFETS for 27Mc? The limit would be the switching time, say if we have 1nS switching FETS, and 37 nS period time, we use a bridge, so per 37 nS we switch 4x = 4nS We dissipate any power (not counting Rds-on losses), could we achieve 80% efficiency? There are also losses from transformer and Pi filter of course. And perhaps you would need a switchmode to get a higher operating voltage, mmm that would bring it down to .8 x .8 = 64 % + filter and other losses.... But it COULD take you into the kW range with cheap FETS? Whatdoyouthink? ;-) |
SkyWave 2879AB Amplifier
Telstar Electronics wrote:
JSF... you're right about those "big amps". They are nothing but hay-wired prototypes, mostly designed and constructed by persons having no electronic background. I have looked at many of them over the years and have found that they have major flaws such as inadequate cooling, improper tuning, and instabilities/oscillations caused by improper layout and long wires running around all over inside. Because of these issues, their owners must keep a steady stream of expensive output transistors flowing through them... if you know what I mean... LOL www.telstar-electronics.com Kind of like building an amp and running it with class C bias? You know what that means? |
SkyWave 2879AB Amplifier
Jan,
Sure you can run class D at 27MHz... the problem is distortion. Class D is very efficient but is really only meant for digital signals. www.telstar-electronics.com Jan Panteltje wrote: On a sunny day (22 May 2006 04:45:06 -0700) it happened "Telstar Electronics" wrote in .com: JSF... you're right about those "big amps". They are nothing but hay-wired prototypes, mostly designed and constructed by persons having no electronic background. I have looked at many of them over the years and have found that they have major flaws such as inadequate cooling, improper tuning, and instabilities/oscillations caused by improper layout and long wires running around all over inside. Because of these issues, their owners must keep a steady stream of expensive output transistors flowing through them... if you know what I mean... LOL www.telstar-electronics.com Hi, I am reading on your website http://www.telstar-electronics.com/S...Amplifiers.htm about efficiency and conductingangle. My question, has anyone ever attemped a class D (pulse width) modulated amp with MOSFETS for 27Mc? The limit would be the switching time, say if we have 1nS switching FETS, and 37 nS period time, we use a bridge, so per 37 nS we switch 4x = 4nS We dissipate any power (not counting Rds-on losses), could we achieve 80% efficiency? There are also losses from transformer and Pi filter of course. And perhaps you would need a switchmode to get a higher operating voltage, mmm that would bring it down to .8 x .8 = 64 % + filter and other losses.... But it COULD take you into the kW range with cheap FETS? Whatdoyouthink? ;-) |
SkyWave 2879AB Amplifier
On a sunny day (22 May 2006 07:47:53 -0700) it happened "Telstar Electronics"
wrote in .com: Jan, Sure you can run class D at 27MHz... the problem is distortion. Class D is very efficient but is really only meant for digital signals. www.telstar-electronics.com Hi, you know class D audio amps exist I suppose? There are even class D power amp chips for audio. These use PWM (pulse width modulation). You can make any output waveform with PWM (as long as the switching frequency is much higher then the output frequency). This links shows some basics for a modulator (driving class D for example): http://www.netway.com/~stevec/ham/pd...lid_state.html I can also think of a 'digital' solution, say you have 8 RF amps, 1W, 2W, 4W, 8W, 16W, 32W, 64W, and 128W, now simply switching these on with an 8 bit digital audio signal (one on each bit) and summing the RF output together, will give you a 255W AM modulated transmitter with less then 1/255 (0.4 percent) distortion (have not tried)? Since these RF amps can be class C (no need for A, AB, B, any linear!!) you should get good efficiency. The stages are only 'on' or 'off'. So, maybe someone could combine some :-) Nice for experiments.... hehe |
SkyWave 2879AB Amplifier
On a sunny day (Mon, 22 May 2006 15:32:12 GMT) it happened Jan Panteltje
wrote in : On a sunny day (22 May 2006 07:47:53 -0700) it happened "Telstar Electronics" wrote in s.com: Jan, Sure you can run class D at 27MHz... the problem is distortion. Class D is very efficient but is really only meant for digital signals. www.telstar-electronics.com Hi, you know class D audio amps exist I suppose? There are even class D power amp chips for audio. These use PWM (pulse width modulation). You can make any output waveform with PWM (as long as the switching frequency is much higher then the output frequency). This links shows some basics for a modulator (driving class D for example): http://www.netway.com/~stevec/ham/pd...lid_state.html I can also think of a 'digital' solution, say you have 8 RF amps, 1W, 2W, 4W, 8W, 16W, 32W, 64W, and 128W, Actually I think I have this wrong, should be Volts (RF output) ratio or powers of 2. So 1 W in 50 Ohm: U^2 / 50 = 1, so U = sqrt(50) = 7V eff, the next higher higher one would be 14V eff or 3.92 W, better start at the high side... So for your 300W in the highest bit: U^2 / 50 = 300, U^2 = 15000, so U = sqrt(15000)= 122V eff. The next lower one (bit 7) would be 122 / 2 = 61V eff, so 61^2 / 50 = 74.42W, bit 6 would be 61 / 2 = 30.05 V, makes 18.06W bit 5 would be about 15 *15 / 50 = 4.5W bit 4 would be 7.5 x 7.5 / 50 = 1.125 W etc etc. I have also been thinking about doing SSB this way. For SSB we need half the bits, and one bit to change the phase of the driving carrier 180 degrees. Hope I got that right. You'd be selling lots of amps!!! |
SkyWave 2879AB Amplifier
On a sunny day (Mon, 22 May 2006 16:41:03 GMT) it happened Jan Panteltje
wrote in : I have also been thinking about doing SSB this way. For SSB we need half the bits, No, same bits, but bit 8 as sign bit changing carrier phase 180 degrees.... We'll get there.... |
SkyWave 2879AB Amplifier
Your statement about having the switching freq much greater then the
output freq I agree with. But if you wanted to make an amp for 27MHz... what switching freq would you have? 2X, 5X, 10X ? Also, with a high switching rate... with square-waves... you have tremendous harmonic content. You also would require much higher frequency amplifers... along with the quantum leap in complexity of combining all those amplifiers, A/D conversion, etc... I think your idea would work... it's just not practical in my mind. www.telstar-electronics.com |
SkyWave 2879AB Amplifier
On a sunny day (22 May 2006 10:29:39 -0700) it happened "Telstar Electronics"
wrote in .com: Your statement about having the switching freq much greater then the output freq I agree with. But if you wanted to make an amp for 27MHz... what switching freq would you have? 2X, 5X, 10X ?\ Look at that example link, it uses 100kHZ (KILO Hertz) in the PWM AM modulator, leaved the RF stage as is, but the PWM modulates it supply voltage. that way the output. In case of direct pwm to the RF, yes, I mentioned 1nS switching time, could be done. I like the digital idea better..... Also, with a high switching rate... with square-waves... you have tremendous harmonic content. You also would require much higher frequency amplifers... along with the quantum leap in complexity of combining all those amplifiers, no no, MOSFETS can switch that fast.... A/D conversion, Any PC gives 16 bit audio, just some shift registers or some i2c io expanders, no need for an AD converter, we are going to drive digital now :-)!!! etc... I think your idea would work... it's just not practical in my mind. Remember the modulation frequency is in the audio range, at that speed you have to change the PWM. You need a pi filter lowpass in ANY case to get good harmonic surpression. In the digital case (swithing 8 amplifiers), there are some more advantages. Problem is adjusting the exact power level (so a ramp (sawtooth) waveform has equal steps), adding (summing) the output takes inductors couplers... impedance matching. Hey, I have done that DA thing for up to 10 MHz or so.... the big boys can do it, why not we? Probably will be worth a fortune on ebay 50 years from now. |
SkyWave 2879AB Amplifier
"Lancer" wrote in message m... Telstar Electronics wrote: JSF... you're right about those "big amps". They are nothing but hay-wired prototypes, mostly designed and constructed by persons having no electronic background. I have looked at many of them over the years and have found that they have major flaws such as inadequate cooling, improper tuning, and instabilities/oscillations caused by improper layout and long wires running around all over inside. Because of these issues, their owners must keep a steady stream of expensive output transistors flowing through them... if you know what I mean... LOL www.telstar-electronics.com Kind of like building an amp and running it with class C bias? You know what that means? I think some of those Amps are getting close to class D now, they drive 250 Watt amps with 5 watts in to a 50 watt driver 10- 13 DB gain then a pair of finals with 10-13 DB of gain, no bias on the base , I can just see the crap the poor transistors go through. Then they mod their radios to give SWING which does nothing but make the wattmeter swing like SSB but their no louder, but I will say it helps keep the poor finals cooler. In the new Commerical Broadcast AM transmitters their Audio is Class D audio amps driving the finals saving allot of AC power. |
SkyWave 2879AB Amplifier
"Jan Panteltje" wrote in message
... On a sunny day (22 May 2006 07:47:53 -0700) it happened "Telstar Electronics" wrote in .com: Jan, Sure you can run class D at 27MHz... the problem is distortion. Class D is very efficient but is really only meant for digital signals. www.telstar-electronics.com Hi, you know class D audio amps exist I suppose? There are even class D power amp chips for audio. These use PWM (pulse width modulation). You can make any output waveform with PWM (as long as the switching frequency is much higher then the output frequency). This links shows some basics for a modulator (driving class D for example): http://www.netway.com/~stevec/ham/pd...lid_state.html I can also think of a 'digital' solution, say you have 8 RF amps, 1W, 2W, 4W, 8W, 16W, 32W, 64W, and 128W, now simply switching these on with an 8 bit digital audio signal (one on each bit) and summing the RF output together, will give you a 255W AM modulated transmitter with less then 1/255 (0.4 percent) distortion (have not tried)? Since these RF amps can be class C (no need for A, AB, B, any linear!!) you should get good efficiency. The stages are only 'on' or 'off'. So, maybe someone could combine some :-) Nice for experiments.... hehe Class D audio amps are only designed for low frequency as they would sound like crap for the higher freqs. |
SkyWave 2879AB Amplifier
On a sunny day (Mon, 22 May 2006 19:02:24 -0500) it happened "Dr.Death"
wrote in : Class D audio amps are only designed for low frequency as they would sound like crap for the higher freqs. Can we have some math please? Or did you design the one for the full audio range? |
SkyWave 2879AB Amplifier
On a sunny day (Mon, 22 May 2006 17:44:40 -0500) it happened "JSF"
wrote in : In the new Commerical Broadcast AM transmitters their Audio is Class D audio amps driving the finals saving allot of AC power. Exactly, and no excessive distortion in the audio either. I see no reason why it cannot be done for CB AM (at high power too). |
SkyWave 2879AB Amplifier
Jan, please contact us when you have a working prototype.
www.telstar-electronics.com Jan Panteltje wrote: On a sunny day (Mon, 22 May 2006 17:44:40 -0500) it happened "JSF" wrote in : In the new Commerical Broadcast AM transmitters their Audio is Class D audio amps driving the finals saving allot of AC power. Exactly, and no excessive distortion in the audio either. I see no reason why it cannot be done for CB AM (at high power too). |
SkyWave 2879AB Amplifier
On a sunny day (23 May 2006 04:34:52 -0700) it happened "Telstar Electronics"
wrote in .com: Jan, please contact us when you have a working prototype. Why do you not use the one from http://www.netway.com/~stevec/ham/pd...lid_state.html and pay the guy something for his design? You can then use a FET (at the higher voltage) for the RF power stage. I, myself have a Ranger RCI-2970, so am in no hurry to build something atm. But I would help you with the design for fun. Dunno everything, but I did my thing to 500W in the past. The reason of all this, is, that when I look at you power amp, (and the Ranger also has this rather large 'cooling block' at the bottom), those huge fins say: Waisting Power. Any watt dissipated is a watt not transmitted. I think I can do this thingy for AM, CW or course, and likely DSB.. For SSB things would be more complex, you need 2 DSB versions, and the audio / RF 90 degrees phase shifts. But it would be SSB class D + C :-) |
SkyWave 2879AB Amplifier
Jan, I read the entire article by WA1Q1X. It's very interesting but
doesn't change my mind. One of the major problems that I see... and why it could never replace external amplifier blocks such as our SkyWave amplifier is that this digital system is high level modulated. This does not lend itself to being added into an existing tranciever system... like CB or Ham. This design is something that would have to be incorporated inside the transmitter where a seperate audio signal is available. www.telstar-electronics.com |
SkyWave 2879AB Amplifier
On a sunny day (23 May 2006 05:42:22 -0700) it happened "Telstar Electronics"
wrote in .com: Jan, I read the entire article by WA1Q1X. It's very interesting but doesn't change my mind. One of the major problems that I see... and why it could never replace external amplifier blocks such as our SkyWave amplifier is that this digital system is high level modulated. This does not lend itself to being added into an existing tranciever system... like CB or Ham. This design is something that would have to be incorporated inside the transmitter where a seperate audio signal is available. Agreed. Your amp sure has a lot of merit on its own. My remark was actually triggered somehow by yours about 'flying wires', This picture of the RF stage: http://www.classeradio.com/2module.htm and somebody elses suggestion to have more tech.... postings. Regards Jan |
SkyWave 2879AB Amplifier
By all means keep tech posting. It's much better than the usual
bickering/name-calling that accounts for 95% of the posts here. www.telstar-electronics.com |
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