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Message |
    
Baker
New member
Username: Baker
Post Number: 1
Registered: 2-2013
| | Posted on Friday, January 24, 2014 - 9:46 am: | 
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So will i really see any more out of the 667 vs 500v ???? Thanks |
Dale
Senior Member
Username: Dale
Post Number: 2018
Registered: 12-2002
| | Posted on Saturday, January 25, 2014 - 9:31 am: |
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very little. the 667 has a built in driver
so so needs a low power radio to drive it.
the 500 has no driver so ya can use a little more
drive with it
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
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Sitm
Intermediate Member
Username: Sitm
Post Number: 482
Registered: 1-2004
| | Posted on Thursday, February 06, 2014 - 12:15 am: |
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Baker, first off, welcome to the copper forum. I hope that you enjoy the reading and learning that I did since I have been a member.
You are asking the same question that I did once upon a time about the TS 500 and the TS 667. I hope that this gives you the answer that you might be looking for.
The TS 500 is a four transistor amplifier with four 2sc2879 transistors manufactured by Toshiba reported by Toshiba to produce 100 watts pep at 12.5 vdc. Now results will change with voltage from most power supplies that produce 13.8 vdc or have variable up to 15 vdc. Just for reference the Ameritron ALS 500 utilizes the Toshibia 2sc2879 transistors and boast near the same power output levels. This “pills” or transistors are very durable and will last you decades if you do not abuse them. Now, let us get to the difference.
The TS 500 should according to Texas Star be driven with a five watt or less (I use four) and a pep around 25 watts. You will have many people that will tell you to drive it with more. Your performance and ability to “reach out” will not be enhanced by the additional watts that you will achieve by abusing the amplifier. The “500” with the variable knob engaged a variety of outputs, with a four watt rms (dead key) you can set it to produce anywhere from 20 to 100 rms and anywhere from 150 watts to 350 watts pep on am. On SSB this is where this unit really produces the output. If you run the amplifier modestly you will see 400 plus watts and get excellent audio reports. Remember the 500 is an AB bias amplifier and it needs around 70 amps at full output. An Astron 70 will feed it well. I recommend a dual final radio like the Ranger 2950 to match with this amplifier, you won’t be disappointed. This amplifier produces crystal clear audio reports, but you must put a clean signal into it from a decent radio.
Now on to the TS 667 amplifier with one Toshiba 2290 transistor driving four Toshiba 2sc2879 transistors. The 2290 is the same that is utilized in the Texas Star Variable. This allows you to utilize a single transistor radio that can be adjusted to a 1 or 2 watts rms (dead key) with a 10 to 15 watt pep (swing) and reach full operational output from the 667. Could you utilize a dual final radio with this unit, you could, in my opinion if you adjusted the radio to the specification that TS recommends to operate the TS 667. The most noticeable difference with the 667 is that the variable knob will operate in all modes. I found that leaving the dial a watt off and just regulating the output through the variable knob produced the most desirable results for me. This amp needs about 80 amps to safely reach full output.
I would run a cooling fan on either one of these units regardless of the output, general rule is if the amp is on, so is the fan. Additional advice, no one buys a new car and runs it 100 mph everywhere they go. Run this type of amplifier modestly, any problem you have with your set up, grounding, swr, etc, will be multiplied by output.
I hope this helps.
Most likey someone will post a different opinion and different out put results, that is fine, but this is what results I have from mine. |
Sitm
Intermediate Member
Username: Sitm
Post Number: 483
Registered: 1-2004
| | Posted on Thursday, February 06, 2014 - 11:23 am: |
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My last comment didn't post, but shows that it posted. |
Alsworld
Senior Member
Username: Alsworld
Post Number: 1039
Registered: 1-2002
| | Posted on Saturday, February 08, 2014 - 6:12 pm: |
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That was a very thorough and intelligent answer Sitm. No disagreements on my end. Drive either one sweetly and you can sound great for years. Way too many people overdrive their amps trying to achieve every last watt and all it does is distort the signal, create harmonics and shorten the lifespan. Great answers from both members above! |
Keithinatlanta
Advanced Member
Username: Keithinatlanta
Post Number: 975
Registered: 3-2003
| | Posted on Monday, February 10, 2014 - 7:45 pm: |
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Nothing worse than when I am driving down an interstate trying to have conversation and someone is doing exactly that. So as a result, it usually ends any conversation with me as I cannot understand overdriven stuff. But some do not learn I guess.
Keith in Atlanta
CEF 150 |
Sitm
Intermediate Member
Username: Sitm
Post Number: 495
Registered: 1-2004
| | Posted on Tuesday, February 11, 2014 - 3:40 pm: |
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I would strongly suggest that when selecting an amplifier, especially for single side band, that utilizing an amplifier that has good linearity and can reproduce a clean signal when one is applied to it. In the end it will serve you better. If you intend to use am only, don't negate using an B,AB1 or AB2 class amplifier due to the additional cost as well as the additional amps that it will take produce watts.
AB1 and AB2 class amplifier are not as efficient at converting amps into watts.
Class C amplifiers are more efficient but they are nonlinear. They have the capability to produce more RF power per amp but generally will not produce as "clear" of a signal as B, AB1 or AB2 |
Press_man
Advanced Member
Username: Press_man
Post Number: 740
Registered: 5-2008
| | Posted on Thursday, February 13, 2014 - 5:17 pm: |
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Class C is OK if you want swing on AM they tend to be dirty and filtering is recommended behind the radio and amp and not SSB friendly. AB is cleaner and much clearer. The discussion about the 500s and 667 have been ongoing. Several techs remove the pre-drive from the 667 to avoid over drive. The 500 does the same wattage plus you can push it a little harder.
73 Pressman
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