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Look at what Griffey thinks his amp will do...
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Look at what Griffey thinks his amp will do...
On Fri, 29 Sep 2006 02:03:34 GMT, "U-Know-Who"
wrote in : 516 watts PEP, huh? You are ignorant. http://www.telstar-electronics.com/SkyWave%202879AB.pdf Yeah, it's a great piece of science fiction..... You -can- run the transistors that hard..... they will splatter all the way up into the UHF band for about 10 seconds then burn up. The transistors are designed for 100 watts PEP each but the IMD product jumps dramatically above 60 watts PEP. Then there's his claim of 55% efficiency from a Class AB amp..... and built with transistors that are only rated for 35% efficiency. Hey, if you believe that, I have some really nice farmland for sale just off the coast of Montana! My favorite part is his "compression region" scam. Audio compression can be a good thing in radio communications, but he's using the term as a euphamism for non-linear amplification of the -radio- signal. Not only that, he arbitrarily designates a "1% compression point" as some sort of threshold beyond which harmonics -might- cause a problem. Let there be no confusion he Harmonics -will- be a problem beyond this point, especially if you run AM because you will need to reduce your carrier (dead-key) to less than one fourth of this threshold. So don't expect to run more than 30-50 watts AM from this amp or you will have a lot of ****ed-off neighbors. But I'll give him credit where credit is due: If you want an amp that -LOOKS- like it was professionally made then his is the one to buy. Just don't use it and compare the performance with the spec sheet or you'll be sorely disappointed (if not furious!). |
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U-Know-Who wrote:
516 watts PEP, huh? You are ignorant. http://www.telstar-electronics.com/SkyWave%202879AB.pdf Actually it will do that... and more, if you will accept compression distortion. I suggest you great electronics wizards go to http://www.rf-amplifiers.com/index.php?topic=peak_power and read the defibition of PEP. Or maybe you think the people at EMPower don't know what they're talking about either... LOL www.telstar-electronics.com |
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Frank Gilliland wrote:
My favorite part is his "compression region" scam. Audio compression can be a good thing in radio communications, but he's using the term as a euphamism for non-linear amplification of the -radio- signal. Frank, you're showing your ignorance once again. If you knew anything... you would know that all RF amplifiers are power rated to a 1dB compression point. That is the point where linearity starts to deteriorate. I suggest you look here... http://www.rf-amplifiers.com/index.php?topic=rf_power Now don't you feel stupid?... you should... LOL www.telstar-electronics.com |
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On 29 Sep 2006 05:53:39 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: My favorite part is his "compression region" scam. Audio compression can be a good thing in radio communications, but he's using the term as a euphamism for non-linear amplification of the -radio- signal. Frank, you're showing your ignorance once again. If you knew anything... you would know that all RF amplifiers are power rated to a 1dB compression point. That is the point where linearity starts to deteriorate. I suggest you look here... http://www.rf-amplifiers.com/index.php?topic=rf_power Now don't you feel stupid?... you should... LOL Where's any 2SC2879 data sheet that specifies its "1% compression point"? |
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On 29 Sep 2006 05:40:05 -0700, "Telstar Electronics"
wrote in om: U-Know-Who wrote: 516 watts PEP, huh? You are ignorant. http://www.telstar-electronics.com/SkyWave%202879AB.pdf Actually it will do that... and more, if you will accept compression distortion. I suggest you great electronics wizards go to http://www.rf-amplifiers.com/index.php?topic=peak_power and read the defibition of PEP. Or maybe you think the people at EMPower don't know what they're talking about either... LOL Yep, their 'defibition' is right on the money. Now I suggest -you- do a little math with power dissipation and efficiency ratings. BTW, how did you get your distortion figures? |
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Frank Gilliland wrote:
Yep, their 'definition' is right on the money. Want to refute my 516W PEP figure any more?... LOL www.telstar-electronics.com |
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Frank Gilliland wrote:
BTW, how did you get your distortion figures? The 1dB compression point was calculated using an HP spectrum analyzer I have access to at work. It was also used to get the harmonic readings. www.telstar-electronics.com |
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On 29 Sep 2006 06:36:22 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: Yep, their 'definition' is right on the money. Want to refute my 516W PEP figure any more?... LOL I didn't dispute it in the first place. This has to be about the tenth time you failed to understand what I wrote. Do you have lysdexia or some other communication deficit? |
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Frank Gilliland wrote:
Where's any 2SC2879 data sheet that specifies its "1% compression point"? Frank, I'm surprised at you. It doesn't... that parameter doesn't apply to the transistor itself... only a final amplifier. After all, how would Toshiba know what frequency or class of operation were being used? Both of these, as well as the actual amplifier circuit chosen are critical to where the compression point will lie. www.telstar-electronics.com |
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On 29 Sep 2006 06:39:35 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: BTW, how did you get your distortion figures? The 1dB compression point was calculated using an HP spectrum analyzer I have access to at work. It was also used to get the harmonic readings. So how did you calculate the "1dB compression point"? |
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Frank Gilliland wrote:
So how did you calculate the "1dB compression point"? RF power in vs RF power out. When the gain reduces by 1dB... you're there. www.telstar-electronics.com |
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On 29 Sep 2006 06:49:47 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: So how did you calculate the "1dB compression point"? RF power in vs RF power out. When the gain reduces by 1dB... you're there. But how do you measure power with a spectrum analyzer? And have you done the math yet for your power dissipation problem? |
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On 29 Sep 2006 06:47:15 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: Where's any 2SC2879 data sheet that specifies its "1% compression point"? Frank, I'm surprised at you. It doesn't... that parameter doesn't apply to the transistor itself... only a final amplifier. After all, how would Toshiba know what frequency or class of operation were being used? Well, they designed the transistor for a specific application, and the test circuit is rated at 28MHz, so I'm pretty sure they knew exactly how it was going to be used. |
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On Fri, 29 Sep 2006 06:30:53 -0700, Frank Gilliland
wrote in : On 29 Sep 2006 05:40:05 -0700, "Telstar Electronics" wrote in . com: U-Know-Who wrote: 516 watts PEP, huh? You are ignorant. http://www.telstar-electronics.com/SkyWave%202879AB.pdf Actually it will do that... and more, if you will accept compression distortion. I suggest you great electronics wizards go to http://www.rf-amplifiers.com/index.php?topic=peak_power and read the defibition of PEP. Or maybe you think the people at EMPower don't know what they're talking about either... LOL Yep, their 'defibition' is right on the money. Now I suggest -you- do a little math with power dissipation and efficiency ratings. snip Since you don't want to do the math yourself, I'll do it for you..... You claim 516 watts PEP and 55% efficiency. And I'll be super-nice and say that's at 14 volts and you aren't going into saturation. So that means: 516 watts / 14 volts = 36.86 amps 36.86 amps / 55% efficiency = 67 amps 67 amps / 2 transistors = 33.5 amps Ic on each transistor. Well that's a problem since the transistor is rated for an absolute maximum of 25 amps at the collector. A paradox to be sure. But wait... An efficiency of 55% means that 45% is dissipated as heat. So: 33.5 amps * 45% = 15.1 amps 15.1 amps * 14 volts = 211 watts Wheee, that's friggin' hot!!! Especially when the device is only rated for 250 watts dissipation max, assuming a perfect heat sink! Now a 200 watt soldering gun will glow red in just a few seconds..... should we take a brief sojourn into reality and calculate junction temperature? I'm betting it will greatly exceed the max rated 175 degrees. Care to take that bet, Brian? |
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Frank Gilliland wrote:
You claim 516 watts PEP and 55% efficiency. And I'll be super-nice and say that's at 14 volts and you aren't going into saturation. So that means: 516 watts / 14 volts = 36.86 amps 36.86 amps / 55% efficiency = 67 amps 67 amps / 2 transistors = 33.5 amps Ic on each transistor. Amplifier efficiency isn't based on peak power (PEP) you putz... see http://www.rf-amplifiers.com/index.php?topic=dc_input Are you really this stupid?... or are you just putting us on? www.telstar-electronics.com |
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On 29 Sep 2006 08:01:56 -0700, "Telstar Electronics"
wrote in .com: Frank Gilliland wrote: You claim 516 watts PEP and 55% efficiency. And I'll be super-nice and say that's at 14 volts and you aren't going into saturation. So that means: 516 watts / 14 volts = 36.86 amps 36.86 amps / 55% efficiency = 67 amps 67 amps / 2 transistors = 33.5 amps Ic on each transistor. Amplifier efficiency isn't based on peak power (PEP) you putz... see http://www.rf-amplifiers.com/index.php?topic=dc_input Once again you didn't understand what I wrote. I wasn't calculating amplifier efficiency; I calculated peak collector current -based on- your very own amplifier efficiency claim. Would you rather I use the transistor's collector efficiency of 35%? Are you really this stupid?... or are you just putting us on? I have thought of asking the same question of you, but I haven't because you would ignore it just like all the other tough questions. That, and I already know the answer. |
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Frank Gilliland wrote:
I have thought of asking the same question of you, but I haven't because you would ignore it just like all the other tough questions. That, and I already know the answer. Great response... you really are a piece of work... LOL www.telstar-electronics.com |
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Hello TE:
What is the harmonic content with your amp? Do you have a filter in the output circuit? Just wondering, here waiting for the Fedex guy. Jay in the Mojave Telstar Electronics wrote: Frank Gilliland wrote: BTW, how did you get your distortion figures? The 1dB compression point was calculated using an HP spectrum analyzer I have access to at work. It was also used to get the harmonic readings. www.telstar-electronics.com |
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On 29 Sep 2006 08:18:43 -0700, "Telstar Electronics"
wrote in . com: Frank Gilliland wrote: I have thought of asking the same question of you, but I haven't because you would ignore it just like all the other tough questions. That, and I already know the answer. Great response... you really are a piece of work... LOL Ok, we'll use the collector efficiency..... 516 watts / 14 volts = 36.86 amps 36.86 amps / 35% efficiency = 105.3 amps 105.3 amps / 2 transistors = 52.65 amps Ic on each transistor. And since 65% is dissipated as heat, 52.65 amps * 65% = 34.22 amps (Scary!) 34.22 amps * 14 volts = 479 watts.... HOLY ****!!! You better have a BIG MF HEAT SINK!!! Are these transistors water-cooled? |
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Jay in the Mojave wrote:
What is the harmonic content with your amp? Do you have a filter in the output circuit? Jay, the harmonic content is specified in the brochure at http://www.telstar-electronics.com/SkyWave%202879AB.pdf But Frank probably doesn't believe that either... LOL P.S. No output filtering at this time. www.telstar-electronics.com |
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On 29 Sep 2006 08:38:40 -0700, "Telstar Electronics"
wrote in .com: Jay in the Mojave wrote: What is the harmonic content with your amp? Do you have a filter in the output circuit? Jay, the harmonic content is specified in the brochure at http://www.telstar-electronics.com/SkyWave%202879AB.pdf But Frank probably doesn't believe that either... LOL You measured output power with a spectrum analyzer, so why should I believe that you measured harmonic distortion with anything more than a wattmeter? Of course I don't believe you, Brian; you haven't made a single verifiable claim regarding any of your amps. In fact, I can guarantee that your 516 watt PEP figure was never measured but only fabricated (what you call 'estimated', just like you 'estimated' the distortion figures on your previous Class C splatter-boxes). P.S. No output filtering at this time. Never had it, never will. |
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Frank Gilliland wrote:
You measured output power with a spectrum analyzer, so why should I believe that you measured harmonic distortion with anything more than a wattmeter? Of course I don't believe you, Brian; you haven't made a single verifiable claim regarding any of your amps. In fact, I can guarantee that your 516 watt PEP figure was never measured but only fabricated (what you call 'estimated', just like you 'estimated' the distortion figures on your previous Class C splatter-boxes). I think everyone here who has read has this entire thread has figured out by now: You have never used a spectrum analyzer Don't know what PEP power is Don't understand how to measure efficiency Don't know how to measure harmonics I can't wait to see your new amplifier... LOL www.telstar-electronics.com |
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On 29 Sep 2006 09:49:48 -0700, "Telstar Electronics"
wrote in .com: Frank Gilliland wrote: You measured output power with a spectrum analyzer, so why should I believe that you measured harmonic distortion with anything more than a wattmeter? Of course I don't believe you, Brian; you haven't made a single verifiable claim regarding any of your amps. In fact, I can guarantee that your 516 watt PEP figure was never measured but only fabricated (what you call 'estimated', just like you 'estimated' the distortion figures on your previous Class C splatter-boxes). I think everyone here who has read has this entire thread has figured out by now: You have never used a spectrum analyzer Don't know what PEP power is Don't understand how to measure efficiency Don't know how to measure harmonics I can't wait to see your new amplifier... LOL Since you still can't address the issues, once again I will address them for you: The PEP to carrier ratio of 4 to 1 presumes a linear response. The problem is that these transistors (operating above 100 watts PEP; or, more specifically, your "1dB compression point") are not only horribly NON-linear, but you will be pushing them into saturation way before reaching your fabricated figure of 516 watts PEP. Don't believe me? Crank up your amp and try it. Pump in enough carrier to bring the output to 129 watts then modulate at 100%. I doubt it will even reach 400 watts PEP, and I have -no- doubt that the harmonic content will be absolutely horrendous. I also have no doubt that the amp won't last ten seconds under these conditions because the thermal resistance of the heat sink that is required to operate at this power is -0.26 degrees C/W.... and yes, that's a NEGATIVE number which means you need ACTIVE cooling, and a lot of it!!! See what happens when you refuse to do the math? You end up proving that you have don't have the engineering background to build even a -CHEAP- CB amp....."LOL"!!! |
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On Fri, 29 Sep 2006 02:03:34 GMT, "U-Know-Who"
wrote: 516 watts PEP, huh? You are ignorant. http://www.telstar-electronics.com/SkyWave%202879AB.pdf According to his own graph the output power levels off at about slightly above 155 watts. Assume 165 watts. This in reality means that a 100% single tone modulated AM signal can reach PEP values of around 165 watts. So that his amp should be rated around 40 watts carrier on AM and around 160 watts PEP on sideband. |
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wrote:
This in reality means that a 100% single tone modulated AM signal can reach PEP values of around 165 watts. So that his amp should be rated around 40 watts carrier on AM and around 160 watts PEP on sideband. In properly-adjusted AM, average power at 100% modulation = 1.5 X resting carrier power, and PEP = 4 X resting carrier power This was taken from http://www.ab4oj.com/peptest.html which also agrees with http://www.rf-amplifiers.com/index.php?topic=peak_power Nice try... www.telstar-electronics.com |
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On 29 Sep 2006 16:24:06 -0700, "Telstar Electronics"
wrote: wrote: This in reality means that a 100% single tone modulated AM signal can reach PEP values of around 165 watts. So that his amp should be rated around 40 watts carrier on AM and around 160 watts PEP on sideband. In properly-adjusted AM, average power at 100% modulation = 1.5 X resting carrier power, and PEP = 4 X resting carrier power This was taken from http://www.ab4oj.com/peptest.html which also agrees with http://www.rf-amplifiers.com/index.php?topic=peak_power Nice try... www.telstar-electronics.com You are doing the math backwards. You must take the maximum power the amp can deliver before saturation. That will be your approximate PEP rating. Then divide that figure by four to get the approximate carrier level for AM. You are determining the max output and then just assuming that you can multiply that by four to get the PEP rating. (129 x 4 = 516) It doesn't work that way. |
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"Telstar Electronics" wrote in message ups.com... Frank Gilliland wrote: Yep, their 'definition' is right on the money. Want to refute my 516W PEP figure any more?... LOL That's theoretical, based on maximums, and you know this amp is not capable of that. In real life, and with the components involved, it will not happen. |
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wrote in message ... On 29 Sep 2006 16:24:06 -0700, "Telstar Electronics" wrote: wrote: This in reality means that a 100% single tone modulated AM signal can reach PEP values of around 165 watts. So that his amp should be rated around 40 watts carrier on AM and around 160 watts PEP on sideband. In properly-adjusted AM, average power at 100% modulation = 1.5 X resting carrier power, and PEP = 4 X resting carrier power This was taken from http://www.ab4oj.com/peptest.html which also agrees with http://www.rf-amplifiers.com/index.php?topic=peak_power Nice try... www.telstar-electronics.com You are doing the math backwards. You must take the maximum power the amp can deliver before saturation. That will be your approximate PEP rating. Then divide that figure by four to get the approximate carrier level for AM. You are determining the max output and then just assuming that you can multiply that by four to get the PEP rating. (129 x 4 = 516) It doesn't work that way. Oh my! Reality strikes again. But then again, only to those of us who live in the real world. Some live in a calculated world. |
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U-Know-Who wrote:
"U-Know-Who" wrote in message tomm way are you enaged in more of the crossposting you claim to hate |
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On 29 Sep 2006 16:24:06 -0700, "Telstar Electronics"
wrote in .com: wrote: This in reality means that a 100% single tone modulated AM signal can reach PEP values of around 165 watts. So that his amp should be rated around 40 watts carrier on AM and around 160 watts PEP on sideband. In properly-adjusted AM, average power at 100% modulation = 1.5 X resting carrier power, and PEP = 4 X resting carrier power This was taken from http://www.ab4oj.com/peptest.html which also agrees with http://www.rf-amplifiers.com/index.php?topic=peak_power Nice try... Oh for crying out loud..... you can't even read a simple graph? Here's the transistor's power curve for everyone to see: http://www.icehouse.net/wirenut/2879curv.jpg Let's say you start with a 4 watt carrier (multiply all the numbers in the graph by 2 since you are using two transistors). The transistors will amplify that carrier to 120 watts. Now modulate the carrier 100% so your input power is 16 watts PEP. If the response was linear then the output power would be 4 * 120 watts, or 480 watts. Alas, the graph says different. VERY different. Your output power is only about 250 watts, or about HALF of your fabricated PEP figures. Crank up the supply voltage and you MIGHT reach 400, but then you have some real power dissipation problems that I pointed out in the other post and you are ignoring, just like every other post where I have proven you both wrong and ignorant.... "LOL"!!! |
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"an old friend" wrote in message ups.com... U-Know-Who wrote: "U-Know-Who" wrote in message tomm way are you enaged in more of the crossposting you claim to hate This applies to the topic. You enjoying being humiliated does not. |
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Telstar Electronics wrote: Jay in the Mojave wrote: What is the harmonic content with your amp? Do you have a filter in the output circuit? Jay, the harmonic content is specified in the brochure at http://www.telstar-electronics.com/SkyWave%202879AB.pdf But Frank probably doesn't believe that either... LOL P.S. No output filtering at this time. If it doesn't splatter all over the spectrum then in see-bee land it ain't a big radio. |
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Premium Quality PC Board, Components and Chassis
13.8VDC 10 Meter Amateur Radio Band Coverage All Mode (CW, AM, FM, SSB) Toshiba 2SC2879 Push-Pull Configuration with Beta/Gain Matched Transistors Regulated Class-AB Biasing High Output Power High Efficiency Heat Sink Polarized Detachable Power Cord Fuse Protected Extremely Low Stand-By Power Remote Operation Ready Carrier Operated Relay (COR) or Multiplexed Keying† SSB Delay to Eliminate Relay Chatter High Reliability Design Low Harmonic Content 90 Day Limited Warranty † Contact Telstar Electronics for details on using this feature www.telstar-electronics.com |
Look at what Griffey thinks his amp will do...
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wrote in message ... On Sat, 30 Sep 2006 02:22:02 GMT, "U-Know-Who" wrote: "an old friend" wrote in message roups.com... U-Know-Who wrote: "U-Know-Who" wrote in message tomm way are you enaged in more of the crossposting you claim to hate This applies to the topic. no topic your crossposting it to RRAP does not apply to the topic Yes it does. You are too stupid to understand. Don't try. |
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SkyWave 2879AB RF Mobile Linear Amplifier
Premium Quality PC Board, Components and Chassis 13.8VDC 10 Meter Amateur Radio Band Coverage All Mode (CW, AM, FM, SSB) Toshiba 2SC2879 Push-Pull Configuration with Beta/Gain Matched Transistors Regulated Class-AB Biasing High Output Power High Efficiency Heat Sink Polarized Detachable Power Cord Fuse Protected Extremely Low Stand-By Power Remote Operation Ready Carrier Operated Relay (COR) or Multiplexed Keying† SSB Delay to Eliminate Relay Chatter High Reliability Design Low Harmonic Content 90 Day Limited Warranty † Contact Telstar Electronics for details on using this feature www.telstar-electronics.com |
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"Telstar Electronics" wrote in message oups.com... SkyWave 2879AB RF Mobile Linear Amplifier Premium Quality PC Board, Components and Chassis 13.8VDC 10 Meter Amateur Radio Band Coverage All Mode (CW, AM, FM, SSB) Toshiba 2SC2879 Push-Pull Configuration with Beta/Gain Matched Transistors Regulated Class-AB Biasing High Output Power High Efficiency Heat Sink Polarized Detachable Power Cord Fuse Protected Extremely Low Stand-By Power Remote Operation Ready Carrier Operated Relay (COR) or Multiplexed Keying? SSB Delay to Eliminate Relay Chatter High Reliability Design Low Harmonic Content 90 Day Limited Warranty ? Contact Telstar Electronics for details on using this feature And it's pretty, too! |
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On 1 Oct 2006 06:06:27 -0700, "Telstar Electronics"
wrote: SkyWave 2879AB RF Mobile Linear Amplifier Stability issues passed down to the amp from its builder Premium Quality PC Board, Components and Chassis 13.8VDC 10 Meter Amateur Radio Band Coverage All Mode (CW, AM, FM, SSB) Toshiba 2SC2879 Push-Pull Configuration with Beta/Gain Matched Transistors Regulated Class-AB Biasing High Output Power High Efficiency Heat Sink Polarized Detachable Power Cord Fuse Protected Extremely Low Stand-By Power Remote Operation Ready Carrier Operated Relay (COR) or Multiplexed Keying† SSB Delay to Eliminate Relay Chatter High Reliability Design Low Harmonic Content 90 Day Limited Warranty † Contact Telstar Electronics for details on using this feature www.telstar-electronics.com |
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SkyWave 2879AB RF Mobile Linear Amplifier
Premium Quality PC Board, Components and Chassis 13.8VDC 10 Meter Amateur Radio Band Coverage All Mode (CW, AM, FM, SSB) Toshiba 2SC2879 Push-Pull Configuration with Beta/Gain Matched Transistors Regulated Class-AB Biasing High Output Power High Efficiency Heat Sink Polarized Detachable Power Cord Fuse Protected Extremely Low Stand-By Power Remote Operation Ready Carrier Operated Relay (COR) or Multiplexed Keying† SSB Delay to Eliminate Relay Chatter High Reliability Design Low Harmonic Content 90 Day Limited Warranty † Contact Telstar Electronics for details on using this feature www.telstar-electronics.com |
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